Cornell University Library The original of this book is in the Cornell University Library. There are- no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924003371576 New York State College of Agriculture At Cornell University Ithaca, N. Y. Library Cornell University Library R 125.R3 V.1 A Reference handbook of the medical scie 3 1924 003 371 576 Reference Handbook MEDICAL SCIENCES Being a Complete akd Convenient Work of Reference for Information UPON Topics belonging to the entire range of Scientific and Prac- tical Medicine, and Consisting of a Series op Concise Essays and Brief Paragraphs, arranged in THE Alphabetical Order of the Topics op which they treat rREPAUED BY WRITERS WHO ARE EXPERTS IN THEIR RESPECTIVE DEPARTMENTS ILLUSTRATED BY CHEOMOLITHO.GRAPHS AND FINE WOOD ENGRAVINGS Edited by ALBERT H. BUCK, M.D. Naw York City VOL. L WILLIAM WOOD cfe COMPANY NEW YORK COPTBIGHT, 1885, BT WILLIAM "WOOD & COMPAKX LIST OF CONTRIBUTORS TO VOLUME I. WILLIS J. ABBOT, LL.B Chicago, III. Counsellor and Attorney-at-Law. GORHAM BACON, M.D New York, N. Y. Aural Surgeon, New York Eye and Ear Infirmary. FRANK BAKER, M.D Washington, D.C. Professor of Anatomy, Medical Department of George- town University. ELIAS H. BARTLEY, M.D Brooklyn, N. Y. Lecturer on Chemistry, Long Island College Hospital ; Chemist to the Board of Health of Brooklyn. E. A. BIRGE, Ph.D Madison, Wis. Professor of Zoology, University of Wisconsin. ALBERT N. BLODGETT, M.D Boston, Mass. Professor of Pathology and Therapeutics, Boston Den- tal College. W. P. BOLLES, M.D , . . .Boston, Mass. Professor of Materia Medica and Botany, Emeritus, at the Massachusetts College of Pharmacy ; Visiting Surgeon to the Boston City Hospital. L. BREMER, M.D St. Louis, Mo. WILLIAM N. BULLARD, M.D Boston, Mass. Physician to the Nervous Department, Boston Dispen- sary ; Physician to Out-Patients, Carney Hospital. FRANK BULLER, M.D Montreal, Canada. Professor of Ophthalmology and Otology, McGill Uni- versity. CHARLES H. BURNETT, M.D.. Philadelphia, Pa. Professor of Otology, Philadelphia Polj^clinic and Col- lege for Graduates in Medicine ; Aurist to the Pres- byterian Hospital. ARTHUR T. CABOT, M.D Boston, Mass. Surgeon to Out-Patients, Massachusetts General Hos- pital. DONALD M. CAMMANN, M.D... New York, N. Y. Instructor in Diseases of the Chest, New York Poly- clinic ; Visiting Physician to the Orphans' Home and Asylum. RUSSELL H. CHITTENDEN, Ph.D New Haven, Conn. Professor of Physiological Chemistry, Yale College. W. J. CONKLIN, M.D Dayton, O. Professor of Diseases of Children, Starling Medical College. WILLIAM T. COUNCILMAN, M.D. .Baltimore, Md. Associate Professor of Pathological Anatomy, Johns Hopkins University. EDWARD CURTIS, M.D New York, N. Y. Professor of Materia Medica and Therapeutics, College of Physicians and Surgeons, New York. CHARLES L. DANA, M.D New York, N. Y. Professor of Diseases of the Mind and Nervous System, and of Medical Electricity, New York Post-Graduate Medical School and Hospital ; Physician to the North- western Dispensary, Nervous Department. N. P. DANDRIDGE, M.D Cincinnati, 0. Professor of Genito-Urinary and Venereal Diseases, Miami Medical College. D. BRYSON DELAVAN, M.D....New York, N. Y. Surgeon to Department of the Throat, Derailt Dispen- sary. BASKET DERBY, M.D Boston, Mass. Ophthalmic Surgeon, Massachusetts Charitable Eye and Ear Infirmary, Boston. HENRY FLEISCHNER, M.D New Haven, Ct, Lecturer on Dermatology, Yale College. WILLIAM H. FLINT, M.D New York, N. Y. Attending Physician, Presbyterian Hospital ; Assistant to the Chair of Principles and Practice of Medicine, Bellevue Hospital Medical College. EUGENE FOSTER, M.D Augusta, Ga. President of the Board of Health of Augusta. FRANK P. FOSTER, M.D New York, N. Y. Assistant Surgeon, Woman's Hospital in the State of New York. GEORGE B. FOWLER, M.D New York, N. Y. Professor of Physiological Chemistry, New York Poly- clinic ; Physician to the New York Infant Asylum. JAMES M. FRENCH, M.D Cincinnati, O. Assistant Demonstrator of Pathology and Instructor in Physical Diagnosis, Medical College of Ohio. WILLIAM W. GANNETT, M.D Boston, Mass. Assistant in Pathological Anatomy, Harvard Univer- sity. WILLIAM GARDNER, M.D. ...Montreal, Canada. Professor of Gynaecology, McGill University ; Gynse- cologist to the Montreal General Hospital. GEORGE W. GAY, M.D Boston, Mass. Surgeon to the Boston City Hospital. H. GRADLE, M.D.. Chicago, III. Professor of Physiology, Chicago Medical College. JOHN GREEN, M.D St. Louis, Mo. Lecturer on Ophthalmology, St. Louis Medical College. CHARLES E. HACKLE Y, M.D. . . .New York, N. Y. Attending Physician, New York Hospital. ALLAN McLANE HAMILTON, M.D. . . .New York, N. Y. Professor of Diseases of the Mind and Nervous System, New York Polyclinic. CHARLES HARRINGTON, M.D Boston, Mass. Instructor in Chemistry, Harvard Medical School. FREDERICK P. HENRY, M.D. .Philadelphia, Pa. Professor of Pathology and Microscopy, Philadelphia Polyclinic and College for Graduates in Medicine ; Physician to the Hospital of the Protestant Episcopal Church. WILLIAM B. HILLS, M.D Boston, Mass. Assistant Professor of Chemistry, Harvard University. CHARLES B. KELSEY, M.D New York, N. Y. WILLIAM. G. LE BOUTILLIER, M.D..New York, N. Y. HENRY LEFFMANN, M.D Philadelphia, Pa. Professor of Clinical Chemistry and Hygiene in the Philadelphia Polyclinic ; Assistant to the Chair of Chemistry, Jefferson Medical College. GEORGE W. LEONARD, M.D. . . .New York, N. Y. Late House Surgeon, New York Hospital. R. L. MACDONNELL, M.D Montreal, Canada. Demonstrator of Anatomy and Lecturer on Hygiene, McGill University. LEWIS L. Mc ARTHUR, M.D Chicago, III. WALTER MENDELSON, M.D. . . .New York, N. Y. Instructor in Clinical Microscopy in the Physiological and Pathological Laboratory of the Alumni Associa- tion of the College of Physicians and Surgeons ; At- tending Physician to the Roosevelt Hospital, Out- Patient Department. Ul LIST OF CONTRIBUTORS TO VOLUME I. T. WESLEY MILLS, M.D Montreai,, Canada. Lecturer on Physiology, McGill University. JAMES LAUNCELOT MINOR, M.D. . . .New Yobk, N. Y. Assistant Surgeon, New York Eye and Ear Infirmary ; Visiting Ophthalmic Surgeon, Randall's Island Hos- pitals. CHARLES SEDGWICK MINOT, M.D Boston, Instructor in Histology and Lecturer on Embryology, Harvard University. WILLIAM OLIVER MOORE, M.D. .New York, N.Y. Professor of Diseases of the Eye and Ear, New York Post-Graduate Medical School ; Assistant Surgeon, New York Eye and Bar Infirmary. WILLIAM H. MURRAY, M.D. . . .New Yokk, N. Y. Late House Surgeon, New York Hospital House of Relief ; Attending Physician, New York and North- ern Dispensaries. JOHN H. MUSSER, M.D Philahblphia, Pa. Chief of the Medical Dispensary of the Hospital of the University o^ Pennsylvania ; Pathologist to the Pres- byterian Hospital. WM. OLDRIGHT, M.D Tobonto, Canada. Lecturer on Sanitary Science, Toronto School of Med- icine ; Chairman, Provincial Board of Health. HENRY F. OSBORN, Sc.D Princeton, N. J. Professor of Comparative Anatomy, Princeton Uni- versity. ROSWELL PARK, M.D BtJi-i-ALO, N. Y. Professor of the Principles and Practice of Surgery, University of Buffalo, N. Y. T. MITCHELL PRUDDBN,M.D..New York, N. Y. Lecturer on Normal Histology, Yale College ; Director of the Physiological and Pathological Laboratory of the Alumni Association, College of Physicians and Surgeons, New York City. MARY PUTNAM JACOBL M.D..Nbw York, N. Y. Professor of Materia Medica and Therapeutics in the Women's Medical College, New York. LEOPOLD PUTZEL, M.D New York, N. Y. Visiting Physician to Randall's Island Hospital. JOSEPH RANSOHOFF, M.D Cincinnati, O. Professor of Descriptive Anatomy and Clinical Sur- gery, Medical College of Ohio ; Surgeon to the Good Samaritan Hospital, Cincinnati. J. C. REEVE, M.D Datton, O. Late Professor of Materia Medica and Therapeutics, Medical College of Ohio ; Chief of Staff of St. Eliza- beth's Hospital, Dayton. HUNTINGTON RICHARDS, M.D. .New York, N.Y. Assistant Aural Surgeon, New York Eye and Ear In- firmary. M. H. RICHARDSON, M.D Boston, Mass. Demonstrator of Anatomy, and Assistant in Surgery, Harvard University. HENRY A. RILEY New York, N. Y. Attorney and Counsellor-at-Law. GEORGE ROSS, M.D Montreai;, Canada. Professor of Clinical Medicine, McGill Univefsity ; Phy- sician to the Montreal General Hospital. IRVING C. ROSSB, M.D Washington, D.C. THOMAS E. SATTERTHWAITE, M.D. .New York, N. Y. Professor of Pathology and General Medicine, New York Post-Graduate Medical School ; Pathologist to the Presbyterian Hospital. WILLIAM T. SEDGWICK, Ph.D Boston, Mass. Assistant Professor of Biology, Massachusetts Institute of Technology. N. 8ENN, M.D Milwaukee, Wis. SAMUEL SEXTON, M.D New York, N.Y. Aural Surgeon, New York Eye and Ear Infirmary. FRANCIS J. SHEPHERD, M.D. .Montreal, Canada, Professor of Anatomy, McGill University. CHARLES SMART, M.D Washington, D.C. Surgeon, United States Army. M. ALLEN STARR, M.D New York, N. Y. Late House Physician, Bellevue Hospital ; Attending Physician, New York Dispensary. THOMAS L. STEDMAN, M.D. . . .New York, N. Y. Assistant Surgeon, New York Orthopedic Dispensary and Hospital. HENRY W. STEL WAGON, M.D. .Philadelphia, Pa. Physician to the Philadelphia Dispensary for Skin Dis- eases ; Chief of the Skin Dispensary of the Hospital and Instructor in Dermatology, University of Penn- sylvania. GEORGE M. STERNBERG, M.D. .Washington, D.C. Surgeon, United States Army. JAMES STEWART, M.D Montreal, Canada. Professor of Materia Medica and Therapeutics, McGill University. LEWIS A. STIMSON, M.D New York, N. Y. Professor of Physiology, University of the City of New York ; Visiting Surgeon, Bellevue and Presbyterian Hospitals. SAMUEL THEOBALD, M.D Baltimore, Md. Professor of Diseases of the Eye and Ear, Baltimore Polyclinic and Post-Graduate Medical School; Sur- geon to the Baltimore Eye, Ear, and Throat Charity Hospital. WILLIAM GILMAN THOMPSON, M.D. .New York, N. Y. Assistant Physician to the New York Hospital, Out- patient Department ; Physician to Roosevelt Hos- pital, Out-Patlent Department. WILLIAM H. THOMSON, M.D. . . .New York, N. Y. Professor of Materia Medica and Therapeutics and Dis- eases of the Nervous System, Medical Department of the University of the City of New York ; Visiting Physician to Bellevue and Roosevelt Hospitals. L. McLANE TIFFANY, M.D Baltimore, Md. Professor of Surgery, University of Maryland. ARTHUR VAN HARLINGEN, M.D. .Philadelphia, Pa. Professor of Diseases of the Skin in the Philadelphia Polyclinic and College for Graduates in Medicine ; Consulting Physician to the Dispensary for Skin Dis- eases. WILLIAM L. WARD WELL, M.D. .New York, N. Y. Surgeon to the Eastern Dispensary ; Assistant Sur- geon, New York Polyclinic. CHARLES WARE, M.D New York, N. Y. Assistant Gynsecologist, Out-Door Department of Roosevelt Hospital. J. COLLINS WARREN, M.D Boston, Mass. Assistant Professor of Surgery, Harvard University; Surgeon to the Massachusetts General Hospital. LEONARD WEBER, M.D New York, N. Y. EDMUND C. WENDT, M.D New York, N. Y. MOSES C. WHITE, M.D New Haven Conn Professor of Pathology, Medical Department of Yale College ; Medical Examiner for New Haven, Conn. GEORGE WILKINS, M.D Montreal, Canada Professor of Medical Jurisprudence, McGill University CHARLES F. WITHINGTON, M.D...B08TON Mass JOHN McG. WOODBURY, M.D. . .New York', N Y Assistant Demonstrator, Bellevue Medical College W. GILL WYLIE, M.D New York N Y Professor of Gynaecology, New York Polvclinio- Gynaecologist to Bellevue Hospital ; Surgeon to St Elizabeth's Hospital. IV PREFACE. The character and scope of the Handbook may be judged better from a brief inspection of the present volume than from any detailed description which I might be able to give. It is essentially a collection of articles — some brief, others of considerable length — treating of many of the more impor- tant topics in regard to which medical men are likely to desire information. In selecting these topics, and in determining how much space should be allotted to each, I have been guided by the following considerations : In the first place, the size of the entire work — eight volumes of about eight hundred pages each — precluded the possibility of treating exhaustively all the topics for which one might fairly consider it necessary to make provision. In the presence of this difficulty I was obliged to choose be- tween two courses : either to retain a reasonably full list of topics, and give to each its proper share of space ; or to curtail the list, and so gain enough space for a fairly satisfactory and thorough treatment of at least the more important subjects. The former plan, which to many would appear to be the more natural one of the two, and which is in fact the one generally pursued in works of a similar character, leads inevitably to the production of a book containing articles so brief and so lacking in fulness of in- foi-mation that the reader cannot fail to experience more or less disappointment in them. The latter plan, on the other hand, is open to the objection that the reader will now and then search in vain for information in regard to some topic in which he is interested. Between these two plans I have not hesitated to choose the latter. The objections which may be brought against it seem to me to be fewer and of less weight than those which are inseparable from the more strictly symmetrical plan of construction. The advantages, on the other hand, appear to me to more than compensate for the de- fects. Under this plan the editor feels himself at liberty to use his own judgment in regard to the selection of topics and in regard to the degree of importance which shall attach to each. In the next place, it has seemed to me desirable to bear in mind the varied tastes and professional wants of those who are likely to make use of the Handbook. While, therefore, I have given the lion's share of the space to matters of a practical nature — the diagnosis and treatment of disease — I have not forgotten to make ample provision for such departments as medical botany, cHmatology, embryology, physiological a,nd pathological chemistry, applied anatomy, medical jurisprudence, military and naval surgery. In harmony with these considerations I have not hesitated to leave out separate articles on some of the topics which appear as independent headings in other works of a similar character ; and, on the other hand, I have introduced articles on many topics which are not discussed in any of the treatises which ordindTrily find their way into the libraries of medical men. In working out the problem which was set before me as editor, I have derived not a little as- sistance from Quain's "Dictionary of Medicine," from Eulenburg's Real Encyclopddie, and from Jaccpud's Nouveau DicHonnaire de MMecine et de Chirurgie Pratiques. I have also received valuable aid from Drs. Charles Sedgwick Minot, James J. Putnam, and W. P. Bolles, of Boston ; Drs. William Osier and Arthur Van Harlingen, of Philadelphia ; Dr. John Green, of St. Louis ; Surgeons Charles A. Smart, B. A. Clements, and Alfred A Woodhull, of the United States Army ; and Drs. Frank P. Foster, PREFACE. Huntington Sichards, D. Bryson Delavan, Edward Curtis and Mr. Benjamin Vaughan Abbott, of New York, to all of whom I desire to express publicly my thanks. In the difficult task of correcting the proof-sheets, I have been aided by Drs. William H. Flint, Huntington Richards, and Thomas L. Sted- man, of this city. I also take pleasure in acknowledging the assistance afforded, in the department of Climatology, by Hon. H. B. Small, of Ottawa, Canada ; Professor J. C. Smock, of New Jersey, and many others whom I have not the space here to mention. It also gives me pleasure to acknowledge the generous manner in which the publishers have acceded to all my requests and suggestions in regard to the construction of the book ; some of these requests involving a considerable increase in the expense of publication. This volume, as will be noticed, is not self-indexing. Without a reasonably exact knowledge of the contents of the remaining seven volumes, it would not be possible to introduce such a running index, or at least one that would be sufficiently complete to be really useful. It seemed to me, therefore, that much valuable space might be saved by omitting altogether the independent cross-references {i.e., those which constitute separate headings), and introducing, instead, at the end of the work, a reason- ably fuU index. Finally, I desire to call attention to the running titles at the upper corners of the pages. These are intended to aid the reader in searching for a particular topic, and they are therefore placed where they can be most easily seen in turning over the pages rapidly. The upper title always indicates the first topic on the left-hand page, and the lower one the last topic on the right-hand page. A. H. B. New Yoke, August 31, 1885. vi A KEFEEENOE HANDBOOK MEDICAL SCIENCES Aachen. Aactaen. AACHEN (Fr. Aix-la-Chapelle), renowned for the num- ber, variety, and singular efficacy of Its springs since the days of Charlemagne, has maintained its ancient repute, and in our own times ranks as one of the most valuable of health resorts. It is a city of Bhenish Prussia, near the western border of the empire (Lat. 50° 47' N., Long. 6° 12' E.). Its elevation above the level of the sea is about 565 feet. Its name is derived from the Teutonic Aa, Aach = water (Latin, Aqua). The great quanti- ties of thermal waters which well up from numberless springs in its immediate vicinity justify the appellation. The most noteworthy of the springs are the Kaiserquelle, having a temperature of 55° C. (131° F.), Quirinusquelle, 50° 0. (123° F.), Rosenquelle, 47.5° 0. (117.5° F.), and the Corneliusquelle, 45.5° C. (114° F.). Their waters supply, in addition to the Elisenbrunnen, which has a temperature of 53° C. (127.5° F.), eight sumptuously arranged bathing establishments, of which those known as the " Kaiserbad" (rebuilt in 1864), the " Konigin von Ungarn," the "Neubad," and the " Quirinusbad " are the most prominent. The waters are all of them but slightly impregnated with carbonic acid gas ; their chief saline constituent is sodium chloride. They contain, besides, a small proportion of bromine and iodine. Sul- phur is an important component part. The Kaiserquelle contains it in greatest abundance ; but in all of the springs the amount and chemical condition of the sulphur pres- ent are subject to great and frequently varying change. The presence of sodium carbonate in the water points to the proximity of extinct Eifel volcanoes. The chemical composition of all the waters varies only within very narrow limits. According to the analysis of J. von Liebig, the Kaiserquelle, which may serve, for all prac- tical purposes, as a standard for the others also, contains in 10,000 parts of water : Sodium chloride S6 101 Sodium bromide 0.036 Sodium iodide 0.005 Sodium sulphide O-OSS Sodium eulubate 2.836 Potassium sulphate - lo27 Sodium carbonate no Lithium carbonate 0.029 Magnesium carbonate 0.506 Calcium carbonate 1-579 Strontium carbonate n noc Ferrous carbonate n?e5 Silica hydrate 0.661 Organic matter U. (b9 Total 40.791 Carbonic oxide (free and partially free) B.OOO Traces of fluorine, boron, and arsenic. There is probably an organic sulphide (allyl) present in minute quantity. The action of the Aachen thermal water on the econ- omy is analogous to that of any chloride water of the same temperature. By reason of its alkalinity it does not generally disturb the stomach. The sulphates fre- quently produce a slight aperient effect ; but where baths are taken simultaneously with the habitual drinking of the waters, this laxative action is annulled, and a slight constipation not infrequently ensues. The sodium sulphate is probably the great factor in producing therapeutic effects in torpid conditions of the abdominal VoL L-1 viscera, "particularly on the mucous membranes of the intestinal tract. Its presence, although in minute quan- tity, is easily appreciated by the senses. The sulphate is either absorbed unchanged, or is decomposed into hydrogen sulphide, and taken into the blood-current as such : in either case it promotes metamorphosis of the blood-disks and albumen, and has a distinct solvent action on metallic deposits in the tissues. The researches of Guntz have shown that the internal use of Aachen waters promotes the secretion of urea, and it follows that protein decomposition is accelerated in proportionate ratio. This is further proven by the appearance or in- crease of xanthin in the urine of Aachen patients. In hydrargyrosis, the drinking of the water of the Kaiser- quelle produces elimination of mercury by the kidneys. ■ For purposes of local treatment the waters are used as baths, which are taken in stone basins. There are no in- tegumentary irritants in the waters ; hence there are no immediate local effects. Neither is the temperature at which the bath is taken high enough to act by its caloric property ; but the sulphur, which in the bath water is suspended in the most minute particles, adheres to the skin, and finds lodgment in the pores, but it is still an open question whether it is possible for the sulphur to find its way into the absorbents in this way. The alka- line reaction of the bath imparts emollient properties to it ; it exerts also a solvent action on the sebum and other fatty skin elements, and promotes absorption in this way ; and this may explain why inunctions immediately fol- lowing the bath, are so remarkably prompt in their action. The temperature of the bath usually varies from 38° to 36° C. (91.4° to 96.8° F.) ; it rarely fails to act as a seda- tive. A method of bathing peculiar to Aachen consists in the application of a douche in a manner differing from that pursued in any other place. A stream of warm water is poured from a hose upon the bather for ten or fifteen njinutes, from a height varying from five to ten metres (16 to 83 ft.). The streams used vary in diameter from three to nine millimetres, and the temperature of the water ranges from 35° to 37° C. (95° to 98° F.). For a period of from five to twenty minutes the douche is kept playing upon the back and limbs, and especially over the affected regions. At the same time, massage and shampooing are carried out by a skilled attendant. The mechanical and thermic effects of these procedures are made manifest by reddening of the skin and profuse diaphoresis. They are very agreeable to the patient, and do certainly act as a lymphatic stimulant. They promote absorption of chronic inflammatory products, and of syphilitic, rheumatic, and gouty new-formations ; and it is this tissue metamorphosis which is the object of an Aachen cure and which is hardly attainable, in the same degree, at any other bath on the Continent. Syphilis is not treated exclusively by the water cure : inunctions with mercurials and the internal administra- tion of mercury and potassium iodide are resorted to simultaneously ; and although such a complex treat- ment would seem to prove nothing as ^o the waters themselves, experience has shown that the specific treat- ment alone is not as efficacious as the combined specific and thermal treatment. The same statement will hold Aaclien. Abdomen. REFERENCE HANDBOOK OF THE MED ICAL SCIENCES. good with regard to gout, rheumatism, acne, eczema, furunculosis, metallic deposits and their systemic effects ; and, lastly, with regard to all diseases of the abdominal viscera characterized by engorgement, hypertrophy, and new growth. The singular effectiveness of the Aachen baths has led to the artificial preparation of the same, but neither the prepared Aachen bath water nor the Aachen soap produces the least effect, excepting in the imagination of the patient. The water of the ' ' Elisen- brunnen " is bottled for export. Aachen enjoys another advantage which is of some moment : it is situated in a mild latitude, where no great variation of temperat^ire is ever experienced ; it is rarely visited by epidemics ; in the main there is plenty of space around the houses ; in a word, it is admirably adapted for a place, of sojourn in the winter months, and the number of guests who fre- quent it during this season of the year is gradually be- coming greater, so that it can hardly be said that there is a limited season. (The preceding account is derived from Eulenberg's "Real Encyclopadie.") Hemry Fleisehner. ABDOMEN. — Medical and Surgical Appldbd An- atomy. — The term abdomen is applied to the cavity bounded above by the diaphragm, below by the iliac fossae and brim of the true pelvis, behind by the luinbar verte- brae, and at the sides and front by the abdominal mus- cles. The space thus included extends upward far under the chest-walls. Its summit is formed by the con- vexity of the diaphragm, which reaches upward to the level of the fifth right chondro-sternal articulation. A horizontal section of the body at this level will shave off just a thin slice of liver covered by the diaphragm. On the left side the arch of the diaphragm reaches but as high as the level of the junction of the sixth rib with the sternum. Posteriorly the vertebral column, covered by the crura of the diaphragm, projects into the abdominal cavity. The distance from the umbilicus to the lumbar vertebrae is scarcely more than two inches. The lateral portions of the posterior wall are formed by the psoas, which rests closely against the sides of the bodies of the lumbar vertebrae, as well as the quadratus lumborum, a thin plane of muscle lying between the posterior portion of the crest of the hip-bone below and the last rib above, and the apices of the transverse pi-ocesses of the lumbar vertebrae toward the middle line. The sides and front of the abdomen are formed by the three flat muscles, the ob- liquus externus, obliquus internus, and the transversalis, united at the linea semilunaris to enclose the fourth ab- dominal muscle, the rectus, which is the anterior bound- ary of the belly- wall. The space thus enclosed contains the stomach, the intestines, the liver, the spleen, the pancreas, the kidneys and their ducts, the vessels of the trunk, nerves and lymphatics. Superficial Anatomy of the Abdomen. — The belly is convex on its anterior surface, more especially so in the corpulent. Unusual prominence of the lower part of the belly is often seen in those whose chests are shal- low. Infants are normally pot-bellied, owing to the relatively large size of the solid viscera, as well as to the narrowness of the pelvis. In rickets, as in other condi- tions of malnutrition in children, the belly becomes very prominent, partly from a depression of the liver and spleen, partly by reason of the anterior curvature of the spine and the fact that the intestines in this disease are commonly distended with gas. In cretins the belly is pendulous from laxity of the skin, and after pregnancy, ascites, and ovarian dropsy the abdominal wall tends to remain permanently flaccid. Retraction of the anterior abdominal wall is seen in diseases accompanied by much emaciation. In tubercular meningitis it is a very marked symptom, helping to distinguish it from enteric fever, in which there is usually tympanitis. In peritonitis gas distends the cavity, and abdominal respiratory move- ment ceases. Various kinds of skin eruption appear upon the surfece of the abdomen. Herpes zoster is seen upon one or other side of the trunk, following the course of the intercostal nerves. The rash of typhoid fever is dotted over the front of the abdomen. Often, when ab- sent in front, it is to be found over the lumbar region, and the same may be said of the syphilitic secondary rash. Tinea versicolor sometimes descends from its fa- vorite position on the front of the chest, and spreads out upon the abdomen. In the vicinity of the navel, scabies is often met with, while eczema prefers the scrotal in- tegument. The pit of the stomach is that depression in the middle line just below the ensiform appendix. Here the skin is tender and sensitive. A blow upon the scrobiculus cordis, as the older writers called it, is dangerous. The solar plexus lies underneath the pit of the stomach. In a few cases fatal results have immediately followed an in- jury of this nature. The epigastrium is the seat of pain m stomach affections generally, and to it is referred the feeling we call hunger, and that condition impossible to define, nausea. The ingestion of irritant poisons is fol- lowed by burning pain at the pit of the stomach. Con- versely, counter-irritation in this region will relieve gas- tric pain and nausea. There are few remedial agents so efficacious as a mustard poultice to the pit of the stomach in severe gastralgia, whether of organic origin or not. What, then, is the connection between the stomach and the skin of the epigastric region ? The sympathetic nerves which supply the stomach are the branches of the coeliac plexus, which is derived from the fore part of the great solar or epigastric plexus. The semilunar ganglion is part of the solar plexus ; it receives the great splanch- nic nerve, the origin of which is from the lower thoracic ganglia. Each of these thoracic ganglia is connected to the nearest anterior root of the spinal nerves. Now it happens that the skin of the epigastrium is supplied by these very same nerves, viz., from the fourth to the seventh intercostal nerve. There is therefore a com- plete nervous circuit from the mucous membrane of the stomach to the skin of the epigastrium. In the .jnid-line in front is the depression of the linea alba, the abdominal furrow. At about its centre is the umbilicus, the remains of that opening in the abdominal wall through which there passed the structures connect- ing the embryo with the internal surface of the ovum. The linea terminates below in the symphysis pubis, and above in the tip of the sternum. In this median depres- sion, the linea alba, the incision is made in all cases where the surgeon has to open the abdominal wall, as in ovariotomy, Caesarean section, and other operations. The prominence formed by the rectus muscle lies on each side of the furrow. In thin, muscular subjects the transverse marks on the rectus are plainly perceptible. There are usually three of these cross-marks— one at the level of the navel, one just below the ensiform appendix, and a third between these two points. In the living body not more than two are commonly perceptible. The abdominal aorta lies a little to the left of the middle line, with the inferior vena cava on its right side. The bifurcation takes place opposite the middle of the body of the fourth lumbar vertebra, three-quarters of an inch below and to the left of the umbilicus. This point is nearly on a level with a line drawn from the highest point of the iliac crest to the other. A line drawn from it to the midpoint between the iliac spine and the sym- physis pubis indicates the direction of the common and external arteries. The upper third of this line represents the common, and the lower two-thirds the external iliac. The cffiliac axis arises from the aorta at a point four inches above the uinbilicus. Posteriorly it corresponds to the lower part of the body of the last dorsal vertebra opposite the first lumbar spine. Immediately below the coeliac axis is the pancreas, which crosses the arch of the aorta and the vertebral column at a point between three and four inches above the umbilicus. Below the pancreas is the superior mesenteric artery, two or three inches above the navel. One inch above the umbilicus the duodenum crosses the aorta. Immediately beneath the duodenum, about one inch above the navel, the inferior mesenteric artery is given off. At the outer border of the prominence formed by the rectus muscle is a shallow depression on each side, the upper ends of which are bent in toward the middle line. This is the REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Aachen. Abdomen. linea semilunaris, the point where the aponeuroses of the ahdominal fasciae unite just before they diverge to form the sheath of the rectus. Its direction corresponds with that of a slightly curved line drawn from the tip of the ninth costal cartilage to the spine of the pubes. In former days incisions for paracentesis were made in the linea semilunaris. In one reported case at least, the tro- car struck the epigastric artery, just as it crossed the line. The operator was the illustrious Cline. ' The prepara- tion is to-day in the Museum of St. Thomas' Hospital. The spine of the pubes is an important landmark. In the male subject it is to be felt from below by tucking up the scrotal tissues with the forefinger. The line of the adductor longus, which is made manifest by abduc- tion of the thigh, leads up to it. The spine having been Fio. 1. — Superficial Abdominftl Veins distended from Intra-tboracic Pressure. The superficial thoracic veins are also enlarged, though not represented by the engraver. found, the external ring may be felt immediately to its outer side. In the normal condition of parts the tip of the finger should feel a slight depression over the ring, and when the patient coughs anything like a distinct impulse should not be felt. When a patient has had a rupture for some time, the sharp edges of the ring dis- appear, and the finger slips easily through the opening into the abdominal cavity. The spine of the pubes is on a horizontal line with the upper edge of the great tro- flhanter. The internal ring corresponds to a point upon the surface midway between the anterior superior spinous process of the ileum and the symphysis pubis and half an inch above Poupart's ligament. Between the two rings the epigastric artery takes its course from its origin from the external iliac artery upward and inward to- ward the umbilicus. Passing over Poupart's ligament, and superficial to the deep abdominal (Scarpa's) fascia are the branches of the femoral artery and vein which ascend up the abdominal surface, the superficial epi- gastric and superficial circumflex iliac. These veins be- come enlarged when there is obstruction to the circula- tion in the abdomen. Figure 1 is a portrait of my patient, Jean Larance, aged fifty-nine, in whose case thoracic aneurism was diagnosed. The superficial abdominal veins are as thick as one's little finger, and are very tortuous. The superficial epigastric vein becomes lost in the enlarged venous plexus on the surface of the thorax ; the superficial circumflex iliac vein is directly continuous with the axillary veins. Billroth records a similar case of enormous enlargement of superficial ab- dominal veins. The autopsy showed the presence of a malignant bronchocele in the upper part of the chest, causing pressure upon the innominate vein on the left side. Regions of the Abdomen and their Contents. For purposes of description the abdomen has beeh divided into nine regions. The landmarks from which the boundary lines of these are to be drawn vary according to difl'erent authors. The most satis- factory directions are as follows : Draw a. horizontal line on a level with the lowest part of the tho- racic wall on each side, another horizontal line on a level with the highest part of the iliac crests. Bisect Poupart's ligament, and through each point of bisection draw a vertical line upward. The abdominal surface is thus divided into nine regions, named as in the diagram. The Right Htpochondkiac Region. — This region contains the greater part of the right lobe of the liver, whose convexity is in relation with the concavity of the diaphragm, the hepatic flex- ure of the colon, and part of the right kidney. "That surface of the liver which is now called upper, corresponds with the surface in contact above with the diaphragm, and in front with a portion of the anterior chest- wall. Morb- id adhesions between the liver and dia- phragm are of not un- common occurrence, notably in cirrhosis, where the junction of the two surfaces en- ables the branches of the portal vein to communicate with the veins of the dia- phragm. These vein? take the course of the phrenic arteries, on the left side often joining the left renal vein. Portal engorge- ment is in this way partly relieved. Fre- richs has been able to make out this com- munication in every case in which he has Fig. 3.— Outline of the Front of the Abdomen, showing the Division into Begions. 1, Epigastric region ; 2, um- bilical ; 3, hypogastric ; 4, 4, right and left hypochon- driac ; 5, 5, right and left lumbar ; 6, 6, right and left iliac. (Proiri Quain.) Pia. 3.— Area of Hepatic Dulness Viewed Anteriorly. A, B, right mammary line ; C, D, median line ; B, splenic dulness ; P, cardiac dulness. (After Murcbison.) injected the portal vein. Hepatic Dulness. — The upper margin of hepatic dulness on percussion is not exactly defined. The flat note elicited on percussion over, the liver be- comes gradually clear as we percuss upward, the reason being the fact that a margin of clear lung overlaps the convex upper surface of liver. The line at which abso- Abdomen. Abdomen. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. lute dulness ceases is spoken of as the upper margin of hepatic dulness. This line is not quite horizontal, but is somewhat arched. " Commencing posteriorly at about the tenth or eleventh dorsal vertebra, it ascends gradually Fig. 4. — Area of Hepatic Dulness viewed from tile Bight Side. A, B, right axillary Hne. Fig. 5, — ^Area of Hepatic Dulness viewed Posteriorly. A, B, right dorsal line ; G, splenic dulness ; D, left kidney; B, right kidney; F, descending colon; G, ascending colon. toward the axilla and nipple, and then again descends slightly toward the middle line in front" (Murchison). In the right mammary line, which is an imaginary straight line let fall vertically from the right nipple, the upper margin of hepatic dulness is situated in I the fifth intercostal space. In the median, line in front, it usual- ly corresponds to the base of the ensiform. cartilage, or rises slightly above it. To the left of the ster- num, the upper mar- gin of liver dulness is lost in that of the heart (see Epigastric Re- gion) ; " but a line drawn from the upper margin of hepatic dul- ness in the middle line to the apex of the heart, will usually cor- respond to the line of separation. In the right axillary line, a line falling perpen- dicularly from the centre of the axilla. ninth right costal cartilage, close to the outer edge of the rectus abdominis. The size of a liver is usually measured by the extent of dulness in the right mammary line, which in an or- dinary adult is about 4 inches, and by that in the axil- lary and dorsal lines, which measure respectively 4^ and 4 inches. Paris in the Transverse Fissure of the IMer. — From be- fore backward there are found in the transverse fissure of the liver the bile-duct, the hepatic artery, and the portal vein. These structures lie between the layers of *?*«*» ffC*PB«W^ tttp* I- I \ the upper margin of j-,a, 6._Horizontal Section just above the Body of the First Lumbar Vertebra hepatic dulness corre- Dwight.) sponds to the seventh intercostal space, or more rarely to the seventh rib. In the right dorsal line, or a line falling perpendicularly from the angle of the scapula, when the arm is dependent, it cor- responds to the ninth intercostal space or the ninth rib " (Murchison). Percussion and palpation determine the lower margin of hepatic dulness. In the right mammary line it corresponds roughly to the lower margin of the thoracic wall. In the right axillary line it is opposite the tenth interspace, and in the right dorsal line, the twelfth rib. The gall-bladder projects opposite the Fig. 7. — The Liver of a Toung Subject, sketched from below and behind. (From " Quain's Anatomy.") B. Z., right lobe ; L. £., left lobe ; Z. S., lobe of Spigelius ; Z. C, caudate lobe ; L, Q., quadrate lobe ; p, portal fissure; M./., umbilical fissure; /. d. »., fissure of the ductus veno- sus ; ff. 6i., gall-bladd%r ; v. c. i., vena cava inferior ; /, g, impression on the under surface of the left lobe corresponding to the stomach ; c, position of the cardia ; t. o., projection of the posterior surface of thq left lobe against the lesser omentum (tuber omentale, His) ; i. c, im- pressio colica ; i,r,, impressio renalis; i. s, 7*., impressio supra-renalis ; P}^ P^i i?^, P^t lines of reflection of the peritoneum ; +, surface of the liver uncovered by peritoneum. the gastro-hepatic omentum at its right border, in front of the foramen of Winslow. The duct lies most to the right side, the artery toward the left. There are many lymphatics and nerves in the transverse fissure. These important structures are so closely related that alterations in size or shape of one affect the function of the others. The hepatic artery may be the seat of an aneurism, which may press upon the vein and cause portal obstruction and its attendant symptoms, or upon the bile-duct and cause obstructive jaundice. An hepatic aneurism has been known to burst into the gall-bladder (Fre- richs). The lymphatic glands in the trans- verse fissure may en- large and obstruct either duct or portal vein. Neighboring tumors of all sorts act in the same way. Concretions in the bile-ducts may ob- struct the portal vein, Into it, an occurrence the death of Ignatius (From or even ulcerate their way which is said to have caused . _. „ Loyola. The close relation of the hepatic flexure^ofthe colon to the duct explains the fact that an overloaded bowel may cause jaundice. The nerves of the liver are derived from the ccellac plexus of the sympathetic and the vagus, more especially the left, which sends some filaments between the layers of the gastro-hepatic omen- tum to join the hepatic plexus. The connection of the nerves of the liver with the solar plexus, and indirectly REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Abdomen. Abdomco. with the splanchnic nerves, serves to explain the pain in and about the right shoulder which is felt in some dis- orders of the liver, the skin of the parts about the scapula being supplied by the upper dorsal spinal nerves, which are in direct communication with the origin of the splanchnics. The hepatic artery conveys the main supply of blood for the nourishment of the organ. It may, however, be occluded without causing serious interference with, the functional activity of the liver. The collateral circula- tion, when there is complete or nearly complete obstruc- tion, may be kept up by (1) accessory hepatic arteries, which are sometimes met with coming from the gas- tric arteries, less frequently from neighboring arteries ; (3) the anastomoses of the pyloric artery, provided the obstruction be beyond the giving oflE of that branch ; (3) possibly the portal vein may in sucli a case nourish and keep up the secreting functions of the liver. The reverse is positively true. The hepatic artery can sup- ply the liver with sufiBcient blood to carry on its func- tions when the obstruction of the portal vein occurs. The hepatic veins which collect the blood from the lobules of the liver open into the inferior vena cava by an oblique entrance, which serves as a valve. In cases of abdominal tumor the effects vary as to the relation of the pressure to this junction of the hepatic vein. If the tumor compresses the inferior vena cava above the Fio. 8. — The Pancreas and Adjoining ViRcera, seen from before. (From Quain.) The stomacb, the greater part of the Rmall intestines, and the transverse colon have been removed. P., pancreas ; d., duo- denum ; d.j.^ its iunction with the jejunum ; above the duodenum and between it and the head of the pancreas are seen the bile-duct, portal vein, and hepatic artery ; aac. col.^ deac. coL, ascending and descending colon; apl., spleen; r. X:., Z. X;., right and left kidney; s. n, 8. ri, right and left suprarenal capsules ; pt.^ peritoneum, at the back of the abdominal cavity ; 7n., line of reflection of the mesen- tery ; the line of reflection of the transverse mesocolon is seen along the lower edge of the pancreas and crossing the duodenum. hepatic vein the result will be a damming up of the blood-current in the liver as well as in the general cir- culation. (Edema of the lower extremities and portal obstruction will both occur. If, on the other hand, the pressure be below the hepatic vein, then cedema of the feet will be the most prominent symptom. The Portal Vein. — There are no valves in the portal vein. Its-left branch is joined in the longitudinal Assure of the liver by the so-called round ligament, which is really the obliterated umbilical vein. This latter is sometimes open during adult life. Osier ("Montreal General Hospital Reports," vol. i.) reports a case of cirrhosis of the liver where the collateral circulation was carried on by means of an enlarged umbilical vein. At the navel this enlarged vessel became continuous with the deep epigastric vessels of the left side. The trib- utaries of the portal vein originate in the stomach, intes- tines, pancreas, and spleen. It is made up of the superior and inferior mesenteric and splenic veins, joined by the pyloric and gastric veins, and sometimes by the cystic vein from the gall-bladder. All these viscera, then, would suffer interference of function were there to be impeded circulation in the portal vein. This condition is com- monly met with. Its causes, from its anatomical rela- tions, are easily understood, and the symptoms pro- duced thereby are such as might be expected to be met with after consideration of the sources of its tributaries. 1. Engorgement of the gastric and mesenteric veins gives rise to catarrh and hemorrhages from the mucous membrane of the stomach and bowels. 3. Ascites from the over-distention of the veins that return the blood from the peritoneum. 3. The spleen is enlarged from obstruction of the current in the splenic vein. 4. An attempt is made to carry on the current by enlargement of the abdominal veins. 5. Hemorrhoids from stagna tion in the hemorrhoidal plexus, the superior hemor- rhoidal vein being a tributary of the portal vein. The hepatic duct leaves the liver and passes down in front of the portal vein, between the two layers of the gastro-hepatic omentum, behind the first part of the duodenum. A stone in the duct may work its way into the stomach and be expelled by vomiting. Pistulse . into the duodenum are not uncommon, indeed a calculus may ulcerate into the duodenum and cause death by ob- struction of the small intestine. The Epigastmo Region. — In this region the re- mainder of the right and nearly all the left lobe of the liver are found. In the middle line of the trunk the heart rests upon the upper surface of the liter, separated Fig. 9. — The Portal Vein. (From Wilson.) The pancreas drawn down to show the splenic vein behind it. 1, Inferior mesenteric vein, passing behind 3, the pancreas, to terminate in 3, the splenic vein ; 4, the spleen ; 5, gastric veins opening into the splenic vein ; 6, superior mesenteric vein; 7, descending portion of the duo- denum ; S, its transverse portion crossed by the superior mesenteric vein and part of the trunk of the superior mesenteric artery ; 9, por- tal vein ; 10, hepatic artery ; 11, ductus communis choledochus ; 13, division of the duct and vessels at the transverse fissure of the liver ; 13, cystic duct leading to the gall-bladder. from it by the pericardium, the diaphragm, and the peri toneum, this last extending three-quarters of its way back between liver and diaphragm before its reflection The left ventricle and right auricle of the heart are in close relationship with the liver, and there passes through it the inferior vena cava. This relation is illustrated by a remarkable case quoted by Treves. " A loose piece of liver, weighing one drachm, was found in the pul- monary artery. The patient had been crushed between two wagons ; the liver was ruptured and the diaphragm torn. A piece of the liver had been squeezed along the vena cava into the right auricle, whence it had passed into the right ventricle, and so into the pulmonary ar. tery. The heart was quite uninjured." A needle thrust through the abdominal wall at the tip of the xiphoid appendix, from before backward, would most probably pass through the diaphragm, the left lobe of the liver, the lobus Spigelii, the diaphragm again, the vena azygoa A-bdomen. Abdomen. BBFERBNCE HANDBOOK OF THE MEDICAL SCIENCES. jiajor, and strike the lower edge of the tenth dorsal ver- tebra. The lower margin of the liver in the epigastric region extends in contact with the abdomen in a line from the ninth right to the eighth left costal cartilage, and in the middle line its depth below the subcostal angle may be roughly estimated at 3^ or 4 inches, about a hand's breadth. On the right of the epigastric region tio. 10.— Horizontsl Section through the Upper Part of Abdomen. (From Treves, after Eiitdinger. ) a, Liver ; &, Btomach ; c, transverse colon ; tZ, spleen ; e, kidneys ; /, pancreas ; ff, inferior vena cava ; A, aorta, with thoracic duct behind it. is found the gall-bladder, opposite the ninth cartilage, close to the margin of the rectus muscle. Underneath the liver on the right, and under the diaphragm on the left of the space, the stomach is situated, occupying from time to time a varying position. Its two orifices are found in the epigastric region ; the cardiac, usually a fairly fixed point, is behind the seventh left costal car- tilage, one inch from the sternuln; while the pyloric end is continually shifting its position, being found two or three inches below the ensif omj appendix, and mov- ifie. 11.— View of the Abdominal Viscera from Behind, after removal of the Spinal Column and the whole of the Posterior Wall of the Abdo- men, the Peritoneum being left, (Prom Quain, after His.) jP,, pan- creas; /", its head; d., duodenum; 9t„ stomach; spi., spleen; R. X., right lobe of the liver ; L, S.j Spigelian lobe ; v. c. i., vena cava in- ferior; p, ?*., portal vein ; &., common bile-duct; i. r., impression for the right kidney on the posterior surface of the liver (the situation of the two kidneys is well sliown by the corresponding impressions in the cut) ; asc. CO?., aeac. eol., ascending and descending colon ; pt., back of the perit-^ e a,-^ A B A Fig. S Fig. 28. In Fig. 38, let as be a point in the air from which rays proceed toward the convex surface b c separating the air from the glass. Let o be the centre of curvature of the refracting surface b e. Let the ray a c be vertical to the surface, i.e., coinciding with the direction of the radius oc; it will hence not be deflected from its course. The ray ab is, however, refracted. If o J is the radius of the surface, and is hence vertical to the point b, the angle of refraction /S o can be found by the formula sine fb : sine ab d = n : n' It is evident from Fig. 28, that if the point a be not too near t» the refracting surface, the refracted ray J/will verge toward the undeflected axial ray, and will meet it in some pomt which we will designate /. It can be shown by a mathematical analysis, that not only this one ray, but that all rays proceedmg from the point a toward the convex surface b c are so refracted as to meet, the axial ray at the 38 point/, provided we limit our analysis to those rays only which are not very oblique to the axis, and do not strike the surface far from the axis. With this provision, the point/ is the collecting point of all rays coming from a/ the point/ is therefore the image of the point as. If we trace, however, the course of the rays which are very oblique to the axial ray, or which strike the surface far from its axis, we will find that they meet the axial ray at various points different from /. Such a want of exact reunion of all the rays, when too large an extent of the refracting surface is exposed, constitutes the fault of optic instruments known as spherical aberration. The refrac- tion of such very oblique rays is represented, in a some- what exaggerated manner, in Fig. 29. Fio. 29. 5. Focal Length. — When the luminous point is situated in the rarer medium at a distance infinitely great com- pared with the dimensions of the refracting surface, the different rays emanating from that point strike the refract- ing surface with so little divergence as to be practically parallel to each other. These parallel rays are rendered convergent by their refraction. The point where these refracted rays meet is called the principal posterior focus, and its distance from the refracting surface is the- posterior focal length. This distance, designated usually as F", depends on the relative indices of refraction of the first and second medium and on the radius of curvature of the refracting surface. If we call this radius r, the formula for the posterior focal length is F" =- n (3) The plane drawn through the posterior focus vertical tt the axis of the refracting surface is called the posieriot focal plane. As the luminous point moves nearer to the refracting surface, so as to make the incident rays more and more divergent, their focal reunion recedes further from the surface, until a certain point in front of the convex sur- face is reached, the rays proceeding from which are so divergent that they can no longer be rendered convergent by their refraction, but only parallel. Their point of focal reunion may then be considered as infinitely fai behind the surface. The point in front of the surface from which these rays proceed is the principal anterior focus, and its distance from the surface, which we will call F', is the anterior focal length. A vertical plane laid through it is the anterior focal plane. F' can be found by the formula F' = (2a) A comparison of formulae (3) and (2a) shows that the ante- rior and posterior focal lengths are noi alike under the circumstances, but that F' : F" = n : rC (2b) Remembering that the path of rays is the same, whether these rays travel forward or backward, the anterior focus can also be defined as the point in which rays unite, which proceed parallel to each other in the denser medium to- ward the refracting surface. 6. The distance of the focal reunion from the refract- ing surface can be calculated for any set of rays, coming from any point, if we know the distance of that point from the surface, and also the anterior and posterior focal lengths of the refracting surface. If/' be the known di» REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Accommodation. Accommodation. tance of the luminous point, the distance of the corre- sponding focal reunion /" will be / ~ fi pi (3) Conversely the distance of a luminous point, /", can he found, if we know the distance of its corresponding focal reunion or image/', according to the formula A very convenient formula for finding the place of the focal reunion of rays coming from a point at a known distance can be obtained by the transformation of (3) and (3a). If we designate the distance from the luminous point to the anterior focus, viz. : f'—F' as I' (counting I' negative if /' is nearer to the surface than F'), and the distance from the posterior focus to the point of focal re- union of the rays in question, viz. : /"— F" as I", then V I" = F' F" (3b) In all these instances the relation of luminous point and corresponding image can be reversed without change of position ; in other words, if the point x is the image of the point a, then for rays proceeding in the reverse direc- tion, a is also the image of the point x. Any two points having such a relation of luminous point and correspond- ing image, are called conjugate points. 7. Virtuallmage. — When the rays, coming from a point nearer than the anterior focus, strike the refracting sur- Fio. 30. face, their divergence is too great to be entirely over- come by the refraction. They cannot therefore be united to form an actual image ; but if their direction, after the refraction, be prolonged backward, their prolongations meet to form a virtual image. The focal reunion of such rays is therefore negative. Thus, in Fig. 30, if F' be the principal anterior focus of the refracting surface s s', and/' the luminous point, the rays proceedmg from/' will have a divergence after their refraction, as if they came from the point /", which is therefore the image of/'. Since /" is on the same side of the surface as /', its distance is counted negative. It can be determined by formula (3a) or (Bb). 8. Formation of Images. — Since an object is made up of an infinitely great number of points, and since of every such point in front of the refracting surface an image is formed somewhere behind the surface, therefore an image must also be formed of the entire object. Prom every point of the object there proceeds one ray, which is not bent from its course by refraction, viz. : the ray which strikes the surface perpendicularly, and hence coincides in direction with the radius of the point of the surface. Such rays are termed rays of direction Since all other Fio. 31. rays proceeding from any one point of the object meet the ray of direction at the corresponding distance of focal reunion, the Image of every point of the object is situated somewhere in the path of the ray of direction coming from that point. Since every ray of direction coincides with one of the radii of the refracting surface, the rays of direction must, therefore, like the radii, intersect at the centre of curvature of the surface. Since the focal length of a refracting surface is always greater than its radius, according to formulae (3) to (3a), therefore the actual images of objects farther off than the anterior focus are formed somewhere beyond the point of intersection of the rays of direction, and are hence inverted. This is illustrated by Fig. 31. The point where the rays of direction cross, viz. : the centre of curvature of the surface, is also called the optic centre. 9. When the object lies in a plane vertical to the axis of the refracting surface, all points of the object near the axis are sensibly at the same distance from the refracting surface, as measured by the length of the rays of direc- tion. Their images are therefore likewise situated at Fio. 32. equal distances behind the surface, and hence lie in a plane vertical to the axis. But this is true only as long as the angle included between the ray of direction com- ing from that point of the object, and the axis of the re- fracting surface is so small as to permit the substitution of its chord for its arc without practical error. In the case of objects of dimensions exceeding this limit, the images lie in a curved line, with the concavity toward the refracting surface, as shown in Fig. 33. Such extensive images are blurred, on account of spher- ical aberration. (See Section 4.) 10. Circles of Diffusion. — An image is sharply defined only in the plane of focal reunion of the rays. In any plane anterior to this the rays are not yet united ; in any plane Fig. 33. posterior to this the rays diverge again. Hence a screen placed in front or in the rear of the focal reunion receives a blurred image, since every point of the object is repre- sonted^not by a single point — but by a circle of diffu- sion. The size of the circles of diffusion increases with the distance of the screen from the point of focal reunion in either direction, and with the extent of the refracting surface through which rays pass. This is evident from Fig. 33. 11. Size of Images. — The size of the image is to the size of the object as the distance of the image from the optic centre is to the distance of the object from the same point. B"- If we designate, in Fig. 34, the distance of the object A B from 0, the optic centre, as g', and the distance of the image 39 Accommodation . Accommodation. REFERENCE HANDBOOK OP THE MEDICAL SCIENCES. a b from o a.s g", we can express the relation of size by the formula ■ , ,,^ ab:AB = g'':g' (4) the truth of which is evident from the similarity of the two triangles A B o and a bo. For certain calculations the relation of size can be more conveniently stated as ab:AB:=f"-F": F' (4a) in which formula F" is the principal posterior focal length, and/" the distance of the image from the sur- face. The derivation of this formula is shown in Fig. 35. Fig. 35. For if we draw in this figure the ray A d from the point A parallel to the axis, it is refracted as if it were a ray coming from some point in the axis at an infinite dis- tance, that is to say, it is deflected to F" the posterior focus, and proceeds beyond F" until it meets the other rays coming from A in the point of focal reunion a. Thereby are formed the two similar triangles d c F" and a b F"- Hence, ' ab:dc=f"F": e F" Since the line A d has been drawn parallel to B e, the side d c is equal in size to the object A B. If we substitute the term F" for the line c F", and the term/"— J?"' for the iinB f"F' according to our premises we get the equation ab:AB=f"-F" : F" 12. Virtual Images.— When the object is nearer to the refracting surface than the principal anterior focus, there is no real image, but only a virtual image is formed on the same side of the surface as the object is itself. In this case/" is hence negative, otherwise the same formulse apply as above. Since the rays of direction do not cross, this virtual image is erect, and since it is always farther from the optic centre than the object, it is larger than the object. The amplification of the image diminishes as the ob- ject approaches the refracting surface, for when the object has just passed through the anterior focus the image is at an infinitely great distance, and is therefore in- finitely enlarged, while when the object touches the re- fracting surface, object and image coincide in position and size. The formation of virtual images is shown in Fig. 36. Fig. 36. 18. All the facts above stated with reference to images formed in the denser medium of objects situated in front of the refracting surface, are equally true conversely of images formed in the rarer medium of objects situated behind the refracting surface. 14. Bef Taction by Gonoane Bwrfaces. — When the refract- ing surface is concave on the side of the rarer medium, rays coming from any one point are not reunited in an actual focus. But if the direction which they assume after their refraction be prolonged backward, the pro- longed rays will meet in a point representing the focus. This focal length is therefore always negative, that is to say, the focus is alwws on the same side of the surface as the object itself. The position of the principal foci or any conjugate point of focal reunion can be found by the same formula as in the case of a convex surface, but these values are always negative, because the radius of cur- vature of the concave surface is negative in direction. The images formed by a concave refracting surface are hence always on the same side as the object, that is to ■say, they are not real, but virtual, and can only be smaller than the object, as is shown in Fig. 37. Fib. 37. 15. Refraction hy Successive Surfaces. — When light passes through a number of surfaces of different media, the above developed formulae apply to the refraction through each surface. Thus the focus of the first surface forms the luminous point for the second refraction, Its distance being counted positive when it is in front of the second surface, and negative when it happens to be behind that surface. Similarly the image formed by the second sur- face is the object for the third surface, and so on. But such calculations become very cumbersome if we try to follow a,ctually the course of the rays through their suc- cessive refractions. The matter is simplified by treating the series of surfaces as one system having certain fixed points, the position of which determines the path of all rays. These are called the cardinal points. Their posi- tion remains constant in any given system, and can be calculated, if the refractive indices of the media, the radii of curvature of all the surfaces, and the distances of all the surfaces from each other are known, provided the centres of curvature of all the surfaces lie in a straight line, the axis of the system. If the latter condition is fulfilled, the system is said to be centred. The cardinal points are the two foci, the two principal points, the two nodal points. 16. The Foci. — The foci, anterior or first, and posterior or second, are the two points — one on either side of the system — at such distances that rays coming from the focus are rendered parallel to each other by their last refraction. Conversely parallel rays, entering the system from either side, are united in a point in the focus on the other side, as has been shown to occur in the case of a single refracting surface. The distance of either one of the foci of a compound system from the surface next to it may be computed in the following manner : Let n be the refractive index of the first medium, rii of the second, »a of the third, and so on. Let /S, be the first refracting surface, and ri its radius of curvature ; Si the second surface, and r^ its radius, and so on. The value of r is positive if the surface is convex on the side of the lumi- nous point ; negative if it is concave. Let di be the distance from the first surface to the second, d^ from the second to the third, and so on. Determine the foci of each surface by itself, without reference to the other surfaces. According to formulae (3) and (3a), we get for the first surface. F,' = nri Wi — ra and for the second surface andi?'i"=: rii ri fii — n F,' = Wi ?'a -andi'V' = n, ra — «! Wa — Wi The posterior focus for the first and second surfaces taken together will now be found by considering F^'' as the luminous point for 8, ; and, on applying the formula (3), jpii j>i viz., /' = , _ m" "^^ g^' t^6 equation Wf 4- 1" - J'»" id' - F," ) (5) 40 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Accommodation. Accommodation. ■w hich states the distance of the posterior focus of the system of surfaces Si and St from S2. The distance of ttie anterior focus of Si and S, together, from S,, is simi- larly found by the application of formula (3a), viz.,/' = -^ and following the light in the reverse direction, hence Fu+^y _ Fi'{di-F,') By treating the surfaces ^1 and 8, as one system, we can then proceed to determine the foci for (9 d + 2) and 8>, and so on. The foci of an optic system having been determined, the focal length is now measured by the distance of each focus from its corresponding principal point. If we call the anterior or first principal point H', and the posterior or second principal point H ", then F'H' is the anterior focal length, and H"F" is the posterior focal length. 17. The Principal Points. — The principal pomts are the two points where the axis of the system is cut by the two .principal planes. The significance of the principal planes can be best explained on comparing the refraction by a single surface with the course of rays through a compound system. In the case of the single surface a b. Pig. 38, the ray F' a, coming from the anterior focus, is, by its refraction, made parallel to the axial ray F' F". Incident and refracted rays intersect here in the plane of the refracting surface. The same is true of the ray F" b coining from the posterior focus, and its continuation, b c, after refraction. In Fig. 89, however, where there are two refracting surfaces, a b and a' b', the ray, F' a, coming from the anterior focus, is twice bent from its course, viz., at each surface, so as to finally assume the direction a' d, parallel to the axial ray. In this .case the incident ray, F' a, and the refracted ray, a' d, do not intersect, being separated by the space between a and a' ; but if we prolong them through this space, their pro- longations intersect at the point h'. A plane, K H', laid through this point, vertical to the axis, is the first prin- cipal plane. Similarly, if we prolong the ray F" V, which proceeds from the posterior focus to the surface as' V, it will cut the backward prolongation of the refracted ray S c at the point li", which point determines the position of the second principal plane. It is evident, from Fig. 39, that the ray which before entering the system is directed toward the point h' in the first principal plane, has a direction after its last refraction as if it came from a point in the second principal plane at the same distance from the axis as the point K. Likewise the ray which proceeds in the opposite direction from F° toward the point h" has a direction, after its last refraction, as if it came from a point in the first principal plane at the same distance from the axis as the point h". This mutual relation of the two principal planes is the same for all rays, not merely those coming from F' or F'; and it is true also for any distance at which the points K and h," may be from the axis within the limitations of Section 4. In other words, any ray which is directed toward a given point in the principal plane, on the side from which It comes, ap- parently emerges from the other principal plane at the same distance from the axis. We can thus determine by construction the direction of any ray after its refraction through a compound system, and thereby find the place of the image formed by such rays, if we know the position of the foci and the two principal planes. In Fig, 40, let a./ u . nC \ 1 --^ /« rf" T ^-^ ^ '•*> 1 ^"^^^ ~-~" — It ^i^ W k Fig. 40. a a' be the first, and x x' be the last refracting surface of a compound system ; let H' be the first, and H' be the second principal point, F' the anteiior, and F' the posterior focus. Draw the axis F' F". Prom the point B there proceeds the ray B a, parallel to the axis, and verging toward the point m' in the first principal plane. Hence, after its last refraction, that ray has a direction as if it came from the point to" in the second principal plane, going through the posterior focus F". Another ray con- venient to follow is the one coming from B and passing through F'. This verges toward the point n' in the first principal plane. Hence, by its refraction, it is turned in the direction n" b, as if coming from m" and proceeding parallel to the axis. Where the two refracted rays meet, at the point b, is the image of the luminous point B. Since the course of rays is determined by their relation to these imaginary principal planes, the focal lengths of a system must be measured by the distance of each focus from its corresponding principal point, and not by the distance of the foci from the refracting surfaces. Indeed, for all subsequent purposes, we can practically ignore the position of the refracting surfaces of any system, after we have once determined the position of the foci and of the principal planes. For now all the problems relative to the position of object and image can be solved by the same formulae as in the case of a single refracting surface, by measuring the focal lengths from the principal planes. 18. The position of the two principal points is deter- mined by the position of the two planes in which the images of a certain other plane are of equal size and direction. In every refracting system there exist only two such planes, and these are the principal planes ; and there exists, moreover, only one plane of which two images of equal size and direction are possible. Hence, in order to find the principal points, we must determine where a line must be in order to form two images of the 1 .•/ Uh. \,- 1*---^ T' S' H< LH" S" Fio. 41. same size and direction, and then learn the place of these two images. This proposition can be demonstrated by means of Pig. 41, in which we have a refracting system bounded by the surfaces s' 8' and s" 8". F' is the first and F" the second focus. Draw the ray F' c, which is deflected toward s" by the surface «' ^S", and is made parallel to the axis by the surface «" 8". By the intersection of the prolonged incident and refracted rays the point h' determines the 41 Accommodation. Accommodation* REFERENCE HANDBOOK OP THE MEDICAL SCIENCES. positioQ of the first principal plane. Similarly a reverse ray going from F" to e is bent twice, so as to follow ulti- mately the direction s' b parallel to the axis. The pro- longations of the ray before entering and after leaving the system give us the point h", and thereby the position of the second principal plane. If we draw a line d d' verti- cal to the axis from the point d, where the rays coming from each side intersect after their first refraction, the virtual image of d d' produced by the surface »' 8' coin- cides with the first principal plane A' !£, while the image formed by the surface s" -S" coincides with the second principal plane h" S", as is evident from the refraction of the rays according to the construction ; and these two images are aUke in size. The distance of d' from each surface is determined by the equation (4a). a b (image) : A B {object) =f' — F" : F" or more conveniently on account of the erect position of the virtual image, ab : AB = F" —f" : F" Each surface is here considered independently of the other. Hence it can be deduced that the distances of d' from each surface must be to each other as the focal lengths of the surfaces, in order to have the images formed by the two surfaces of equal size. This is shown in Fig. Via. 4S. 4Si, where P' ,S" is the focal length of the surface s" 8" in the medium between the two surfaces and P' 8' ot the surface s' 8'. A consideration of the two triangles P 8" i' and P" 8' «' and their segmentation by the lino d d' proves that d' 8' . d' 8" - P" 8' : P 8" (6) Hence, in order to find the principal planes of a system, determine the position of a point in the axis, the distances of which from the two refracting surfaces are to each other as the focal lengths of these surfaces in the medium between them. Then calculate the place of the images of this point formed by each surface independently of the other, according to formula (3). When the optic system consists of more than two re- fracting surfaces, determine the principal points for two adjoining surfaces, and then divide the distance between the one principal point next to the third surface and the third surface into two parts, which are to each other as the corresponding focal lengths in the intervening medium. The images of the dividing point formed independently by the third surface, and by the system of the other two surfaces are then the principal points of the system of three surfaces. 19. The Nodal Points. — The nodal points of a compound system replace the optic centre of a single refracting sur- face. For while all rays of direction pass undeflected through the optic centre of a single surface, a second sur- face will deflect all rays with the exception only of the axial ray. Hence a single optic centre cannot exist in a compound system. But there exist two points in the axis, viz. , the nodal points, of such properties that a ray directed toward the first before entering the system pur- sues a course after its final refraction as if it had passed through the second nodal point parallel to its original direction. That a pair of points of such properties must exist in any compound system is evident from Fig. 43, where F' is the first and F" the second focus, and m' E! n' the first and m" R" n" the second principal plane. A ray B m', coming from the luminous points B, forms with the re- fracted ray m" b any angle of less than 180° as seen from below, while the ray B n' forms with its refracted pro- longation n' b an angle greater than 180° as seen from be- low. Somewhere between m! and n' there must be a Fia. 43. level where the incident ray includes with its continua- tion beyond the second principal plane an angle of 180° exactly, in other words, where the two are parallel. Let this be at the level V. If we prolong the incident ray 5?, the points where this prolonged ray and the refracted ray I" b cut the axis, viz., K' and K" answer the require- ments of the nodal points. The position of the nodal points relative to the principal points is made evident in Fig. 44. In this figure we will draw the line B F' on F' vertical to the axis. From the point B there proceeds a ray of direction B K' to the first nodal point K'. According to our premises the ray K' b must be parallel to B K and in the direction E" b lies the image of B, at an infinite distance from the optic system. Since the point B lies in the anterior focal plane, every ray proceeding from it is rendered parallel by its refraction to the ray of direc- tion coming from B. Hence the ray B K parallel to the axis is continued after passing through the second princi- IC V pal plane, as h" F" parallel to K' b, and hence also to 5^. From the similarity of the triangle B F' IC and A" E" F" it is evident that the distance F' K' = E" F" (7) and by reversing the figure and constructing the course of rays coming from the posterior focal plane, we can similarly learn that the distance F' K" = S F' (7a) and that hence E E" = K'K" (7b) which latter corollary is also apparent from Pig. 43. The position of the nodal points can hence be at once learned by formulse (7) and (7a), after knowing the posi- tion of the principal points and of the foci. And thus we have all data necessary to follow the course of rays through any compound optic system. 20. Lenses. — It will be best to refer briefly to the optic properties of glass lenses before we proceed to the eye itself. According to the curvature of their surfaces and the distance between them, lenses either reunite into one point all the rays coming from one point, or disperse them. The former, or collecting lenses, have a positive focal length. They form inverted actual images of dis- tant objects, and erect, virtual, and enlarged images of objects nearer than their focus. The latter, or diverging lenses, have a negative focal length, and can form only erect, virtual images, smaller than their object. When both surfaces of a lens are convex, or one is convex and the other plane, the lens belongs to the former variety ; when one surface is concave and the other plane, or when both are concave, we have a diverging lens with negative focus. When one surface is convex and the other con- cave, the positive or negative value of the resulting focal length depends not only on the curvature of the two sur- faces, but also on the distance between them. 42 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Accommodation. Accommodation. The refractive index of the glass used for spectacles is so near 1.5 that we can calculate on that basis without important error, at least for spectacles. Taking this in- dex we find that in a plano-concave, or plano-convex lens, the focal length is twice the length of the radius of the curved surface, measuring from the curved surface, ac- cording to formula (2) or (3a). The first and second focal lengths are of course equal to each other, when the lens is surrounded by the same medium on both sides, accord- ing to (3b). The distance of the foci from the plane sur- face is, however, not the same as from the curved surface, for the focal lengths are measured from the principal points, one of which coincides with the curved surface, while the other is between the two surfaces. But for most of our purposes we can ignore the thickness of the glass lenses, as long as this is slight compared with the other dimensions, and practically measure the focal length from the surface, or, indifferently, from the cen-- tre of the lens. If, hence, we express the focal length of a plano-convex lens as F' z= F" = 2 r we get for a bi-convex lens the formula F = r + rj If the radii of curvature of the two surfaces are alike, we find the focal length equal to the radius, provided the in- dex of refraction is practically 1.5. This applies simi- larly to biconcave lenses, F being, however, negative. In lenses with one convex and one concave surface, the measurement of the focal length is not quite so simple, because the thickness of such a lens cannot be ignored without error, and the principal points can in such a combination be outside of the substance of the lens. The so-called strength of lenses is measured differently, according to the unit which we adopt. Formerly a lens of the focal length of one inch — either negative or posi- tive — was taken as the standard and called 1. Any lens of longer focal distance could only be named in fractions, i, being one-half of that strength ; that is to say, having a focal distance of two inches, and -i^ having twelve inches focal length, while a stronger lens, greater than 1, had a corresponding shorter focal distance. Since the adoption of the metric system in ophthalmology, the opposite way of enumeration has been employed. A lens of the focal length of one metre is now taken as unit, and called one dioptric, or 1 D. Any lens of longer focal length is ex- pressed in a decimal fraction, thus, 0.35 D, means a lens of 4 metres focal length. The stronger lenses, on the other hand, are measured by several dioptrics ; thus, 10 D, being a lens of -iV metre, or 10 centimetres focal length. Since both systems of measurement are yet in use, it is best to become familiar with both. As regards the convenience in calculation, for which purpose the dioptric system was introduced, there is i-eally not much difference between them. In order to convert the num- ber of a lens from one system into another, it is to be remembered that the metre is equal to 39.37 English inches, or 36.94 French inches. On account of inaccura- cies in grinding glasses, the whole number, 40 (English), and 36 (French), are close enough for practical purposes. Hence, to get the dioptric equivalent of an English num- ber, divide that number into 40, and to translate a certain number of dioptrics into the French inch system, divide the number into 86. 31. In order to examine the refraction in the eye we must determine the refractive indices of the different media, the curvature of the surfaces, and the distances between the separate surfaces. 23. Bef r active Indiees of fhs Media of the Eye. — The re- fractive indices have been measured by various observers in dead eyes by means of different physical methods. On account of less perfect methods former results must be taken with some caution. Even the more recent deter- minations made with Abbe's refractometer have yielded not inconsiderable discrepancies amongst different ob- servers, which may perhaps be attributed to individual variations. The following table of refractive indices is copied from Zehender and Matthieson.' complete of all recent determinations. It is the most 1.3770 1.3772 1.3721 1.8754 1^ 1- S f Lens. 1.3348 1.3342 1.3340 1.S848 Subject. h 1.4087 1.4067 1.4044 1.4044 1.4056 1.4062 1.4076 1.4018 1.4078 1.4059 !5 h Male, 50 years, I.... Female. 45 years.!!; Female, 26 years, . . Male, I..... ..... .. L.8338 1.3600 1.3821 1.3780 1.3953 1.8853 1.3867 1.3902 1.3980 1.3811 1.4181 1.4il2 1.4094 1.4164 1.4077 1.4091 1.4096 1.4101 1.4107 1S45S 1.3658 1.8508 1.8672 1.3547 Unknown,! Female, 45 years, !.. ChUd of two days, i! II. Average .3^ 1.3734 1.SS86 1.4106 1.888J The indices of cornea, aqueous humor, and vitreous body are so nearly alike that an average index of the three can be used as a basis for calculation without appreciable error. Helmholtz assumes 1.3365 as the most nearly cor- rect average in his latest publication. While the index of the capsule of the lens is considerably above this figure, this membrane is so thin and its surfaces so nearly paral- lel to each other that its influence on the rays can be neglected without error. The index of the lens itself in- creases from the external layer to the nucleus, so that the lens really consists of a large number of layers of in- creasing optic density. By reason of this stratified ar- rangement the total refractive power of the lens is greater than it would be were the entire lens of the refractive index of its nucleus. For each layer, as we proceed to- ward the nucleus, increases not only in refractive index but also in convexity. This is evident when we compare the following two lenses, the thickness of which must not be more than a small fraction of the focal length. Let one of these lenses. A, be homogeneous and have the re- fractive index n", the index of the surrounding medium being n, while the other lens, B, has only a core or nucleus more convex than the surface of the lens of the index »", the superficial layer having an index n' , intermediate be- tween n and n . If n' is now very nearly equal to n, we have practically a lens of the same index as that of the lens A, but of shorter radius of curvature, and hence of shorter focal length. If n', however, is very nearly equal to n", the lens B will be practically of the same strength as the lens A, but never less. Hence, no matter in what ratio the index increases as we proceed toward the nu- cleus, the lens gains thereby in strength. The special ad- vantages of tliis stratification over a homogeneous lens is the more regular refraction of rays very oblique to the axis, as has been shown mathematically by Hermann.' Thereby the images of objects situated laterally from the axis of the eye are not distorted as they would be when projected by a glass lens. The actual refraction of the excised human lens was found by Helmholtz in two measurements to be equal to that of a homogeneous lens of the same curvature, but with a refractive index = 1.4519 and 1.4414. But in his latest estimate (1874) he adopts 1.4371 as the more nearly correct average total refractive index of the lens in its normal attachment during life. 33. Curvature of the Ocular Surfaces. — The curvature of the surfaces cannot be measured vrith accuracy in the dead eye, on account of the altered tension of the eyeball. In the living eye the curvature can be calculated from a measurement of the size of images reflected from the sur- faces. The cornea, for instance, acts as a polished con- vex mirror, producing diminutive images, apparently behind its surface. The size of such an image is to half the radius of curvature of the mirror as the size of the object is to the distance of the object from the cornea. The size of the image is most conveniently measured by means of Helmholtz's ophthalmometer. This consists of a telescope, in front of which there is a thick plate of glass with parallel surfaces, which has been cut in two, 43 Accommodation. Accommodation. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. so that the line, separating its two halves, exactly bisects the field of the telescope. The two plates can be turned on an axis vertical to the line of separation. As long as the two plates are practically one, that is to say, lie m one and the same plane, objects are seen through them m their natural shape ; but when the two plates are turned in opposite directions, the objects appear split into two halves, which are displaced laterally in opposite direc- tions, in proportion to the rotation of the plates. The ex- planation of this displacement has been given in Section 3. For actual use the ophthalmometer is directed toward the observed eye, at a distance of several metres, and the images of two lights, one placed on either side of the tele- scope, or, rather, the ideal line uniting the two lights, are observed as reflected from the cornea. The two lights are, of course, placed in the prolongation of the line separating the two glass plates of the instrument. These plates are then turned by a screw until the image is doubled ; that is to say, until the two halves are dis- placed laterally through the open space occupied by the image. From the observed degree of rotation, and the thickness of the plates, the extent of displacement, and hence the size of the image, can be calculated, and there- by the radius of curvature of the cornea be determined. The radius of curvature, measured by reflection from the middle portion of the cornea, has been found to vary in different ej'-es from 7 to 8.2 mm., an average near 7.8 mm. being the most common. No deflnite relation has been found between this radius and any ex- isting ametropia. On observing the reflection from the marginal portion of the cornea, it can be seen, even with the unaided eye, that the images are larger than in the centre ; that is to say, that the convexity of the cornea diminishes from the centre toward the periphery. The cornea is therefore not a segment of a sphere, but of an ellipse, the major and minor axis of which are to each other in the ratio of about 9 to 10 or 11. The posterior surface of the cornea is found in the dead eye to be nearly concentric with the anterior surface. This fact, in con- nection with the rather slight difference in the indices of cornea and aqueous hrnnor, allows us to consider the cornea, aqueous humor, and vitreous body as one opti- cally homogeneous medium, bounded hy a single surface. The radius of curvature of the anterior surface of the lens has been found to vary between 9 and 12, and, ex- ceptionally, even 14 mm. ; and that of the posterior sur- face between 5.5 and 6.5 mm. The images reflected from these surfaces are so faint, on account of the small difference in the refractive indices of aqueous humor and lens, that the ophthalmometer can be used to advantage only with sunlight. The apparent size of these images requires a correction, for the cornea and aqueous humor act as a magnifying lens, interposed both in the path of the rays from the object to the reflecting surface, and, again, between the latter and the ophthalmometer. In the case of the images reflected from the posterior sur- face of the lens, the substance of the lens must also be taken into account as part of the magnifying system. It is necessary hence to know the distance from the cornea to the anterior surface, and from the latter to the pos- terior surface of the lens, in order to calculate the radii of curvature. The posterior surface of the lens acts as a concave mirror, giving an inverted and very small image; 24. Distances between the Befracting Surfaces. — The dis- tance of the anterior surface of the lens from the cornea has been determined according to various methods by Helmholtz and his pupils. By means of a focussing microscope with graduated screw, or by means of the ophthalmometer with the aid of movable lights, it was learned how far the rim of the iris appears behind the cornea, and the true position of the pupil was then calcu- lated from the known refractive power of cornea and aqueous humor. Values between 3.2 and 4 mm. have been found in different eyes. Helmholtz adopted 3.6 mm. as a sufficiently accurate average to use in his diagram- matic eye. The distance of the posterior surface of the lens from the cornea can be measured only by compli- cated methods, based on the observation of the parallax between the reflection from the cornea and that from the posterior surface of the lens, and by taking into account the influence of cornea, aqueous humor, and lens-substance on the rays. It has been found to approximate very closely to 7.2 mm., which gives 3.6 mm. as the average thickness of the lens (while the eye is not accommodating). The lens taken out of the eye increases in thickness on account of elastic retraction, as will be explained in the article on accommodation. 25. Diagrammatic Eye. — "We learn thus that there are noticeable differences in the optic constants of normal eyes, so that two eyes, both emmetropic, are not neces- sarily identical in construction. But within the latitude of emmetropic eyes the deviations of the different figures from the average counterbalance each other, so that the object, the formation of sharp images of distant objects in the plane of the retina, is equally attained in all. From numerous measurements made by himself and others, Helmholtz has constructed the following diagrammatic eye, corresponding to the average figures of human em- metropic eyes : Hi11imetito 4 mm. Thereby the focal length of the lens in the diagrammatic eye would be reduced from 50.671 mm. during rest to 39 mm. during a strong accommodative effort. Calculating on this basis the refractive strength of the diagrammatic eye, we shall now find the principal posterior focus 1.644 mm. in front of the retina, while the retina itself is in the plane of focal reunion for rays com- ing from an object 146.6 mm. (not quite 6 inches) distant from the first principal point, which latter is 1.566 mm. behind the cornea in such an accommodated eye. Mathe- matical analysis thus confirms that the increased curva- ture and the advancement of the front surface of the lens sufBce to account for the accommodative changes. During accommodation the pupil diminishes in size. The utility of this contraction of the fa'is is evident on re- membering that according to Section 4, the spherical aber- ration would increase with the divergence of the rays, and hence with the proximity of the object. On account of the advancement of the front surface of the lens the iris is also moved forward, which can be seen on looking in profile view at an eye during accommodation. 40. Mechanism of Accommodation,. — The accommodative changes of the lens are brought about by the action of the ciliary muscle. The lens itself is not a muscular or- gan, it is devoid of contractility. It is, however, an elastic body kept stretched by its attachment to the an- nular ligament, as an elastic hoop would be flattened by the traction of two cords attached at two opposite points. Relieved of this traction the lens increases in convexity and becomes more nearly globular, so that the lens re moved from the eye is more convex and thicker than while in place. During the accommodation effort the ciliary muscle contracts. . Its meridional fibres pull the choroid forward. This has been shown by Hensen and Voelkers, by the movements of a needle put through the sclera and choroid on sending an electric current through the ciliary muscle in the ej'es of animals and in a human eye just extirpated on account of disease. The circular, rmg- shaped muscular fibres of the ciliary body on contracting cause the ciliary processes to project further toward the centre of the pupil, which movement of the processes is favored by the above-described traction on the choroid and consequent relaxation of its anterior insertion. In eyes in which a sufilciently extensive segment of the iris has been removed by the operation of iridectomy, and through the translucent intact iris of albinos this ad- vancement of the ciliary processes toward the centre of the pupil has been directly observed. Since the ligament of the lens is attached to the ciliary processes the crowd- ing of this ring-shaped structure into a narrower space necessarily re- laxes the circular band stretched across the aper- ture within this ciliary ring. Thus the lens is permitted to re- tract by yielding to the tension of its own elastic substance ; for the arrangernent of the fibres of the lens-sub- stance is such that they are re- laxed by the ap- proach of the lens toward the globular shape, while the flatten- ing of the same by traction of its ligament puts them on the stretch. The changes in an eye during ex- treme accommo- dation are shown in Fig. 49, in which the upper half represents the front half of the eye at re'st, and the lower half the contraction of the ciliary muscle and its effect upon the shape of the lens. 41. Bange of AccommMation. — The most distant points of which the "eye at rest can form a sharp image on its re- tina has been termed by Donders the far-point (punctum remotum = R) of the eye. In the emmetropic eye the far-point is— according to our definition of emmetropia— at an infinite distance. The myopic eye, however, can- not see distinctly beyond a certain short finite distance, depending on the degree of shortsightedness, while in hypermetropia the eye cannot bring into focal reunion on the retina any but convergent rays, and the far-point is therefore negative, that is to say, situated at some finite distance behind the eye. The fact that many hyperme- tropes can see distinctly at a distance with the unaided eye, is due to their using a part of their accommodation continuously in order to increase the actual refraction of the eye. The near-point (punctum proximum ~ P) on the other hand, is the nearest point of which the accom- modated eye can get a well-defined image. The range of FlQ. 49. 47 Accommodation. Accommodation. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. accommodation is the total accommodative power which an individual eye possesses. We can represent it by the strength of the lens equivalent to the refractive difiference between the eye at rest adjusted for the far-point and the eye accommodated for the near-point. Thus, an emme- tropic eye, which can see distinctly an object as close as five inches, has a range of accommodation representable by a lens of five Inches focal length or of the strength of about 8 D. For deprived of its accommodative power this eye would require such a lens to be held in front of it in order to get a sharp image of this near object on its retina. Practically, it will do to hold the lens Very close to the cornea ; for theoretical accuracy, however, the lens in question, of an infinite thinness, must be assumed situated in the first principal plane of the eye. The sig- nificance of the range of accommodation is made plainer by the use of Donders' formula, J__ 1 1 A - P ~ a' in which we represent by A the range of accommodation, by P the near-point, and by M the far-point. This for- mula is applicable to ametropia eyes as well as to emme- tropia, for anomalies of the refraction do not necessarily alter the range of accommodation. Thus a myope whose far-point is at twelve in- ches' distance, and who ^'^^ can accommodate for ob- jects four inches from the eye has an accommo- dative range = \ — -,^=: i. Another instance will illustrate both the con- dition in hypermetropia and the use of the diop- tric system. Suppose a certam hypermetropic eye, the axis of which is so short that it requires a correcting glass of 4 D in order to obtain sharp retinal images of distant objects. In this eye the far-point is neg- ative, that is to say, it is situated twenty-five cen- timetres behind the an- terior principal point. If this eye possesses an accommodative range equal to eight dioptrics, four of them are re- quired to see distinctly at a distance and only 4 D are left, enabling the person to get distinct images of objects twenty-five centimetres distant by the extreme em- ployment of his accommodation. Donders' formula re- versed expresses this on using centimetres as follows : 1 1 13.5 D. which is in numerals ^li + P 35 "*■ 12i - 25' or employing dioptric notation, which is the reciprocal of the focal length, P= _42) + 8Z> = 4i>; in other words, the distance of the near-point from the eye IS equal to the focal length of a glass of 4 D strength = 25 centimetres. ° J^?^J^^'^^^^ "f ^3" ^ *^«« Accommodation.— From childhood on, the rigidity of the crystalline lens increases ana the extent of its elastic retraction diminishes. Hence the range of accommodation diminishes as the years ad- vance because the lens cannot retract as much in the later period of life as during youth, though the contracting ciliary muscle relaxes the annular ligament. The rano-? ot accommodation sinks thus from beyond ten dioptrics, 48 during childhood, to zero toward the age of sixty years. Donders has constructed a diagram (Fig. 50), based on numerous observations, which illustrates this decline in a graphic manner. The heavy line represents the refraction of the eye at rest. As before stated, the emmetropic eye becomes slightly hypermetropic in advanced age, presumably from an actual flattening of the lens or a diminution of its refractive index. The range of accom- modation extends from the heavier line of passive re- fraction to the thin line indicating the extreme active adjustment of the eye. The figures at the bottom give the age in years ; those at the side the (active or passive) adjustment in French inches (or expressed in dioptrics on the right side). Occasionally deviations are found from this standard of decline. Thus, among others, the writer has seen a gentleman, seventy years of age, who could read the finest type up to eight inches' distance. He had a slight myopia and myopic astigmatism, less than 1 D, so that this accommodative range was still a trifle over 4 D, a very unusual amount for his age. Ex- ceptions of the opposite liind, a falling short of the accommodative range normal to the age of the patient, are always due to disease of the eye or general impair- ment of the health. 43. Innervation of the Accommodative Apparatus. — The ciliary muscle derives its nerve supply from the third cranial nerve or motor oculi, which sends the motor root to the ciliary ganglion, whence issue the ciliary nerves which penetrate the sclera. It is a common clinical observation to find paralyses of other branches of this nerve accompanied by paraly- sis of the mechanism of accommodation. Expe- riments by Trautvetter* have shown that tlie fibres of accommodation run in the trunk of the motor oculi in pigeons, while in other animals the results were nega- tive. In dogs, Hensen and Volkers have traced the fibres up to the floor of the third ventricle of the brain, as shown by the result on stimulating those parts. Although the ciliary muscle consists of unstriated fibres in mammals, its movements are both as rapid and as much under the control of the will as those of any striated muscle. In birds, indeed, having evidently a very ener- getic accommodative mechanism, the ciliary muscle is striated. "While the ciliary movements are voluntary in a certain sense, we are ordinarily not conscious of any accommodative effort. The movements of the ciliary muscle are guided by the retinal impressions which we get ot the objects viewed, and may hence be classed among the complicated cerebral reflex movements. The accuracy of these movements is wonderful, inasmuch as the most rapid changes of adjustment of the eyes for different distances never give rise to any blurring of the images for which the eye accommodates. The regulating mechanism does not miscalculate the distance of the objects. The accommodating movements are always accompanied by an exactly corresponding convergence of the two eyes, so that in normal instances the object accommodated for is also the one toward which both eyes are directed, so as to place its image in the centre of the retina of each eye. The association of the movements of accommodation and convergence is so intimate that we cannot voluntarily perform either movement to any appreciable extent without the other. But by optic means + 1.5 l.BD. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Accommodation. A cconaniodatlon. ■which simulate the effect of one or the other movement, -we can temporarily rupture the association. Thus, with a given degree of convergence for a certain fixed object, we can either force ourselves to a greater accommodative effort by looking through concave glasses, or relax the accommodation by means of convex spectacles. Simi- larly, we can vary the degree of convergence associated with a certain accommodative effort by jSacing prisms of variable strength and inclination in front of one or both eyes. The ability to separate these two movements ordinarily associated is increasQd by practice. It is evi- dent that the correlation of the two movements, as well as the disturbance of this association by optic means, subserve the same purpose, viz., distinct vision without double images. 44. Movements and Nerves of the Iris. — On account of the association with the accommodation, the movements of the iris can be best discussed in this connection. The iris serves the purpose of an optic diaphragm, the aperture of which can vary in size according to necessity, the physiological limits being from two to six millimetres diam- eter. By reflex action the pupil contracts with increasing illumination, therebjr diminishing both the fatiguing brightness of the retmal image and the width of any cir- cles of diffusion due to optic imperfections. When the light is relatively feeble, a large pupil, on the other hand, permits a relatively greater brightness of the retinal images,, while the enlarged circles of diffusion do not blur the sight so much, on account of their feebler inten- sity. The pupil contracts also with each accommodative effort, thereby diminishing the spherical aberration, which the proximity of the object and the increased convexity of the lens would produce. Independently of external light, the pupil is very narrow during sleep and during artificial narcosis. The mechanism of this latter contrac- tion is not yet known. When the narcosis is interrupted by any sensory stimulation, or by asphyxia, the pupil in- dicates this change by dilatation. The nerves of the iris are the ciliary nerves, coming from the ciliary ganglion, which, in man, has three roots — the short root from the motor oculi, the long root from the naso-cUiary branch of the fifth nerve, and the sympa- thetic fibres reaching the ganglion along with its arteries. The motor oculi controls the sphincter muscle of the iris. Its experimental irritation contracts the pupil ; its section or accidental paralysis, allows it to remain dilated. The reflex pupillary contraction produced by light starts with the excitation of the optic nerve. When the optic nerves are rendered inactive by disease, the normal play of the pupils ceases, and they remain in a state of moderate dila- tation. Excitation of one optic nerve, however, controls the pupUs of both eyes, at least in those animals which, like man, have a visual field common to both eyes. Hence, in cases of unilateral blindness the two pupils are usually alike in size. The centre concerned in this reflex action is the anterior half of the tubercula quadrigemina (Budge). Various instances of disease of higher parts of the brain have been observed with integrity of these parts, and hence sensitiveness of the pupils to light, although conscious sight did not exist. According to i3rown-S6- quard the muscular tissue of the iris itself is somewhat sensitive to light, a tonic contraction being induced in it by strong Ught, even after extirpation of the eyeball. The sympathetic nerve fibres control the dilator muscle of the iris. The existence of these radiating muscular fibres, which seemed pretty well established by the re- searches of Henle, Iwanoff, and Merkle, after much con- troversy with Gruenhagen, has latdy been questioned again by Eversbusch (meeting of the Heidelberg Ophthal- mological Society, September, 1884). He maintains that the radiating fibres in the posterior layer of the iris, which have been interpreted as smooth muscular fibres, are really nerve fibres, as shown by various staining methods. If these statements are corroborated, it will be impossible to account satisfactorily for the action of the sympathetic nerve on the iris. The view that these nerves change the size of the pupil, through their action upon the muscular walls of the blood-vessels of the iris, is not well supported by the facts. Vol. I.— 4 Their course toward the eyeball is partly along the walls of the arteries, partly along anastomoses which join the fifth cranial nerve. Section or paralysis of the sympa- thetic nerve of the neck is followed by contraction of the pupil, while its irritation dilates that aperture. These fibres can be traced through the rami communicantes of the last two cervical and the first two dorsal nerves into the spinal cord (Budge and Waller). The reflex centre of these fibres is partly in the corresponding region of the spinal cord, and partly in the medulla oblongata. Reflex dilatation of the pupil through this nerve-channel can be readily induced by any sensory impression through most any sensory nerve,' at least when the pupil is not con- tracted by strong light, especially during sleep and in- complete narcosis. The pupil, indeed, is very sensitive to irritations of sensory nerves. It is not known that this reflex dilatation is of any utility. It has recently been asserted by Tuwim ' that the su- perior cervical sympathetic ganglion maintains a shght tonus of the dilator nerves of the iris, independently of, and even after, its separation from the central nervous systein. Although his experiments seem conclusive, the question should be further investigated, since this would be the first instance known of tonic activity of nerves maintained by a sympathetic gangUon. The fifth cranial nerve is the sensory nerve of the iris, endowing it with very great sensibility. Irritation of this nerve contracts the pupil very energetically in some ani- mals, for instance the rabbit. Section of the nerve has the same effect, temporarily, the fibres being evidently kept in a state of transitory irritation by the injury, as occurs as well in certain other nerves. This influence of the fifth nerve upon thf pupil does not exist in carnivo- rous animals. The observations in disease of that nerve in man are too conflicting to be decisive. The study of eye diseases attended with irritation renders it very likely that in man the fifth nerve is the vaso-dilator nerve of the iris, and that its reflex excitation congests the iris and contracts the pupil mechanically by the engorgement of the vessels. This is also the most plausible explanation of the intense pupillary contraction obtained on punctur- ing the anterior chamber, which result does' not occur on operating on the dead eye. BiBLiOGKAPHY. — The optic properties of the eye were not understood until Kepler, in 1602, evolved the theory of optical instmments in general. The importance of the various parts of the eye in refraction was further eluci- dated by the Jesuit Scheiner in 1619. Minor additions were successively brought out by the labor of different authors, but it was only after Gauss had published his mathematical investigation of the cardinal points (" Diop- trische IJntersuchungen," Gottingen, 1841) that the com- plete theory of the refraction in the eye could be deduced. This was done successfully by Listing, in the article "Dioptrik des Auges" in Wagner's " Handworterbuch der Physiologic " (1853), who, by a critical selection of the older measurements of the refractive indices of the eye by Chossat and by Brewster, of the anatomical measurements of dimensions and curvature by Krause, Kohlrausch, and others, determined the position of the ocular cardinal points with considerable accuracy. The most marvellously accurate methods, however, for measurements of the living eye were first introduced by Helmholtz, who, in his " Handbuch der physiologischen Optik" (1867), has pro- duced a masterly treatise of rare originality, which every student of the subject must consult in the original. Since the publication of his large work, the first part of which on refraction appeared in 1856, Helmholtz has pursued these studies vnth the aid of numerous students, most of whose articles have appeared in the running numbers of the ArcMv fur OphthMmologie. In an article by Reich {Arch. f. Oplith., 1874, vol. xx., 1), Helmholtz corrects some of his former measurements and figures, and accepts as more nearly representing the values of the cardinal points in the average eye the figures which we have re- produced in the text of this article. Extensive measure- ments, especially of the curvature of the cornea, have also been made by Donders ("Anomalies of Accommodation and Refraction," 1864) and by Mauthner (" Vorlesungen 49 Accommodation. Accommodation. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. fiber d. optlschen Fehler des Auges," 1872), and more re- cently by Reuss {Areh.f. OpMhalmologie, xvii., 1, p. 37). The entire theory of the formation of images in the eye, including physiological optics in general, is most exhaus- tively treated in Aubert's " Grundzuge der phys. Optik," in vol. ii. of Graefe and Saemisch's "Handbuch der ge- sammten AugenheUkunde " (1876), while important recent additions are to be found in Nagel's " Anomalien der Re- fraction," in vol. vi. of the same work. Very complete is also the treatise of Fick in vol. iii. of Hermann's " Hand- buch der Physiologic." All of these works must be con- sulted for the complete literature of the subject. In the English language the most extensive but older treatise is the work by Donders on " Anomalies of Accommodation and Refraction " (1864), which book marked quite an era in our knowledge of the physics of the different refractive conditions of the eye. In connection with this latter sub- ject the work of Jaeger (" Einstellungen d. dioptrischen Apparats," 1861) must also be mentioned. ■The mechanism of accommodation has been extensively discussed by former authors, by whom, however, no facts were brought forth beyond those taught by every-day observation. By some the accommodative changes were refeiTed to the variations in the size of the pupil, while others even denied the existence of any accommodation. The most complete mathematical discussion was furnished by Th. Young in the "Philosophical Transactions" of 1801, in which it was shown by experiments and by deduc- tions that the accommodation cannot depend on any changes except those in the form of the lens. The experi- mental proof that such changes do occur was furnished simultaneously and independently of each other by Cramer (in various publications in the Dutch language, between 1851 and 1855) and by Helmholtz {MoTiaUbenchte d. Ber- liner Academie, February, 1853). The mode of action of the ciliary muscle was first explained by Helmholtz theo- retically, and has since been confirmed experimentally by Hensen and Volkers, who have likewise studied the in- nervation of the accommodative apparatus ("Experi- mentaluntersuchung fiber den Mechanismus der Accom- modation," 1868, and Arohivf. Ophthalrmlogie, 1873, vol. xix.). Important measurements of the changes in the curvature of the lens during accommodation, and a mathe- matical inquiry into their efliciency were published by Knapp (Archw f. Ophth., 1860, vols. vi. and vii.). Our knowledge of the range of accommodation in health and disease is due mainly to the researches of Donders ("Anomalies of Accommodation and Refraction"). On the innervation of the iris there exists an extensive literature, scattered throu^out numerous physiological and ophthalmic serials. The older literature is exhaus- tively compiled in Budge's " Bewegungen der Iris," 1855. The present writer presented likewise a full review of the physiology of the iris in the Chicago Journal of Mrwus and Mental Diseases (April and July, 1874), in which the complete literature up to that date can be found. What- ever has been done since 1874 is explicitly referred to in tlietext. s. GradXe. ' Nagel : Anomal. d. Kefraotion, in &riiefe and Saemisch's Handb. d ges. Augenheilkunde, p. 461. " Ueber schiefcn Durchgang von Strahlenbiindeln durch Linsen, Gratulationschrift an C. Llidwig. 3874. > Archives of Ophthalmology, toI. ix, p. 29. < Proceedings of the International Congress at Copenhagen, 1884 Ophthalmic Section. ' » Report of the Heidelberg Ophth. Society iu Deutsche med. Wochen- achrift, October 9, 1884. • Archiv f. Ophthalmologie, 1866, xli., p. 9B. ' Archiv f. d. gesammte Physiologie, Bd. xxlv., p. 115. ACCOMMODATION AND REFRACTION. Patholo- GT.— The normal refractive condition of the eye {emmetro- pia, E) is best described as a correct relation between the curvatures of the refractive surfaces and the length of the antero-posterior diameter (axis) of the eyeball. In emmetropia, parallel rays, such as are received from any distant object, are accurately focussed upon the retina by virtue of the refractive power of the eye, without aid from the accommodation. If this normal relation is dis- turbed, whether through abnormal curvature of the cor- nea or the anterior or posterior surface of the crystalline 50 lens, or through a variation from the normal length of the axis of the eyeball, a refractive anomaly (ametropia) is the result. In the two principal tjrpes of ametropia the axis of the eyeball is actually, in most cases, either too short or too long. In the former case the refractive power of the eye is insufficient to focus parallel rays accurately upon the retina, and some exercise of the accommodation is neces- sary for distinct vision at a distance. For the focussing of divergent rays, such as are received from any near object, the accommodative adjustment is necessarily in excess of that which the emmetropic eye employs for dis- tinct vision at the same distance, and this excess is always equal to the degree of accommodation required for vision at a distance. From the fact that the focus for parallel rays is behind or beyond the retina, this refractive anom- aly has received the name hypermetropia, H (from iirepfierpos, overmeasure, and ^^, eye). The hyperme- trope, if his accommodation is sufficient to overcome the refractive deficiency, may see distinctly at all distances, but only through active accommodative effort, and gen- erally with more or less sense of fatigue, when the eyes are used continuously. Moreover, as the range of the accommodation has always a nearly definite limit, which is closely related to the age of the subject, the nearest point of distinct vision (near-point, p) is always somewhat further from the eye than in emmetropia. Hypermetro- pia is ordinarily an inherited condition, and may be prop- erly considered as a form of incomplete development of the eyeball. (See Hypermetropia.) In the case of an abnormally long axis of the eyeball, parallel rays are focussed in front of the retina, and only divergent rays are focussed accurately upon it. Such an eye is, therefore, fitted only for near vision, and for this reason is called near-sighted or short-sighted. Short- sightedness was known to the classical writers, who men- tion it under the fanciful name myopia, thus precluding the adoption of the really descriptive name Irachymetro- pia (from Ppaxi, short, /ifrpoy, measure, and &\ji, eye), as suggested by Donders to express the opposite condition to hypermetropia. The myope sees all distant objects indis- tinctly, and he sees objects at some definite shorter dis- tance (far-point, r) clearly, without exercise of the ac- commodation. For objects which lie nearer to the eye than its far-point, the myope accommodates, but always less than does the emmetrope for the same distance. When the myope makes use of his entire accommodation he is able to see clearly at a somewhat shorter distance (near-point, p) than can the emmetrope under the same condition of full accommodation. Myopia is generally an acquired condition, and is then the result of pathological distention of the eyeball. (See Myopia.) The emmetropic eye has its far-point at an infinite dis- tance, and its near-point at some sliort distance, which is determined by its range of accommodation. At the age of twenty years this is equal to about ten metric units (dioptrics'), and the near-point is about one-tenth of a metre (10 ctm. =4 in.) from the eye. In myopia the grade of the refractive anomaly, expressed in diop- trics, determines the position of the far-point, and from this the near-point may be found by adding the number of dioptrics which expresses the range of the accommoda- tion. With a myopia of five dioptrics (5 D), and a range of accommodation of ten dioptrics (10 D), the far-point is one-fifth of a metre (20 ctm. = 8 in.) from the eye, and the near-point is about one-fifteenth (tt^tis = -h) of a metre (6.6 ctm. =2.6 in.) from the eye. In hy- permetropia the grade of the refractive anomaly is sim- ilarly expressed in dioptrics, but with the minus (— ) sign, and the place of the near-point is determined by the alge- braic sum of this minus quantity and the plus (-I-) quan- tity which represents the range of the accommodation. With a hypermetropia of five dioptrics (— 5 D), and a range of accommodation equal to ten dioptrics (10 D), the place of the near-point is determined by the algebraic ad- dition of those two quantities (10 D — 5 D = 5 D), and is one-fifth of a metre (30 ctm. =8 in.) from the' eye. In a higher grade of hypermetropia, say of ten dioptrics (10 D), with a range of accommodation equal to ten diop- REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Accommodation. Accommodation. tries (10 D), this addition (10 D — 10 D = = ^-) places the near-point at an infinite distance, which means that the full exercise of the accommodation is only sufficient for distinct vision at a distance, and that the eye has no ac- commodation to spare for vision at shorter distances. In a still higher grade of hypermetropia, say of fifteen diop- trics ( — 15 D), with the same value of ten dioptrics (10 D) for the range of accommodation, we find 10 D — 15 D = — 5 D, or, in other words, a virtual hypermetropia of five dioptrics ( — 5 D), notwithstanding the full exercise of the accommodation. In the highest grades of hypermetropia there is no distinct vision at any distance. It is only in emmetropia that the entire range of the accommodation is available for distinct vision at all dis- tances from infinity to the normal near-point. In ame- tropia the range of accommodation remains unchanged, but the limits within which it acts are displaced, so that it is rendered less effective in adjusting the eye for distinct vision at different distances. This region of aecomm. m myopwi, P = R - A' M' M + . P = A-H As, however, the actual limit of vision for distance is infinity, this must represent the position of the far-point (»•) in hypermetropia, and the expression of the real con- dition becomes : In hypermeii'opia, R = oo, From a comparison of these formulae it will be seen that, with the same range of accommodation, the region of ac- commodation is most extensive in emmetropia. In my- opia this region is greatly contracted through the approach of the far-point (r), with but slight and generally unim- portant compensation in the approach of the near-point (p) to the eye. In hypermetropia the region of accommo- dation is seriously curtailed through the recession of the near-point (p) from the eye, while the far-point (r) re- mains, as in emmetropia, at infinity. By the correction of the ametropia, by means of the proper concave or convex glass, the far-point (r) is ad- justed to infinity, and the near-point (p) is then determined solely by the range of accommodation (A). The formula then becomes indentical with that of emmetropia : 1 1 In myopia R = R = M — M 1 M — M + A 1 = 1 H — H 1 H = — = CD, 1 ^A' J. A' H + A We have thus far considered only the case of ametropia as if in a single eye, and have ignored all complications growing out of the fact that vision is actually the result of the concurrent action of the two eyes. In brief, it may be stated that we see with each eye the object or part of the object to which the eye is directed, and that in order to see the same object with the two eyes, the two eyes must be accurately directed each to the same point, and this point must be a point for whose distance each eye is accommodated. There is, in fact, a very intimate connection between the two adjustments of accommodation and conmergence, which may lead to important complications both in myopia and m hyper- metropia. In myopia, we have seen that there is com- paratively little occasion for the exercise of the accom- modation, but the need for convergence remains un- changed, or may even be somewhat mcreased by reason of the shorter distance at which the strongly myopic eye sees small objects. This normal, or excessive, conver- gence may in turn evoke excessive accommodation, and so necessitate the holding of the book still nearer to the eyes, thus again necessitating still stronger convergence. The needless accommodation which is thus excited may cause the myopic eye to appear more strongly myopic than it really is, and may lead to injurious tension of accommoda- tion, and through this to a progressive increase in the grade of the myopia. On the other hand, the eyes may fall into the habit of relaxing the accommodation to the degree requisite for distinct vision at or near the far-point, and this relaxation of the accommodation may be attended by a corresponding relaxation of the convergence, which may lead to weakness or insufficiency of the recti interni muscles (muscular asthenopia) , and ultimately to divergent strabismus. In hypermetropia, as we have seen, the eyes accommodate even in distant vision, and must accommo- date more strongly than in emmetropia in order to see near objects distinctly. Accordingly in hypermetropia one of two complications may arise ; either the conver- gence may be habitually adjusted to the distance of the object, in which case the correlated degree of accommoda- tion may be insufficient for distinct vision or for continu- ous work, and so the eyes may suffer from accommodative insufficiency or fatigue (accommodative asthenopia) ; or, on the other hand, the accommodation may be maintained to the degree requisite for distinct vision, and this excessive accommodative effort may evoke a tendency to excessive convergence, which may ultimately develop into conver- gent strabismus. (See Strabismus.) The effect of the disturbed correlation between the ac- commodation and the convergence in ametropia may be concisely formulated, as follows : In myopia there is a tendency to abnormal tension of the accommodation, and through this to a progressive in- crease in the grade of the myopia, or else to muscular asthenopia and insufficiency of the recti interni muscles, and ultimately to divergent strabismus. In hypermetropia the tendency is to fatigue or insuffi- ciency of the accommodation (accommodative asthenopia), or else to abnormal tension of the recti interni muscles, and ultimately to convergent strabismus. Astigmatism is a refractive anomaly in which the re- fractive power of the eye is unequal in different merid- ians (see Astigmatism). This inequality is greatest in two meridians which lie at right angles to each other, and 51 A ccommodatlon. A ccommodatlon. EEFERBNCB HANDBOOK OP THE MEDICAL SCIENCES. which are called the principal meridians. The astigmatic eye may be emmetropic in one of its principal mendians, in which case it is either myopic or hypermetropic in the other ; or it may be either myopic or hypermetropic in both meridians ; or, lastly, it may be myopic in one of its principal meridians and hypermetropic in the other. If the astigmatic eye is hypermetropic in its horizontal merid- ian, the accommodative disturbances are generally those which belong to hypermetropia, namely, accommodative asthenopia, or a tendency to convergent strabismus ; if, on the other hand, the eye is myopic in its horizontal merid- ian, the complications are ordinarily those which belong to myopia, namely, accommodative tension, or muscular asthenopia, or insufficiency. Moreover, as in astigmatism the acuteness of vision is more or less impaired, the incli- nation is always to hold the book quite near to the eyes, and thus the tendency to accommodative tension or to muscular insufficiency, on the one hand, or to muscular tension, or to accommodative insufficiency, on the other hand, is materially aggravated. Irregular astigmatism (see Astigmatism) necess'arily impairs the acuteness of vision at all distances, and may prove a source of disability or of danger through the forcing of the accommodation and convergence in the effort to read continuously at a very short distance. The correction of astigmatism, together with anjr ac- companying ametropia, by means of appropriate cylindri- cal or spherico-cylindrical glasses, both improves the acuteness of vision and removes the disabilities incident to the displacement of the region of accommodation. Even in irregular astigmatism a part of the refractive defect may often be corrected by means of cylindrical glasses, with corresponding improvement in the acute- ness of vision. Unequal refraction in the two eyes — anisometropia (from o privative, To-os, equal, /i^rpov, measure, and &\li, eye) — may give rise to certain complications growing out of the close connection between accommodation and convergence. Moreover, as the accommodation is always equal in the two eyes, the same degree of inequality must exist in ac- commodation as in a state of rest, so that the two eyes are never accurately accommodated for the same distance at the same time. In order to see any object clearly, one of the eyes must accommodate accurately for its dis- tance, while the other eye is necessarily accommodated for some other distance. Hence, one of the retinal images Is distinct, while the other is imperfectly defined. This difference in definition is, however, not of much impor- tance, for, practically, the attention is attracted to the clearer image, and the confused details of the other im- age are disregarded. Both images are, however, utilized in binocular vision, as is shown by the persistence of the faculty of estimating differences of distance and of ap- preciating the form of solid objects (stereoscopic vision). On theoretical grounds a certain improvement in the acuteness of vision might be expected from the accurate correction of both eyes by means of glasses of different foci, and this is undoubtedly true in the case of lesser differences in refraction, but in cases of greater difference, equalizing glasses may not be readily accepted. A per- son with one emmetropic eye of normal acuteness will not ordinarily accept . glasses for the sole purpose of remedying a visual defect of which he is perhaps un- conscious and which causes him no inconvenience, and, similarly, most persons with ametropia of a different grade in the two eyes will rest satisfied with glasses of equal foci, which leave the existing refractive difference unchanged. Hence the general rule not to give glasses for an uncomplicated refravUive error of one eye, and, except in the case of a trifliing difference (one dioptric or less), to give glasses of equal foci, selected with reference to the eye which is habitually in use, in cases of uncom- plicated refractive error of a different grade in the two eyes. The complications which may make it necessary to pre- scribe glasses of different foci in anisometropia; occur chiefly in cases of myopia of one eye, or of myopia of a different grade in the two eyes. In myopia of one eye, with emmetropia or moderate hypermetropia of the 52 other, the myopic eye is ordinarily used in reading and the emmetropic or hypermetropic eye in distant vision. Such a person may suffer from muscular asthenopia or insufficiency of the recti interni, as a consequence of the habitual relaxation of the accommodation in reading, or from injurious tension of the accommodation, with a ten- dency to progressive increase of the grade of myopia, . incident to the habit of converging accurately for the reading distance. In such cases it is .generally best to correct the myopic eye by means of a suitable concave glass, and to prescribe for the other eye either a plane glass or a convex glass suited to the grade of its hyperme- tropia. In myopia of a different grade in the two eyes it is the rule to correct the less myopic eye for distance, and to give the same glass, or one of shorter focus, to the more myopic eye, as may be found most satisfactory upon trial. If the difference in the refraction of the two eyes is large (two dioptrics or more), a partial correction of the more myopic eye may be preferred in the beginning, and the full correction may be demanded after the lapse of a few weeks or months.' Apliakia (from o, privative, and ^oxh = lens, a lentil) is the condition in which the crjsstalline lens is either wholly wanting or is so displaced that it no longer lies in the axis of the eyeball. Of the total refraction of the eye (about 50 dioptrics) about five-eighths (31.5 dioptrics) is due to the cornea, and about three-eighths (18.5 dioptrics) is due to the crystalline lens. The aphakial eye has there- fore sustained a loss of refractive power equal to 18.5 dioptrics, besides the loss of its entire accommodation, which in youth amounts to about ten dioptrics more. In correcting aphakia by means of a convex glass, the position of the glass (about half an inch in front of the cornea) is considerably more advantageous than that of the crystalline lens which it replaces, and consequently a glass of about eleven dioptrics is sufficient, in most cases, to make good the refractive deficiency. The retinal image is also enlarged by about one third, in consequence of the change in the position of the nodal point. A certain de- gree of accommodation, with additional enlargement of the retinal image, may be obtained by holding the glass farther from the eye, but the distance at which the glass can be easily held is limited to the length of the nose, and is too small to admit of the necessary adjustment for read- ing. Hence two glasses are generally required, a weaker glass, of ten or eleven dioptrics, for distant vision, and a stronger glass, of fourteen or fifteen dioptrics, for reading. If the aphakial eye is of hypermetropic construction, pro- portionally stronger glasses, and if of myopic construction, proportionally weaker glasses, are required. In the case of aphakia of one eye, with normal visual acuteness of the other eye, it is hardly practicable to equalize the refrac- tion, even for distance, by means of glasses of different foci ; but the aphakial eye, though uncori'ected, takes some part in binocular vision, and is of use not only by enlarging the general field of vision, but also by assisting in the estimation of distances. A considerable grade of astigmatism is frequently present in aphakia, which may be due either to original asymmetry of the cornea or to an acquired distortion of the cornea incident to the healing of the incision in the operation for the extraction of cataract. Low grades of astigmatism are often overcome by looking obliquely through the strong convex glasses worn to cor- rect the aphakial condition ; higher grades may require correction by a spherico-cylindrical lens. (See Astigma- tism.) DisoRDEBS OP ACCOMMODATION may occur as a result either of an abnormal condition of the special organ of ac- commodation, the crystalline lens, or of disordered in- nervation. The absence of the crystalline lens involves not only a notable reduction in the refractive power of the eye, but also the total loss of accommodation. Cases of ectopia lentis (from ^leroros, out of place), and of incomplete luxation of the crystalline lens from injury to the eye have been observed, in which the lens has re- mained nearly, or quite, transparent. In such cases the refractive power of the eye is generally considerably in- creased, owing probably to an increase in the convexity of REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Accommodation, Accommodation. the lens, but the faculty of voluntaiy accommodation is wholly wanting. The progressive hardening of the crystalline lens, which has already begun in youth, and which goes on, probably, throughout the entire duration of life, becomes, after mid- dle life, an insurmountable obstacle to such changes in the form of the lens as are essential to perfect accommo- dation for the usual reading distance (see Presbyopia). Only in myopia is there an apparent exception to this statement, owing to the fact that the far-point (?•) often lies so near to the ej;e as to bring it within the ordinary reading distance of thirty centimetres (twelve inches). In such cases the myope never becomes presbyopic in the sense of being unable to read without the aid of convex glasses; but whereas in youth he reads easily with the concave glasses which perfectly correct his myopia, he is compelled, with advancing age, either to lay aside his glasses in reading, or to exchange them for weaker con- cave glasses than those through which he sees well at a distance. In hypermetropia, on the other hand, the loss of accommodation shows itself by an early recession of the near-point {p), so that help is sought from convex glasses, perhaps long before the usual age of from forty to forty-flve years. Still the hypermetrope, wearing con- vex glasses which correct his hypermetropia, is able both to see at a distance and to read, and it is only at the age of about forty-flve years that he finds himself compelled to exchange these glasses for stronger reading glasses. Under no circumstances can a presbyope see clearly at a distance and read easily with the same glasses. Either he is an emmetrope, in which case he requires convex glasses for reading, but none for distant vision ; or he is a myope, and so requires concave glasses for the distance, and weaker concave glasses, or no glasses at all, for reading ; or he is a hypermetrope, and so sees distinctly at a dis- tance with convex glasses, but requires stronger convex glasses for reading. Paralysis or paresis of accommodation from defective innervation may be the result of an affection implicating the terminal branches of the ciliary nerves, or any part of the nervous tract between these and the central origin of the motor-oculi nerve in the ganglia and cortex of the brain. With rare exceptions it is accompanied by dilata- tion and loss of mobility of the pupil (mydriasis), and in many cases also by paralysis or paresis of one or more of the ocular muscles supplied by the motor-ocuU nerve, namely, the levator palpebrae superioris, the rectus supe- rior, the rectus inferior, the rectus internus, and the obliquus inferior. A typical example of paralysis of accommodation de- pendent on impairment of the function of the terminal branches of the ciliary nerves, is that which follows the instillation of a mydriatic solution into the conjunctival sack. Within fifteen minutes after the instillation of a drop of a solution of atropia sulphate of a strength of one per cent. (1 : 100), the pupil begins to dilate, and within half an hour the dilatation reaches its maximum, and the pupil no longer contracts under the stimulus of strong light. Shortly after the establishment of full mydriasis, or about half an hour after the instillation, the near-point (p) begins to recede rapidly from the eye, and the paralysis of accommodation is complete at the end of an hour and a half. The dilatation of the pupil and the paralysis of ac- commodation continue without sensible change for about two days, after which both begin to pass away, the former very gradually, the latter more rapidly for two or three days and afterward more slowly, until at the end of ten or twelve days the effect of the diTig disappears altogether. The effect of very weak solutions of atropia, say of a strength of one-hundredth of one per cent. (1 : 10,000) is to dilate the pupil in the course of an hour and a half or two hours, but without rendering it immovable under the influence of bright light, and without greatly affecting the accommodation. Under the action of atropia the near- point (p) recedes from the eye until it comes to coincide with the far-point (r). Hence the visual disturbance varies very conspicuously according to the refractive condition of the eye. In emmetropia distant vision remains clear, but accommodation for the near is rendered impossible ; in hypermetropia vision becomes indistinct for the dis- tance, and still more so for the near ; while in myopia of a rather high grade there may be no trouble in reading, and the loss of accommodation, within the narrow limit of distance between the far-point and the near-point, may give rise to little inconvenience or may even pass un- noticed. To the hypermetrope or myope wearing glasses which correct his refractive defect the visual disturbance is the same as in emmetropia. Several other plants, be- longing mostly to the natural family solanacem, or to a closely allied order, yield alkaloids whose action is nearly identical with that of atropia, and quite recently a valuable mydriatic property has been discovered in cocaine, the active principle of erythroxylon coca. Concussion of the eyeball is sometimes followed by weakening or loss of the accommodation, conjoined with dilatation of the pupil. This condition may soon pass away, or it may be permanent. It is evidently the result of injury to the ciliary nerves, in the ciliary region of the eye. Diphtheria is often followed by paresis of accommo- dation, with some enlargement of the pupils. It occurs, as a rule, after recovery from the throat affection, and has ordinarily a duration of several weeks, or perhaps of two or three months. It is frequently associated with paresis of the palatine muscles, giving rise to charac- teristic alteration of the speech. The external muscles of the eye are seldom affected, but cases of true convergent strabismus have been observed as a result of excessive efforts to accommodate in the weakened condition of the accommodative apparatus. The symptoms of paresis of accommodation following diphtheria are essentially the same as in asthenopia resulting from the overloading of the accommodation in hypermetropia, and the use of con- vex glasses is often indicated as an aid in reading during the continuance of the disability ; the instillation of a drop of a weak solution of pilocarpine, two or three times a day, is also of positive utility ia many cases. Syphilis is recognized as an occasional cause of paralysis of accommodation with mydriasis. It occurs ordinarily as one of the later manifestations of the disease, and is not generally amenable to treatment. Pressure upon the ciliary nerves, from intraorbital haemorrhage, inflammatory exudation, tumor, etc., may give rise to loss of accommodation and dilatation of the pupil, without affecting the function of any of the exter- nal muscles of the eyebaU. In lesions affiecjting the conductivity of the motor-oculi nerve, the accommodative disturbance and dilatation of the pupil are accompanied by paralysis of the levator muscle of the upper lid, of the recti muscles (excepting the abducens), and of the inferior oblique muscle. Mydriasis, with loss of accommodation, may occur as a symptom of intracranial disturbance, affecting the central origins of the motor-oculi nerve. Such disturbance may be the result of a pathological process (syphilis, embolism, etc.), in which case it is apt to be associated with paraly sis of one or more of the external muscles of the eyeball. Exposure to sudden changes of temperature, sitting in a cold draught, etc., are sometimes followed by paralysis of one or more of the motor nerves of the eye or of the eyelid. These cases, which, in the absence of positive knowledge, are generally designated as rheumatic, end frequently in perfect recovery after a few days or weeks ; in other instances they prove rebellious to all treatment. The constitutional effect of an overdose of any one of the common mydriatic drugs (belladonna, datura, hyos- cyamus, duboisia), administered by the stomach or hy- podermically, is marked by conspicuous dilatation of the pupils, with loss of accommodation. If the patient survives the toxic influence, these symptoms disappear after a short time. True spasm of accommodation, as distinguished from the condition of accommodative tension already noticed in connection with ametropia, is of quite rare occurrence, and is a result of irritation of the ciliary nerves or the oculo-motor nerve-centres,' or of a paralytic affection of the cervical sympathetic. It is associated with contraction of the pupil (myosis), and is the exact opposite of accom- 53 Aocoinmodatlon. Acetabulum. REFERENCE HAKDBOOK OF THE MEDICAL SCIENCES. modative paralysis with mydriasis. Certain drugs {myo- tics), Instilled into tlie conjunctival sack, have the property of evoking accommodative spasm with myosis, which may be studied hy observing the action of a single drop of a solution of eserine sulphate (the active alkaloid of Calabar bean) of the strength of one-half of one per cent. (1 : 200). Contraction of the pupil and spasm of accommodation begin nearly simultaneously within about ten minutes, and both reach a maximum in from thirty to forty min- utes. After about two hours, the far-point (r), which at the height of the action of the drug is not over twenty centimetres (eight inches) from the eye, is found to have receded to its normal position (oo in the emmetropic eye), but the near-point, in voluntary accommodation, is con- siderably nearer to the eye than normal after the lapse of six hours, thus showing a positive increase in the range of accommodation. The contraction of the pupil begins to diminish after about two hours, at first slowly, then more rapidly for about four hours more, and afterward slowly until, at the end of two days, the pupil has nearly or quite regained its normal diameter. With a weaker solution of eserine the spasm of accommodation is much less than with the half per cent, solution, and is painless ; with the stronger solution the action is accompanied by a sensation of spasmodic twitching, and with some pain. Pilocarpine, the active alkaloid of jaborandi, is much milder in its action than eserine, but is nevertheless an efficient myotic, and exerts also a very positive effect in stimulating the accommodation. Contraction of the pupil is frequently observed in cen- tral nervous affections, and notably in tabes dorsalis. Myosis, with spasm of the accommodation, follows also the administration of large doses of eserine, opium, and, probably, some other drugs, internally. The internal or hypodermic use of pilocarpine does not produce contrac- tion of the pupil or spasm of accommodation. John Cfreen. ' Dioptric (or dioptry), a word proposed by Monoyer to designate the unit of the metric system ; it is the generally received expression for a lens of one metre focal length, which is almost exactly equivalent to the glass numbered 40 ( V40) ^ ^^^ °^^ French system. 3 In a case of myopia of 4.5 dioptrics in the right eye, with hyperme- tropia of 5.5 dioptrics in the left eye, which came under the care of the writer about ten years ago, the right eye was first corrected by a concave glass of 4.5 dioptrics, and a; plane glass was given for the left eye. The patient, a young man of eighteen years, was well satisfied with those glasses for a few weeks, and then demanded a correction for the left eye. At the end of ten weeks he was wearing correcting glasses for both eyes with comfort, and still wears the same glasses with entire satisfao- tion. 8 Irritation of the fifth cranial nerve (ophthalmic division) is followed by contraction of the pupil, and the same phenomenon may attend iiTi- tation of the terminal branches of this nerve in the cornea. Myosis from this cause may also be attended with spasm of accommodation. ACETABULUM, Fbactukbs of, may be divided into compound and subcutaneous, or, as regards their causa- tion, into direct and indirect. The hip-joint is so deeply situated and so efficiently protected by the surrounding bony projections and soft tfssues against direct violence that fractures produced in this manner almost invariably be- long to the compound variety, and, in the great majority of cases, they are the result of gunshot injuries. Gunshot wounds of the hip- joint, with or without fracture of the acetabulum, have always been considered by surgeons as formidable and dangerous lesions. Pirogoff made the statement that during the Crimean War all injuries of this kind proved fatal. During the war of the Rebellion nearly all eases of gunshot injuries of the hip-joint treated on the conservative plan resulted in death. Of 63 cases of similar injury where resection was performed, only 5 recovered. In his classical treatise on this subject, B. von Langenbeck collected 119 cases which occurred dur- ing the Franco-Prussian war, with 29 recoveries ; 88 were treated on the expectant plan, with 25 recoveries ; 31 were submitted to excision, with 4 recoveries. The acetabulum may be fractured without injury of the head or neck of the femur, as the bullet may impinge upon the floor of the acetabulum, from within the pelvis, with sufficient force to break the bone, producing a fissure or stellate fracture of its base, or it may, in its course, carry away the rim of the cotyloid cavity. An exceed- 54 ingly interesting case, illustrating the latter assertion, is reported by Dr. J. F. Miner, of Buffalo (Buffalo Med. and Surg. Journal, vol. v., p. 383). Lieutenant-Colonel James Strong, of the Thirty-eighth New York Volunteers, was wounded. May 5, 1862, at the battle of Williamsburg, Va. The ball entered a little below the anterior superior spinous process of the ilium, and made its exit near the outer margin of the sacrum. The ball passed deeply, and fractured, in its course, the rim of the acetabulum, which was removed, an inch and a half in length, and of a diameter sufficient to show that the whole upper rim had been carried away. This fragment of bone was removed from the wound at the dressing made in the hospital to which he was carried, after having lain on the field for some hours. The wound was very large, and a thorough examination could be made by the easy passage of the finger. The patient passed through a serious and pro- longed illness from the suppuration and hectic fever which followed, but finally recovered, with five inches shorten- ing of the limb, inward rotation of the foot, and bony anchylosis between the dislocated thigh-bone and the ilium. The points of entrance and exit of the projectile furnish valuable information in regard to the probable injury of the acetabulum in gunshot fractures of the hip- joint. In the case just reported, the ball entered just below the anterior superior spinous process of the ilium, and passed out near the margin of the sacrum, leaving intact the head of the femur, but opening the hip-joint by carrying away the superior and posterior margin of the rim, thus permitting the subsequent dorsal dislocation of the head of the femur by muscular force. B. von Lan- genbeck states that, in case the ball enters directly below and toward the outer side of the spine of the pubes, and takes its exit in the region behind the greater trochanter of the same side, as a nile it penetrates the hip- joint ; and, at the same time, it fractures in its course the upper rim of the acetabulum. Escape of synovial fluid, swell- ing in the region of the hip- joint from extravasation of blood or the products of inflammation, preternatural mo- tion in the joint, crepitation, and dislocation of the head of the femur spontaneously, or on manipulation, are other important diagnostic symptoms. The most important information regarding the exact nature of the injury is, however, obtained by enlarging the track of the bullet and rendering the hip-joint accessible to touch and sight. This procedure, done under antiseptic precautions, alfords not only an opportunity to ascertain the true nature and grav- ity of the injury, but it is imperatively called for as the first and most important step in the treatment. All for- eign bodies and detached pieces of bone should be re- moved, all haemorrhage carefully arrested, and'the whole injured surface and surrounding parts thoroughly disin- fected ; effective drainage should be established, and every possible source of infection guarded against by dressing the wound antiseptically. All these measures are essential, as the success of the operation and the life of the patient depend on procuring and maintaining an aseptic condition of the wound. The leading principle in the treatment should be, from the very beginning, to convert the com- pound into a simple fracture, and thus protect the patient against the disastrous consequences of traumatic infection, exhausting suppuration, pyaemia, and septicaemia. Subcutaneous or simple fractures are again divided into those which involve the floor and those which involve tho rim of the acetabulum. This division rests on clinical ex- perience as well as on the results of experimental research. Fractures of the base or floor of the acetabulum, notwith- standing their rare occurrence, yet present a great diver- sity in the direction and extent of the line of fracture. Courant observed a fracture which traversed the ilio-pec- tineal tubercle, the entire acetabulum, and the ischium. Earle and Travers describe two cases where two lines of fracture passed through the acetabulum ; Neill and San- som saw cases with three lines of fracture which extended beyond the rim. In Dr. Neill's specimen the lines of fracture followed those Of the embryonal division of the bone ; the union which followed was complete, and there was very little callus on the articular surface, a circum- stance undoubtedly due to the slight displacement of the EEFERENCE HANDBOOK OF THE MEDICAL SCIENCES. A ccommodatlon. Acetabulum. fragments. More serious to the life of the patient and the future utility of the limb are those cases where a mul- tiple fracture at the base exists with such wide separation between the fragments as to allow the head of the fe- mur to be driven into the pelvis by the fracturing force, thereby producing an intrapelvic dislocation of the thigh. A number of such cases have been reported. Astley Cooper alludes to three cases. In two of these the thigh was rotated inward, in the third, case the leg and thigh were supinated. Mr. Moore's case demonstrates the pos- sibility and manner of repair in these cases (" Medico- Chir. Transactions," vol. xxxiv., p. 107). A man suffered a severe injury of the hip, which was diagnosticated and treated for fracture of the femoral neck. The thigh was not inverted or everted, only slightly flexed and adducted. The man recovered, and several years afterward died from other causes, when an autopsy revealed that the in- jury had been a fracture of the pubes, ilium, and acetabu- lum, which allowed the head of the femur to pass through into the pelvis, the trochanter resting against the acetabulum. Similar cases have been reported by Kendrick and Morel-Lavellee. In all cases of fracture at the base of the acetabulum, without displacement of the head of the femur, the diagnosis usually remains doubt- ful. Main reliance must be placed on the manner in which the injury was inflicted, the intensity of the force applied, and the location of the pain. Accurate measure- ment will always furnish important negative evidence. In case of intrapelvic dislocation of the head of the femur through the fractured base of the acetabulum, the . shortening of the limb, and the approximation of the tro- chanter major toward the pelvis will be proportionate to the degree of penetration of the head and neck into the pelvis ; rotation of the limb will not be practicable ; flexion and extension' will be found to be either impaired or rendered impossible ; and at the same time the head of the femur may be felt within the pelvis on making a digi- tal examination through the rectum. In the adoption of therapeutic measures it is necessary to ascertain the de- gree of impairment of the functional capacity of the ace- tabulum. If the head of the femur is retained firmly in its normal position the fracture will unite promptly and firmly without any special retentive measures. Rest in bed with the thigh slightly flexed and resting upon pil- lows ■wall be sufficient to fulfil the local indications. If the pelvic ring is more extensively fractured, a plaster-of- Paris splint including the pelvis, both thighs, and the en- tire leg on the affected side, or Verity's suspension splint, will prove most efficient in securing immobility of the frag- ments, and will aflEord the greatest amount of comfort to the patient. When the base of the acetabulum has been perforated by the head of the femur it is of paramount importance to replace the dislocated bone and retain it in situ by a plaster-of -Paris dressing, or by applying exten- sion by weight and pul- ley, as advised by Hueter, until the opening is closed by callus or connective tissue which will definite- ly prevent redislocation. Fracture ov the Rim of the acetabtiltjm. — A number of well-authen- ticated cases of this acci- dent have been reported, so that no further doubt can exist that some por- tions of the rim can be fractured without further injury to the acetabulum. Some years ago the writer collected from various sources twenty-seven cases of this kind of fracture, the cases being supported by. an accurate clinical history, and in some cases verified by a post-mortem examination. Dr. H. O. Walker, of Detroit, has in his possession a typical specimen of this kind, an illustration of which is here inserted (Detroit Lancet, July, 1879). In the text-books on Surgery this subject is usually referred Fio. 61. to under the head of complicated dislocations of the head of the femur. As this fracture usually involves the upper and posterior portion of the rim, the resistance to the head of the femur in that direction is lost, and as a result — either with the concurrent aid of some extraneous force, or even without such aid, simply by the force of muscu- lar contraction — a dorsal dislocation of the thigh takes place, with adduction, flexion, and rotation of the thigh inward. The difficulty experienced in retaining the head of the femur in the acetabulum under these circumstances, as well as the obscurity of the diagnosis, imparts to this sub- ject an unusual amount of interest. The older works on surgery mention direct and gi'eat violence as the only cause of fracture of the acetabulum ; indeed, until more recently, it has been considered impossible for a fracture of the rim to take place without more extensive injury to the ilium. When the fracturing force is applied over the centre of the trochanter major, in the direction of the neck of the femur, the head of the bone is driven directly against the socket, and a stellate or perforating fracture of the base of the acetabulum is the result, according to the amount of violence applied ; but if the force is applied in such a manner that it first rotates the femur outward or inward, then one margin of the acetabulum acts as a fulcrum to the neck, and the head is forced against the opposite side, and a linear fracture through the acetabulum, or a fracture of the rim, takes place. In such cases, the traction of the capsular ligament assists the head of the femur in produc- ing the fracture of the rim, but independent of other causes such traction is insufficient to produce the injury. When the force is applied to the posterior part of the pel- vis, the pelvis becomes the movable point, and the foot, if the leg is extended, or more frequently the knee, becomes the fixed point, and furnishes the necessary amount of re- sistance. These assertions have been verified by the writer by numerous experiments on the cadaver. At the moment the injury is received, it is essential for the thigh to be abducted, as adduction would favor a dislocation by the head of the femur gliding over the inclined plane of the internal surface of the acetabulum. The pelvis may be the fixed point, and the force may be transmitted through the femur by a blow or fall upon the knee. In most in- stances where this accident occurred, the thigh was more or less flexed at the time of injury ; hence, in the majority of cases, the upper and posterior segment of the rim was fractured, and the head of the femur dislocated into the upper sciatic notch or upon the dorsum ilii. Of the twenty-seven cases of fracture of the rim of the acetabu- lum, the extremes of the ages were eighteen and seventy- eight years, so that most of these cases occurred during the time of life when the individual is most exposed to grave injuries. It is also well to remember that, in young per- sons, dislocation and diastasis occur in preference to fract- ure, while in the aged, the altered position of the neck of the femur, as well as the increased fragility of its tissue, is a potent predisposing cause of fracture of the femoral neck. The symptoms presented by a case of fracture of the rim of the acetabulum are those of dislocation and fracture combined ; the symptoms of the former resemble ordinary dislocation, while those of the latter are directly referable to the broken bone itself. A certain de^ee of displacement of the head of the femur was present m all cases where a diagnosis was made during life. Benjamin Travers be- lieved that in some cases of fracture of the rim of the acetabulum the displacement takes place gradually some time after the injury has been received, but it is more probable that these vrere cases such as have been described by Hueter as inflammatory dilatation of the acetabulum, the interstitial absoi-ption of the margin of the cavity per- mitting the head of the femur to glide upward and back- ward. In twenty-four cases the direction of the disloca- tion is mentioned, and in fifteen of these the head of the femur was dislocated upward and backward, in four into the great sciatic notch, in two directly backward, in two downward, and in one case forward. It will be seen, then, that in a large majoritjr of cases that portion of the rim is fractured which is m the direction of the usual form of dislocation, so that the same injury which pro- 65 Acetabulum. Acetic Acid. REFEBENCE HANDBOOK OF THE MEDICAL SCIENCES. duces a dislocation may also cause a fracture, provided the force applied be sufficiently great, and the hmb happen to be abducted at the time the injury is sustamed. The amount of shortening corresponds to the distance the head of the femur recedes from the socket. In Ag- new's case no shortening could be detected on careful measurement. In all of the other cases where mention is made of this symptom, it was present, but varied in degree from a quarter of an inch to four inches. If the head of tlie femur has left the socket the position of the limb is the same as in simple dislocation, the direction being de- termined by the form of dislocation. Flexion to a greater or less extent was present in all cases where reference is made to this subject. Inversion of the foot and rotation of the femur inward were present in fourteen cases, while the opposite condition existed in three cases, and in ten cases no mention is made of this symptom. When the dislocation was complete, the limb remained immovable in its abnormal position until reduction was effected. The characteristic symptoms of the injury are those which are referable to the fracture itself, and these are crepitus, easy reduction, and difficult retention. Crepitus is always an important symptom in ascertaining the existence of a fracture. If it is distinctly felt there can be no further doubt that a bone has been broken. The presence of this symptom is of special diagnostic value in connection witli this subject, as the symptoms of dislocation are usually so prominent as to engage the whole attention of the surgeon. In the cases reported, this symptom is alluded to eighteen times, and in the following terms ; distinct, eleven times ; faint, once ; marked, twice ; indistinct, once ; slight, once ; and in two cases it was absent. Bigelow lays great stress on this symptom as being essential to the diagnosis of fracture ; his words, as quoted from the work pre- viously mentioned, are : "To afford satisfactory evidence, cases of this sort should have been identified by autopsy, or at least by crepitus." I believe that the crepitus is not the same as in ordinary fractures, for in these it is the re- sult of two rough bony fragments rubbing against each other, while in the cases under consideration it is a rough- ness we obtain by rubbing an articular surface against a broken surface of bone, hence not quite as loud and dis- tinct. The detached margin of the acetabulum, unless comminuted, remains attached to the capsular ligament, and is pushed in front of or to one side of the head of the femur at the time dislocation occurs, and is dragged after it when reduction takes place. In most of these cases it is clearly stated that crepitus was felt just before the head of the femur slipped into the socket, or at the moment reluxation took place, and in both in- stances it must have been produced by the head passing over the rough broken edge of the acetabulum. The ease with which reduction has been effected has attracted the attention of almost every observer. This is due to a more extensive laceration- of the capsular ligament than in simple dislocation, and also to the removal of the obstacle offered by the intact margin of the acetabulum. By the fracture of the rim, a more direct and even route has been prepared for the head of the femur to return to its socket. Reluxation lias always constituted the most perplexing feature of these cases. Its occurrence has usually led to a more thorough examination and correct diagnosis. It is well known that in ordinary dislocations of the hip- joint, when the bone has once been reduced, it remains in its place regardless of the after-treatment, differing greatly in this respect from the same lesion of the shoulder-joint on account of the greater depth of the socket, and the action of more numerous and powerful muscles for main- taining retention. Hueter believed that the cases of ha- bitual dislocation of the hip- joint reported by Karpinski may have been the result of injury to the rim of the ace- tabulum. Reluxation takes place from the inability of the defective margin to resist muscular contraction. The dif- liculty in retaining the bone is increased by the depth of the fracture and its approach to the junction of the supe- rior and posterior portions of the rim. In this connection it is important to determine what po,j:tion of the rim is most frequently the seat of the fracture. In 20 of the cases special mention is made of this fact, as follows: supe- rior portion of rim, 3 ; superior and posterior, 7 ; poste- rior, 5 ; posterior inferior, 4 ; inferior, 1 ; anterior, 1. When the inferior or anterior portion of the rim is fract- ured, there is no tendency to reluxation provided the limb is kept in the extended position and slightly inverted. Diagnom. — A most thorough and critical examination while the patient is profoundly under the influence of an anaesthetic, is always necessary to establish a positive diagnosis. If spontaneous reluxation does not follow immediately after reduction has been accomplished, and there are sufficient symptoms present to warrant a sus. picion of the presence of the injury, it would be advisa- ble to test the functional integrity of the acetabulum by flexion, adduction, and rotation of the thigh ; if any part of the rim has become defective by fracture, re- luxation will be sure to take place. This mancEuvre, associated with the presence of crepitus, may be re- garded as the crucial test. The differential diagnosis must consider fractures of the neck of the femur with displacement, and simple dislocation. To distinguish this fracture from fracture of the neck of the femur, it is necessary to compare their most prominent symptoms : VBACTURE OF THE BIM OF THE ACETABUlitTM. FRACTURE OF THE NECK OF THE FEMUK WITHOUT IMPACTION. PoBition of Limb, Thigh and leg flexed, adducted, and I Thigh and leg straight and rotated rotated inward. I outward. Jfobility of Limb. Mobility of limb is diminiahed. | Mobility of limb ia increased. Arc of notation. The trochanter major rotates in its 1 The arc of rotation of the trochan- normal arc. | ter major la diminished, Crepitun. Crepitation is not rough, and is felt I Crepitation is rough, and is felt aa the head pasHes over the broken when the limb haa been drawn edge of the acetabulam. | down to its normal length. Jlead of Ike Femur. The head of the femur is felt to be I The head of the femur \» normal in displaced. , | its position. ReUntion. The deformity reappears if by any movement of the limb the head of the femur ia made to leave the socket. The deformity reappears as soon as extension ceases. History, Is moat frequent in middle life and is the result of great violence. If intra-capsular in variety, it oo> curs in the aged and is the result of slight violence. Crepitus, and a tendency to reluxation, are the symp- toms on which we place the most reliance to differenti- ate this fracture from simple dislocation. Acupuncture, as advised by Middeldorpf , may be of great service to determine the existence of fracture of the rim. After reduction has been accomplished, a long stout needle, previously well disinfected, is passed through the tissues to the supposed seat of fracture. By lateral movements of its point the defect in the margin, as well as the roughness of its surface, is ascertained. An effort should now be made to fix the detached fragment with the point of the needle, and by rubbing it over the broken margin a rough crepitus is elicited. Prognom. — The prognosis must have reference to the preservation of life and the restoration of the utility of the limb. AIJ of the old authors regarded fracture of the pelvic bones a grave lesion, almost necessarily lead- ing to a fatal termination. I believe that all uncompli- cated fractures of these bones tend to recovery, and that death is attributable in most instances to a lesion of some important pelvic or abdominal viscera. In twenty-three cases where the result is noted in this regard, thirteen re- covered and ten died. The prognosis is less favorable if the floor of the acetabulum is also implicated in the fract- ure. Of four cases of this sort only one recovered. In nine cases out of the thirteen that recovered, the limb remained in place after reduction, and the recovery was complete. In four cases redislocation took place, the limb assuming the same malposition as after simple un- reduced dorsal dislocation of the femur. 56 REFERENCE HANDBOOK OP THE MEDICAL SCIENCES. Acetabulum, Acetic Acid. Treatment.— The indications to be fulfilled in the treat- ment of this class of injuries are : 1, To reduce the disloca- tion ; 8, to retain the head of the femur in the socket until union has taken place between the fragments. The dislocation maj be reduced by manipulation or by exten- sion ; in both instances flexion constitutes an important step in the operation. Bigelow says : " These displace- ments, especially the displacement backward, demand the usual attempts at reduction by flexion. Although the bone inclines to slip from the socket it can be re- tained there, in cases of a sort heretofore considered difficult of treatment, by angular extension, with an angular splint attached to the ceiling, or some other point above the patient ; or if any manoeuvre has reduced the bone, the limb should be retained, if possible, in the attitude which, completed the manoeuvre." In 17 of the cases reported, the maqner of reduction is specified as follows : By extension, 11 (in most of these cases exten- sion and flexion were combined) ; by manipulation, 2 ; by manipulation and extension, 1 ; by manipulation over Sutton's fulcrum, 1 ; by extension with pulley, 3. In all but one of the cases the displacement was corrected without diflSculty. As inmost instances a diagnosis can- not be made before reduction has been accomplished, surgeons will resort to their favorite methods of reduc- tion. Should the nature of the lesion be determined be- forehand, traction in the direction of the broken edge of the rim, and rotation of the limb inward, will readily re- store the normal relation of the parts. As we possess no direct measures of keeping the fractured surfaces in ap- position, all our efforts must be directed toward prevent- ing reluxation bjr appropriate position and fixation of the limb and pelvis. The depth and extent of the fract- ured margin, as well as the location of the fracture will determine the difficulty in retaining the head of the femur in its normal position. If sufficient depth of the upper portion of the rim is left to serve as support to the head of the bone, all that is necessary is to dress the thigh in the abducted position, so as to press the head of the femur against the floor of the acetabulum. As the contusions of the soft parts about the hip and pelvis are severe, a plaster-of -Paris splint cannot be applied as a primary dressing. The healthy limb and pelvis should always be included in the retentive dressing. Bonnet's wire-breeches, Dzondi-Hagedorn's apparatus, or Hamil- ton's splint, as advised by him in the treatment of fract- ures of the femur in children, will be found sufficient to maintain retention. After the swelling in the soft parts has subsided, nothing more perfect could be devised than a plaster-of-Paris dressing, including both limbs and the pelvis. When nearly the entire depth of the upper or posterior portion of the rim has been detached, muscular contrac- tion must be counteracted by permanent extension with the weight and pulley, and immobility of the joint should be secured by appropriate splints. In cases of this sort, angular extension with an angular splint, as advised by Bigelow, will answer an admirable purpose. The un- brokeii part of the rim should be made the support of the head whenever practicable. Thus, for example, when the posterior part of the rim is fractured the thigh should be dressed in the position of hyperextension ; a broad, firm, pelvic band, with a compress above the tro- chanter, being employed to aid in keeping the bone in place, in approximatmg the fractured surfaces, and in preventing muscular spasms. The treatment should be continued for a sufficient length of time to secure a firm union of the detached fragment with the broken rim, which, as in other fract- ures, generally requires from four to six weeks. The patient must be directed to exercise great care in the use of the limb for a considerable length of time after all dressings have been removed, so as to obviate any un- due pressure against the recently repaired rim of the acetabulum. Literature. N. Senn : A Contribution to a. Knowledge of Fracture of the Rim of tlie Acetabulum, etc, Milwaukee, 1880. Emmert: Lehrbuch der spec. Chir., vol. lii., p. 750. Stuttgart, 1862. Detroit Lancet, July, 1879 : H. 0. Walker's case. Buffalo Medical and Surgical Journal, vol. /.. p. 883: Colonel Strong'! caKe. Hamilton : A Practical Treatise on Fractures and Dislocations. Phila- delphia, 1871. Bigelow: The Mechanism of Dislocation and Fracture of the Hip, Phila- delphia, 1869. Travers : Further Observations in Surgery, p. 27. 1860. Hueter : Klinik der Gelenkkrankheiten, part ii., p, 316. Leipzig, 1876. Stimson; A Treatise on Fractures. Philadelphia, 1883. Hueter :' Grundriss der Chir., part ii, Leipzig, 1882, Albert: Lehrbuch der Chir,, vol. iv. Wein. 1883. Agnew : The Principles and Practice of Surgery, vol. i. Philadelphia, iV. Senn. ACETIC ACID. Acetic acid, HCHsOa, the well- known acid of vinegar, is a body fluid at ordinary tem- peratures, and miscible in all proportions w^ith water. Mixtures of the acid and water in different proportions constitute the different grades of the acid in commerce. Strong acetic acid is caustic, largely through its property of dissolving the formed material of the connective tissues to a pultaceous translucent substance. Being caustic, it is of course irritant, and swallowed in concentrated con- dition operates as a corrosive poison, the effects and symp- toms being substantially the same as in poisoning by the strong mineral acids. Two cases of death have been re- corded. The treatment is similar to that to be employed in case of poisoning by a mineral acid. In non-corrosive strength of solution (five or six per cent., the equivalent of vinegar), acetic acid produces the usual local effects of the sour acids — exciting the flow of saliva and tending to oppose sour fermentation of the food, and is also dis- tinctly astringent. Inhaled, the fumes are reviving in faintness and may relieve headache. Acetic acid has many uses in pharmacy ; in medicine the strong acid may be employed as a caustic, as to warts or cancers, and the weak acid used to make refreshing acid draughts in fever, or cooling lotions in inflammatory skin affections. Acetic acid is officinal in the IF, S, Pharmacopoeia in the following forms : Acidum AceiiBum Glaeiale, Glacial Acetic Acid. — This is defined to be "nearly or quite absolute acetic acid," It is "at or below 15° C. {59° P.) a crystalline solid; at higher temperatures a colorless liquid. When liquefied and as near as possible to 15° C. (59° F.) it has the specific gravity 1.056 to 1.058 " (U. S. Ph.), According to Squibb {Sphemeris), the specific gravities thus stated are from 0.0001 to 0.0002 too high. This grade of the acid is for pharmaceutical uses. Acidum Acetieum, Acetic Acid. — The grade of acid thus simply named is a "liquid composed of thirty-six per cent, of absolute acetic acid and sixty-four per cent, of water." It is "a clear, colorless liquid, of a distinctly vinegar-like odor, a purely acid taste, and a strongly acid reaction. Specific gravity, 1.048 at 15° C, (59° P.) Mis- cible in all proportions with water and alcohol, and wholly volatilized by heat" (U. S. Ph.). This grade of acid is somewhat stronger than the best samples of the commercial so-called " No. 8 " acid, these " No. 8" acids rarely being of higher specific gravity than 1.030 and often sinking to 1,025 or less (Squibb). This is the acid that results from the purification of the crude acid — crude pyroligneous acid, so called — obtained by the destructive distillation of wood. Acetic acid of the present quality is sharply irritant and even mildly caustic. Dangerous symptoms have resulted from swallowing it, undiluted, in quantity of two or three ounces. The acid may be used as a mild caustic, but its principal uses under its own form are pharmaceu- tical. Acidum Acetieum Diluium, Diluted Acetic Acid. — This preparation is compounded of seventeen parts of acetic acid of the foregoing grade and eighty-three parts of water. It " contains six per cent, of absolute acetic acid, and has the specific gravity 1,0088 " (U. S. Ph.). Tills diluted acid is of the stren^h of the best qualities of vinegar, and is better than vinegar for all the pur- poses of the same,, medicinal or dietetic. Squibb says, "If one part of alcohol be added to about two hundred and fifty-six parts of this diluted acetic acid — that is. 57 Acetic Acid. Acidity. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. about lialf a fluidounce to the gallon, and the mixture be set aside for a few weeks— the longer the better, enough acetic ether is generated to give it the full, clean aroma of fine vinegar, and then for table use it is very far su- perior to any vinegar made in the ordinary way by fer- menting cider." . Diluted acetic acid is the most convenient grade of the acid for medicinal use, and has also, in the U. S. Pharma- copoeia, superseded vinegar for pharmaceutical purposes. For an acid draught a five per cent, addition to water is appropriate, and for a lotion a twenty-five per cent, ad- dition. The popular notion that the habitual use of vine- gar tends to deterioration of nutrition and health is cer- tainly not true of a moderate indulgence, if indeed it be true at all. Edwa/rd Curtis. ACETIC ETHER. Under the title u^lher Aeeticus, Acetic Ether, the IJ. S. Pharmacopoeia makes oflicinal a preparation consisting of the ethereal salt, ethylic acetate, with a little contaminating alcohol and water. Acetic ether is described as " a transparent and colorless liquid, of a strong, fragrant, ethereal, and somewhat acetous odor, a refreshing taste, and neutral reaction. Soluble, in all proportions, in alcohol, ether, and chloroform, and in about seventeen parts of water. Specific gravity, 0. 889 to 0.897. It boils at about 76° C. (168.8° P.). It is in- flammable, burning with a bluish yellow flame and ace- tous odor" (U. S. Ph.). It should be kept in well-stopped bottles, and away from lights or fire. Dr. Squibb notes, concerning the foregoing description, that while the odor is "refreshing," the tote is rather "pungent and biting almost to acridity ; " and that the solubility in water is nearer one part in 11.86 than one in 17 ; and that few of the commercial samples of acetic ether will reach the oflicinal range of specific gravity. The effects of acetic ether upon the animal economy are similar, in a general way, to those of common ether, the most important point of difference being that acetic ether is the slower in operation. For this reason this ether is not available as a surgical anaesthetic ; but, on the . other hand, by reason of its agreeable odor, it makes an excellent and grateful cardiac stimulant, antispasmodic and carminative, taken internally, or, used externally, it may serve to mask disagreeable odors. It may be given internally, in quantities ranging from fifteen to thirty drops, well diluted with water or with some medicinal preparation, to which the ether is added as an adjuvant or corrigent. Acetic ether enters into the composition of the officinal preparations, perfumed spirit (cologne water), and tincture of acetate of iron. Edma/rd Curtis. ACETONEMIA. This term is used by many writers to express a diseased condition of the blood, due to the supposed presence in it of acetone, or of some of its de- rivatives. This state of the blood, according to their views, accounts for the nervous symptoms peculiar, more especially, to diabetic coma. It is believed to be the cause, also, of somewhat similar symptoms occasionally present in certain anaemic conditions of the blood, such as pernicious anaemia, and that associated with some of the more rapidly wasting forms of cancer, as cancer of the stomach. Fetters first observed the acetone-like smell of the urine in a case of diabetic coma. He drew attention to the sub- ject in 1857, and supposed it to be due to the presence of acetone in the blood. Since then Kussmaul has paid more attention to the subject, and has endeavored to ac- count for the sudden death in these cases by the rapid accumulation of this substance in the blood. He con- siders it a species of intoxication produced by the ace- tone. Numerous experiments on animals have been made by him, which seem to confirm his view of the subject. Dogs, to which he administered acetone hypodermically, as well as by inhalation, presented some of the nervous symptoms in connection with respiration, circulation, dhd locomotion that seemed to support his views. Frerichs decidedly objects to this theory of the causation of the comatose symptoms of these cases of diabetes. He thinks the term acetoneemia should be expunged from pathol- 58 ogy (Zeitschr. f. kliniseh. Med., vi., 28). His experiments do not bear out Kussmaul's conclusions. He adminis- tered acetone in doses varying from ten or twelve to twenty grains, to both man and animals, without pro- ducing any nervous symptoms at all similar to those observed in diabetic patients. He considers it quite a mis- take to attribute the nervous symptoms of diabetic intoxi- cation to the presence of either acetone or its derivatives. Kussmaul has stiU numerous supporters of his views. In the cases described, the breath has been observed to possess a fruity odor, resembling apples ; or, as described by some, an odor similar to chloroform. The mucous membrane of the mouth and throat has a dry and glazed appearance, and is generally very red. The urine also possesses a similar odor. (See Acetonuria.) Von Jaksch asserts that acetone occurs, to a slight ex- tent, as a normal product in the blood as well as in the urine {Zeitschr. f. klin. Med., v., 347). It is doubtful it free acetone can be obtained from the blood ; nevertheless, in many cases of diabetic coma, a substance with which acetone is combined can be obtained from it, and free acetone derived from this. There is yet some doubt as to what this body is. Some investigators are inclined to consider it to be ethyl-diacetate, while more recent authorities believe aceto-acetic acid to be the sub- stance. There seems to be very good ground for thinking this to exist in the blood, as we know it to be one of the products of alcoholic fermentation of glucose. Oeorge WilMns. ACETONE. Acetone, CsHsO, the ketone of acetic acid, called also pyroacetic spirit and pyroacetic ether, is a colorless, limpid, and inflammable liquid of pungent qual- ity, miscible in all proportions with water, alcohol, and ether. Its effects upon the animal system are, doubtless, of the general nature of those of the volatile alcohols and ethers, but the substance has never been systematically employed as a medicine. Edward Curtis. .ACETONURIA. According to Von Jaksch, acetone enters into the composition of every normal urine, to the extent of about one centigramme per day. When the quantity exceeds this amount, the pathological condi- tion of acetonuria is present. In continued fevers, with high temperature, the quantity secreted has been found as high as five decigrammes. In these cases, it is only after the fever has lasted a considerable time that acetone has been found in the urine. There are four principal diseased conditions in which it exists. These are, first, in fever of any kind, especially if the fever rises hi^h and the febrile condition lasts a long time ; second, in diabetes ; third, in cancer ; fourth, in acetoneemia. Observers are not yet quite agreed as to what the sub- stance is that is found in the blood as well as in the urine in these cases ; for, while some believe it to be acetone, others are of the opinion that it is a body such as aceto- acetic acid or ethyl-diacetate, from which acetone can be obtained. Acetone gives to the urine a peculiar odor, de- scribed by some as resembling chloroform, by others as of a more fruity character, such as that of apples, or, again, like that of hot vinegar. Frerichs and others have experimented with acetone, both on man and the lower animals, administering it in doses as large as twenty grains, and have so far found it harmless, although traces of it have been obtained from the urine in these cases. Diabetic urine containing ace- tone gives a deej) red or reddish-brown color in the pres- ence of perchloride of iron' (Gerhardt's test), and a rose- tint in the presence of sulphuric acid. For the former test, take a few cubic centimetres of the urine supposed to contain acetone ; add to it one or two drops of liq. ferri perchlorid.; this gives a grayish- white precipitate; the addition of a few drops more o5 the solution of iron in excess causes the precipitate to disappear if acetone is present, and gives a beautiful reddish-brown, which is not produced in normal urine. The sulphuric-acid test is performed by adding a few drops of the acid to the urine containing acetone when a REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Acetic Acid. Acidity. beautiful rose color is produced ; on subsequently adding a few drops of perchloride of iron, this rose tint is con- verted into a yellowish orange, which is characteristic. The peculiar reaction with perchloride of iron has been obtained from the urine of other diseases than diabetes. Various observers have obtained it in typhus, pneumonia, diphtheria, perityphlitis, pleurisy, and acute rheumatism. The diabetic cases in which but a small amount of acetone is present in thp urine are usually very slight. In many of these cases, Gerhardt's reaction (the bur- gundy red with perchloride of iron) cannot be obtained. On the other hand, the cases in which it is present are usually very severe, and frequently die with comatose symptoms. Treating distilled urine with a solution of iodine in iodide of potassium and caustic soda causes the yellow precipitate of ■ iodoform, if acetone is present. This is known as Lieben's test. Penzoldt recommends a test known as his ivMgo test. It depends upon the fact that acetone, in the presence of an alkali, changes orthonitro- benzaldehyde into indigo. Caustic alkali is to be added to the suspected urine, so as to render it distinctly alka- line. A watery solution of orthonitrobenzaldehyde is to be prepared and the alkaline urine to be added to this. If acetone is present, a yellow color is produced, which changes Immediately to green, and in about ten minutes assumes an indigo color. Other tests are Legal's and Le Nobel's. The former is the addition of cyanide of potassium and a few drops of a concentrated solution of caustic soda or potash to the suspected urine ; this produces a dark-red color, which changes to yellow after a few minutes ; if acetic acid is now added, the solution changes to carmine-red if only a small quantity of acetone is present, to a purple-red color if a large quantity is present ; after two or three hours this changes again to a brownish-green. Le Nobel's test depends upon the fact that substances containing acetone become of a violet-red upon the addition of cyanide of sodium with ammonia or its bicarbonate. Oeorge Wilhins. ' This color is frequently referred to by foreign writers as '* burgundy red," from its resemblance to that of the wine of that name. ACIDITY, literally the quality of being sour, is a term used in medicine to denote either (1) a quality of the normally acid fluids of the body ; (2) a change in their character or amount ; or (3) the alteration of a normally alkaline to that of an acid secretion. It may, then, be either physiological or pathological. Physiological AcroiTY. — We have several well- marked instances of the former, e.g., in the gastric juice, the urine, the cutaneous excretions, and in the secretions of the muciparous crypts of the mouth and vagina. The gcbstne cusidity, in health, is due, so far as is at pres- ent known, to the secretion of lactic acid (Query : from the small but constant quantity of glycogen in the blood ?) by the gastric follicles ; which, reacting upon the sodic chloride (NaCl) also jjresent, produces free hy- drochloric (HCl) acid. The acidity of this secretion va- ries between 0.01. to 0.32 per cent., the average being 0.17 per cent. The normal acidity of the urine is due indirectly to the uric acid excreted. Reacting upon the mildly alkaline sodic phosphate of the blood it abstracts part of the so- dium, leaving the acid sodium phosphate, viz. : "Uric Acid + HaCiHjNiOj -f ""'^htp?!^™ = sodic Hydric Urate " HNaCsHaNiOs NaaHPO, Acid Sodic Phosphate. NaHaPOi This gives urine its acid reaction ; the degree varying within quite a wide range. Variations in health bear an intimate relation to the digestive process and the foods taken. Generally speaking, an hour after meals the acid- ity is least, due to the organic potassium and sodium salts taken in the food having been converted in the blood into the alkaline bicarbonates. Gradually increas- ing in acidity, it reaches a maximum after two and a half to four hours ; this gain being caused by the oxida- tion products (uric acid, etc.) of the proteids and nitro- genous tissues, occasionally, too, by such organic acids as oxalic and hippuric, the latter formed from benzoic acid, and often present in fruits (cranberries). The normal acidity of the cutaneous excretions is owing to the presence of some of the fatty acids of the acetic series, chiefly capric and caproic acids. TThe acids of the buccal and vaginal mucous crypts are unknown. PATHOLoeicAL AciDiTT. — Pathological changes in the acidities of the various body fluids may be of degree or of kind. The blood during life is always alkaline, no investi- gators having ever found it otherwise. (See Art. Alka- linity.) Its degree of alkalinity may vary. To speak of " acidity of the blood," then, is an erroneous expression, but one not infrequently applied to a greatly diminished alkalinity. The oxidation products of the foods and tis- sues form the principal source of the acids in the system ; though some, it is true, are supplied, often intentionally, with the foods. Their representatives are lactic, uric, and oxalic acids. Since the liquor sanguinis is always alkaline, they cannot exist in it in the free state. They must, therefore, remain where they were formed (either in the cells or between them), external to the capillaries, until they can have received either sufBcient alkaline bases to neutralize them or oxygen to destroy them, or both. Thus we have, after muscular exercise, free lactic acid in the muscle- juices ; but, after rest for some time, it disappears. It has be^ repeatedly shown that about 890 grms. (28 oz.) of carbonic acid through the lungs, and acid matter equal to 2 grms. (31 grs.) of oxalic acid through the kidneys, are daily excreted. When under- going oxidation in the system, complex organic sub- stances are not changed to their lowest oxidation pro- ducts at one step, but by gradual transitions, each time to simpler substances, thus affording a gradual liberation of vital energy. So glycogen changes into lactic, then oxalic, and finally carbonic acids. The various acid products are easily, in health, converted by the ozone of the blood into COs — HjO — NHa — and urea, all readily excreted. Inefficient oxidation would increase the intermediate products, which are chiefly acids. The degree of alkalinity of the blood, therefore, de- pends upon (1) the amount of acids formed ; (3) the amount of oxidizable matter furnished ; and (3) the rate of elimination. (1.) The amount of acids formed will be increased by interference with the assimilation of oxygen, because complete oxidation cannot well occur ; and the inter- mediate acid products will result. This interference may be of a mechanical or a pathological character. We may class tumors of the thorax or abdomen and ascites with the former ; leucocythsemia, ansemia, chlorosis (diseased oxygen carriers), or heart and lung diseases with the lat- ter class of causes. (2.) Excess of oxidizable matter with normal oxygen supply will cause increased acid products. Here the oxygen is not diminished, but the matter to be oxidized, being in excess, finds insufficient oxygen for complete combustion. Such an increase occurs in that class of so-called " gouty" patients who, leading a very seden- tary life, consume large quantities of rich animal and vegetable food ; or again, in the acute febrile processes, where the body tissues, having, seemingly, lost theii power of resistance, fall a prey to the insatiable oxygen. (3.) Interference with elimination will, naturally, cause an accumulation in the system of acid products that may diminish the alkalinity of the blood to an extent sufficient to cause death. Diseased conditions of the emunctories, particularly the kidneys and skin, are fre- quent causes, but inattention to hygienic conditions and lack of exercise, without diseased conditions, may do the same. In severe cases of interference with elimina- tion, uric acid has been found in the nasal, pharyngeal, gastric, vaginal, cutaneous secretions (Boucheron), and in the menstrual blood ; also in the saliva in all forms of 59 Acldltr. Acids. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Under any of those conditions in wliicli the alkalinity of the blood has been reduced to a minimum, even the alkaline secretions, by a sort of vicarious action, elimi- nate some of the acid products ; and this continuing tor some time, will induce a catarrhal inflammation. Ihus a bronchial, intestinal, or genito-urinary catarrh, is not infrequently caused. , , , j "Acidity of the stomach," a term rather loosely usea to denote heartburn, pyrosis, acid dyspepsia, etc., raay be dependent upon several causes. The normal acidity ot the stomach, ranging between 0.10 per cent, to 0.33 per cent., and averaging 0.17 per cent., may be increased or diminished. The majority of cases of "acidity of stomach" belong to the former, where a greater amount of acid is secreted than is needed for the purposes of digestion. In a fewer number of cases a diminished flow occurs (0.01 per cent.). Here the foods not protected by the antifermentative action of the gastric juice undergo one of the various acid fermentations (e.g., lactic, butyric, or acetic), thus giving rise to the same phenomena as in excessive flow. Reichmann has recently furnished an in- teresting explanation of the subjective symptoms developed in acidity. His conclusion, based upon carefully con- ducted experiments with such cases, as compared with similar experiments upon the healthy adult, is, that the peculiar burning pain, vrith sensations of oppression, weight, etc., is always the result of regurgitated normally (or abnormally) acid gastric fluids into the lower extremity of the oesophagus. Here the normal secretion is alkaline. It has been shown that irritation of the gastric mucous membrane from any cause induces, by a reflex action transmitted through the vagus to its branch (the nervus dilator cardise recently demonstrated by Openchowski), an active dilatation of the cardiac orifice, thus permitting a partial regurgitation of the acid fluids. By an ingenious method he found the reaction always acid here, when the patients complained of the above symptoms, while in other cases it was alkaline. Now, th e irritant which produces this dilatation permitting regurgitation is most frequently that arising from too acid secretions acting on the membrana mucosa ; but it should be borne distinctly in mind, for purposes of diagnosis, that any other irritant might occa- sion the same phenomena without an increased acidity. Such we see exampled frequently in those who drink irri- tating liquors, and eat hot sauces with their highly spiced foods ; or characteristically in the "sour stomach" of the beer drinker, where the gastric acidity has been demon- strated as reduced to a minimum (0.01 per cent.). Nor is the gastric juice abnormally acid when from the irritation of small gastric ulcers all the signs of so-called acidity arise. In the conditions described as existing in so-called "acidity of the blood," the amount of acid matter ex- creted by the kidneys is greatly increased, particularly the uric acid. When a slightly larger quantity of uric acid is excreted than can be neutralized by the replaceable sodium in the sodic phosphate, the excess remains free and uncombined in the urine, which, the condition en- during, will often induce a catarrhal inflammation of the mucous membranes with which it comes in contact. Should the uric acid be in still greater quantity, it, being very insoluble (1 to 15,000), may be precipitated in any part of the urinary tract, or after emission in the cooled urine. Thus originate the uric acid calculi of the kidney and- bladder. The normal cutaneous excretions contain some of the volatile fatty acids (chiefly capric), which, under certain conditions or idiosyncrasies not well understood,, are greatly increased. To this condition the term bromidrosis has been applied. When the skin endeavors to eliminate the excess of acids from the blood, not infrequently an urticaria, herpes, or eczema arises, subsiding as soon as the normal alkalinity of the blood is reached. For quantita- tive estimation of acid excreta in urine — an index to the proportion of acids in the system — see Art. Urine. Thekapy.— The existing conditions being known, the indications are evident. If the diflSculty lies in faulty oxidation, then means should be directed to its improve- inent. Such are increased exercise, ferruginous tonics, simple foods in moderate quantity, and especially an in- crease of the alkalinity of the blood, because it is a phys- iological fact that ' ' oxidation occurs easiest in alkaline media." (See Art. Alkalinity.) The idea, then, is not simply to neutralize, but to destroy the acid products. This can be accomplished by the use of either the alkaline salts of potassium, sodium, or lithium {e.g. , their carbon- ates), or, better, by the employment of, the neutral salts of those bases with the (easily oxidizable) organic acids, such as acetic, citric, or tartaric acid. These are pref- erable, because entering the circulation without neu- tralizing the gastric acids and impairing digestion, they are soon converted into the bicarbonates by oxidation, when they will neutralize any acids present in the econ- omy. All the vegetable acids entering the circulation, combined with the alkaline bases, are completely de- stroyed, appearing in the excreta as carbonates ; but if taken in the free state (in quantity) they are excreted wholly or in part unchanged. Liebig's explanation is • that the alkalinity of the blood is so greatly reduced by their absorption that oxidation cannot well take place, and they are excreted as salts. Thus the existence of gallic acid in alkaline media with oxygen is impossible. Where an immediate effect is desired, two or three large doses, 1 to 3 grms. (grs. 15 to 45), of the bicarbonates (prefer- ably sodium), given in considerable water at short inter- vals, will accomplish the desired result. Thus an urticaria caused by acid excretions through the skin may often- times be relieved. If the "acidity" be through faulty elimination, the good sense of the physician will dictate appropriate remedies. The urate of lithium, being far more soluble than either the potassium or sodium salts, the carbonate of this base would form a more scientific remedy in cases of the so-called " uric acid diathesis." Lewis L. McArthur. ACIDS. PHYSioiiOQiCAL. — Normal Butyric Acid, CsHi, CO. OH, occurs principally as a glycerine ether in but- ter, but also in Sweat. It is formed abundantly by the butyric fermentation of lactic acid, SCsHeOs = CiHsOa + 2C0a + SHj, and at the same time also acetic and caproic acids are formed. It may be conveniently isolated by allowing grape-sugar or cane-sugar to ferment with rotten cheese and some calcium carbonate. After standing for a con- siderable time, calcium butyrate is formed, which sepa- rates out on boiling, and the acid may then be set free by hydrochloric acid. Normal butyric acid, CHs, CH^, CHa, CO. OH, is an oily fluid, boiling at 162.3° C. (324° F.) (Linnemann), solidifying at —19° C. (— 2.3° P.), and mix- ing in all proportions with water. The glyceride tri- butyrin, C3Hs(CiH,02)3, occurs in cows' butter, but can also be made synthetically. It is a colorless neutral oil of specific gravity, 1.056 at 8° C. (46.4° F.). Isovalerianic {Isopropj/laeetic) Acid, CiH,, CO. OH, oc- curs as a glyceride in the blubber oil of certain dolphins {delpMnus globiceps and phoemncC). It is also formed by the decomposition of albuminous bodies (casein), but is most easily prepared by the oxidation of fusel oil (amyl alcohol) by chromic and sulphuric acids. Isovalerianic Acid, (CHs),, CH, CH,, CO. OH, is an oily, colorless fluid, smelling like rotten cheese. It boils at 176.8° C. (349.4° P.) (Kopp) ; specific gravity, 0.931 at 20° C. (68° F.), and soluble in water. Triismalerin, CsHt(C6H90a)s, found in dolphin blub- ber, is a colorless oil, neutral, and insoluble in water. Oaproic Acid, CtHu, CO. OH, occurs as a glyceride in cows' butter ; also formed, as a rule, with butyric acid in fermentation. It is an oily, colorless liquid, solidifying at-18°C. (-0.4° F.), boiling at 205° C. (401° F.) ; specific gravity, 0.938 at 30° C. (68° F.). Insoluble in water, with a faint, unpleasant smell. The pure glyceride has not been isolated. Oaprylic and Owpric Acids. — Normal caprylic acid, C,H,5, CO. OH, and normal capric acid, CjHu, CO. OH, occur in very small quantities as a glyceride in cows' butter. The first crystallizes in leaflets, melting at -1-16.5° C. (62° F.), boiling at 236° to SS?" C. (457° to 60 REFERENCE HANDBOOK OP THE MEDICAL SCIENCES. Aclditr. Acids. 458° P.), and of very difficult solubility, even in boiling water. Capric acid occurs in fine needles, melting at 30° C. (86° P.), boiling at 368° to 270° C. (514° to 518° P.) : very insoluble in boiling water. The pure glycerides of these acids are not known. Laurie and Myj-ktie Aeids. — Laurie acid, CuHjs, CO. OH, and myristic acid, CisHai, CO. OH, are both found as cetylic ethers in spermaceti (Heintz). The first crys- tallizes in needles, melting at 43.6° C. (110.5° P.) ; the lat- ter in leaflets, melting at 53.8° C. (139° P.). Palmitic Acid, CisHsi, CO. OH, is found in all fats, generally as a glyceride, in combination with stearic and oleic acids, sometimes as cetylic ether (spermaceti) and myricylic ether (beeswax). When pure, palmitic acid crystallizes in scales, which melt at 63° C. (143.6° P.). The glyceride, Ifripalmitin, C3Hii(Ci6H3iO!i)s, is crystal- • line, melts at 61.5° C. (143° P.) ; is almost insoluble in spirit of wine, but slightly so in absolute alcohol (boiling) ; very easily in ether. Cetylic Mh&r, CieHsa, CxeHaiOs, constitutes the prin- cipal part of spermaceti. It crystallizes in leaflets, and melts at 53.5° C. (138.5° P.) (Heintz). Myricylic Ether, CsoHg,, CieHjiOa, forms the principal part of beeswax ; is insoluble in alcohol ; crystallizes in feathery aggregations, and melts at 73° C. (161.6° P.) (Brodie). Bteamc Acid, CitHjs, CO. OH. — Pound as a glyceride, especially in the solid fats, and may be obtained in large quantities from mutton- or beef-suet. Pure stearic acid crystallizes in leaflet, melting at 69.3° C. (156.5° P.) (Heintz) ; soluble with difficulty in cold ^irit of wine, but easily in benzol, carbon disulphide, and ether. The glyceride THstearin, C8H6(Ci8Hsi>Oa)a is found in all fats. It crystallizes in scales, glistening like mother-of- pearl. According to Heintz, it has two melting-points — first at 56° C. (133.8° P.), becoming again solid at a higher temperature, and melting again at 71.6° C (161° P.). It is easily soluble in boiling absolute alcohol and ether. Arachie Acid, dsHsj, CO. OH. — This acid is found in cows' butter as a glyceride. It crystallizes in small glis- tening leaflets, which melt at 75° C. (167° P.). THarcuihin,, C3H6(CaoH8jOa)a, is granular ; very slightly soluble in ether. Medullic Acid; Oi^liii, CO. OH. — According to Eylerts, the glyceride of this acid is found in the spinal cord of the ox. It melts at 73.5° C. (162.5° P.). Hyamrm Acid, CjiHio, CO. OH. — The glyceride of hysena' acid was found by Carius in the secretion of the anal glands of the hyaena, from which it is obtained by saponi- fication and fractional distillation. The pure acid crys- tallizes in small clumps of feathery needles, melting at 77° to 78° C. (170° to 173° P.) ; soluble in cold absolute al- cohol with difficulty, more easily in hot absolute alcohol, and very easily in ether. The pure glyceride is probably contained in hysena fat, but has not been isolated. Gerotic Acid, CaeHss, CO. OH, is found free in beeswax. As cerylic ether it forms the principal part of Chinese wax. The free acid forms granular crystals, which melt at 78° C. (173° P.) ; it dissolves with difficulty in alcohol. The cerotic acid cerylic ether, C27H66(Ca7H6a02) is crys- talline, wax-like, and melts at 83° C. (179.6° P.). Phyaetoleic Acid, Cis, Ha«, CO. OH, was found by Hof- stadter in the oil from physeter macrocephalus. It melts *t 30° C. (86° P.) ; oxidizes in the air. Oleic Acid. CnHaa, CO. OH, is found as a glyceride in almost all fats, solid and fluid, especially the latter. When pure, it crystallizes in colorless needles, which melt at 14° C. (57.2° P.); specific gravity, 0.898 at 14° C. (57.2° P.). When perfectly pure, it is soon oxidized in the air. With ioduretted hydrogen and phosphorus, when heated to 300° to 210° C. (393° to 410° P.) it passes into stearic acid. Triolein, CaH6(C,6H8s03)a, is a colorless neutral fluid, which is very little soluble in spirit of wine, but very easily soluble in ether. At body temperature it dissolves solid fats. Another acid ("Doglingsdure") has been found in the blubber of iaUena rosVrata, as a glyceride. T. Wesley Mills. ACIDS. Therapeutics.— The acids in general are substances, either solid, liquid, or gaseous, possessed of a sour taste, corrosive action, and the property of turn- ing blue litmus paper red, and of combining with bases or their oxides to form salts. Two of the acids of the Pharmacopoeia, however, carbolic and oleic, are, when pure, of a neutral reaction and will not redden litmus paper. The following-named substances are the ones which possess the characteristics of the acids in the most marked degree, and which are commonly understood when mention is made of this group. Though the Phar- macopoeia contains many other drugs which are, chemi- cally speaking, acids, nevertheless, as regards their thera- peutic action, they belong rather to some other family, and will be more properly considered in connection with the other members of their respective groups. (See articles Antiseptics, Astringents, Disinfectants, Sedatives, etc.) The pharmacopoeial " acids," commonly so called, and which will be here considered, are acetic, chromic, citric, hydrochloric (or muriatic), lactic, nitric, nitro-hy- drochloric (or nitro-muriatic), phosphoric, sulphuric, and tartaric. To these may also be added arsenious and car- bolic acids, which may, with propriety, be treated of here as regards their toxicology and external uses, and oxalic acid, which is of interest in this connection only as a poison. Toxicology. — Before speaking of the therapeutic uses of the acids, a portion of the space allotted to this article may perhaps be profitably devoted to a very brief con- sideration of the symptoms and treatment of poisoning by these substances. The mineral — arsenious, carbolic, oxalic, and tartaric — acids are those from which poison- ing, either by accident or design, most frequently occurs. When the mineral acids have been swallowed in concen- trated form, the symptoms are those produced by a cor- rosive poison — intense burning pain in the mouth and throat, wherever the acid has come in contact with the mucous membrane, severe thirst, weak pulse, and dyspnoea. If hydrochloric or sulphuric acid have been taken the lips will show black stains, while the corrosive action of nitric acid colors the parts yellow. In cases of poisoning by these acids, alkalies should be at once ad- ministered in large draughts of milk or water. Any alkali that is nearest at hand may be used — chalk, tooth- powder, whitewash scraped from the ceiling, soap, or washing- or cooking-soda. The patient should then be made to swallow olive oil, melted butter, or lard. The attempt to use the stomach-pump in these cases should never be made, as serious injury may thereby be done to the softened tissues. (Por the symptoms and treatment of arsenical poisoning, see under the head of Arsenic). Poisoning by carbolic acid is evidenced by extreme de- pression, weakness of the heart, and dyspnoea. The breath is redolent of the drug, leaving little doubt as to the nature of the case. It is not very often that carbolic acid is swallowed in sufficiently concentrated form to produce severe local escharotic effects. When this hap- pens the eschars are white in color. The treatment em- braces the use of the stomach-pump or emetics, washing out the stomach, the administration of oily or mucilagi- nous drinks, and, later, stimulants to combat the depres- sion. Poisoning by oxalic acid is not infrequent, owing to the resemblance of this substance to Epsom salts. Oxalic acid also exists in the leaves of the common rhubarb or pie-plant, and several cases of poisoning from eating these leases have been recorded. This substance is an acro- narcotic poison, and when taken in toxic dose causes burning in the throat, intense gastric pain, vomiting, and collapse. Lime and magnesia are the proper antidotes, and should be given at once in large quantities, after which the stomach may be emptied by emetics or the pump. Potash or soda must not be given, as these alka- lies form poisonous compounds with oxalic acid. After the immediate danger of death is averted by these means there remains a gastro-enteritis which is to be treated by the ordinary remedies. Instances of fatal poisoning by tartaric acid are extremely rare. The symptoms are those of an irritant, and consist in burning of the throat and stomach, with the signs of gastric inflammation. Any 61 Acids. Acne. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. alkali that is nearest at hand should be given, and the re- sulting gastritis is to be treated on general principles. The therapeutic uses of the acids are varied and im- portant, but their consideration here must necessarily be brief. For a detailed account of the individual prop- erties of the acids the reader is referred to the special ar- ticles under their respective titles. External Uses. — The stronger acids are markedly es- charotic in their action, this property depending upon their strong affinity for the water and the bases in the tissues, and upon their power of coagulating and dis- solving albumen. They are employed for the purpose of destroying new growths, removing sloughs, stimulating indolent and unhealthy granulating surfaces, cauterizing poisoned wounds, and, in diluted form, as astringents and haemostatics. The caustic action of the acids is difficult of exact limitation, and hence they should not as a rule be used where only a superficial destruction of tissue is desired. They may be applied by means of a glass rod or a clean splinter of wood, and the surrounding integument should be protected by previously smearing it with oil or some other fatty substance. After the cauterizing action has proceeded far enough it may be in a measure limited, and the resulting pain relieved, by washing the part with an alkaline solution or soap-suds. The acids are used for the destruction of condylomata, small haamorrhoidal tumors, naevi, chancres, and chan- croids, to provoke healthy action in sloughing and phage- dfenic ulcers, and in uterine applications. Nitric acid, on account of its comparatively superficial action is the one usually selected for these purposes, though in many cases chromic acid is to be preferred. The latter pene- trates deeply, and its application is not so painful as that of the former. Sulphuric acid is seldom employed as an escharotic, as it penetrates deeply and is with diffi- culty limited in its action ; sometimes, however, it is selected because of these very qualities. It has been highly recommended, when diluted with two or three parts of water, as an application to carious or necrosed bone. Glacial acetic acid is one of the best applications for the removal of warts or corns. Carbolic acid (un- diluted) is an excellent mild escharotic ; it is employed for the removal of small condylomata, in the treatment of herpes, and as a uterine application. Somewhat diluted it finds employment in various ways as a local anaesthetic. Sponging the body with water acidulated with sulphuric or acetic acid is of service in excessive sweating, and it is also grateful as a refrigerant measure in feverish conditions. Dilute acetic acid or vinegar may be used to control epistaxis and other slight capil- lary haemorrhages. Nitro-hydrochloric acid is employed externally in baths or on compresses applied over the liver in the jaundice due to cirrhosis or other chronic hepatic disorders. Hydrochloric acid was at one time, on the authority of Bretonneau, largely employed locally with a view to dissolving away the false membrane in diphtheria, but it has now, and justly, fallen into disuse. Lactic acid has also been recommended for the same purpose, but it is seldom so employed at the present day. InUmal Uses. — The acids are to be ranked among the antipyretics, since their power of reducing the body temperature in febrile conditions, though not very great, is yet not to be gainsaid ; in healthy individuals, how- ever, their effect upon the temperature is nil. Dilute hydrochloric is the best to use for this purpose, though, when an astringent effect is also desired, aromatic sul- phuric acid may be substituted. The vegetable acids are frequently employed in the preparation of cooling drinks for fever patients. Citric acid or lemon-juice is the more palatable, but when for any reason this cannot ^e obtained, a very refreshing drink may be made by adding a little vinegar to sweetened water. Tartaric acid may also be used for the same purpose, but is in- ferior to citric. Perhaps the most frequent use of the mineral acids is in the treatment of dyspepsia, either to correct excessive acidity of the stomach or to supple- ment a defective secretion. Hydrochloric acid is the one usually selected, and is to be given before meals when 62 the fault lies in too great acidity of the gastric secretions. When the opposite condition prevails, the acid is to be given after meals, and for this purpose lactic acid is preferred by many to hydrochloric ; indeed, it is prob- able that when the latter is exhibited it is converted into lactic acid in the stomach. The acids just mentioned are also frequently employed when there is an excess of uric acid in the urine. In alkaline conditions of the urine the mineral acids, as well as citric or tartaric acid, are often of service. In hepatic disorders nitro-hydrochloric acid should be selected, and its internal administration, as mentioned above, may be supplemented by external ap- plications. Carbonic acid water is of value in slight nausea and in the acute indigestion following excesses in eating or drinking. The mineral acids possess some value in the treatment of scurvy, but are far inferior to citric acid, especially as it exists in lemon-juice. The acids are also largely employed to control haemorrhages of the uterus, lungs, or intestinal tract, especially of the first and last-named ; in haemoptysis they are of less effi- cacy. Sulphuric and phosphoric acids are the ones given for this object, but sulphuric is to be preferred. Aro- matic sulphuric acid is used to restrain excessive sweat- ing. Atropine and other drugs find more favor in the treatment of the night-sweats of phthisis ; but in certain conditions, especially in corpulent individuals, in which profuse perspirations occur at night or foUow upon very slight exertion, aromatic sulphuric acid given in ten or fifteen drop doses before 'retiring is very efficient. Care should be observed, however, not to continue its exhibi- tion for too long a time, owing to the danger of disturb- ing the digestive functions. Sulphuric acid is useful as a temporary measure for the relief of lead colic, but it does not eliminate the poison from the tissues, and should never be relied upon to the exclusion of other more efficient remedies in the treatment of this condition. Workmen in lead factories make use of sulphuric acid lemonade as a prophylactic against poisoning, and the same drink is vaunted as a preventive of cholera. Sul- phuric acid when added to Epsom salts markedly in- creases their purgative action. The acids, finally, are very often given, with or without iron, as a tonic. For this purpose either nitric, hydrochloric, or phosphoric acid is to be selected. For a certain class of nervous ansemie women who present an indescribable train of symptoms, various indefinite pains, nervous startings, palpitation of the heart, headache, etc. , no tonic answers Ibetter than the following : Sulphate of iron, 13 grammes (3iij.); nitric acid, 13 grammes ( 3 iij.) ; water, 90 grammes (|iij.) ; fifteen drops to be taken in water three times a day after meals. It should never be forgotten that the action of acids is very injurious to the teeth, and they should therefore always be taken through a glass tube. The mouth should immediately afterward be rinsed out with a solution of bicarbonate of soda or other weak alkaline solution, as a further precaution. Tlwmas L. Stedman. ACNE. Acne is an inflammatory, usually chronic, disease of the sebaceous glands, characterized by the formation of papules, tubercles, or pustules, or a com- bination of these lesions, occurring for the most part about the face. It may occur alone or in connection with other affections of the sebaceous glands, as comedo and seborrhoea. The lesions are of various sizes, from a pin's head to a large split-pea, and are commonly seen in both the papular and pustular, or the tubercular and pustular forms combined. There is not often any sensa- tion of burning or itching, but occasionally a feeling of soreness when the lesions are touched. Their color may vary from bright red to dusky or violaceous, with usu- ally a pustular centre. The number of lesions varies greatly in different cases. There may be only one or two present, or they may be verjr numerous. The inflam- mation may be superficial or it may be deep, even occa- sionally leading to the formation of abscesses. The indi- vidual lesions may come and go within a few days or they may be of slow evolution, but the disease itself is apt, in all cases, to run a chronic course, the process REFERENCE HANDBOOK OP THE MEDICAL SCEENCES. Acids. Acne. frequently lasting for j-ears. If there has been much suppuration, more or less unsightly scars may remain. The chief seat of acne is upon the face, neck, shoul- ders, and chest, although it may occur upon any part of the body, except the palms and soles. The severity of the disease varies very greatly. In some instances it may be represented by one or two lesions only, while in others the face, neck, shoulders, chest, and even the whole trunk may be covered with unsightly papules, pustules, suppurating tubercles, and abscesses. Acne is one of the commonest diseases of the skin. In this country the statistics of the American Derma- tological Association show its occurrence, in the practice of specialists, to be in the proportion of seven per cent, in all diseases of the skin, and its comparative frequency among the people is probably much greater. Acne oc- curs in the young of both sexes, appearing about the age of puberty. It does not occur in children, and only rarely makes its appearance for the first time in mature years. Acne may occur in several different forms, described as "acne punctata," "acne papulosa," "acne pus- tulosa," but all these are stages of the same process, and all may usually be found represented in the same individual simultaneously. As one kind of lesion rather than another usually predominates, it will be convenient to consider the aflcection more closely under several heads. Papular acne is the earliest stage of the disease, and is chiefly characterized by the occurrence of papular lesions, of pin-head to small-pea size, flat, or more or less pointed, lightish in color, situated about the sebaceous follicles, and often showing a minute black point, which indicates the mouth of the sebaceous duct. This variety of acne is often accompanied by comedo. (See Comedo.) There are usually a few pustular lesions scattered among the papules. The latter are not acutely inflam- matory, and papular acne is the least developed form of the disease. Pustular acne is the typical form of the disease, though even when fully developed pustules form the chief feat- ure of the eruption many lesions of a papular and inter- mediate character are found. The pustules are pin-head to large-pea size, rounded or acuminate, seated on a more or less infiltrated base of superficial or deep inflam- matory product. Suppuration may be slight or abun- dant Occasionally several lesions run together, or the suppurative process extends more widely and deeply, and abscesses form. Such lesions are apt to occur about the lower part of the face, neck, and chest, but chiefly on the shoulders and back, forming the most serious and annoying phase of the disease. The smaller pustular lesions may heal up without a scar, while the larger ones leave a pitted cicatrix like that of small-pox. When abscesses f oi-m, very deforming cicatrices, with pockets or bridles of tissue, and with large comedones about or in them, may result. The disfigurement thus produced is increased by the occasional supervention of keloid in the cicatrix, but the lumpy scars thus produced usually assume the ordinary cicatricial condition after some months, the keloidal condition spontaneously disap- pearing. "Artificial acne" is sometimes observed as the result of the external employment of tar, chrysarobin, and other agents. The acieform eruptions produced by the in- festion of various medicinal substances, will be found escribed under the head of "Dermatitis medicamentosa." Tho causes giving rise to acne are numerous and varied in their nature. In its commoner forms it appears to be dependent, to some extent, upon the character of the skin. Persons with thick oily skins are most apt to suffer from the diffuse form of acne with numerous papular and pus- tular lesions mingled with comedones, while the sparse eruption of flat and papular lesions is often found in pnlo, anaemic individuals, with dry, rather harsh skins. The most frequent cause of acne is puberty. The affection shows itself for the first time, in the vast majority of cases, at this' period, and is apt to continue, unless re- medial measures are adopted, until the system has assumed the equilibrium of adult life, or in women until a later period. Other causes which may, either alone or combined, give rise to the occurrence of acne, are scrofula and ca- chexia or general debility, anaemia, and chlorosis. Habitual derangement of the alimentary canal is of great importance in the causation of acne, and dyspepsia, with, or more rarely without, constipation will be found present in the majority of cases. Very often a fresh attack of acne, with a new crop of lesions, follows closely upon each attack of dyspepsia or constipation. Disorders of menstruation are often the direct cause of acne, and in many women suffering from this skin affec- tion, a fresh outbreak may be expected before, during, or just after each menstrual period. At other times the cause of the disease remains obscure, the patient enjoying otherwise good health. The anatomical seat of the inflammation in acne ia about the sebaceous glands and hair-follicles, with their common opening. In the milder forms of papular acne (acne punctata) we have a comedo about which the sur- rounding papUlee and corium show enlarged blood-vessels, serous effusion, and exudative cells in the widened net- work. When the process goes on to form pustular acne, there is purulent exudation in the gland-ducts. When larger tubercles and pustules are found, extensive inflam- mation of the glandular structure and surrounding tis- sues with purulent collections in the gland-duct, and hair- follicle, and loosening of the hair-sheath, with destruction of the epithelium, is observed. When the inflammation is more intense, the sebaceous gland may be entirely lost in the suppuration, while the hair-follicle may escape. In large acne abscesses, gland, hair-f oUicle, and all are swal- lowed up in suppuration. The diagnosis of well-developed acne presents no diffi- culty. When only a few lesions are present, however, and especially when these are illy developed, it is by no means easy, at times, to decide whether we have to deal with this affection or with others of a widely different nature. The age of the patient, the seat of the lesions, their chronic character, and their inflammatory nature, must be taken into account. Tar acne may be recog- nized by the smell of that drug, and acne due to chryso- phanic acid by the purplish discoloration of the skin where it has been applied. In both forms of acne the presence of the drug in the follicles causes a marked ap- pearance of black points. Acne may be distinguished from the similar eruptions due to iodine and bromine (see Dermatitis medicamentosa) by the fact that the le- sions in these drug eruptions are apt to be larger, and that they come out in considerable numbers simultane- ously. In addition the lesions are of a brighter and more inflammatory nature in the drug eruptions, and when fully developed are apt to cluster together, coa- lesce, and form inflammatory areas covered with charac- teristic crusts. The lesions of true acno raroly occur in groups or coalesce, -rd never show the cheesy sebaceous secretion of the acnef orm dermatitis from the ingestion of drugs. Acne often closely resembles the papular and pustular syphilodermata, and the two affections are not infrequently mistaken for one another. The history of the case, the presence or absence of characteristic lesions on other parts of the body not ordinarily attacked by acne, the uniform or scattered distribution of the lesions, those of syphilis tending to group, are all elements of the diagnosis which must be taken into consideration. When the syphilitic lesions occur on the forehead, or only to the extent of one or two about the nose, without any history, it is sometimes difficult to make the diag- nosis, and great caution must be exercised in coming to a decision at the first examination. Acne in a severe and pustular form looks not unlike small-pox, but the absence of fever or other concomitant symptoms, and the chronicity of the acne eruptions, should prevent this mistake from being perpetrated even by one quite unac- quainted with skin diseases. The treatment of acne should be both constitutional and local. In order to use the constitutional treatment with effect, we must first ascertain by careful cross- 63 Acne. Acne Rosacea. KEFERENCE HANDBOOK OF THE MEDICAL SCIENCES. examination of the patient exactly what is the weak point. If constipation exists, this must be remedied. If dyspepsia is present, a careful regimen, with remedies ap- propriate to the peculiar form of digestive disturbance operative in the case under consideration, must be em- ployed. When uterine difficulties present themselves as probable causes of the acne, these must be attended to, and, m short, to deal successfully with acne, the physi- cian must he a master of his art. Of course, only the outline of treatment can be given in an article like this, and the treatment must be varied to suit the case. When anaemia seems to be the efficient cause, without concomitant digestive difficulty, iron and arsenic alone or combined are called for. The tincture of the chloride in five to ten minim doses, always prescribed in water, so that the patient is not left to measure out the drops, is one of the best forms of iron to use alone. The arsenic is preferably given in the form of Fowler's solution in water or in wine of iron ; the dose at first should not be more than two to four minims, which may be gradually increased to eight minims if the case require it : beyond this it is rarely advisable to go. Constipation is a very common accompaniment of acne, and should always be removed. Saline or vegetable laxatives, with an occa- sional dose of blue pill, is useful in some cases. The majority of patients will get along best under the admi- rable mixture devised by Startin, and known as " Mistura ferri acida." It is composed as follows: 8. Magnesii sulphat., § j. (31 grm.) ; ferri sulphatis, gr. iv. (.26grm.) ; sodii chloridi, 3 ss. (1.95 grm.); acid, sulphuric, dil., f 31]. (7.75 grm.) ; infus. quassise, ad f |iv. (130 grm.). M. Sig. : A tablespoonf ul in a tumbler of water before breakfast. Although a very disagreeable mixture to most persons on first taking, it usually agrees well with them, and becomes less revolting after use for a short time. In the dyspepsia with constipation of acne it is an incom- parable remedy. Its use should be governed by the effect on the bowels. If it is too purgative the amount can be diminished, or if not sufficient laxative effect be produced the proportion of magnesium sulphate can be increased, or the dose repeated before supper, or it may even be given thrice daily. The natural mineral waters are some- times useful in acne, especially the Hathorn water of Saratoga and the Hunyadi Janos as sold in the bottled form. Where there is much irritability and hyperaemia ac- companying the acne, good results are often gained by the prolonged administration of alkalies. Taylor recom- mends the following formula : 3 • Potassii acetatis, § j. (31.10 gi"m.) ; sodii et potassii tart, |ij. (62.20 grm.); syr. zingiberis, f § ij. (60 grm.) ; aquae, q. s. ad f J viij. (240grm.). M. Sig.: A tablespoonful in a wine-glass of water after meals. When there is a scrofulous taint, and especially in those cases in which there is a tendency to the formation of abscesses, cod-liver oil is indicated. Occasionally, when this disagrees, extract of malt may be substituted. The bitter tonics and mineral acids are likewise of value in many cases. Hygiene is of the utmost value in the management of acne, and the beneficial effect of change of air, particu- larly to mountainous regions, is often more marked than that of drugs. The sea-shore, it may here be remarked, usually disagrees with acne patients. Exercise in the open air, cold bathing, moderate gymnastics, all are of use. Occasionally a sea voyage benefits a patient whom medicines have failed to relieve. The local treatment of acne is of great importance, especially with regard to the choice of remedies. Appli- cations innumerable are recommended in the books and in periodicals, but only a few are generally useful. Some cases of acne show acutely inflammatory symptoms, and must be treated by means of soothing applications, of which the bland ointments and lotions used in acute eczema are examples. (See the treatment of acute eczema.) But by far the greater number of acne cases demand stimulant treatment, often of a vigorous sort. When the skin is coarse and sluggish, with numerous comedones and a general greasy look, and without much acute in- flammation, frictions with alkaline soaps, as sapo viridis or the solution of the latter in one-half its weight of alcohol, known as " spiritus saponis alkalinus," are of use. These should be briskly rubbed in and then washed off the skin again, and followed by applications of cold water or of powdered starch. Occasionally a solution of potassa, fifteen grains to the ounce of water, may be applied with advantage, followed by a stimulant ointment, as the fol- lowing: ]j. Ung. hydrarg. praecip. alb., 3 j. (3.90 grm.) ; ung. aquae rosae, 3 iij- (11.65 grm.). M. Sulphur and its preparations are among the most valuable remedies in our possession for the treatment of acne in most of its forms. The following is a generally useful formula: ]J . Sulphuris precipitat. , 3 j. (3.90 grm.) ; ung. aquae rosae, vaselini, aa3iv. (15.50 grm.). M. Camphor may some- times be added in the proportion of a scruple (1.30 grm.) to the above formula. Sometimes lotions are more suit- able, especially where there is a tendency to rosacea (see Acne Rosacea). The following is a convenient prepara- tion : B. Sulphuris precipitat. , 3 j. (3. 90 grm.) ; pulv. cam- phorae, gr. v. (.32 grm.); pulv. tragacanthae, gr. x. (.65 grm.) ; aquae calcis, aquae rosae, sa f | i. (30 grm.). M. When the lesions are sluggish, and especially in in- durated acne of the back, V lemingckxs's solution is a valuable local application. ? . Calcis vivae, | ss. (15.50 grm.) ; sulphuris sublimat., | j. (31.10 grm.) ; aquae, f | x. (311 grm.). Boil down to six ounces and filter. This is a very stimulating application, almost caustic in fact, and should always be diluted with several parts of water be- fore using, at least until the effect upon the skin has been ascertained. Indurated and pustular acne may sometimes be bene- fited by the application to each lesion of a drop of solu tion of the acid nitrate of mercury on the end of a sharp- ened match, followed by bathing with hot water. The lesions may also be punctured with a sharp instru^nent when there is a tendency to the formation of abscesses. (See Fig. 53.) The severer plans of treatment, as rubbing with sand, scraping with the sharp spoon, are not par- ticularly beneficial, and are usually objected to by pa- tients. In some cases the use of sulphur soaps, applied in lather and allowed to dry on, is of advantage. Whatever plan of treatment be adopted^ it is essential that it should be thoroughly carried out, and the patient should be frequently examined to ascertain if the direc- tions have been complied with. In any case the prog- nosis should be guarded. The more extensively devel- oped cases are very often more amenable to treatment than those where half a dozen lesions alone represent the disease, and where the patient enjoys apparently good health. The question is, in the long run, one of time only, as a spontaneous cure sooner or later invariably occurs. If neglected, however, unsightly and disfigur- ing scars, sometimes keloidal, supervene in severe cases, and unremitting efforts should, therefore, be used lo ob- tain, if possible, a speedy cure. Arthur Van Harlingen. ACNE ROSACEA. Acne Rosacea is a chronic, hyper- aemic, or inflammatory disease of the face, more par- ticularly the nose, characterized by redness, dilatation and enlargement of the blood-vessels, hypertrophy, and more or less acne. Hyperaemia is the first symptom, and this shows itself in a diffuse flush on the nose and neighboring parts, and in some cases over the cheeks, chin, and even the ears. This may at first occur only intermittently, but after a longer or shorter period the redness becomes settled, more marked, and permanent, A condition at first only brought on by exposure to cold or a close atmosphere, or following the use of alcoholic stimulants or a full meal, finally becomes habitual. Small tortuous blood-vessels can be seen ramifying over the tip of the nose and the prominence of the cheek-bones, the nose is cold to the touch and often shows slight seborrhoaa. This condition may remain stationary for months, or even years, and may then disappear, or it may go on to the gradual formation of pin-head to split-pea-sized hard papules, either iso lated or grouped into indurated masses. This second 64 EEFERENCE HANDBOOK OP THE MEDICAL SCIENCES. Acne. Acne Rosacea. form shows best the combination of conditions which has given the affection -its name, acne rosacea. A third and much rarer variety affects the nose alone, and consists in an inflammatory connective-tissue hy- pertrophy, with enlargement of the sebaceous folli- cles and hypertrophy of the papillary layer of the corium. The organ becomes grotesquely enlarged and misshapen, the surface rugous and covered with irregu- lar, sometimes overlapping growths, showing, enlarged and tortuous blood-vessels, thickly strewn with acne pustules and with the blackened points of comedonef and of a deep vinous red color. At other times the sur- face remains smooth and shining, while a uniform thick- ening of the skin causes great increase in the size of the aose. The causes of acne rosacea are various. The first two varieties may occur in men as well as in womeL, but fhe third is found in men alone. In women the disease is apt to be connected with disturbance of the generative apparatus. Dyspepsia, anaemia, and chlorosis are also among the causes. Habitual indulgence in alcoholic and malt liquors is among the commonest causes, al- though the disease is in no sense an indication of alco- holic indulgence, as it is very common among dyspeptic water-drinkers. Persons whose business or profession leads to much exposure to inclement weather, as hack- drivers, sailors, etc., are apt to become the subjects of acne rosa- cea. The immediate cause of the lesion is paresis of the most minute capillaries of the skin at their cxt tremities, leading to chrotoic enlargement and sluggish circula- tion. The pathology of acne rosacea is in part explained by what has been said regarding its etiology. In the first variety or stage there is simply a blood stasis in the skin. This condition may last for years Without change. Sooner or later, how- ever, permanent dila- tation and hypertro- phy of the capillaries takes place, together with an involvement of the seba- ceous glands in the form of acne. Still later more or less hypertrophy of all the tissues of the affected part takes place, and a connective-tissue new-growth is the result, with the marked distortion above described. Piffard has described a case, microscopically examined by him, where the horny layer was scanty, but the rete mucosum thick with well-formed cells. The papillae were enlarged in lerigth and breadth, and contained round and fusiform cells. Some of the sebaceous, glands were unaltered, others were undergoing degenerative changes. The corium was greatly thickened, and presented the appear- iLCv 3f a formed tissue. The only diseases with which acne rosacea is liable to be confounded are syphilis, lupus vulgaris, lupus ery- thematosus, and acne. From the tubercular syphilo- derm acne rosacea is to be distinguished by its chronicity. The syphiloderm is indeed chronic, but it lasts months where acne rosacea lasts years. In syphilis the-lesions do not especially involve the glands, in acne rosacea the glands form the centre of the pustular lesions. Crusts are apt to be present in syphilis, and some of these on removal show ulcers beneath. Ulcers never form in acne rosacea. The color of the syphilitic eruption is apt to be a dull, coppery red ; in acne rosacea the color is either a bright red or violaceous, according to the stage Vol. L— 5 Fio. 52.— Acne Bosaceii. (After Dnhring.) of the disease and its form. The characteristic enlarge- ment of the bloodvessels seen in acne is wanting in syphilis. Syphilis occurs on one side of the nose more than on the other in many cases, whereas acne is symmet- rical. In doubtful cases the history may be of some aid, but is not always to be depended upon. The characteristic roundish, reddish, or yellowish papules or tubercles of lupus vulgaris, pin-head or larger in size, and usually involving only a portion of the nose, as the tip or one ala, usually serve to distinguish this af- fection and to prevent its being mistaken for acne rosacea. Moreover, ulceration, followed by crusts and disfiguring cicatrices, is present in lupus vulgaris, but is absent in acne rosacea. Sometimes lupus erythematosus, when it occurs upon the end of the nose, may be mistaken for acne rosacea, but the presence of sebaceous crusts, with the wide-open mouths of the oil-follicles, are> characteristic of this form of lupus, and are quite absent in acne rosacea. Prom acne the affection under oonsideration may be distinguished by the presence of enlarged blood-vessels and by the hypersemia. As the line dividing acne and acne rosacea is in some cases an arbitrary one, and as the former may merge into the latter, of course many cases are practically undistinguishable. The treatment of acne rosacea varies with the stage of the disease and with the cause in the given case. Constitutional and local remedies are both to be employed. The cause of the disease is in each case to be diligently sought out and, when possible, removed. Especially is this the case when disorders of the generative apparatus in women are involved. The stomach and bowels are to be kept in good order. Iron, arsenic, and bitter tonics are to be used as occa- sion requires. Change of air to the mountains, or to the sea-shore, may in some cases be re- quired. Locally, the acne lesions when present are to be gotten rid of by the remedies above described under acne. The sulphur preparations are the best, both for this purpose and for the removal of the rosaceous condition, and the sulphur and tragacanth wash, described above, may be ap- plied frequently with the greatest benefit. G. H. Pox recommends the following : B . Pulv. chrySarobin, 3 ss. (1.95 grm.) ; collodii, fjj. (33 grm.). This is to be painted over the af- fected part daily, the effect being watched with the view of avoiding possible untoward results from over-action of the chrysarobin. In the later stage, when well-defined blood-vessels can be seen coursing under the skin in numbers, the treatment must be different. _ _ fio. 53.— The dilated capillaries may be incised with a Aone-puno- flne, sharp knife, in the hope that adhesive in- tor- flammation may result, with the effect of closing the caU- bre of the vessels. Cold water compresses or pledgets of dry lint may be applied to control any bleeding, and a small number of vessels may thus be operated upon thoroughly until the ground has been entirely gone over. A lance-headed punctor (Pig. 53) may be used for the same purpose, small punctures being made in the line of the di- lated vessels at short intervals. Hardaway recommends electrolysis, using a No. 13 cambric needle inserted into any convenient handle, and connected with the negative pole of a galvanic battery ; a sponge electrode is then connected with the positive pole. The needle is inserted sufficiently deep to enter the dilated vessel ; as soon as this has been accomplished the patient completes the circuit by taking the sponge electrode into his hand. When the electrolytic action has been properly devel- oped, the patient releases the sponge electrode, after which the operator withdraws the needle. Six or eight elements will generally suffice. If the vessel to be op- erated upon is a long one, several punctures must be made at suitable intervals of space. The needle may be inserted perpendicularly or in a line with the course of the vessel. One discouraging fact must be taken into 65 Acne Rosacea. Aconite. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. consideration in the endeavor to heal acne rosacea by means of destruction of the calibre of the enlarged blood- vessels, that is, that a collateral circulation is apt to be established which will bring the same condition of the skin back again, and which must be expected and met by a renewed operation. In these rare and severe cases of acne rosacea, when knobby and gross hypertrophic deformity of the nose exists (Fig. 53), decortication with the knife is the only effectual remedy, although in less advanced cases scraping with the sharp spoon may im- prove the condition of the skin to a considerable degree. The prognosis in the early stages of acne rosacea is favorable, and there are few affections of the face in which more striking and rapid results can be attained, up to a certain point, than in these cases of acne rosacea where there is a red, flushed condition of the face, with numerous acne papules and pustules, and with little or no distinct capillary dilatation. When, however, the disease has become thoroughly established, only thorough and long-continued treatment will avail. When the capillary enlargement is already marked, treatment be- yond a certain point is only palliative ; it may prevent further progress— a result of no small value, and pa- tients should be encouraged to persevere. Arthur Van Harlingen. ACONITE \A.amUum, U. S. (the root) ; Aconitum napellus L. (DelpMnum aconitum Baillon) ; order Ea- nunculacm, Monkshood] is a tall, handsome herb, with large, irregular, purplish blue flowers, compound leaves, and a fleshy, conical, biennial — but by stolons, perennial — root. It is a variable and widely distributed species, growing abundantly in the mountainous districts of Central Europe, Asia; and the western part of America ; extending up the mountain sides to a very high eleva- tion, as well as deep into the valleys. It is cultivated for medicinal use in parts of continental Europe and England, and as an ornamental flower in the United States, where it occasionally escapes from gardens, and takes an uncertain possession of waste places. The aconites were known to the ancients, both in Europe and Asia, as poisons, and are said to be still used by some of the hill tribes of India to envenom their arrows. They were employed as medicines in Germany in the twelfth, and on the island of Great Britain in the thirteenth centuries ; but afterward fell into disuse until 1763, when Stoerck, of Vienna, again introduced them to the medical profession, since which time they have been constantly but not ex- tensiveljr used. The simple, stiff, upright stem of aconite rises from fifty to one hundred centi- metres (twenty to forty inches) from the ground, bearing numerous alternate leaves, and a long, close, terminal, spike-like raceme. The leaves {folia aconiti, Br. Ph. ; feuiUea Waconit napel, Codex Med.) are from five to twenty centimetres in diameter (two to eight inches), are rather stiff and thick, smooth, shining, and . , mi, I., , . , dark green above, and paler below. The blade is palmately three-parted ; the lateral segments are again divided nearly to the base. The narrowly wedge-shaped divisions are further three- or two-lobed, and these lobes are again incised, or cleft with linear or pointed tips. The leaves become less compound toward the upper part of the stem, and are finally reduced to three- or several-cleft bracts. They 66 Fio. 54.— Dclphlnum Aconitnm (Bnillon). Fio. B5.— Entire Flower of Aconitum Kapellua. have no marked odor, but upon being chewed, produce, like the root, a persistent stinging sensation in the mouth. They contain a small and uncertain amount of aeonitine, and considerable aconitic acid; the latter of no therapeutic importance. The flowers are of striking appearance ; the corolla is nearly wanting, and its place is taken by a large, colored calyx, of which the upper sepal is de veloped into a deep cup-shaped helmet, that sits upon the rest of the flower like a bonnet. The pistils are three, containing numerous small ovules. The mature root gives the speci- fic name to the plant (napellus, a little turnip). It is a simple, coni- cal, tapering tuber, ending in a long, slender, cylindrical tap-root, and bearing numerous rootlets upon its sides. (See Fig. 57.) From its scaly crown arises the flowering stem, and at the base of this stem a short stolon extends horizontally under the ground, and bears, on its extremity, a young tuber, more or less developed according to the season, and destined to produce the plant of the succeeding year. There may also remain upon the other side of the crown a similar but dead connection between the present root and the remains of that of the preceding year. Fresh aconite root is brown externally, white within, and has a biting, benumbing "taste," which has caused it to be occasionally stupidly mistaken for horseradish. The dried root, which constitutes the usual drug {pMnitum, U. S. Ph. ; aconiti radix, Br. Ph. ; tubera aconiti. Ph. G. ; raeine d'aconit napel, Codex Med., etc.), is from one to two centimetres in diameter at the base, and from five to seven inches in length (two-fifths to four-fifths inch by two to three inches) ; much shrivelled- and wrin- kled longitudinally, especially below; often curved and twisted, or broken. The exter- nal color is dark brown ; internally it is grayish, showing, in a transverse section, a distinct, five- to eight-pointed stellate cam- bium ring, in each angle ' of which is a well-developed flbrd-vascular bundle. Frequently the roots are attached in pairs ; when not, the scar where they were broken apart can be seen. The taste is similar to that of the fresh root, but the stinging sen- sation may be a little slower in coming. Aconite root, even when coming solely from aconitum napel- lus, is very variable in quality and often poor. The age of the root has much to do with this ; when gath- ered just before blos- soming it is large and juicy, and of the best quality ; after this it rapidly deteriorates, and the autumn-flow- ering root is worth- less. The young root, in the autumn or spring, however, is of good size and next in value to the first named. Light, hol- low, rotten-stemmed „ . j.~ pieces should be dis- Grown in different countries, or under varying circumstances, it is subject to considerable variation in Fio. B6.— Seed- veEsel of Aco- nitum Napel- lUB. Pig. B7.— Hoot of Delphinum Aoonitnm (Baillon). carded REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Acne Rosacea. Aconite. quality. Commercial aconite is also frequently mixed with the tubers of several other similar but less active species. On the whole, it is one of the most unreliable medicines in the market. Aconite owes its medical value and poisonous qualities to the alkaloid oeonitiTie, which it contains, associated with one or two others, and in combination, probably, with aeonitic acid. It was discovered in 1833 by Geiger and Hesse in the leaves of aconitum na/pelltis, and after- ward, in the root, by Bley. It exists also in several other species in smaller quantity. Although easily sep- arated as an amorphous powder of varying quality, it has proved to be an exceedingly difficult base to prepare in a state of chemical purity. Groves first obtained it in crystals. Duquesnel, and finally Wright and Luff, have distinguished themselves in more recent studies upon it. Crystallized aconite is now offered as an article of com- merce by several chemists, especially by Duquesnel of Paris, whose product is considerably used in the United States. It is in regular rhombic tables, or short four- sided prisms, or often in small crystalline masses, anhy- drous, nearly insoluble in water, but soluble in alcohol, ether, etc. ; usually not quite white, often pale brownish yellow, of a bitter taste, which is followed by an intense prickling of the mouth and fauces (it must only be tasted with great care in a dilute solution). The nitrate is similar to the above, but more soluble. According to the conclusions of Messrs. Wright and Luff {Phai'maceutical Jour, and Trans., 1875 et seq.), aconite contains also another similar and equally poison- ous crystalline alkaloid, but in very minute quantity, namely, paeudaconitine, the alkaloid of aconitum ferox (see below). Both these bases exist also in an uncrystal- lizable condition. Besides these, two inferior bases, aeonine and pseiidaconine, are always found in the course of the examination, but as they are easily produced as decomposition products of aconitine and pseudaconitine respectively, their separate existence in the plant, al- though probable, is not -proved. The ordinary commer- cial, amorphous "aconitine" is an uncertain mixture of all the above. " English aconitine " is said, by German chemists, to be pseudaconitine. Resin, fats, starch, gum, sugar, etc., are ordinary vegetable products found in aconite, but of no medical interest.' Too much value must not be placed upon the various estimates of the yield of aconite root. Fliickiger (" Pharmakonosie des Pflan- ■ zenreiches") gives it as 0.04 per cent., the older authori- ties as much higher. Aconitine, as would be expected, considering its active qualities, has been repeatedly and assiduously studied in its physiological aspects, but, excepting as far as its most evi- dent action goes, much remains yet to be made sure. This is, in part, undoubtedly ascribable to the uncertainty of the composition of many of the preparations heretofore used, but it is in part also due to the peculiar difficulties pre- sented by the drug itself. Its physiological properties appear to be the following ; First. — To disturb and reduce sensation. A mild feeling of prickling or tingling of the extremities and tongue is often noticed after one or two moderate medicinal doses, and is a recognized warning that the limit of its thera- peutic use has been reached. In large doses this symp- tom is one of the first to appear, and becomes very intense, accompanied by diminution of sensation, due to anaesthesia of the surface and, perhaps also, of the deeper parts. Second.^— To paralyze the motor nerves. This is not as prominent an effect of aconitine as the preceding ; and, after moderate doses, may be even unnoticeable, excepting as a slight clumsiness oi the limbs ; but in large ones is evident enough. Both the sensory and motor effects appear to begin, and have their intensest manifestation, at the surface, and to proceed gradually upward along • the nerve-trunks. Whether a portion of them are also due to direct action upon the sensory or motor centres, in the brain itself, is still a matter of doubt, but not unlikely. Thvrd^—Uhe depressing action of aconite upon the heart is one of its most prominent and dangerous qualities, as well as the one for which it is most often given. Slowness and feebleness of the pulse, and consequent reduction of the arterial pressure, are constant results of its administra- tion ; but liow these results are brought about, whether by direct action upon the heart itself, or upon its nerve- centres, or all together, is not known. Much of the weakness attending aconite poisoning — the cold sweats, blindness, syncope, fall of temperature, etc. , which occur — is undoubtedly due to the enfeebled circulation. Fourth. — The respiration is retarded and enfeebled, probably from both peripheral and centric paralysis. Convulsions are not common ; the mind is usually clear. Medicinal Uses. — One rational application of the above effects of aconite is to reduce the frequency and force of the heart's action, when uncomfortably or dangerously excessive. Conditions indicating its use are often present in acute febrile affections, especially at the onset : pneu- monia, pleurisy, bronchitis, scarlet fever, and other ex- anthemata, as well as the febrile excitement attending the passage of the catheter, menstrual disturbances, coryzas, etc., are examples. Marked and grateful relief often follows, very quickly, the use of aconite in these cases ; and, if the condition is a transient one, it effects an apparent cure. In the later stages of dangerous fevers, or when the fever is of an adynamic type, it should never be used. It sometimes relieves the palpitation of exoph- thalmic goitre. Another application, which may be logically deduced from its action upon the nerves, is it» use in certain pain- ful affections, especially certain neuralgias, in which it occasionally gives marked relief — often, unfortunately, not any. The greater the probability the pain is trivial or peripheral in origin, the greater the amount of benefit which may be expected. It sometimes diminishes the vomiting of pregnancy, and may be useful in other cases where diminution of nervous irritability is desired. Empirically, it has been used in many chronic diseases and opprobria mediea without establishing itself in the treatment of any. Locally applied to painful parts, as a liniment or an "oleate," it is often more beneficial than when taken internally. Administration. — Aconite is not often given in sub- stance, but its dose, as authorized by the Pharmacopoeia Germanica, may be taken as a standard for computing those of its preparations. The maximum single dose, according to that authority, is one decigramme (0.1 grm. = gr. jss.), or not more than five times as much in a single day. The officinal preparations are all made by first ex- hausting the root with alcohol, slightly acidulated by the addition of tartaric acid, and then evaporating or otherwise reducing to the standard of strength. They are : 1. Abstract of aconite (a^stractum aconifi), in which the alcoholic liquid is evaporated nearly to dryness, and then standardized by the addition of enough sugar of milk to make the product weigh one-half the amount of aconite used. Full dose, therefore, five centigrammes (0.05 grm. = gr. f). 3. Extract of aconite {exir actum aconiii), made by evaporating to a pilular consistence, and preserved from drying completely by the addition of a little gly- cerine. This product varies in strength from \ to f, according to the season in which the root was gathered, and other conditions. Dose uncertain. 8. Fluid extract of aconite (extractum aconiti fluidum), strength |. Dose, the same as that of the root. A good, but inconveniently strong preparation. 4. Tincture of aconite (tinetura aco- niti), strength f ; the most generally used form. Full dose, two and a haU decigrammes (0.25 gr. = Ht iv. gtt. viij.). Aconitine is not officinal. The old amorphous prepara- tion should never be used. Pure crystallized aconitine, or its nitrate, appears to be more uniform, and may be given in doses of three or four ten-thousandths of a gramme (0.0003 to 0.0004 grm. = gr. li-^ to gr. tW- Oleate of aconitine, a two per cent, solution of the above, is useful for painting painful surfaces, but should be used very cautiously. Liniment may be made by mixing the tincture or fluid extract with other liniments. Fleming's tincture is an old preparation, which, on 67 Aconite. Acromion Process. EEFERENCE HAKDBOOK OP THE MEDICAL SCIENCES. account of its strength (|), should be known; but it is better not to call for it, as it has no advantages over the United States tincture or fluid extract. The above-mentioned are full adult doses, and should not be repeated more than three or four times a day without close watching. In febrile cases it is much better to divide each dose into twenty, and give, say a quarter of a drop of the tincture, every fifteen minutes until some effect is produced, than to give the larger Botanical RBLATioisrs.— The genus aconite contains eighteen species, natives of hills and mountains of the northern hemisphere, like our species, showy, handsome, large-flowered, perennial herbs. Aconitumferox, Wallitch ; Indian aconite, or bish, re- sembles the A. napellus, but has a larger, fuller, and longer root. It contains chiefly pseudaconitine, with a little aconitine. Qualities, similar to ^. wajjeZ^M*/ said to be more active. Supposed to be the source of some of the "English aconitine." Aconiium variegatum, L., has short, roundish, egg- shaped tubers ; Europe. Acomtum Stoerckeanum, Rehb., has its tubers in threes, or even more together. Both the above species occur occasionally in lots of commercial aconite. Aconiium , Japanese aconite, yields Jap- aconitine ; very poisonous ; similar to aconitine. Aeordtum lycootonum, L., has yellow flowers and branched, not tuberous, root ; poisonous. Aconiium lieterophyllum, Atis, a yellow-flowered spe- cies, native of the Himalayas, yields a bitter, not poison- ous alkaloid, atisine; used in India as a tonic and anti- periodic ! The natural order Banunculacem, of which aconite is, medically, the most important member, contains between five and six hundred species, distributed over nearly all parts of the globe, but especially abundant in the north- ern temperate zone. It furnishes our gardens with scores of beautiful flowers — clematids, anemones, butter- cups, the Christmas rose (hellebore), columbines, lark- spurs, monkshoods, peonies, etc. — the medicinal plants being among the number. They are, as a rule, herbs (occasionally soft- wooded shrubs or vines) with large, handsome flowers, alternate, more or less divided leaves, and a clear juice. They have a bitter, often peppery, biting taste, which benumbs the tongue, and frequently leaves it anaesthetic for several hours. Their principal active constituents are anemonin, helleborin, delphinine, aconitine, and berberine ; all but the last are intense poisons, having a strong family likeness. Although it contains some perfectly innocent plants, the general character of the order is poisonous. The following enumeration of its most important genera will give an idea of its qualities : Clematis, poisonous vines, having a benumbing, bit- ing taste, irritant and vesicant, have been used both internally and externally ; now obsolete ; contain a pun- gent stearoptine allied to anemonin. Adonis, a European wild flower, contains "adonin," an active heart-poison resembling digitalin. Thalictruin: several species said to resemble aconite in poisonous properties ; active principle, thalictrin. ArtsmMies (see Pulsatilla) contain a poisonous sub- stance, which finally separates into anemonin and ane- monic acid. Ranunculus : numerous species of ranunculus appear to have properties similar to Pulsatilla, and to contain also anemonin ; not now used. Hydrastis (see Seal, Golden) : not poisonous ; contains hydrastine, berberine, etc. Helleborus (see Hellebore, Black), an active heart- poison, resembling digitalis ; also drastic, like many other ranunculaceae ; contains helleborein and helle- borin. Coptis : not poisonous ; contains berberine and "cop- tine." (See Goldthread.) Delphinium (see Stavesacre) : very poisonous, and somewhat like aconite ; contains delphinine, etc. Aconitum, various aconitines. Cimieifuga (see Snake-root, Black) : active principle and qualities not definitely known. Xanthorrhiza, not poisonous, contains berberine ; obsolete. PcBonia : not active ; properties obscure ; obsolete. Allied Drugs. — Besides those given above in the section upon allied plants, the following may be men- tioned: Veratrum, mride, as a cardiac depressant, acts very much like aconite (and is often employed for similar conditions), as also do the now comparatively little used tartar emetic and tobacco. As a peripheral ansesthetic, the local anaesthesia produced by cold gives much the same subjective results. It is too earhr yet to say whether cocaine will take its place. Carbolic acid, locally applied, benumbs the nerve extremities. There is no other drug known which, taken internally, haf exactly the effect of aconite. W. P. JBolles. 1 For a detailed resume of the chemical history of aconite, see Hiis< man^s paanzenstoffe, 2cl ed., i., 6S4. ACONITE. Toxicology.— The first symptoms of aco nite poisoning are manifested in from five to twenty minutes after a toxic dose has been taken, and are those of an acro-narcotic poison. There is burning in the throat and stomach, and soon a tingling sensation is felt in the extremities, and extends over the whole body ; at the same time there is numbness, proceeding even to anaesthesia of the integument. There is a very brief period of cardiac stimulation, but the pulsations are speedily reduced in frequency and force, then becoming irregular and flut- tering, and finally cease. The respirations are infrequent and shallow, gasping, and then are arrested altogether. The skin is livid, cold, and bathed in a clammy perspira- tion. The eyes are staring, and the whole countenance is expressive of great anxiety. The pupils are, as a rule, dilated, though they may be contracted or normal, and vision is often disturbed. There is extreme muscular weakness. Nausea and vomiting are not infrequently noted, and retention of urine is a common symptom. The temperature, both internal and external, is lowered, sometimes as much as 3° F. (1.1° C). Convulsions sometimes occur, but consciousness is usually preserved to the end, except during the convulsive seizures. Death often occurs in syncope, after some slight exer- tion. The characteristic sign of aconite poisoning is the peculiar numbness and tingling of the integument and . buccal mucous membrane. In cases of recovery, the. effects of the drug have usually almost entirely passed off at the expiration of from three to six hours, and by the following day the patient is in his ordinary health, except that he feels weak and languid. Poisoning by aconite is not a very rare accident, since at the present day the drug is so extensively used in the febrile conditions of childhood that it has come to be regarded almost as a domestic remedy, and a bottle of the tincture majr be found in nearly every house. Many cases of poisoning have occurred also from eating the root by mistake for horseradish, which it greatly re- sembles. Children sometimes chew the leaves of the plant, and are poisoned in this way. Great care should be observed in the employment of aconitine, since toxic symptoms have followed its external application to an extensive surface. It should never be given internally, as very alarming symptoms have followed the ingestion of TiV grain (0.0013 grm.) Recovery has been recorded after the swallowing of an ounce (30 grms.) of Fleming's tincture. Treatment. — After the stomach has been emptied by emetics or the pump, prompt measures must be taken to sustain the action of the heart. The patient should be kept in a recumbent position with the head low, and should on no account be permitted to sit up or stand. Stimulants, ammonia and alcohol, should bie given by the mouth and hypodermically, and external warmth applied to the body. Strychnine, digitalis, or atropine, are to be given for their cardiac effects. There is no chemical antidote to aconite, though astringents and ani mal charcoal are said to be useful. Thomas L. Stedman. 68 REFERENCE HANDBOOK OE THE MEDICAL SCIENCES. Aconite. Acromion Process. ACQUI, Lat. 44-40' N., altitude, 139 metres (423 feet), a Piedmontese watering-place of considerable repute, situated in the beautiful valley of the Bormida, within easy reach of Alessandria by a branch railroad, or of Nizza by stage. The bathing establishment is situated on an elevated plateau, which is planted with mulberry trees, and is distant about a mile from the town, in a southerly direction. The medicinal hot springs at this point do not possess either the thermal force or chemical value of the "Bollente," a spring which is located within the precincts of Acqui itself, but which has fallen into complete disuse. No satisfac- tory analysis has been made of the waters of these springs, but they are said by Baedeker to be not unlike those of Aachen. The chief chemical constituents are sulphur, in inconstant but not inconsiderable propor- tions ; sodium chloride, and earthy sulphates. There are also traces of iodine and carbon dioxide. The cold springs of Puzzolente or Ravanesco, which are situated at some distance from the others, have essentially the same chemical composition. The temperature of the waters varies from 17.9° to 43° C. (64.5° to 109.4° F.). Although mention is made of certain sulphur springs whose waters are used as a beverage, and although the "Grande Vasca" and "Hemicycle" are employed for bathing purposes (both the douche and the ordinary bath), yet the customary mode of employing these medicinal waters is in the form of mud baths. The sediment which collects in the basins of these springs, and which consists partly of soil and partly of sulphur, various salts of slight solubility, and a little organic material, is removed in the month of April to large reservoirs, and thoroughly mixed with the thermal water. The resulting m$,ss is a greyish, soft, unctuous mud. The temperatures of the mud in the different reservoirs are, respectively, 31° C. (88° F.), 43.5° C. (110° P.), and 51° C. (124° F.). The bather does not enter the reservoir, but is laid upon a mattress, and the affected part of the body is then plas- tered with a layer of the warm mud to a depth of five or six centimetres (about two inches), and enveloped in thick cloths. According to the thickness, extent, and temperature of this mud plaster, the immediate effects are an acceleration of the pulse, increased heat of skin, profuse perspiration, redness of the skin, and even, at times, an eruption of one kind or another. These mud- baths are particularly efficacious in the various forms of rheumatism. Sciatica of the worst type is often not only benefited, but in many very rebellious cases a com- plete cure is obtained After the mud has been removed, the patient is put into an ordinary warm bath, of mod- erate temperature, and allowed to remain there for from fifteen to forty-five minutes. The bathing establishments of Acqui are the most ex- tensive to be found in Italy (Bulenburg). Henry Vleiacliner. ACROMION PROCESS, iKjrmiES Am) Diseases of. Very little appears to have been written on diseases and injuries of the acromion process, except in relation to simple fractures of the part. A few cases only of caries and necrosis have been reported ; not more than one case being reported by the same writer. In no instance is there anything more than a brief report of the case ; nothing being said in general as to the symptoms and treatment of these diseases. Nothing appears to have been written concerning new-growths of this process. Injurieb. The principal injury, in fact the only one of impor- tance, to which the acromion process is subject, is fract- ure. This may be simple or compound. Simple Fkacturb. — Fracture of the acromion process is a very uncommon accident. It is, however, the most frequent of fractures of the scapula. Out of 1,901 cases of fracture (Middlesex Hospital) 18 only were of the scapula, and 8 of these were of the acromion process. Out of 1,578 cases of fracture (Pennsylvania Hospital) 14 were of the scapula, and of these 4 were of the acro- mion process. Out of 41 cases of fracture of the scapula collected by Dr. Agnew, 13 were of the acromion pro- cess. Causes. — As the acromion process is the highest point of the shoulder all blows from above impinge upon it, and all violence occurring in consequence of falls on the shoulder, as well as violence transmitted through the arm, is expended at this point. Hence fractures of this process are caused by blows from above, by a fall on the shoulder, elbow, or hand, and by muscular contraction, as in a case reported in the London Medical Gazette for 1846. In this instance the fracture was caused by the sudden contraction of the deltoid muscle in raising the arm quickly. Situation of Fracture. — The acromion process is gener- ally broken at or internal to the acromio-clavicular ar- ticulation, near the junction of the epiphysis and dia- physis. The general direction of the fracture, according to Malgaigne, is transverse and vertical. Nelaton says, however, that it is generally oblique. If the fracture is at or internal to the acromio-clavicular articulation, there will generally be displacement of the outer end of the clavicle. In some cases merely the tip of the pro- cess is fractured off. In four cases seen by Dr. Hamil- ton the point of fracture was as follows : in two cases the bone was broken external to the acromio-clavicular articulation ; in the third case the fracture extended into the articulation and was accompanied by dislocation of the outer end of the clavicle upward ; in the fourth the fracture was in the same place, but there was no dis- placement of the acromion or the clavicle. Diagnosis. — The signs of this fracture vary with the situation. In nearly all cases there will be crepitus, the false point of motion may be made out, and frequently the loss of continuity may be appreciated by passing the finger along the process. . There will be distinct flatten- ing of the shoulder with loss of power in the arm, as in fracture of the clavicle ; the fragment being drawn downward with the arm. If there be no displacement the diagnosis will depend on crepitus and local tender- ness ; there will be partial loss of power in the deltoid muscle, which would become manifest after the patient attempts to raise his arm to the head. Erichsen says that when the clavicle is involved the flattening is more noticeable from behind. Treatment. — Two forms of treatment have been recom- mended. The ordinary form is similar to that employed in fracture of the clavicle. The shoulder is raised by supporting the elbow in a sling, and a pad is placed in the axilla. A body-bandage binding the arm to the side will insure complete immobility. The other form, de- scribed by Dr. Hamilton, requires the patient to be kept in bed : the arm is then carried out at nearly a right an- gle with the body and retained in that position ; by this method the fibres of the deltoid muscle are completely relaxed and the fragment allowed to remain in its natu- ral position. Prognosis. — Bony union is comparatively rare as a re- sult of this injury ; generally the union is ligamentous, with formation of a false joint ; this is particularly the case with fractures of the tip of the process. When the fracture is external to the clavicle it generally unites with a slight downward displacement. When the acro- mio-clavicular articulation is involved, it is doubtful if complete reduction can be accomplished if there be dis- location of the clavicle. When the fracture is internal to the clavicular articulation, if much displacement ex- ists, perfect readjustment will be difficult. Separation of the epiphysis of the acromion process is no doubt the real injury in a great manv cases of sup- posed fracture. As the centres of ossification for this process do not appear until the fifteenth or sixteenth year, and as ossification is not complete until the twenty- second to the twenty-fifth year, it seems very probable that in some cases of supposed fracture resulting in liga- mentous union the separate parts had never completely united. Several pathological specimens confirm this opin- ion. (Holmes states that there is some unexplained con- nection between this imperfect ossification and chronic Acromion Process, Active Principles. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. rheumatic arthritis of the shoulder-joint.) The causes, symptoms, and treatment of this condition are the same as in fracture of the acromion process. CoMPOimD FBACTTIBBS of the acromion process are of very rare occurrence, very few cases having been re- ported. In one instance (Dr. H. N. Fisher, New Tm-k Medical Press, 1860), where the injury was inflicted by a moving crank striking the shoulder, a wound large enough to admit the finger was made, on exploring which it was found that the whole of the acromion process was fract- ured off, the deltoid muscle being torn from its attach- ment. The fragment of bone was removed, and the wound treated as an ordinary severe lacerated wound, a counter-opening being made posteriorly to allow of drainage. There was considerable sloughing, followed by healthy granulation. The patient was progressing favorably when the case was reported. No cases of com- minuted fracture of the acromion are reported. Diseases. The reported cases of disease of the acromion process are so few that it is evident that such disease is very rare indeed. A case of caries was reported by Mr. Ferguson, in the London Lancet for 1843, the first manifestation being pain in the shoulder, followed by the formation of an abscess, which discharged itself and resulted in the for- mation of two sinuses, through which the probe passed to bare bone ; there were also the usual signs of caries. Eventually both sinuses were laid open, and the entire acromion process was found to be carious and was re- moved, a large gap being left between the spine of the scapula and the outer end of the clavicle. The patient made a good recovery, with fair use of the arm, the outer end of clavicle and spine of the scapula being iti close approximation. Two cases of necrosis have been reported, one by Du- play and one by; Friton. In the first case (Bull, et Mini, de la 8oc. de Olm-urg. de Paris) there was death of the en- tire acromion process, and also of a small portion of the outer end of the clavicle. The disease was first mani- fested by pain, swelling, abscess, and the formation of a fistulous tract ; after an interval of some months resection was performed and the necrosed portion was removed. The patient recovered, with good use of the shoulder. Diseases of the acromio-clavicular articulation are dis- cussed under the head of Disease of Joints. Willia/m H. Murray. ACTINOMYCOSIS. This is an infectious disease, characterized by the appearance of new formations which are esjjecially prone to undergo degeneration, and give rise to inflammation and suppuration in the surrounding tissues. The disease is most common in cattle and hogs ; in man it is rare, not more than twenty or thirty cases of its appearance having been recorded. It is only in the past few years that actinomycosis has been recognized as a true specific disease. Bollinger described, in 1877, un- der this name, a disease of cattle chiefly marked by great swelling of the lower jaw. The swelling is due to the formation of large tumor-like masses, which seem always to originate in the alveolar process of the jaw, and by gradual growth to involve the neighboring tissues. The tongue is frequently attacked, and here numbers of nodu- lar growths from the size of a walnut to that of a pea are found. Sometimes these nodules are single, at other times numbers of them are bound together by dense masses of connective tissue. Various names had before been given to designatb this condition ; it was called medullary sar- coma of the jaw, osteo-sarcoma, and was generally known simply under the name jaw sarcoma, and was thou£rht to iDe a peculiar form of sarcoma only occurring here It IS due to the labors of Dr. W. T. Belfleld, of Chicago, that we know the disease termed "swelled head " which IS not uncommon in the cattle in the United States, to be Identical with the disease Bollinger has named actinomy- cosis. •' 70 Bollinger described as peculiar to this disease certain yellowish seed-like bodies which were always found in the pus of abscesses and in the middle of the tumors. These were visible to the naked eye, and when rubbed between the fingers had a greasy feel. Microscropically, they were found to consist of threads similar to the ordi nary mycelium, which terminated in bulbous ends (Fig. 58). Sometimes but one of these bulbs is connected with a thread, at other times there may be several. The forms which they assume are various ; in many cases a filament is connected with a mass of bulbs which branch in every manner {a. Fig. 58). Apparently the highest type of de- velopment is seen in the mulberry-like body in Fig. 59, where all the filaments and bulbs seem to radiate from a common centre. The nodules are found on microscopic examination to be composed of a great number of small masses not larger than miliary tubercles, which they greatly resem- ble. They are composed of small cells similar to the granulation tissue in the centre, and cells more spindle- shaped at the periphery. Each of these small masses is surrounded by a capsular investment of firm fibrous tis- sue. In the centre of each the fungous mass is seated; somewhat as the giant cell usually occupies the centre of the miliary tubercle. By the constant growth and agglomeration of smaller and larger tumors, masses as large as a man's fist and even larger than this are formed. Fio. 68.— Various Forma of Aotlnomyoea. (After Ponfiok.) o, Pecnliiir formation of bulbs; 6, beaded form: c, branohlog of bulbs from bypha. Degenerative processes usually begin early, and destruc- tion of the nodule by necrosis and suppuration takes place. Still the formation of new tumors keeps pace with the processes of decay ; a termination of the disease in this way seems never to be brought about. Both in animals and man the disease usually begins in the alve- olar processes of the jaw, and from here spreads along the base of the skull and the vertebral column. In man, the soft parts of the neck, the lungs, and chest- walls are often attacked. In consequence of the necrosis and at- tending suppuration abscess cavities and fistulee are formed, in which the fungus is always seen. In the pus the recognition of the fungus is as easy macroscopically as microscopically. Here it appears in radiate masses like that shown in Fig. 59 ; these are about the size of a mil- let-seed and of a bright yellow color. The pus from these abscesses and fistulee is always devoid of a fetid odor. The bones attacked are roughened, and an abun- dant formation of osteophytes takes place, leading to for- mations as bizarre as are seen after the maceration of an osteo-sarcoma. The disease spreads by gradual infection of adjoining parts. Metastasis seldom occurs, owing to the large size of the fungus and the diflSculty of its entry into blood-vessels. Ponfick, however, mentions one very interesting case in which the tumor projected into the lumen of the internal jugular vein. In this case there was a metastatic growth about the size of an orange in the right auricle, and numerous metastases in the lungs. REFERENCE HANDBOOK OP THE MEDICAL SCIENCES. Acromion Procesa. Active Principles. The peculiar fungus associated with the disease has been named actinomyces, or ray fungus, from its pecu- liar manner of growth (as seen in Fig. 59). It occupies a place by itself and forms a distinct species, no other allied forms being known in botany. By some it has been placed among the bacteria, but more probably it comes nearer to the hyphamycetes, and the bulbous en- largements may be regarded as analogous to the conidia. It may be regardea as the cause of the disease. Not onljr will inoculations with pieces of tissue or pus con- taining the fungus produce the disease, but it has been cultivated in suitable media outside of the body, and inoculations made with the product of a pure cultivation have been equally successful. Infection seems to take place, in most cases, from the buccal cavity. Israel, Johne, and Ponflck have found the fungus growing in the crypts of the tonsils and in concretions of the lachrymal duct, under normal conditions. It has aJso Fig. 59.— Perfect Form of Fungus. (After Ponflck.) A long filament termluating in bulbs is given ofC at one eide. been found in carious teeth. From these places it could easily be taken into the tissues by means of injuries of the mucous membrane or by the extraction of teeth. According to Israel, the fungus can be aspirated into the lungs, and infection may take place in this way. Among animals, the carnivora seem to enjoy an im- munity. Outside of the body the fungus has never been found ; most probably here it exists on various plants and green food. The honor of having recognized the disease in man belongs to Ponflck. Israel published, shortly after Bollinger's publication, the account of two cases in man, but he regarded it as a peculiar form of septi- caemia, and not as identical with the disease described by Bollinger. Up to the present, no case of its occur rence In man has been recorded in the United States, but judging from the frequency with which it occurs here in cattle it is probable that it has also, without being recog- nized, affected man. Clinically, it can always be de- tected by the presence of the yellow, seed-like bodies in the pus. W. T. Goundiman. ACTIVE PRINCIPLES. A name given to a ^reat variety of substances, chiefly alkaloids and glucosides, existing in drugs, and to the presence of which the drugs owe their peculiar physiological and therapeutical action. Many of the active principles have been isolated and are employed medicinally — either in their basic form or in combination with acids as salts. They possess advan- tages over the crude drug for therapeutic purposes by reason of the smallness of the dose in which they can be exhibited, oftering themselves especially for hypodermic use. But they do not always correspond in their eft'ccts to the plants or other drugs from which they are derived, A single plant, as, for example, opium, may contain a large number of active principles which produce effects upon the animal organism, varying_ among themselves both in degree and in kind. ■ Hence in certain cases it is more desirable to exhibit some preparation of the crude drug rather than any single one of its isolated active principles. Or again, the active principle may be so ac- tive a poison that its administration is inconvenient or dangerous by reason of the extremely minute dose re- quired. AliEAIiOIDS. The substances thus designated are natural organic bases, containing carbon, hydrogen, oxygen, and nitro- gen, which possess an alkaline reaction and a bitter taste and which unite with acids to form salts. They are generally of crystalline form, though some, like nicotine, which contain only carbon, hydrogen, and nitrogen, exist as oily liquids. They are supposed to be substitu- tion compounds of ammonia, but their chemical consti- tution is very complex and but little understood. They are for the most part derived from plants, though some are formed in the animal organism, and attempts have recently been made, with partial success, to produce them'synthetically. They are, as a rule, the active prin- ciples of the plants in which they reside. Several may exist in the same plant, opium, for example, containing at least eighteen or twenty distinct alkaloids, which differ not only m chemical composition but also, more or less, in their effects upon the animal organism. The pure alkaloids are sparingly soluble in water, but soluble usually in alcohol, chloroform, and ether ; their salts, however, dissolve with much more readiness in water. Most of the alkaloids used in medicine are active neu- rotic poisons, being either excitants or paralyzers of the nervous centres. The mode of action of the alkaloids is difficult of explanation. Rossbach believes that they render the cells incapable of taking up oxygen, and thus disturb their function ; and possessing no affinity for the superflcial tissues, as most of the other chemical poisons do, they are carried by the blood in a free state until they reach the nervous centres, upon which their force is expended. The names of the alkaloids termi- nate in English in -ine ; in Latin the termination was f or- rnerly -ia, as morphia, atropia, but at the last revision of the U.S. Pharmacopoeia in 1880 this was changed to ■ina, as morphina, atropina, etc. There is another class of substances derived from plants, many of which are similar in their action to the alkaloids, called glucosides or neutral principles. They are substances which, on boiling with a dilute acid, take up the elements of water and are split into sugar and some other compound, varying in each case with the glucoside used. They are distinguished in the Pharma- copoeia of 1880 by the termination -in in English, and ■inum, in Latin. There are some other substances used in medicine which are commonly called by names having a terminology similar to that of the alkaloids, but which are very different both in their chemical composition and in their therapeutical action from this group of drugs. Thus podophylline is not an alkaloid, but is the resin of podophyllum, and what is usually called ergotine (of Bonjean) is the aqueous extract of ergot. There is also an alkaloid called ergotine, which, however, is not used in medicine. The employment of these incorrect terms should be avoided in prescribing. The following is by no means a complete list of the alkaloids and glucosides, but includes only the more important members of these groups. Only the briefest mention is made of their physical characters and medic- inal uses. For a full account of the physiological ac- tions and therapeutical applications of these active prin- ciples, the reader is referred to the special articles treating of them or of the plants from which they are derived. The principal alkaloids are : Aconitine, apo- morphine, atropine, caffeine, cinchonine, cocaine, co- deine, daturine, hyoscyamine, morphine, physostigmine, pilocarpine, quinine, strychnine, and veratrine. The only glucosides that require any notice are digitalin, picrotoxin, salicin, and santonin. Aconitine, CsoH^tNOt, non-officinal, derived from the root of cbconitum napelhis and other varieties of aconitum. It exists in the form of a white amorphous powder, or of colorless rhombic crystals. It is used ex- ternally for the relief of neuralgia, especially of the fifth nerve. Atropine, CnHsjNOa, officinal, prepared from atropa 71 Active Principles. Arnpuucture. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. belladonna. It exists in the form of "colorless or white acicular crystals, permanent in the air, odor- less, having a bitter and acrid taste, and an alkaline reaction." It is usually exhibited in the form of the officinal sulphate. Atropine is employed to dilate the pupil for the purposes of ophthalmoscopic examination, and in the treatment of keratitis, conjunctivitis, and other affections of the eye. It is used externally to re- lieve superficial pain, and internally in neuralgia. It is one of the most effectual means which we possess to pre- vent the night-sweats in phthisis. It finds further em- ployment in chorea, epilepsy, mania, and in nocturnal incontinence of urine. Daiurina, an alkaloid of datura stramonium, and Hyoseyamina, derived from liyoseya- mus niger, possess almost identical properties with atro- pine, and are ocoasiohally employed for the same pur- poses. The sulphate of hyoscyamine is ofiicinal. Caffeine, CBH10N4OS-I-H2O, officinal, exists in tea, cof- fee, guarana, and other plants. Occurs in the form of "colorless, soft, and flexible crystals, generally quite long, and of a silky lustre ; permanent in the air, odor- less, having a bitter taste and neutral reaction." It is employed as a cardiac stimulant and diuretic, being of especial value in many cases of cardiac dropsy. It also frequently relieves headache. Cocaine, OnHjiNOi, non-officinal, derived from the leaves of erythroxylon coca. Occurs in the form of large colorless prismatic crystals. The hydrochlorate exerts a local anaesthetic and astringent effect, especially on the mucous surfaces. It is also a mydriatic. It is employed as a local anaesthetic in operations upon the eye, and also to reduce inflammation and relieve pain in conjunctivitis, toothache, earache, coryza, and gonor- rhoea. It is likewise of value in superficial neuralgias, pruritus vulvae, and many other affections in which an astringent and benumbing effect is desired. Alkaloids of Cinchona. — There are several of these al- kaloids used in medicine, but we need consider but two here. 1. Quinine, CjoHjiNaOj, officinal, derived from all varieties of cinchona, but existing in greatest propor- tion in cinoTwna flava. It occurs as "a white, flaky, amorphous, or minutely crystalline powder, permanent in the air, odorless, having a very bitter taste, and an alkaline reaction." The sulphate, bisulphate, hydrobro- mate, hydrochlorate, and valerianate are the officinal salts. Quinine has a very wide therapeutic application. It is employed in the treatment of malaria, septicaemia, neu- ralgia, and as a tonic, antipyretic, and microbicide. 2. CincTwnine, C2oH24NaO, officinal, exists in all varieties of cinchona, but in greatest proportion in the pale bark. Occurs in the form of " white, somewhat lustrous prisms or needles, permanent in the air, odorless, at first nearly tasteless, but developing a bitter after-taste, and having an alkaline reaction." Cinch'onine possesses properties similar to quinine, but is weaker. It is employed as a substitute for quinine, chiefly on account of its cheap- ness. The sulphate is the officinal salt. The other offi- cinal alkaloids of quinine are sulphate of cinchonidine, prepared chiefly from cinchona rubra, and sulphate of quinidine, derived principally from cinchona pitayensis. Alkaloids of Opium. — This drug contains a very large number of alkaloids, of which, however, only three deserve special mention : 1. Morphine, CuHioNOa-f-HsO, officinal, occurs as " colorless or white, shining, prismatic crystals, or a crystalline powder, permanent in the air, odorless, having a bitter taste, and an alkaline reaction." The officinal salts are the sulphate, hydrochlorate, and acetate. Morphine is anodyne, antispasmodic, and hyp- notic, and is employed in the relief of cough, asthma, diarrhoea, convulsions, to control vomiting, to relieve pain, and for a variety of other conditions. 8. Codeine, CisHsiNOa-t-HjO, officinal. " "White, or yellowish- white, more or less translucent rhombic prisms, somewhat efflo- rescent in warm air, odorless, having a slightly bitter taste, and an alkaline reaction." It is employed as a hypnotic, and to relieve cough, and is similar to, but weaker in its effects than morphine. It has been specially recommended in the treatment of diabetes. 3. Apemorphine, C„Hi,NOj, The hydrochlorate is offl- 73 cinal. This is not a natural alkaloid existing in opium, but is prepared artificially from morphine by heating with concentrated hydrochloric acid. The salt occurs in "minute, colorless, or grayish- white, shining crystals, turning greenish on exposure to light and air ; odorless^ having a bitter taste, and a neutral or faintly acid re- action." It is employed hypodermically to produce emesis. Vomiting occurs promptly with little or no nausea. It is also highly recommended by some as an expectorant. In very small dose (0.0005 grm. = -^311 grain), it is said to control vomiting. Narceina, nar- ootina, papaverina, and thebaina, are other alkaloids derived from opium, which have been used to some extent in medicine ; none of them is officinal. Thebaine is somewhat analogous in its effects to strychnine. Physoatigmine, CibHjiNsOj, an amorphous, colorless powder, derived from physoatigma venenosum or Cala- bar bean. The salicylate (officinal) and sulphate are the salts used in medicine. The officinal salt occurs as "colorless, shining, acicular, or short, columnar crystals, gradually turning reddish when long exposed to air and light ; odorless, having a bitter taste, and a neutral re- action." It has been recommended in tetanus, but finds its principal employment in ophthalmology. It produces contraction of the pupil, thus opposing atropine. It is employed in the treatment of paralysis of accommodation, and in glaucoma to diminish intra-articular pressure, and to produce rupture of posterior and anterior synechiae. Pilocarpine, ChHibNiOs, derived from the pHocai-piis pennatif alius, or jaborandi. The hydrochlorate is offi- cinal. This occurs in " minute white crystals, deliques- cent, odorless, having a faintly bitter taste, and a neutral reaction." Like the preceding alkaloid, pilocarpine causes contraction of the pupils. It increases very markedly most of the secretions of the body, especially those of the salivary and sweat glands. It is employed chiefly as a diaphoretic, in the treatment of uraemia, puerperal eclampsia, cardiac dropsy, and to promote the absorption of pleuritic exudations. Very small doses have been used to check the night-sweats of phthisis. Strychnine, CnHaaNiOj, officinal, derived from strych- nia nux vomica or strychnos ignatia, occnia as "color- less, octahedral, or prismatic crystals, or a white crystalline powder, permanent in the air, odorless, but having an intensely bitter taste, which is still perceptible in highly diluted (1 in 700,000) solution, and of an alka- line reaction." The sulphate is the officinal salt. Strych- nine is a tetanizing poison. It is employed in spinal and peripheral paralysis (when there is absence of rigidity), in the treatment of functional amaurosis, in constipation, prolapsus ani, in atony of the genital organ, and as a stomachic tonic. Veratrine, CsTHtsNOu, officinal, prepared from the seeds of asagrma officinalis or mratrum aabadUla. " A white or grayish-white, amorphous, rarely crystalline powder, permanent in the air, odorless, of a distinctive acrid taste, leaving a sensation of tingling and numbness on the tongue, producing constriction of the fauces, and highly irritant to the nostrils." Veratrine is not employed internally. It is used externally in the treatment of neuralgia of the flfth pair, of sciatica, and for the relief of rheum^itic nerve-pains. The ointment and the oleate are officinal preparations. GlucoSides. Digitalin, CiHsOa, non-offlcinal, prepared from the leaves of digitalis purpurea. It occurs as small, white scales, or a yellowish-white powder. It is employed for the same purposes as digitalis, but possesses no advan- tages over the officinal preparations of this drug, and its use is not to be recommended. Pierotoxin, CbHuO,, officinal, prepared from the seeds of anamirta panieulata or cocculus indicus, occurs in " colorless, shining, prismatic crystals ; permanent in the air, odorless, having a very bitter taste, and a neu- tral reaction." It is highly excitant of the medulla ob- longata, accelerating and finally arresting respiration. It has been employed successfully to arrest the night REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Active PrlnclpIeB, Acupuncture. sweats of phthisis, and has also been recommended in certain varieties of headache and in epilepsy. Salicin, CisHibOt, officinal, prepared from the bark of salix helix and other varieties of willow, occurs in "colorless, or white, silky, shining crystals, perma- nent in the air, odorless, having a very bitter taste, and a neutral reaction." It is employed as an antipyretic and as a stomachic tonic, but its principal use is in the treatment of rheumatism. .Santonin, dsHisOs, officinal, prepared from the unexpanded flower-heads of a/rtemimif mariiima (san- tonica), occurs in "colorless, shining, flattened, pris- matic crystals ; not altered by exposure to air, but turn- ing yellow on exposure to light ; odorless, and nearly tasteless when first placed in the mouth, but afterward bitter, and having a neutral reaction." Santonin is employed as an anthelmintic. It causes the death and expulsion of round- and thread-worms, but has little effect on tape-worm. It is Said also to be of value in amaurosis. Thomas L. Stedman. ACUPRESSURE. A procedure devised by Sir J. Y. Simpson, of Edinburgh, in 1859, for arresting haemor- rhage from a vessel by means of pressure made by a needle transfixed through the neighbor- ing tissues. The flow of blood through an ar- tery may be arrested in any one of three ways. The vessel may be sim- ply compressed between the needle and some firm tissue, as a bone or the integument, as repre- sented in Figs. 60 and 61. "When the artery lies imbedded in a soft tissue, as in a divided muscle, its occlusion may be accomplished by torsion. This is done by introducing the needle on one side of the vessel, and, when it has passed through a portion of the tissue, twist- ing it around the artery and fixing its point in the tissue in a direction opposite to that in which it was first entered ; or the artery need not be included in the bight of the needle, but the latter may be turned before reach- ing the vessel, the latter then being compressed by the elastic force of the twisted tissues acting upon the needle. A third method, applicable also in cases in which the vessel lies in a yielding tissue, consists in pres- sure between the needle and a slip- knot. The needle is passed beneath the artery, and a loop of fine wire is slipped over its point, the ends of the loop passing over the artery, and being fastened by two or three turns over the shaft of the needle (see Fig. 63). In the case of small vessels, the needles may be withdrawn at the expiration of twenty-four hours ; but when large arterial trunks are occluded, the pressure should be maintained for forty-eight hours at least. The advantages claimed for this method are : the ease and rapidity with which the needles may be applied, no delay being caused in the operation ; the absence of dan- ger from suppuration of the ends of the divided vessels, and non-interference with rapid closure of the wound, no inflammation being excited by the presence of the n6edles in the tissues for so short a period of time. These advan- tages, however, are less manifest at the present time, since the introduction and general employment of antiseptic Fig. 61. Fio. 63. ligatures, and it is not likely that the procedure will ever again enjoy the popularity which it at one time Thomas L. Stedman. ACUPUNCTURE. An operation which consists in the introduction of needles into the body, either as a means of giving exit to the fluid in (Edematous tissues or for the relief of pain in neuralgia and muscular rheuma- tism. It is a method in great vogue in China, and is used by the physicians of that country not only to assuage pain, but to promote reparative action in ulcers and in the treatment of various other affections. It is said to have been introduced into Europe from China, by the missionaries in the seventeenth century. The instrument employed is a round polished needle, having a cylindrical handle of sufficient size to permit of its being readily manipulated by the fingers. It is intro- duced into the tissues by a quick rotatory movement, and is then left m situ for a number of minutes, or even for an hour. Sometimes the insertion of a single needle is sufficient to relieve the pain, but ordinarily half-a-dozen or more are employed. This little procedure may be practised almost painlessly, and is sometimes wonder- fully effective in controlling neuralgic and rheumatic muscular pains. It often fails, indeed, and it seems im- possible to determine beforehand in what cases it will prove serviceable, but certainly no case of lumbago or sciatica should be abandoned until acupuncture, as well as the more ordinary remedies, has been tried. In ana- sarca, when the scrotum and lower extremities are dis- tended with fluid, the patient may experience comfort from a few punctures with a three-cornered surgical needle. The operation should be practised with caution, however, as it is apt to excite an erysipelatous inflamma- tion of the integument. In the treatment of paralysis insulated needles are sometimes used as a means of in- troducing the electric current into the deeper tissues. This procedure has received the name of eleeiro-puneiure. There is another form of acupuncture, called Baiin- soheidtismibs, whicli at one time enjoyed a great popular reputation, and which even now is hot very infre- quently employed. It was devised by a German named Baunscheidt, who is said to have conceived the idea from observing that the irritation caused by the bites of in- sects afforded him considerable relief from the pain of an articular affection from which he was suffering. The instrument employed consists of a cylinder enclosing a button into which are inserted from twenty to thirty short needles. The open end of the cylinder is placed on the integument, and then by means of a handle the button with needles attached is drawn up into the cylin- der compressing a spiral spring ; when the handle is released the force of the spring impels the needles sud- denly and sharply into the skin. The operation may rest here, or an irritating fluid, such as mustard-water or cajeput oil, may be applied to the punctures. This is employed for the relief of neuralgia and muscular pains, and often proves of very great service. There is still another form of acupuncture, if such it can be called, though it is more nearly related to hypo- dermic medication. It consists in the hypodermic injec- tion of pure water, and has received the name of aqua- puncture. Many superflcial pains, even though quite severe, may be relieved by this simple procedure. That the relief thus obtained is not merely the effect of im- agination, is evidenced by the fact that neuralgias of distant parts are not benefited by aqueous injections, but in order to be effectual the operation must be practised at a point as near as possible to the seat of pain. Aqua- puncture is employed in various forms of neuralgia, in lumbago, and in painful functional affections of the ab- dominal viscera. Bartholow states that he has obtained excellent results from the injection of water into the substance of paralyzed and atrophied muscles. From two to four grammes (one-half to one drachm) of fiuid may be used for each injection, and the operation may be repeated if no relief is experienced at the expiration of two or three minutes. Thomas L. Stedman. 73 Adams Go. Springs. Addison's Disease. EBFERENCE HANDBOOK OF THE MEDICAL SCIENCES. ADAMS COUNTY SPRINGS, Ohio. The springs are situated in a picturesque region of Southern Ohio, sev- enty-five miles east of Cincinnati, and thirty miles west of Portsmouth. The name of the nearest station, on the Cincinnati & Eastern Railroad, is Mineral Springs Analysis.— A qualitative analysis by Prof. E. S. Wayne states there are fifteen grains of solid matter to the pint, composed of chloride of magnesium, sulphate of lime, carbonate of lime, chloride of sodium, chloride of cal- cium, and oxide of iron. The water is a chalybeate, and has a temperature of 56° P. (Walton.) O. B. F. ADAMS SPRINGS. Location and Post Office, Glen- brook, Lake County, Cal. Access. —By railroad from San Francisco to Calistoga, seventy-three miles, thence by stage to Glenbrook, twen- ty-three miles, over an excellent road, where teams from the hotel meet the stage to convey guests to the springs, three miles distant. Analysis. One pint contains : Soma. OraltiB. Carbonate of lime i^'^«q Carbonate of magnesia 12.378 Carbonate of soda "^'n^? Carbonate of iron 064 Chloride of sodium B14 Silica 908 Organic matter 351 Nitric acid traces. Salts of potash " Total 24.9S7 Carbonic acid gas, 38 cubic inches. Thbbapbutic Pbopbrties. — This is a valuable alkaline water, diuretic and purgative, and has proved very use- ful in kidney and liver diseases, dyspepsia, and aggra- vated cases of constipation. These springs are located in the pine mountains of Lake County. The geological formation of the sur- rounding country is soft granite, in which are embedded veins of slate, iron, and gravel. The spring issues from a deposit of blue clay and gravel. The climate is salu- brious, with a mean temperature of 85° P. in summer and 15° to 20° above zero in winter. The average annual rain- fall is twenty-five to thirty-five inches. Accommodation is supplied by the Adams Springs Hotel and cottages, hav- ing a capacity for forty people. Pure and soft drinking- water is brought to the hotel by pipes from a distance of one mile. The neighborhood is covered with pine for- ests. Game, such as grouse, quail, hare, and deer, fur- nish amusement for the sportsman. Clear Lake, eight miles distant, stocked with various kinds of fish, and the creeks full of trout, give occupation to the lovers of the piscatorial art. HiSTOBY. — The springs are said to have been discovered accidentally eighteen years ago, by a man named Adams, travelling in search of health. He was suffering at the time from " liver disease," and, having been cured by the water, he spread the fame of these springs. George B. Fowler. ADDISON'S DISEASE (Bbonzed Skin Disease ; Me- lasma Supba-rbnale). Of the above terms the first is to be preferred, for while the peculiar discoloration of the skin is not an invariable characteristic of the affection, the credit of Addison to the discovery of the disease called by his name has never been called in question. DBppiTiON.— A disease characterized by progressive asthenia, digestive disorders, pain and tenderness chiefly seated in the epigastrium, hypochondria, and lumbar re- gions, and an abnormal pigmentation of the skin and mucous membranes. Historical Notice.— The first case of Addison's dis- ease on record is to be found in Lobstein's treatise, " De nervi sympathici humani fabrica et morbis," Paris, 1823 from the English translation of which, by the late Pro- fessor Joseph Pancoast, I take the following extract : " I have myself observed the nerves forming the supra- renal plexus, much thicker in disease, where the capsule renales, which were more than twice as large as usual, 74 had degenerated into tuberculous substance." The pa tient was an unmarried woman, twenty-five years of age, who died in " convulsive spasms analogous to the epilep- tic. . . . Nothing unusual was discovered in the body of this woman but the aforesaid change in the supra- renal glands, and the enlargement of the nerves." Notwithstanding the fact that there is no record of any darkening of the complexion, the above was undoubt- edly a typical case of Addison's disease, in which, more- over, death by convulsions is not uncommon. "The ob- servation regarding the thickening of the nerves in this, the first recorded instance of the disease, is of remarka- ble interest. The second case was recorded in the "Halle Hospital Reports" by Dr. Schotte, in October, 1823, and is published in volume vii. of the Deutsches Archivf. Klin. Med. by Risel, in the course of his article " Zur Pathologic des Morbus Addisonii." The third case came under the observation of Dr. Richard Bright at Guy's Hospital, in July, 1829. It is contained in Dr. Bright's classical "Reports of Medical Cases," and also figures as Case V. in Addison's original memoir. The lesions of the <;apsules were characteristic ; there was no other affection of any consequence, and for the first time in the history of this disease it was noted that the " com- plexion was very dark." A few other cases were re- ported before the year 1855, when Addison published his work " On the Constitutional and Local Effects of Dis- ease of the Supra-renal Capsules," but it was reserved for his sagacity to detect the relation between the well- marked constitutional symptoms of the aflEection, the pe- culiar pigmentation of the skin, and the structural changes in the suprarenal capsules. It IS no disparagement to the memory of Addison to say that the general acknowledgment of his discovery has been retarded by his including in his treatise cases which, at the present day, would be rejected from the category of Addison's disease. Of his eleven cases there are but four uncomplicated with other affections, two complicated, while of the remaining five, one was a case of softening of the brain with advanced kidney disease and tubercular deposit in various organs, among others in one suprarenal capsule, and the other four were cases of widespread carcinomatous deposit, the suprarenal capsules being more or less involved in each. Addison was evidently under the impression that the symptoms of the disease were due to the suppression of the un- known function of the suprarenal capsules, and that, therefore, any destructive lesion of these bodies was capable of causing them, but it is now established that they are invariably associated with one particular lesion, to be described under the head of the Anatomical Charac- ters of the affection. Anatomical Chaeactbbs. — The lesion of typical cases of Addison's disease is a primary, chronic, interstitial in- flammation of the suprarenal capsules, beginning in the medullary substance in the form of gray granulations precisely resembling those of tubercle, which enlarge, coalesce, and undergo caseous degeneration. The in- flammation extends to the cortical substance, and finally obliterates all traces of the primary structure of the or- fans. The fibrous investment alone resists destruction. t becomes much thickened through an inflammatory hy- perplasia, and contracts adhesions with neighboring or- gans, such as the kidney, liver, diaphragm, pancreas, etc. Under the microscope the process is seen to consist of a small-celled infiltration of the connective tissue septa of the organ, which partly develops into fibrous tissue, while the remainder undergoes caseous degenera- tion. The latter change occurs in the form of nodular masses varying from the size of a pea to that of a pigeon's egg, which are at first dry, then undergo puri- f orm softening, and, later, through the absorption of their fluid portions, become converted first into putty- like, and finally into calcareous masses. These last changes are accompanied with much shrinking of the previously greatly enlarged organ. The puriform fluid of the stage of softening has precisely the naked-eye ap- pearance of pus, but under the microscope is seen to con- sist of granular detritus and oil-globules. "The gross ap REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Adams Co. Springs. Addison's Disease. pearances correspond with the stage of the disease. There is nocase on record in which the morbid deposit could be said to be at its earliest stage in any portion of the capsule. In those cases in which the anatomical al- terations are least advanced, the suprarenal capsules are enlarged, indurated, and nodular, the enlargement some- times equalling that of the subjacent kidney, as in a case of my own, recorded in the tenth volume of the " Trans- actions of the Pathological Society of Philadelphia." On section of such an enlarged capsule it is seen to be com- posed of a grayish, semi-translucent substance, in which are imbedded irregular roundish masses of a yellowish color and friable consistence. At a later stage, the yellow nodules soften and the organ is honeycombed with cavi- ties containing the puriform fluid above mentioned. The last stage is that of absorption of the fluid contents of the altered organ and the deposit of cretaceous matter, with coincident shrivelling to a size perhaps below the normal. As to the exact nature of the morbid process, authorities are united in considering it an inflammation which they variously qualify as strumous, tubercular, or caseous. These terms are one and all appropriate, conveying, as they do, to the minds of all pathologists the Idea of an abundant infiltration of cells of low vitality, which partly become organized into fibrous tissue and partly undergo caseous and puriform degeneration. The affection is generally bilateral, although Rlsel (Deutsches Arch, fur klin. Med., vol. vii., 1870) has reported two cases, in each of which the left capsule only was involved. Of equal interest with the morbid changes in the supra- renal capsules are certain alterations in the neighboring nerves and ganglia, of which mention has been made in a number of cases. The significance of these lesions of the nervous system is impaired by the fact that they are not invariably found. Eulenberg and Guttmann {Jour- nal of Menial Science, January, 1879) have collected twenty cases in which well-marked lesions of the supra- renal plexus and the ganglia and nerves of the solar plexus were found, opposed to which are twelve cases in which careful examination demonstrated no change whatever. The positive observations include fatty de- generation of the semilunar ganglion and solar plexus, first observed by Queckett in' one of Addison's cases ; swelling and redness of the nerves of the lesser splanch- nic and ganglia of the solar plexus, atrophy, pigmenta- tion of ganglionic cells, increase- of connective tissue In the ganglia and in the neurilemma of the nerve-fibres ; and, finally, suppuration and caseation of the semilunar ganglia. Notwithstanding the above-mentioned negative exami- nations, It is the opinion of the writer that the abdominal sympathetic Is functionally impaired in every case of Addison's disease. This question will be more fully dis- cussed under the head of the Pathogeny of the disease. Enlargement of the mesenteric and retro-peritoneal glands is frequently observed. In one of my own cases it is recorded that the " mesenteric glands were greatly, and the lumbar glands enormously, enlarged" ("Path. Soc. Trans., Phila.," vol. x.). More or less gastro-intestinal hypersemla and catarrh, with enlargement of the solitary and agminated follicles, are present in every case. A mammlllated condition of the gastric mucous membrane was observed by Dr. Hodgkin in one of Addison's cases. Ecchymoses and hsemorrhagic erosions of the gastric mucous membrane are sometimes present. Enlargement of the spleen is oc- casionally observed ; also an abnormally dark color of spleen, liver, kidneys, and -pancreas, and brownish hue of the peritoneum. These lesions are due to long-con- tinued hypersemia of the abdominal organs. This hy- persemia is sometimes evident at the necropsy, as in the case of my own last referred to, in the report of which it is noted: "The blood was fluid, and on removing the liver It poured out of the inferior vena cava in large amount. There was none of the dryness and translu- cency of tissue so constantly met with in severe cases of anaemia." Many of the symptoms of Addison's disease are attrib- uted by vn:iters to a high grade of general anaemia, with- out any evidence in favor of such an opinion. In several of Greenhow's cases the blood was examined microscop- ically with "virtually negative results." In another case, under the care of Dr. Bristowe, Greenhow exam- ined the blood, and found it "rich in red globules." Wilks states positively that anaemia Is not present. These statements require some modification. In many cases of Addison's disease, especially those complicated with pulmonary tuberculosis, there is a high degree of anaemia, although not to be compared with that found in cases of progressive pernicious anaemia, and In almost all cases I am confident that a careful enumeration of the red globules would demonstrate their deficiency. Long- continued intestinal hypersemia invariably leads to anae- mia, as is commonly seen in the cachexia of heart dis- ease, the cacMxie ea/rdiaqim of Andral. An Increase in the number of the white cells has been observed in sev-. eral cases, but as no figures are given, it is impossible to' say how near the condition approached that of leucocy- thaemla. Free pigment is said to have been found in the blood in one case, by Van den Corput. Dr. W. E. Hughes, of Philadelphia, kindly sent me the following notes of his examination of the blood of a case of Addi- son's disease ; the patient left the city, and the diagno- sis, which was based upon the presence of all the charac- teristic symptoms of the disease, was never confirmed by a necropsy : _ " Addison's disease, two years' duration. Pigmenta- tion of skin and mucous membrane of mouth ; no ema- ciation ; moderate anaemia ; great weakness. Red cor- puscles, 5,180,000 ; white corpuscles, 9,000 per cubic milli- metre. Red are a little below normal in size and a trifle pale, well shaped ; some few are deeply pigmented, the pigment granular. Floating free in the blood-plasma are irregular granules of black pigment, from one to four times the size bf red corpuscles. They are not at all numerous, not more than two in field at one time ; some- times not more than two on the slide." The abnormal surface pigmentation has its seat in the skin and mucous membrane of the buccal cavity, includ- ing that of the tongue ; It has been said also to attack the vagina, but this Is not established. The pigment is de- posited in the youngest layers of the rete Malpighii, in contact with the papillae. It appears both as a diffuse coloration of the cells and also in the form of distinct granules in the cells, or free ; in the latter case It is supposed to be left after the dissolution of the cells. It rarely appears in the corium, though sometimes branched, pigmented connective-tissue cells are found. The parts of the external surface most deeply pigmented are those which, under normal circumstances, are the seat of oft-recurring hypersemia, either from atmospheric influences or friction, such as the cheeks, neck, and backs of the hands. There is also a special tendency to the deposit of pigment in those parts where It is found normally in greater amount, such as the nipples, genital organs, and axillae. In well-marked cases, it pervades the entire cutaneous surface, being deeper in the parts just mentioned. The discoloration, at first of a grayish hue, deepens into a more or less deep brown, in which there is, in some cases, a yellowish or greenish hue. The color depends to some extent upon the nor- mal complexion of the patient. It Is most striking, on account of its incongruity, when the patient is naturally fair, with light hair and blue eyes. It has been noted in numerous cases that the heart was abnormally small, and in several that it had undergone fatty degeneration. The urine is normal in the majority of cases. The most careful study of the urine in any single case was made by Dr. Thudichum, for sixty-five consecutive days, in a patient of Dr. Burdon-Sanderson. Without com- plicating fever or diarrhoea, there was a great diminu- tion in the daily amount of urine, it being reduced more than one-half ; the specific gravity was l.OSO, and up- ward, and the reaction acid. The observations were chiefly directed toward the determination of the per- centage of uric acid as well as uromelanln, omicholln, and uropittin, three products of decomposition of the urinary pigment of which the first is the most Important. 75 Addtsoa's Disease. Adenoma. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. It has almost the same chemical composition as the melanin of the choroid, and of melanotic tumors, and, like the pigment in the skin in Addison's disease, is iron- free. Thudichum found that these pigments were greatly reduced in amount, the uromelanin never rising above one-twelfth of the normal, and he appears to be of the opin- ion that the diminution in the amount of these pigments may be in relation to the excess of pigment in the skin. Symptoms.— The sum of the symptoms of Addison's disease may be divided into four parts : a progressive asthenia, disorders of digestion, an abnormal pigmenta- tion of the skin and oral mucous membrane, and pain seated chiefly in the lumbar and abdominal regions. Of these, the asthenia is the first to appear. In all histories of this disease the patient has been compelled to aban- don his usual occupation by muscular weakness, and where there is no complication with other wasting dis- ease, this prostration is unattended, at least in the early stage, with any marked diminution in the volume of the muscular and adipose tissues. Symptoms referable to disordered digestion soon become prominent, such as anorexia, nausea and vomiting, constipation alternating with diarrhoea, and epigastric tenderness. Cardialgia is often complained of, and the ingestion of food is sometimes followed by painful meteorism. The pulse is remarkably weak and small, and usually slightly accel- erated. Dyspnoea is produced by the slightest exertion such as sittmg up in bed. Cephalalgia, vertigo, and men- tal hebetude are often observed at an early stage, also pain and tenderness in both hypochondria, and in the back, loins, and epigastrium. This tenderness on pressure was a prominent feature in two cases that were under my care at the Episcopal Hospital, Philadelphia. In the report of the first I noted that "at times there was great tenderness about the umbilical region, and on one occa- sion, after palpating the abdomen, the patient uttered lohd cries for ten or fifteen minutes, and seemed in great agony" ("Trans. Path. Soc, Phila. ," vol. v.). In the second of my cases, "the pain was latterly most severely felt in the left lumbar region, in which situation there was also a great degree of tenderness on pressure " (" Trans. Path. Soc, Phila.," vol. x.). In the first of these cases nothing was found at the necropsy to account for this remarkable tenderness ; in the second it might have been due to the great tumefaction of the lumbar glands. As the disease progresses, restlessness, iactitation; delirium, sometimes maniacal, delusions of sight and hearing, at- tacks of epileptiform convulsions, and uncontrollable vomiting make their appearance ; also attacks of pro- longed prostration and loss of consciousness ; some- times a condition of collapse that has been compared by "Wilks to that of cholera. Contrary to the usual frequency of the pulse in collapse, a remarkable diminution in the number of the heart-beats has been observed in several cases (Risel mentions seven), and this without any dis- ease of the brain or important cardiac disease. In a case reported by Cholmeley {Medical I%mss and Gazette, 1869, vol. ii., p. 319) in which death was preceded by profound collapse, dyspnoea, and convulsions, the pulse fell to thirty-six per minute. The date of the appearance of the pathognomonic discoloration of the skin is very varia-. ble. It may either precede or follow the constitu- tional symptoms, or the disease may terminate fatally without its manifestation. Greenhow has collected a number of cases illustrating the erratic appearance of this, the only pathognomonic feature of Addison's dis- ease. In many cases the symptoms have pursued an irregularly remittent course. The digestive disorders may temporarily cease, the appetite improve, the muscular power increase, and the skin become decidedly paler. This is invariably followed by a fresh exacerbation, after which the status of the patient is on a lower plane than during the previous remission. The words of Dr. Weir Mitchell, as applied to the course of locomotor ataxia, are here appropriate: "I have," says he, "else- where compared the progress of Duchenne's disease to that of a man who has an inevitable staircase to descend. He may linger or go back, but the descent is still to be taken, and the best he can hope for is to go down slowly 76 and with long pauses and rare retrogressions " (" Pro- ceedings Phila. County Med. Soc," vol. ii.). Pathogeny. — The symptoms of Addison's disease being invariably associated with a destructive lesion of the supra- renal capsules, vi[ere at first naturally attributed to sup- pression of the function of these bodies. Brown-Sequard first endeavored to ascertain the effect of removing the capsules from animals. The animals speedily died with, according to his statement, the accumulation of pigment in different parts of the body. On the other hand, a num- ber of other experimenters, such as Harley, G-ratiolet, Philippeau, and Martin Magron, have removed the supra- renal capsules without the supervention of death or melanoderma. Again, well-marked cases of Addison's disease have been observed, as above stated, in which but one capsule was involved in the morbid process. Finally, instances are on record of congenital absence of the supra- renal bodies ' without the cutaneous pigmentation or other symptoms of Addison's disease. The attention of pathol- ogists was next directed to the ganglia and nerves of the abdominal sympathetic, and experiments instituted upon animals to determine the effect of their removal or sec- tion. Pincus invariably found, after extirpation of the solar plexus, alterations in the mucous membrane of the stomach and upper part of the small intestine, consisting of hyperemia, blood extravasation, and ulceration. These were absent in control experiments, in which the same operation was performed minus the removal of the solar plexus. "When the deeper plexus encircling the aorta was removed, the alterations in the mucous membrane of the stomach were absent, but the whole of the small and large intestine, including the rectum, was affected. En- largement of the liver and spleen was also observed by Budge after section of the abdominal sympathetic. With the results of these experiments corresponds the invariable intestinal catarrh of Addison's disease, with enlargement of the solitary and agminated glands, and sometimes ul- ceration and ecchymosis. The theory of the pathogeny of Addison's disease at present accepted by many authori- ties, notably by Risel, and the one to which I adhere, is that of a paralytic dilatation of the abdominal blood- vessels, and it is not necessary that there should be a de- structive lesion, such as fatty degeneration or atrophy, of the solar plexus and semilunar ganglion, in order to pro- duce vaso-motor paralysis in the area of their distribu- tion. Irritation of a sensory nerve produces vaso-motor paralysis in tlie irritated region, and the well-known ex- periments of Goltz " (Klopf versuch) have shown that irri- tation of the intestines produces complete vaso-motor paralysis of their blood-vessels, causing thereby so great an accumulation of blood that the animal shows symp- toms of syncope, the same as if it had been bled copi- ously.^ The irritation of the numerous nerves of the suprarenal capsule produced by inflammation with new formation of tissue and subsequent softening, such as exists in Addison's disease, is transmitted to the semi- lunar ganglion and solar plexus from the beginning of the deposit in the medullary substance of the suprarenal capsule, and later by direct extension of the inflammatory process to these nerve-centres. By this means a vaso- motor paralysis of the intestinal vessels is produced, as in the experiments of Goltz, except that, unlike in the latter case, it is constant. This constant hypersemia of the in- testinal vessels leads to enlargement of the solitary glands and Peyer's patches so constantly found in Addison's dis- ease, and, when more intense, to catarrh and ulceration of the stomach and intestinal mucous membrane. It ac- counts for the dark color of the liver, spleen, kidneys, and pancreas so often observed, as well as for the brown- ish hue of the peritoneum noted in a few instances. In- directly it explains the anaemic and dry condition of other parts of the body, and fully accounts for the great mus- cular weakness, syncope, gastro-intestinal disturbance, dyspnoea on slight exertion, and small radial pulse. These symptoms have been, and still are, attributed to a high grade of general anaemia, such as exists in progres- sive pernicious ansemia ; and this is due to the fact that many of the symptoms in these two affections are iden- tical. Repeated examinations of the blood have, however, REFERENCE HANBBOOK OF THE MEDICAL SCIENCES. Addison's Disease. Adenoma. demonstrated that the reduction in the number of the red corpuscles in Addison's disease is trivial compared with that found in cases of progressive pernicious anaernia. The symptoms resembling those of pernicious aneemia, such as dyspnoea on slight exertion, syncope on assuming the upright posture, rapid, small, and feeble pulse, are due to an insutflcient supply of blood, albeit of fair quality, to the supra-diaphragmatic portion of the trunk. The permanent changes in the muscular tissue of the heart are to be attributed to the same cause, oligaemia. Etiologt. — The affection is much more common in the male sex and among the laboring classes. In one hundred and eighty-three undoubted cases tabulated by Greenhow, one hundred and nineteen Tvere males and sixty-four females, and more than nine-tenths of the whole number were engaged in laborious physical work. Several cases have been associated with psoas or lumbar abscess, caused by injuries of the spine. In others, devoid of such spinal complication, the origin of the disease has been attributed by the patient to over-ex- ertion of the spinal muscles. Such was the fact in one of my own cases, the patient's first symptoms having been weakness and pain in the back immediately follow- ing the occupation of weeding her garden. As regards age, the majority of cases occur between the ages of twenty and fifty, that is to say, during the most active period of adult life. BiAGNOSis. — When the disease is primary, the con- stitutional symptoms well-marked, and the discoloration of skin present, the diagnosis presents no difficulty to one who has studied a single case of the disease. On the other hand, when the constitutional symptoms are well pronounced in a primary case, and the bronzing of skin not yet developed, the diagnosis is only to be made by the absolute exclusion of other wasting diseases, espe- cially cancer of abdominal organs and progressive per- nicious anaemia. When the disease is secondary to psoas or lumbar abscess, the diagnosis is often very difficult, and especially so when there is the further complication of amyloid kidney disease which 'is so apt to be associated with extensive suppuration. Several years ago there came under my care at the Episcopal Hospital, a case of lumbar abscess with several open sinuses leading to carious vertebrae. The general surface of the body was of a dark, dingy hue, and the orifice of each sinus was surrounded by a broad, deeply pigmented ring. The case had previously been at the tJniversity Hospital, where secondary disease of the suprarenal capsules had been suspected. The autopsy showed these bodies to be perfectly normal. A dingy discoloration of the skin is not uncommon in amyloid disease of the kidney, as first pointed out by Grainger Stewart. The discoloration of skin, although not the most essen- tial characteristic of the disease, is justly regarded as its most important diagnostic feature. It is to be dis- tinguished from melasma gravidarum, pityriasis versi- color, lichen, and pigmentary syphilides, and this is readily done by anyone faimlliar with these affections. The melanoderma of phthisical patients presents more serious difficulty. Although the latter is often confined to the face and does not invade the mucous membrane of the buccal cavity, the difficulty is a real one and is augmented by the fact that pulmonary tuberculosis is the most frequent complication of Addison's disease. The seat of the melasma suprarenale upon the face and neck, the dorsum of the hands, areola of the nipple and about the umbilicus, in the axilla, groin, and genitals is characteristic. Its outline is never circumscribed as in other pigmentary affections, but gradually fades into the surrounding dingy integument. Upon the darker patches also are frequently seen black specks resembling moles or freckles. Another discoloration of the skin liable to be confounded by the inexperienced with that of Addison's disease, is sometimes seen in badly nour- ished paupers, of dirty habits, whose skin is the abode of vermin. 'The pigmentation shows itself in the form of patches separated by healthy skin ; the epidermis is often roughened, and the discoloration more marked upon the trunk than on the face and hands. The skin is also often marked with the nails on account of the in- tense itching. Under the microscope, the particles of pigment in this affection are found in all the layers of the epidermis, instead of being limited, as in Addison's disease, to the deeper layers of the rete Malpighii. The pigmentation of chronic malaria} poisoning is dis- tinguished from that of Addison's disease, not only by its distribution, but by the history of the case and the frequent presence of splenic enlargement. Chronic icterus is distinguished by the presence of pigment in the ocular conjunctiva and in the urine. The pulse also is rapid in Addison's disease, whereas in icterus it is habit- ually slow. Prognosis. — The prognosis is invariably fatal as to the ultimate result, but the occasional remittent charac- ter of the affection is to be borne in mind in making pre- dictions as to the duration of the disease. A case seen during the period of exacerbation may lead to the progno- sis of a speedily fatal result, but the worst symptoms may disappear and be followed by a prolonged period of re- mission. Sudden death without preceding exaiJerbation is sometimes observed, the fatal result being apparently due to syncope. 'TkeaTmbnt. — The cessation of work is the first thing to be insisted upon in the way of treatment, and during the exacerbations, strict confinement to bed. An im- mediate mitigation of the symptoms has often followed the admission to the, hospital of a patient who, up to that time, had been endeavoring to resist the gradually in- creasing weakness. A moderate amount of stimulants is generally well borne ; but cod-liver oil, which might seeni appropriate on account of the strumous character of the affection, is, as a rule, not tolerated. Remedies to allay irritability of the stomach are frequently indicated, such as ice,. lime- water, carbonic acid water with brandy, bismuth, creasote, hydrocyanic acid, and small doses of opiulh. Massage and faradization of the cutaneous sui;- face are well worthy of a trial, in order to derive from the abdominal vessels. Cathartics are to be avoided, as profound depression has often followed their employ- ment in this disease. When constipation is troublesome, enemata are to be made use of. The diet should be sim- ple, but nourishing, consisting of soups, milk, eggs, meat jelly, and the like. Peptonized foods and koumyss are also indicated. Frederick P. Henry, 1 Martini: Comptes. Kpndus de TAcad. des Sci., 18B6, tome xliii., p. 1053. John Kent Spender; Brit. Med. Jour., September 11, 1868. ^ Vague und Herz., Virchow'B Archiv, vol. xxvi. 3 " II en resulte une dilatation des vaisseaux abdominaux qui constituent en quelqne sorte un bassin de reserve ou de derivation pouvant loger la moitie de la masse totale du sang " (Demontroud, Th^se de Paris, lb78). ADELHEIDSQUELLE. This spring is situated in Up- per Bavaria, at an elevation of 774 metres (3,540 ft.), near the foot of the " Benedictenwand," and about four miles from the station Tolz. The water is mostly bottled for export. It is used internally, and has acquired renown for its beneficial effects in cases of scrofula (in children), in glandular swellings, struma, chronic metritis, and -oophoritis, and in tumors of the female sexual organs. Von Nussbaum speaks of the water in very high terms ; it having produced markedly beneficial effects in some of the worst cases of scrofulous bone disease which had come under his care. Among one thousand parts of this water, by weight, the solid constituents represent a total of 6.01 parts, and'among these the most important are : Sodium chloride 4.956 Sodium iodide 0.0286 Sodium bromide 0478 Sodium carbonate 0.0S09 (Carbon dioxide, 409.3 o.c.) Temperature, 11.2 " C. (62 ° F.). (Bulenburg.) H. F. ADENOMA. The adenoma is a glandular tumor, con- forming, in its histological structure, with the general type of gland-tissue, and originating in glandular epi- thelium. We cannot describe any particular cells or arrangement of cells as peculiar to this tumor any more than we can regard any special cells as peculiar to physi- ological glandular structure. The adenomata differ 77 Adenoma. Adenoma, REFERENCE HANDBOOK OP THE MEDICAL SCIENCES. among each other ia structure as much as the structure of the liver differs from that of the lachrymal gland. Generally speaking, the epithelial cells of the tumor are arranged in alveoli, with a central lumen, the alveoli being separated from each other by connective tissue, in which the nutrient vessels and lymphatics are con- tained. The epithelial cells may be cylindrical or cu- boidal their shape depending somewhat on the character of the cells of the gland in which the tumor has origi- nated. Their arrangement in alveoli, with a central lumen, may be regarded as that which gives the adenoma "We cannot regard every new formation of glandular tissue, every glandular hyperplasia as an adenoma, and sometimes it is difficult or impossible to say whether we have to do with a simple hyperplasia or a tumor. Nature does not create with special ref- erence to the classification of her products, and we come here into the difficulty which is constantly met when we attempt to bring such products under an arti- ficial classification. A gland which is increased in size in consequence of excessive growth or a chronic in- flammatory condition, cannot be called an adenoma, but belongs simply to the hyperplasias. In the same way we must consider those formations in mucous membranes which frequently de- velop in consequence of chronic inflamma- tions, and take the form of tumors. These are local new formations of tissue, which project above the surfaces in the form of polypi or pap- illary masses. This growth commences in the connective tis- sue, and the epithe- lium also takes part, in that, by the increase of the surface, the covering epithelium must also increase. If there are glands present, their ducts are usually stopped up, and cysts are formed with papilla- "i I "0 e' I i V* - "^ -«««• I ■» f- ^ • , » ry projections within them On the other ^"'' 63-— Adenoma of the Kicjney. a, Normal structure of the kiiiney ; 6, adenoma ; c, 1 /q' +V, a i^a sheath of connective tissue investing the tumor and separating it from the kidney ; d, nana, mere are aae- colloid masses in the acini of the tumor, (x ■JO.) nomata which arise in the mucous membranes and which have the form of polypi, and may greatly resemble the simple polypi in structure. Clinically, of course, the two processes can be distinguished, since the simple polypi are usually multiple, and disappear spontaneously when the cause' which led to their formation (i.e., chronic inflamma- tion) is removed. The separation of the adenomata from many other tumors is often difficult. If the devel- opment of glandular vesicles with formation of cavities must be regarded as the essential moment to justify us in naming a tumor an adenoma, this development cannot take place without the formation of new connective tissue with vessels. Since the pathological features of a tumor only consist in the variation of the arrangement of its tissue from that of the normal tissue, we find in the adenoma that at one time the formation of the epithelial elements becomes most prominent, at another that of the connective tissue and vessels. Mixed forms are here com- mon. When the development of connective tissue is ex- cessive, far beyond what we find in a normal gland, it must receive some recognition in naming the tumor, for it is as truly new-formed as the epithelial part ; in such cases we speak of an adeno fibroma. When this neatly formed connective tissue is especially abundant in cells. and represents an embryonic tissue, we speak of an adeno- sarcoma. Though the adenoma may have the most typical gland- ular structure, it is always, when considered as an en- tirety, an atypical formation. As a rule it represents a circumscribed formation and macroscopically differs in consistence and color from its surroundings. These growths usually form nodular tumors, which arise with in glands or in mucous membranes which contain glands. In some cases only a small portion of the gland is taken up by the tumor, in others the whole is inyolved in its growth. The adenoma usually differs in its histological structure more or less from the structure of the tissue in which it originated. This is well seen in the figure here given, which represents an adenoma of the kidney. Nothing could be more typical of glandular structure than the tumor, yet instead of the typical kidney struct- ure with its various tubules and special structures, as the glomeruli, we have here simply the structure of a tubular gland, the tubules being of different sizes and lined with a simple cuboidal epithelium. The tumor from which the specimen was taken was of the size of a walnut, located in the left kidney, and entirely surrounded by normal kidney structure, from which it was separated by a distinct capsule of connective tissue. In other adenomata of the kidney we may find, in place of the cuboidal, long cylin- drical cells. In one lihat I examined, which came from the collection of Rokitan- sky, the cells were cylindrical in shape, and differed greatly in size, some being three times as large as the others. We never find, however, in an adenoma of the kid- ney, the typical kid- ney structure with its glomeruli and tu- bules. This departure from the type of the mother tissue is also seen in other places. In adenoma of the large intestine, where this form of tumor is frequently met with, in place of the simple crypts of Lieberkuhn, we have branched and twisted tubules, with an epithe- lium identical with the ordinary cylindrical epithelium of the intestinal tract. Fig. 64 shows a secondary nodule in the liver from an adenoma of the rectum. The general type of the glands of Lieberkuhn is well shown, though in one place the buds given off and the union of the two tubules show the tendency to a departure from the type. We sometimes find in the liver small circum- scribed nodules about as large as a miliary tubercle, which differ markedly from the liver-tissue. The cells composing them are larger than the liver-cells, are paler, finely granular, and wanting in the ordinary bile pigment in cases where from cirrhosis or other cause the liver-cells are strongly pigmented. This latter fact would show that the cells did not serve the same physiological purpose as the liver-cells. The lines separating the cells of the nodule are more sharply marked than in the nor- mal tissue. The typical arrangement of the liver-struct- ure, the framework of cells branching out from the hepatic vein, with capillaries between them, is wanting here. On the contrary, the cells are in some places ar- ranged in masses, in others they seem to be irregularly arranged around a lumen, as in the ordinary tubular gland. This would seem to represent a return of the \^ » -v. ■ t i 78 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Adenoma, Adeiiomat complicatea liver structure of the higher vertebrates to the simple tubular form of gland which is found in some reptiles. Other large adenomata have been de- scribed in which a distinctly tubular arrangement was found. Whether such larger tumors represent a further stage of development of these small microscopic nodules is not known. The latter seem to have escaped the at- FiG. 64. — MetaBtaBis in the Liver from an Adenoma of the Rectum, a, a. Acini of tnmor ; i, blood-veasel. { x 280.) tention of writers on this subject, and should be con- sidered as true adenomata. There is one adenoma which, from the frequency of its appearance, and its importance as concerning the life of the patient, merits a special description. This is the adenoma of the ovary. We owe to the works of Wal- deyer and Klebs the recognition of this form of tumor in this organ. It generally appears under the form of multilocular cysts, which contain a thick viscid fluid of about the consistency of starch paste. The contents may be colorless, or have every shade of color up to a dark brown, this color depending, of course, on haemorrhages which have taken place within the cysts. The larger of these cysts are lined with a single layer of cuboidal or cylindrical epithelium. In other places, where soft medullary masses are found, and where, macroscopically, no cysts are to be seen, we find a different structure. Here, under the microscope, we find small cysts lined by a membrane in which are indentations similar to simple tubular glands ; these pouches are lined with cylindrical epithelium. There are long papillary projections of the lining membrane into the cysts, and Wilson Fox supposes that the numerous cysts are formed by the union of these papillse, either with each other or with the cyst- wall. Klebs, on the other hand, supposes they are formed from dilatation of the small pouch- like glands of the lining membrane. Pfliiger has pointed out the glandular structure of the ovary, and Spiegelberg and Langhans have shown in it, even after jbirth, residues of its em- bryonic glandular structure, and there is little doubt that the adenoma develops from this tis- sue. Other adenomata are found here which are com- posed of cysts lined with distinctly ciliated epithelium. Although frequently in these tumors nothing of the ovary can be found, there is little doubt that they do not develop in this organ, but at a little distance from it, in the parovarium. There are other cysts in the ovary which are formed from simple dilatation of the Graafian follicles ; but these, as we have shown, should be ex- cluded from the tumors. (See Art. Tumors.) All of the forms of adenoma of which we have spoken differ more or less in histological structure from the parent tissue ; but there are others which conform in every detail with the tissue in which they arise. The thyroid body is very frequently the seat of adenoma formations ; these appear under the form of distinctly circumscribed nodules, separated from the rest of the gland by a sheath of connective tissue. The colloid formation common to the gland is always seen in these adenomata. There is an hypertrophy of the gland caused by a diffuse hyperplasia of all parts of it, which must be separated from the tumors. This appears to depend upon the existence of a distinct miasm, which is found only over a limited geographi- cal area. It can be distinguished from the adenoma by its affecting all parts of the gland, and by its spontaneous recovery when the pa- tient removes from the miasmatic region, or under the use of suitable medication. Here we have a case in which, from a microscopic examination alone, we cannot say whether we have to do with a hyperplasia, a tumor, or normal glandular tissue. Many tumors of the mamma combined with the formation of cysts have been described under the name of adenoma. In such cases the tumor is generally a fibroma or sarcoma, which has grown into the acini and ducts of the gland in the shape of papillary projec- tions. These, of course, will be covered with lining epithelium, and there must be some growth of the epithelium in consequence ; but this is only secondary, and the tumor should be considered as a connective-tissue formation. From some descriptions of circumscribed tumors, in or adjoining the gland, which are almost entirely epithelial in character, we must believe that they are adenomas. Regarding these circumscribed adenomata, Billroth says (" Krankheiten der Brustdrusen," p. 76) that he has never seen a tumor which, after exact histological anal- FlG. 65. — Miliary Adenoma of the Liver. At a the cella are arranged around a lumen; b, &, blood-vessels, (x 380.) ysis, allowed only the interpretation of a pure circum- scribed adenoma to be given it. Cornil and Ranvier take almost similar grounds. There are a few cases on record in which the glands at an early age, the time of puberty or a little later, grew suddenly to enormous dimensions. In one case observed by Billroth, in a virgin of fifteen years, the breasts grew to mammoth proportions in two and one-half months ; the left meas- ured 23 inches in circumference, and in its largest part 79 Adenoma. Aerotherapeutlcs. EEFERENCE HANDBOOK OF THE MEDICAL SCIENCES. was lOi inches In diameter. Tliere is little known about the histological structure in these cases. The one case investigated by Billroth was complicated by the forma- tion of numerous fibroid tumors in the gland. There was, however, between the tumors an abundant forma- tion of glandular tissue which was similar to that of the normal mamma. Such cases are set down as diffuse adenoma of the breast. The rapidity of growth of an adenoma differs in the various parts of the body in which it has its seat, and the same holds true for its malignity. There are few which can be strictly considered as benign tumors ; there are several cases reported in the literature, of fatal metas- tases from the adenoma of the thyroid. In the sweat, sebaceous, and lachrymal glands they grow slowly and usually remain local ; in the lachrymal gland they may reach a large size, and by the displacement of the eye produce great disfigurement. Some, as the adenoma of the ovary, never produce metastasis, though they may endanger life by their immense size. There are few tumors which are more malignant than the adenomata of the digestive tract. They have all the properties of ma- FlQ. 66. — Adenamn Destniens of the Stomach, a. Mucosa j 6, sub- mucoBa ; c, muscular coat ; d, peritoneum ; e, £, e, the acini of the tumor. (FromZiegler.) (x40.) lignant tumors ; they infect surrounding parts and cause metastases. In the intestine the different coats are suc- cessively attacked, and perforation often results. Zieg- ler, in recognition of these destructive properties, has given the name of adenoma destruens to these forma- tions. The figure here given shows such an adenoma of the stomach. As might be expected from the simi- larity of their respective histological structures, transition forms between the carcinoma and adenoma are frequently seen. The typical glandular structure of the adenoma has only to become atypical and we have the carcinoma. In- deed, the relation between the two has always seemed to me to be similar to that between the fibroma and sarcoma, the former representing the typical connective-tissue tumor, and the latter the atypical. Just as we can have every transition stage between the fibroma and the sar- coma, so we can have the same condition of things between the adenoma and carcinoma ; and just as we speak of the fibro-sarcoma in such cases, so we can designate these glandular tumors by the term adeno- carcmoma. Such tumors are frequently seen in the uterus and digestive tract. One part of the tumor will represent the typical arrangement of the adenoma, tn.; alveoli of epithelial cells with a central lumen, and the other part the carcinoma with the solid irregular masses of epithelium growing into the tissue in all direc- tions. All sorts of degenerations are common in the adenoma, and hsemorrhages are frequently met with. In one point they differ most markedly from the hyper- plasias, and that is in their never being able, no matter how typical of gland structure their tissue may be, to exercise the physiological function of a gland. We' know very little with regard to their aetiology ; perhaps they will bear out Virchow's theory as to irritar tion less well than any other tumor except the teratoma. For some, as the adenoma of the axilla, where a tissue is found corresponding to that of the mamma, or the sub- sternal tumors in which a tissue similar to that of the thyroid body is found, it is probable that the germinal theory of Oohnheim gives us the true explanation ; in the one case the axillary tumor depending on a formative defect in the embryonic development of the mamma, and in the other on portions of the embryonic structure of the thyroid gland being left behind in the ascent of the gland. The writer once saw an adenoma as large as a hen's egg seated alongside the lumbar vertebrae, outside of the peritoneum. The tumor was composed of acini, lined with long cylindrical cells ; there were metastases in the livef which showed the same structure. Here it was evi- dent that the tumor was due to an error of formation at a very early stage of embryonic life. It would hardly seem possible that such a tumor could develop from the connective tissue ; there could be no irritative influence at work here. We sometimes find adjoining the various organs, some- times at a distance from them, small formations which resemble the larger organ in every respect. These are known as supernumerary glands, and are most commonly found in the neighborhood of the spleen, suprarenal cap- sules, etc. At other times parts belonging to one organ may be enclosed in another, as portions of the pancreas in the mucous membrane of the stomach. Such super- numerary glands have been accused of being the parents of adenomata ; but there is no proof of this, though such a nodule of pancreatic tissue enclosed in the mucous membrane of the stomach could easily be mistaken for an adenoma. William T. Councilman. ADIPOCERE. [Adeps, fat, and cera, wax French, adipocere, gras des cada/eres. German, Feitwachs, Adi- pocire.] As the name suggests, adipocere is a material resembling in its gross appearances fat and wax It is a semi-translucent, white, or slightly yellowish substance of about the consistency of cheese at ordinary tempera- tures ; has a greasy feel, and yields slightly when pressed between the fingers. If a piece be rolled between the fingers for a few minutes it becomes much softer. When rubbed with water it forms a lather. Its com- position is that of a soap, being made up of oleic and margaric acids in combination with an alkali. Examined under the microscope it shows, occasionally, very nu- merous scales having a crystalline form ; more commonly nothing but fat-globules are to be seen. If it be melted and again allowed to cool, it is found, often, to have crystallized in round masses made up of needle-shaped crystals, radially arranged ; hence like stearin. Most of the specimens of adipocere with which one is familiar come from the macerating-troughs of anatomical departments and from museum jars which have long con- tained specimens immersed in dUute alcohol. It thus represents the results of a metamorphosis of dead animal tissues placed under peculiar circumstances. The only special point of interest in connection with adipocere lies in the fact that it is occasionally found in dead bodies which have been buried a considerable time. In fact, nearly all the structures of the body, except the bones, have been found converted into this material. For centuries its presence had been noted in disinterred corpses, but no opportunity was afforded for studying it on a large scale until 1786, when, upon the removal of 80 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Adenoma. Aerotberapentlcs. the BodifS from one of the cemeteries in Paris, a con- sideraole proportion of those buried in the common grave (veve found by Poucroy to have been converted, to a greater or less degree, into this peculiar, fatty, wax-like material, wd to it he gave the name by which it has since beenkno.A'n. The conditions favoring its formation in buried corpses are still unknown. Doubtless moisture is always neces- sary ; but why, of six or eight bodies buried in close proximity, and hence presumably under like conditions of soil aad moisture, one should undergo almost com- plete change into adipocere, while the others undergo ordinary putrefaction, as has been observed, is at present inexplicable. At one time it was thought that adipocere might be of medico-legal importance in helping to determine the length of time a corpse had been buried. Poucroy be- lieved that thirty years was required for its formation. Later, this was reduced to one year ; and Caspar men- tions finding adipocere in the body of a new-born child, which had lain for three raontl^ in a house cesspool. It is therefore impossible to establish an idea, from the presence of adipocere in a corpse, as to the length of time it has been buried. Artificially, adipocere can readily be produced, either by soaking muscle in dilute nitric acid for two or three days, and then washing it thoroughly in warm water, or by allowing the muscle to soak for months in a trough supplied with running water. Adipocere is probably closely allied to cholesterine. W. W. Gannett. ADIRONDACKS. The Adirondack mountain region has recently come into notice as a health resort for per- sons suffering from pulmonary phthisis. To summer tourists, especially to those of them who are fond of hunt- ing, fishing, and camp life, this region has long been well known, and it is highly esteemed for the beauty and wild- ness of its scenery. The Adirondack Mountains lie in the northern portion of the State of New York, west of Lake Champlain ; many of the mountain peaks attain an altitude of over four thousand feet, and the highest of them (Mount Marcy) is five thousand three hundred and thirty -seven feet in height. " The mountains rise from an elevated plateau, which extends over this portion of the country for one hundred and fifty miles in latitude and one hundred in longitude, and is itself nearly two thousand feet above the level of the sea" (Appletons' " Handbook of Summer Resorts," second edition). Over two thousand square miles of this elevated tract of coun- try is covered with primitive forest growth, the trees be- ing chiefly of the evergreen variety. For his information concerning the climato-therapeutical characteristics of the Adirondack country the writer is indebted to a valuable communication from the pen of Dr. Alfred L. Loomis, of New York City, entitled, " The Adirondack Region as a Therapeutical Agent in the Treatment of Pulmonary Phthisis," and constituting a paper read by its author be- fore the New York State Medical Society in 1879. In this paper Dr. Loomis describes the climate of the Adi- rondacks as steadily cold in winter, cool in summer, and having a preponderance of cloudy weather at all seasons. The soil is dry. The annual rainfall is about fifty-five inches. Quotmg from Dr. E. L. Trudeau, of Saranac Lake, he specifies certain climatic, peculiarities of the re- gion in question as follows: "There is no marked pre- ponderance of clear days at any season ; on the contrary, the sky; especially in winter, is constantly overcast. Tms cool, cloudy weather is a marked feature of this cli- mate. . . . The soil Is very light and sandy, with here and there rocks, but little or no clay. . . . Pine, balsam, spruce, and hemlock trees abound, and the air is heavily laden with the resinous odors which they ex- hale." Dr. Loomis gives the condensed medical histories of twenty cases of pulmonary phthis'is, who, up to the time of presenting his paper, had found an alleviation or cure of their disetise by a more or less prolonged sojourn in the Adirondack country. Of these twenty no less than six- VoL. I.— 6 teen were cases of "catarrhal phthisis," while two were sufferers from " fibrous phthisis," and two were of the "tubercular" variety. Out of the whole number of twenty patients ten recovered, six were improved in health, two received no benefit, and two died. The ten cases cured were without exception cases of "catarrlial phthisis." Of these Dr. Loomis says : "In all the cases of catarrhal phthisis which have reached recovery, either the pulmonary changes were not extensive or they, were of recent origin, and improvement commenced soon after reaching the Adirondacks." Of the six improved cases four were cases of " catarrhal," and two were cases of "fibrous" phthisis. The two patients who died wer3 both affected with "catarrhal phthisis." Dr. Loomis says of these, "Although when they came into this re- gion their lungs were extensively diseased, they were much benefited during their stay, and it seems to me that impatience and imprudence had very much to do with the fatal result." The two unimpi-oved cases were both "tubercular." Dr. Loomis concludes his paper by rec- ommending the Adirondack region as suited to cases of " catarrhal phthisis," while he considers the Colorado cli- mate better for patients presenting the lesions and symp- toms of " fibrous phthisis." "Tubercular " cases he con- siders unlikely to derive much benefit from climate cure. Anything like full and accurate meteorological data for the Adirondack country the writer of this contribution to the Handbook has been hitherto unable to procure. He hopes to be able to present data of this kind for individual health-resorts lying within, or on the borders of, the Adi- rondacks, in the accounts of such places which will ap- pear in their alphabetical order in later pages and later volumes of the book. For description of the Home for Consumptives, established by Dr. E. L. Trudeau at Sara- nac Lake, see article on Saranac Lake. Huntington Bicha/rds. AEROTHERAPEUTICS. Aerotherapeutics, or pneu- mato-therapeutics, treats of the use of atmospheric air as a curative means by artificial changes of its density, as opposed to climatology. This air of increased or dimin- ished density may be applied to the whole or part of the body ; the former by means of a pneumatic chamber, the latter by special apparatus, according as it is desired to affect the air-passages, limbs, or other part. The pneumatic chamber is an apartment usually made of iron, so built that it may be closed air-tight, and capa- ble of standing great pressure external or internal, and large enough for the comfort of the patient. By forcing air in or sucking it out by means of an air-pump, after the patient is in the chamber, the air is increased or diminished in density, the amount of change of pressure being shown by a manometer. There may also be ar- rangements for regulating' the temperature and dryness of the air in the chamber. In using the compressed air- chamber the pressiu:e of the air and the duration of the exposure are gradually increased, possibly to two atmo- spheres. The time of each bath may be from one and a-half to two hours ; the patient going in at the ordinary press- ure, this is gradually increased and as gradually dimin- ished. If the pressure be changed too suddenly, the fol- lowing symptoms maybe induced : redness of face, hard, frequent pulse, dyspnoea, cough, haemorrhages from ear, mouth, nose, or bronchi, spmal troubles, etc. These symptoms are due to the mechanical effect ; but there is also increased supply of oxygen. When in an air-cham- ber, as a diving-bell, the pressure is increased, there comes a feeling of fulness in the ears from difference in density of the air in the ears (i.e., in the drum cavities) and out- side of them ; unless this difference of density be equalized by passing air througii the Eustachian tubes by swall&w- ing, the feeling in the ears becomes very painful, and there may be rupture of the drum-membranes with htemorrhage. This motion of swallowing must be repeated occasionally^ till the maximum density is reached, and again as it is being reduced in density. But the most important effects are on respiration, and these are the usual cause of emploj'- ment of the remedy. Compressed air increases the vital capacity of the lungs, reduces the frequency of inspira- 81 Aerotlierapeutlcs. ^stliesiometer. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. tion ; consumption of oxygen is increased, and excretion of carbonic acid diminished ; change of tissue is pro- jnoted ; the strength, weight, and appetite are increased ; there is no special change in the bodily temperature. Under the continued use of compressed air this improve- ment in symptoms may become permanent. The parts most directly exposed to this compressed air are the sur- face of the body and the lungs ■; hence the blood would be driven from the surface and the lungs dilated. After the change of pressure has continued some time, this dif- ference ceases. As the pressure is reduced, the first effect is again on the surface and lungs ; the skin and external mucous membranes are filled with blood ; the lungs are retracted, until the state of equilibrium is reached. Ac- cording to this, we might hope from treatment in the compressed air-chamber to drive blood from the periph- ery, to arrest secretion from the bronchial mucous mem- branes, by enriching the blood and tissues with oxygen to improve nutrition, to cause absorption of exudations, and to increase excretion of urea, and by expanding the lungs to increase their vital capacity. The action of the compressed air-chamber in lung diseases may be to some extent replaced by portable apparatus for respiration. The diseases in which benefit may be hoped for by using increased air- pressure are chronic bron- chial catarrh, with in- creased secretion; chronic vesicular pulmonary em- physema, especially if due to bronchitis or asth- ma ; pulmonary phthisis. In this latter disease, as well as in pleuritic exu- dations and whooping cough, it is said the symptoms are relieved and actual improvement brought about. Advan- tage has also been claimed for its use in ansBmia and obesity. It is said to be contra-indicated in or- ganic diseases of the heart. The compressed air- chamber may be so ar- ranged (by letting a tube through one of the walls) that while the patient is in it he may expire into the free air ; this has the same effect as if, being in the free air, he expired into rarefied air. The air-chamber may also be used for treating patients by rarefied air; but mountainous regions fur- nish about the same rare- fled air, with various advantages over the pneumatic chamber. In the latter there is diminished supply of oxy- gen ; at first the breathing is superficial and frequent, but after a time the inspirations become deeper ; expiration is facilitated ; the surface colors up ; there may be dizziness and mental hebetude. "Waldenburg found increased ful- ness of the radial artery, increased rapidity of circulation and relief to the heart's work. Health resorts, which are frequented on account of their elevation, are usually from '550 to 1,900 metres (alJout 1,800 to 6,300 feet) above the level of the sea, and this diminution of atmospheric pressure would represent about one-flfteenth to one-flfth of an atmo- sphere. The effect of these is stated in the article on Cli- matology. Portable pneumatic apparatuses are arranged for per- mitting inspiration of, or expiration into, compressed or rarefied air ; of these the only methods used are inspira- 82 Pig. 67.— Waldenburg's Apparatus lor Compressing Air. Natural height is one metre. tion of compressed air, or inspiration into rarefied air. Pneumatic treatment of diseases of the lungs and heart by these portable apparatuses is of recent introduction ; they offer the air under a positive or negative pressure (compressed or rarefied) of yiir to jV of an atmosphere + or — . There are many different patterns, of which perhaps the most practical are Waldenburg's and Biedert's ; the former is made like a gasometer, the latter much like a round accordeon, with one end fast to a stand having guide rods at the side, with an axle in the middle on which the instrument may be rotated so as to bring the end which is fast ■ uppermost ; in this position the pa- tient may breathe into rarefied air, the. rarefaction be- ing increased by ad- dition of weights to the lower, free end; when the attached end is down, more ■weight on top in- creases the density of the air in the reservoir, so the pa- tient may inspire condensed air. An- other instrument, Frankel's, is made on the harmonicon principle, the pa- tient condensing or rarefying the air by compressing or opening the instru- ment. All of these instruments have tubes connecting with them, and have mouthpieces and masks at the other encs for the patients to breathe through, and some of them have means for warming or medicating the air entering the reservoir. Inspiration of compressed air fills the lungs to an un- usual degree, expands the chest, and even causes a feel- ing of distention and fulness ; it multiplies inspiratory inovements, increases the exchange of gases and the capacity of the lungs, relieves dyspnoea and promotes expectoration. Expiring into rarefied air has effects somewhat sim- ilar to those of breathing con- densed air; more air is drawn out of the lungs by this process than can be forced out by the muscles. It is asserted, that, with a vital capacity of 3,000 to 4,- 000 c.c, by ex- piring into air rarefied by one-sixtieth to one-fortieth of an atmos- phere, 500 to 1,000 c.c. more may be drawn out ; this Fig. 68. — Biedert^a Apparatus. — The Same, reversed. would leave so much more air to be breathed in ; and ventilation in the lungs would be increased to this extent, the respiration would become more active than from in- spiring compressed air, and the respiratory muscles would be strengthened, Prof. Bazile Feris, considering dyspnoea in emphysema EBFERENCB HANDBOOK OF THE MEDICAL SCIENCES. Aerotlierapentlcs. .Slstbesloineter. to be due to lack of elasticity of the alveolar walls, has de- vised an '■■ elastic respirator " to facilitate expiration. "It resembles a double hernia truss ; from a pad between the shoulders the two limbs of the truss pass around under the arms to the terminal pads in front." The effect of pressure at the upper anterior part of the chest is to in- crease expiration, inspiration then following easily. In thirteen cases the immediate relief is said to have been marked. In the very aged, with rigid ribs, or when the emphysema is accompanied by bronchitis, the relief is less marked. Inspiration of rarefied air would be merely for gym- nastic purposes, to increase the strength of the respiratory muscles ; the same would be true of expiring into com- pressed air. Inspiration of compressed air increases the pressure of blood in the aortic circulation, and reduces it in the pulmonary. As a consequence, we have its diuretic effect and its aid in removing pleuritic exudations. The deep inspirations, with the consequent movements of the diaphragm and stomach, improve digestion and the general condition of the patient. In cases of lung disease, it is sometimes advised to have the patient lie on the healthy side, or to apply adhesive plaster to the healthy side, or, in disease of the apices, to compress the lower part of the thorax by a bandage, so as to throw more work on the affected part. Another method is to place the hand of the sound side on the hip, the other hand on the head while breathing. Climbing mountains is good gymnastics for those patients able to indulge in such exercise. Inspiration of compressed air is indi- cated where the breathing is weak, where the lungs do not expand well and contain too much blood, to hasten absorption of fluid exudations, in disease leading to phthisis, chronic bronchial catarrhs, etc. In most of these diseases it is well to begin with air but slightly increased in density, and to increase the density up to one-sixtieth or one-twentieth of an atmosphere additional. Medicinal vapors of creasote, turpentine, tar, muriate of ammonia, etc., may be added to the air. The inhalations at one sitting may amount to one hundred, and may be given twice daily. In dyspnoea from asthma, pneumonia, pressure of pleuritic or ascitic fluid, poisoning by gases, etc., compressed air has afforded great relief (just as oxygen has), but, in pulmonary emphysema, expiration into rarefied air has a better effect ; it should be used in the sa,me manner. Especial benefit has been claimed from its use in cases of pleuritic effusions< and in de- formities of the thorax from compression of a lung after pleurisy. In addition to the above cases, in which the pneumatic apparatus may be said to have served as a curative remedy, it is sometimes resorted to for temporary relief in contraction of the larynx or trachea from croup, syphilis, goitre, etc. Contra-mdications to the use of such apparatus are tendency to haemorrhages from the lungs, stomach, and kidneys, haemorrhoids, or profuse menstruation, and ex- istence of atheromatous arteries, in which latter condi- tion cerebral haemorrhage may be induced. Other therapeutic applications of compressed and rarefied air are made by means of various apparatus pre- pared to be applied over different parts of the body ; a metal casing may be made for part of or the entire thorax (especially of children), fitted close at its edges by means of india-rubber and adhesive plasters, so that air may be pumped out of it ; the pressure of ordinary air entering the lungs would then expand them more thoroughly. In chronic inflammations and exudations about the joints » metal casing may be applied over the limbs, and alter- nations of pressure applied in the same way. The old ippliance thus constructed, called Junod's boot, was ^{reatly vaunted in its day. _ In the Bull. gen. de Thh-wp., September, 1883, Dr. Mau- rice Dupont has an article on "Douches of Compressed Air." He employs air under a pressure of three atmos- pheres, conveying it by an elastic tube with a nozzle hav- ing an opening of eight to ten millimetres. The jet of compressed air is played on the patient as water might be ; what he terms the "flagellation" drives the blood from the surface, making it cold ; this is soon followed by reaction, without friction being required, as when water '*is used. After the douche the patient feels warm. This mode of treatment is recommended for phthisis, chlorosis, anaemia, and obesity ; and for certain local troubles of joints, contractures, etc. Compression of air in the lungs, by closing the mouth and nose while making forced efforts at expiration (Val- salva's method) may be tried when a pneumatic apparatus is not at hand ; the effect is something like breathing into compressed air. The reverse, viz., trying to inspire while mouth and nose are closed, would be like breathing rarefied air, and has been advised in diseases of the right heart. Deep, slow inspirations increase the flow of blood to and expand the lungs, and increase the aeration and muscular tone of the thorax ; hence they are useful in phthisis. Expirations may be made more effective by pressure on the thorax walls by the hands ; this forces out some of the residual air, and with it mucus which may have clogged the smaller bronchi. This forced ex- piration may be repeated twenty oi thirty times at one sitting. CJuwles E. Hockley. ^STHESIOMETER. The word sesthesiometer is de- rived from the Greek alaedm/iat, I perceive, aiaitiaLs, per- ception, sensation, and lierpov, a measure ; thus meaning literally a measure of sensation, and is used to denote an instrument, which measures that form of sensation known as tactile sensibility (Tastsinn in German). Tactile sensibility comprises all those forms of sensa- tion which are conveyed to the central organs by the so-called tactile fibres or nerves of touch, and is to be distinguished from the common sensibility, which com- prises the sensations conveyed by the sensitive nerves proper. Through these latter nerves we are enabled to feel the general or common sensations, which include pain, itching, titillation, sensual pleasure, and the sensation resulting from electrical stimulation. On the other hand, through the tactile fibres we obtain the sensations of tactile impression, which are composed of the sensa- tions of locality or position {Raumsinn, Ortsinn, in Ger- man), of pressure and of temperature. Not only is it probable that these different classes of afferent nerves possess different terminations and end organs, but they have, in all probability, each special afferent fibres of their own, which take different courses in the spinal cord. JEsthesiometers, properly so-called, are instruments for testing the sense of locality. The first one used, one which under slight modifications still retains its place, is that of E. H. Weber, who in 1839, appears to have pub- lished his first account of his investigations in regard to the sense of locality. The instrument had probably, however, been for some time in use at that date, for in 1846 he re- fers to its use twenty years ago. It consisted simply of a pair of compasses with cylindrical arms, the points of which were so ground down that their ends had a diameter of one-third line, so that they should pro- duce simply a sensation of touch and should avoid any sensation of pain. To use this instrument it was only necessary to place the two points upon the skin of the person to be examined, taking care at the same time that he should not see whether both points or only one touched his skin, and by examination find out at what distance from each other it was necessary that the points should be in order that they should be distinctly felt as separate. For in any portion of the skin two distinct points if placed near enough together will be felt as only one. Weber found that, the sense of locality, that is, the distance at which the points could be distinguished as two, varied much in healthy individuals in different parts of the body, and varied also somewhat, especially on the limbs, according to the direction in which the points were placed, whether longitudinally, obliquely, or transversely. His figures and those of Valentin for the normal distance between two points, which can be dis- tinguished as such in the various parts of the body, are as follows ; 83 JC8tliesIoineter> iEstbeKiometer. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Table op Vabiations of the Sense of Looaliti in Diffeeent POKTIONS OF THE SEIN (WEBEE AND VALENTIN). [The snbioined table gives the mean minimum distanoee (in Paris lines) for different parts o( the body between the points of the ffisthe- siometer at which two impressions can be distinguished when the points are applied simultaneously. The first column gives the results of the experii*nts of Weber, the second of those of Valentin, while the third column (also from Valentin) gives the relative obtuseness of each por- tion of the body, the most delicate part, the tip of the tongue, being taken as the unit of measurement.] Part of Sdbfaoe. Tip of tongue '. Palmar surface, third phalanx of forefinger l^almar surface, third phalanx of middle finger Palmar surface, third phalanx of ring-finger Palmar surface, third phalanx of thumb Palmar surface, third phalanx of little finger Ked surface of under lip Bed surface of upper lip Palmar surface, second phalapges of fingers . , , Palmar surface, first phalanges of fingers ] }orsum of tongue (one inch from tip, Weber) !Dorsiil surface, third phalanges of fingers Portion of lips not red Tip of nose Edge of tongue, one inch from tip Palmar surface of the metacarpus (capitula ossium). . L-iteral surface of dorsum of tongue End of great toe (plantar side of last ioint, Weber).. Metacarpal joint of thumb External surface of eyelids Palm of hand Dorsal surface of second phalanx of thumb Dorsal surface of second phalanx of forefinger Dorsal surface of second phalanx of middle finger. , . , Dorsal surface of second phalanx of little finger Dorsal surface of second phalanx of ring finger Centre of h )rd palate Mucous membrane of lips near gums . . ., Skin of cheek over buccinator Skin of cheek over anterior part of malar bone Dorsal surface, first phalanges fingers Prepuce Dorsal surface of heads of metacarpal bones Cheek, over posterior part of malar bone Plantar surface of first metatarsal Lower part of forehead Back of hand Lower part of hairy scalp in occipital region Surface of throat beneath lower jaw Back of heel , Pubes Crown of head Patella and surrounding parts Areola around nipple Dorsum of foot, near toes Axilla Skin of forearm (upper and lower extremities of fore- arm. Weber) Back of neck (over spinal column, Weber) .Upper and lower extremities of lower leg Penis Acromion and upper part of arm Sacral region Srernum Gluteal region Middle of arm Middle of thigh Spine near middle of cervical vertebree Spine near fifth dorsal vertebra Lower part of thorax, and over lumbar vertebrje. . . . Middle of dorsal vertebrce 0.60 1.00 1.00 l.CO 1.00 1.00 2.00 2.00 2.00 4'.60 3.0U 4.00 3.0(1 3.00 B.OO 4.00 5.0U B.OO B.OO 5.00 5.00 6.00 6.00 6.00 9.00 B.OO 7.00 7.00 8!6o 10.00 7.00 10.00 14.00 12,00 IB.OO 10.00 15.00 16.00 18.00 18.00 1.5. 24.00 l.S. 18.00 1.3. 18.00 18.00 18.00 00 18.00 .00 00 30.00 24.00 24.00 30.00 .i a 1.000 1.248 1.462 1.497 1.501 1.B18 3.106 3.147 3.226 8.416 3.967 4.400 4.572 4.6'58 6.130 6.434 6.17B 6.729 6.901 7.986 7.936 8.060 8.0H0 8.075 8.163 8.221 8.369 8.540 9.402 9. .666 10.180 10.659 10.869 10.944 12.164 12.422 14.42:1 17.168 17.168 18.634 19.048 19.840 21.1S5 24.982 25.932 26.915 27.520 27.520 28,.S81 28.675 28.708 30.969 875;32.867 62634.420 O&S 35.368 6.S3'36.507 ,.542!38.389 000'39.337 912 41.226 208,60.120 Weber's aesthesiometer is still in constant use, and servos its purpose well, but certain other forms or modi- fications have been introduced. In 1858 Sieveking pub- lished the account of his sesthesiometer in the British and Foreign Medico-Ohirurgical Review. The principle is the ' same as that of Weber's, but the form is somewhat al- tered. Instead of using the common compasses Sieve- king has made his instrument in the form of the beam- compass used by mechanics ; that is to say, of a solid graduated bar of metal, which terminates at one end in a point running at right angles to the bar, while on the bar shdes another point of horn or ivory, which can be 84 fixed at any desired distance from the first, by means of a screw on top. A modification of Sieveking's aesthesi- ometer has been made by Brown^Sequard, who has appar- ently made both the bar itself and the points lighter, and has done away with the screw at the top of the movable point. In his instrument the points are of steel, and there is a roughened prominence on the side of the sec- ond point to enable it to be readily moved by the finger or thumb (see Fig. 70). Nearly all the sesthesiometers Fio. 70. — Brown-Seqnard'B .^stbesiometer (reduced in size). at present used are modifications of these two forms. Hammond's convenient little instrument is a modifica- tion of Weber's, consisting essentially in allowing the index-bar to swing on a rivet fastened to one arm of the compass, the bar, while in use, being held by a catch on the other arm, in which it slides freely, When not in use, it can be lifted from the catch and swings into ap- proximation with the arm to which it is fastened, so that the whole instrument, when closed, occupies but little space and can readily be carried in the pocket. Carroll's instrument is simply a compass, each arm of which ends in two points, one blunt and one sharp, either of which can be used as desired ; while Vance's is an arrangement of compass with flattened arms, which shuts up in a case like a penknife. The delicacy of the sensation of space in various parts of the skin may be tested by the sesthesiometer in two ways. In the first place, as mentioned above, by deter- mining how far apart the points must be placed in order to be felt distinctly as two separate points in any part of the skin; and, secondly, by fixing the points of the sesthesiometer at a certain distance apart and moving the instrument from one portion of the body to another. Thus it is found that the distance of the two points ap- pears to increase when the sesthesiometer is drawn from the cheek horizontally over the mouth, one point resting on each lip, to the median line, and that if continued across that tine to the other cheek, the distance appears proportionately to diminish. This method of testing with the sesthesiometer is, however, of no practical use, as we have no means of measuring the strength of our sensations. From the numerous experiments made in regard to the normal tactile sensibility the following results have been deduced : 1. The points of the sesthesiometer always seem to be farther apart when one point is placed on one side of a natural opening and one on the other. Thus, when one point is placed on the upper lip and one on the lower, they appear farther separated than if both points are placed in a corresponding position on either lip. This in part accounts for the increase apparent when the sesthesiometer is moved from the cheek to the median line in Weber's experiment. 3. Other things being equal the points of the sesthesiometer seem farther apart when they rest upon different tissues. Thus, for example, when one point is placed upon the mucous membrane of the lip and one point upon the skin, they seem farther apart than when both points are upon either the skin or the mucous membrane. 3. As a rule the points seem farther apart when they are on different sides of the median line than they do in corresponding positions when both are on the same side. This law does not, however, always hold good. 4. The direction in which the points are placed in relation to each other is of considerable impor- tance in certain parts of the body, especially on the limbs. When placed transversely they appear to be at a greater distance from each other than when placed longitudinally. On the body proper there seems to be but little difference, while it is more marked on the face, and more so still on the limbs, especially the lower arms and legs. The causa REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. .SIsthesIoineter. ^stlieslometer. of this is as yet unknown, but it may be that the skin over different muscles responds more readily to two stimulations than the skin over the same muscle when touched at two equally distant points. (According to Vierordt the relative delicacy of the sense of locality at any point on the skin of a special portion of the body, as compared to that of the other points of the same portion, is a function of its mobility, and increases proportion- ately to its distance from the axis on which that part moves, since it depends on the relative greatness of the excursions which it effects about its axis through the movements of the part concerned.) In applying the aesthesiometer certain precautions should always be observed. In the first place, the operator should take especial care that both points are applied as nearly as possible simultaneously, as the element of time enters distinctly into our tactile impressions, and the greater the time which elapses between any two impres- sions of a similar kind, the more readily are such im- pressions recognized as distinct. For this reason, also, the points, when once applied, should not be moved, for if they be moved, a new sensation, or a series of sensations, will he produced, which will enable us to interpret the im- pressions mi^re easily. It is a curious fact that, if two points be placed so near together that they are felt as only one, and a third point be drawn across the skin between the two, the sensation of a moving object c^n be felt, although its position cannot be localized. The impression produced by the points, moreover, becomes clearer the longer they re- main in contact with the skin. Hence, in making compara- tive observations, the points should be held on each place for the same amount of time. In addition to the simultane- ousness of the touch, the pressure at the two points should be as nearly equal as possible. As far as possible, all pressure should be avoided, and when this cannot be, it should he as slight as possible. As we shall hereafter see, the ratio of the sense of pressure in different parts of the body varies considerably from that of locality, and the two different sensations should be carefully distinguished. For practical purposes, however, the amount of pressure exercised in ordinary cases when due care is taken is not sufficient to in any way affect the result. It is otherwise, however, when a different amount of pressure is exerted on the two points. The force of the stimulus produced at one point is liable so to act that the stimulus produced at the other is perceived but indistinctly or not at all. A third and obvious precaution to be observed in using the eesthesiometer, when testing corresponding portions of the body, is that the points should in each case be placed in the same direction, that is, longitudinally, obliquely, or transversely, as may be, and that they should be on ex- actly corresponding parts and at an equal distance from the median line. This is of especial importance in patho- logical cases, where the aesthesiometer is used for the pur- pose of diagnosis. In an examination for physiological purposes we must also take into consideration the mental condition of the subject. Whenever the attention is strongly fixed upon any point in the body, sensations produced there by ex- ternal objects are more readily and more quickly perceived than when the mind is occupied by other thoughts. Hence, when the attention is fixed upon the action oi the aesthesiometer, the points wiU be perceived more j:eadily and more distinctly than would otherwise be the case. The readiness with which the points are perceived and their position determined varies also greatly with prac- tice. Cold diminishes the tactile sensibility, as does also extreme heat. Hyperiemia, as well as anaemia, probably likewise diminishes it. BAB2ESTHESI0METEK. The term baraesthesiometer, from $ipos, weight, and jesthesiometer, has been applied to instruments which are used to determine the delicacy of the cutaneous sense of pressure. The first attempts to measure the cutaneous sense of pressure were made by B. H. Weber, who for this pur- pose used weights laid directly upon the parts to be Fia. 71 . — Eulen burghs Barsesthe siometer. Front view. tested, the muscular sense being excluded by firmly sup- porting the part to be examined upon some solid body. Various weights, as nearly as possible of the same size and same temperature, were applied in succession to the part, and the smallest difference which could be thus de- tected was carefully determined for each part. Weber himself made use for this purpose of coins (thalers) which he laid upon the forehead, the head being supported, and thus ob- tained some important results. Ac- cording to his researches, the sense of pressure varies much less in the different parts of the body than the sense of locality, and does not vary in the same proportion in the differ- ent parts. In the place of coins Kammler and Aubert made use of small disks of cork or elder-pith, on which weights could be placed, while Dohrn estimated the sanse of pressure by means of a blunt point attached to tiie arm of a pair of scales. In 1863 Goltz published ithe account of his apparatus, by means of which he sought to d.etermine the smallest rhytlvmical pressure which can be perceived on any given part. For this purpose he made use of an India- rubber tube, both ends of which were closed and which was rendered tense by being filled with water. The pul- sations produced by the experimenter at one end of the tube were transmitted to the other end, which was laid upon the part to be tested. Goltz's results corresponded with those of Weber for the sense of locality, except that the tip of the tongue was found to be proportionately much less sensitive to pressure. To determine the deUcacy of the sense of va/riation of pressure, Bulen- burg used the baraesthesiometer which bears his name (Fig. 71). It consists simply of a hard-rubber plate, on to which is screwed a spiral spring through whose greater or less tension a stronger or weaker pressure can be exerted on the plate. This spring is placed inside a case, and can be more or less compressed at will by means of a. guiding-rod. Through a toothed wheel, which is placed in connection with this rod, an index is set in mo- tion, which marks on a dial-plate the amount of tension of the spring, thus showing the strength of the pressure exerted. Each figure on the dial cor- responds to a pressure of one gramme. Eulenburg found that the sensibUity to variations of pressure was most delicate on the face, especially the forehead, then on the lips, the back of the tongue, cheeks and temples. Here it is ^, often -shr. On the upper extremities it is ^V to-iV, and does not var> much in the different parts. In the lower extremities the anterior portions of the lower leg and thigh seem to pos- sess the greatest insensibility ; next follow the back of the foot and dorsal surface of the toes, while on the plantar surface of the toes, the sole of the foot, and the posterior portions of the lower leg and thigh the sensibility is much weaker. LSwitt and Biedermann found that by the fin- ger-tips the differences between weights which bear to each other the proportion of 39 to 30, could be appreciated, provided the weights were not too light nor too heavy. Thebm^esthesiombtek. For measuring the sensibility to differences of tem- perature, Weber used two long glass phials filled with oil, into each of which he introduced a thermometer, passing it through the stopper. By means of this ap Fig. 72. — Back view of the same instru- ment. 85 ^stbeslometer. Age. REFEBENCE HANDBOOK OF THE MEDICAL SCIEKCES. paratus he found that the skin of the face was the most sensitive, especially that of the eyelids and cheeks. The lips, on the contrary, which are more sensitive to sensa- tions of place, are less so to those of temperature. Moreover, the sense of temperature, as tested in this way, instead of heing greatest in the middle of the lips, is greater on the lateral portions of the upper lip, greatest on the cheeks, and less as we approach the median line. In 1866, Eulenburg described his thermsesthesiometer. The instrument consisted simply of a "frame" and two thermometers thereto attached. For "frame" he made use of Sieveking's aesthesiometer, to the bar of which he fastened two exactly similar thermometers which corre- sponded accurately to each other. Their lower ends were drawn into broad glass bulbs, and flattened at the bot- tom so as to rest readily upon the skin. These ther- mometers worked like the points of the sesthesiometer, one of them being fixed at the end of the bar, while the other could be moved along it as desired, and be fastened at any distance by means of a screw. Thus the distance between the thermometers was determinable at will, and could be estimated by a scale marked on the bar. In using this apparatus, one thermometer was heated or cooled as desired, while the other was left at the tem- perature of the room. In the following year, 1867, Nothnagel published a series of very careful investiga- tions into the cutaneous sensibility of the temperature, in making which he used a special instrument. Noth- nagel's therm£esthesiometer consists of two exactly simi- lar cylindrical vessels, two and a half inches high and one and a half inch in diameter. Their walls are made of wood and are double, some poorly conducting sub- stance, as ashes, being placed between the two parts. The bottom is formed of copper, a good heat-conductor. On the top of the vessel is a tightly closing wooden cover which moves on a hinge, and which has an open- ing on one side. Corresponding to this opening there rises perpendicularly from the edge of the vessel a piece of wood to which are fastened two rings. Through these rings and through the opening in the cover a thermometer is thrust into each vessel, which is partially filled with water, whose temperature may readily be rendered different in the two vessels by plunging into it some good conductor, which has been previously heated or cooled. The vessels should be placed rapidly one after the other on the part to be examined, and the time of contact lasts until the subject has formed a judgment in regard to the temperature. Care must be taken that the whole surface of the bottom of both vessels should rest against the skin, since, as is well known, the strength of the impression and the delicacy of the sensibility to temperature grows with the increase in the number of nerve-fibres affected. By this means Nothnagel deter- mined that the greatest capacity for distinguishing differ- ences of temperature exists when the temperature is between 27° and 33° C. ; up to 39° C. it is but slightly diminished, but from thence to 49° C. it diminishes rapidly, and at the latter point pain occurs. From 37° to 14° C. the capacity diminishes in much the same ratio as from 33° to 39° C, but between 14° and 7° C. it falls off rapidly. He found that in different parts of the body the following differences in temperature could be distinguished : Centigrade. Sternum 0.6° Chest, upper and outer portion 0.4" Epigastrium 0.5° Abdomen, upper lateral portion 0.4° Middle part of back 1.2° Lateral portions of back 0.9° Palm of the hand 0.5° 0.4° Back of hand 0.3° Fore-arm— extensors 0.2° Fore-arm— flexors [ 0.2° Upper-arm — extensors and flexors 0.2° Dorsal surface of foot 0.5°-0.4° Lower leg — extensors 0.7° Lower leg— flexors (calf) .'.'.'.'.'.'.'.'.'".*,'..'." 0.6° Thigh extensors and flexors 5° Cheeks 0.4°-0 2° Temples .......'.."..'.".'!.'.'.'!'..'.' 0.4°-0!3° The sensibility to variations of temperature seems dull- er as we approach the median line, The hand and fingers are generally alike, the lower arm more sensitive than the hand, and the upper arm more so than the lower arm. By extremes of heat or cold a thermansesthesia is produced. Anremia increases sensibility to temperature, hyperaemia is said to diminish it. The only other thermsesthesiometer which deserves mention is Kronecker's, which resembles Eulenburg's, in which the latter's thermometers are replaced by metal tubes, each divided nearly to the end by a partition, as in a double-irrigating catheter. Through these water of a fixed temperature can be caused to flow. Bibliography. E. H. Weber : De piiTsu, resorptione, auditu et tactu. Lipsife, 1834 ; and in Wagner's Handworterbuch d. Physiologie, iii., 2te Abth. Valentin : Lehrbuch d. Physiologie ; Brit, and For. Med.-Chirurg. Be- view, January, 1858. Goltz : Centralb. fiir d. med. Wissensch., 1863, No. IS. Leyden : Virchow's Archiv, 1864, vol. xxxi. Eulenburg : Berl. klin. Woohensch., 1866, No. 46; and 1869, No. 44. Nothnagel; Deutsch. Arohiv. f. klin. Med., 1867, vol. ii. Also the works of Landois, Foster, and Flint, and especially Funke's and Bering's articles in Hermann's Handbuch der Physiologie. William H. Bullard. AGARIC, PURGING. White agaric (agaric blanc, officinal Codex Med.), the decorticated hymenium of PolypoTUS officinalis Fries (Boletus Laricis Linn.) ; order, Basidiomycetea, Hymenomycetea ; a large fungus grow- ing upon the stems of the European larch and one or two other conifers. It forms large hoof -shaped masses upon the sides of the trunks, and penetrates with its mycelium deep into the wood. When young they are soft and juicy, but, when fully grown, hard, and of a consistence between spongy and corky. The masses are collected in Europe, Asia Minor, etc., and usually prepared by dry- ing and peeling. Agaric is in yellowish-white, friable, light, and spongy irregular balls and lumps, from the size of an orange to that of a cocoanut, and larger. It has evidently been peeled, and the surface is finely rough and dusty with minute separated particles. The texture is rather firm, but soft ; it can easily be reduced to a coarsish powder by friction or by rubbing on a sieve, but is difficult to pulverize finely ; its microscopic structure — a tissue made up of interlacing, thread-like cells — explains its peculiar consistence. Agaric has a heavy fungous odor, and a slowly de- veloping, bitter, nauseous taste, which is at first sweetish. Its powder is very irritating to the eyes and nose, and produces violent sneezing. As it is also, light and dusty, persons employed in beating it in mortars are obliged to resort to devices to prevent its rising. It contains nearly one-third of its weight of resinous matters, extractible by strong alcohol, which can be separated further into three or four simple resins by taking advantage of their different degrees of solubility in diluted alcohol, chloroform, etc. (Massing). Agaric is principally a purgative, owing this quality to one or more of the resins just mentioned. It is also said to be tonic, and to reduce the sweating of phthisis. But although it has undoubtedly purgative powers, it has fallen greatly into disuse, and is only now and then called for, even in Europe, in the United States scarcely ever, as a medicine ; jt is still in repute in parts of Asia. Can be given in powder. Dose, as a tonic and anti- diaphoretic, fifteen to sixty centigrammes (0.15 to 0.6 Gm., gr. ij. to x.) ; the last, perhaps, might act upon the bowels. The resin has also been used. Allied Plants. — Polyporus igniarius Fries (see Spunk) is an. allied, although very different-appearing product, used entirely on account of its texture. Com- position unimportant. A number of other polypori have been found to be bitter and laxative ; some poisonous. Agarioua campestris Linn, yields an interesting and very poisonous alkaloid, muscarine (see Jaborandi). For a list of fungi used in medicine, see Ergot. Allied Dbugs. — Cathartics : say jalap, scammony, podophyllum, etc. Its relation to tonics, " anti-rheumat- ics," antisudoriflcs, etc., are too indefinite for compari- son. There are better medicines in each of these groups than agaric, W. P. Bolles. 86 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. -^stbeslometer. Age. AGE. The age of a human being does not, as usualty reckoned, correspond to the length of time it has existed, because the ordinary calculation starts from the date of birth, and excludes the preceding period of uterine exist- ence. If we are to be strictly accurate, the age of any animal ought to be reckoned from the time of impregna- tion, especially if we are to compare different species, one with another, in regard to the changes which corre- spond to successive ages. The act of impregnation creates a new individual, which alters as time elapses, and the liberation from the womb is only one of the altera- tions, one event, occurring in the life-history of the indi- vidual ; it is therefore artificial to arbitrarily select the date of delivery as the zero point from which to start the reckoning of the age, the more so as we know that the period of gestation varies very considerably in length, and that consequently the age of the child at birth is not by any means uniform. In the case of man it is the niost convenient plan to adopt popular custom, because the ages as reckoned from birth are generally known with exactitude, but the age of the foetus at birth is almost never known for a given individual. Indeed, we have at present no means of determining satisfactorily the age of a human embryo or foetus, because we have no sufficient available data for ascertaining when impregnation takes place. As is shown in the articles Foetus and Impregna- tion, there is always a possible error of several days in any estimate of the age of a foetus, even when the history of the case is fully and accurately known, and there are decided reasons for thinking that there may be sometimes an error of a month or whole menstrual period. Obvi- ously it is not practicable to calculate the age of man from an event the time of which we cannot know correctly, and it is the only practicable course for us to follow cus- tom, and assume the commencement of life's journey to be some way along the route, namely, at birth ; at least, whenever we have occasion to measure age. From impregnation to death, at the natural term of life, the organism undergoes a definite series of changes, which are termed the phenomena of senescence ; in plain words, the organism grows old. The most important, if, indeed, not all the changes, may be grouped under three heads : First, the increase in the number of cells ; second, the weight of the cells ; and third, the difEerentiation of the tissues. The first and second are the essential factors of growth, and under Growth they are more fully discussed. Unfortunately, we have no knowledge as to the number of cells in the body at different ages, nor is it possible to make even a valid estimate. It appears entirely practi- cable for some patient investigator to make an approxi- mate determination of the number of cells in the body ; a trustworthy result would be extremely valuable. But though we cannot speak of actual numbers, we are able to say that the rate of multiplication of cells diminishes gradually with one or two possible interruptions in man. The demonstration of this law is given in the article on Growth. As regards the size of the cells, we know that at first the size is reduced ; during the segmentation of the ovum, the amount of material remains nearly con- stant, while the segments (cells) multiply ; hence, they necessarily become smaller. During foetal life they re- main small, even after their differentiation into distinct tissues, but it is still uncertain how much of the growth of children is due to the mere increase in size of the his- tological elements and how much to the increase in their number. The difference between the foetal and adult cells is readily seen ; unfortunately, it is impossible to give a table of comparative measurements, for the micrometric data, even of the best authorities, are, with very rare ex- ceptions, utterly worthless, from their extreme inaccuracy. The structure of the tissues varies according to the age ; for each age there is a characteristic phase of development of the histological elements, both in structure and arrange- ment ; hence, the general anatomy and, therefore, also the functions alter in correspondence with the age. Thus, in a philosophical view of the career of any organism, we are compelled to regard it as a function of the time elapsed since the procreation of the individual. It is important to insist upon this conception, because the student of human anatomy derives his notions almost exclusively from the study of the adult, and consequently fails to seize the idea that much of what he conceives to be essential and typical is only temporary. There is another general consideration to be urged upon the attention of the reader : the older the organism the longer it requires to change. An infant alters more rapidly than a child, an adult more rapidly than an old person. This fact has a more profound significance than at first appears, because it not only suggests the only theory of the origin and nature of natural death having any serious value, but also is the clue to the distribution of variations in age. For the theory of death, see the concluding portion of the article on Growth. The law of variations to which we refer demands brief elucidation. Varieties occur in all degrees ; with living organisms there is in each case a certain variety which occurs most frequently, and on either side of this most frequent type (geometrical mean) occur other varieties which are found to be less frequent the more they depart from the central type. On the doctrine of chances the distribution should be alike above and below the mean, provided always there is no predominating factor or factors of variation to disturb the symmetry. In the development of living organisms there is such a disturbance through the effects of age; a concrete example shows the phenomenon plainly. The following table, after Heinricius,' gives the ages and number of persons observed in 3,500 recorded cases of first menstruation in Finland. Below the table is given the graphic representation of the same data. Tablb of 3,500 Cabeb op First Mxnstbitatioh (observed by Hbinbioius in Finland). Ages (years).. 11 12 1.3 14 15 IB 17 18 19 20 21 22 2.3 25 26 No. ol Cases. . 9 33 135 440 766 846 660 347 198 102 41 12 7 4 1 aw m m "> I nm f£5 r \ m / \ M / im tM 3(NI / f 2fi|] / \ m '^ ^ \ » Ji" 7 ^ *iH fL 1— =4 i_ Age.. 11 12 13 14 16 16 17 18 19 ! Fio. 73. 21 22 83 24 26 26 years. The curve shows that the year in which the first men- struation occurs most frequently is the sixteenth, and the further we follow the curve from the maximum, either forward or back, the lower it sinks. Moreover, from the maximum to the minimum is (probably) only seven years on the young side, but ten years on the old side. Here, then, we see that an equal range of variation covers a much shorter period of childhood than of later life. When a larger series of statistics are compiled, the dif- ference in the pre-maximal and the post-maximal periods is found to be considerably greater. This phenomenon occurs not only with menstruation, but with many, and probably all, or nearly all, phases of the development of the body ; the tirne at which a given change takes place varies in different individuals, and, as far as at present known, always according to the law just indicated. In the article on Growth another set of facts are brought for- ward, demonstrating the same principle, which we may now formulate as follows : Tli^ time required to accomplish 87 Age. Aiken. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. a change of a given extent increases with the age of the organism. It is evident that this generalization needs to be tested with great thoroughness, especially to ascertain whether it is rigidly applicable in details, or only in regard to the whole course of development broadly considered. As no researches have heretofore been made to settle the alter- native stated, it is very desirable that they should be undertaken. It may be discovered that diseases and recovery from diseases vary in rapidity in accordance with age, the rate of change decreasing with the age. This can be decided only by extensive statistics in regard to organic diseases. A large number of observations of the progress of fatal new formations, of cancer, for ex- ample, would be of high value. It is not to be anticipated that the diseases of a parasitic or zymotic character would exhibit, necessarily, any such correlation with age, be- cause their course is dependent primarily on other causes than the condition of the.organism in which they appear. If the rate of disease does vary with age, the desirability of knowing the fact is too obvious to require further emphasis ; we can, therefore, only express the hope that some one having a proper opportunity will soon make an adequate investigation. It is a common custom to divide the period of life into a succession of ages, but all such divisions are more or less arbitrary, and though extremely convenient are quite without scientific significance. The ages commonly adopted are : 1, Infancy, from birth to the appearance of the temporary teeth ; 3, childliood, from the cutting of the first permanent teeth to puberty ; 3, youth, from puberty to the attainment of the full stature, that is, eighteen or nineteen for girls, twenty-one to twenty-two for boys ; 4, maturity, covers the interval from youth to the climacteric, after which follows 5, the period of de- cline or old age. Another very common distinction is made between the period of development, say up to twenty-five or thirty years, and the period of decline, but, as is explained under Growth, there is a steady decline going on during the first period also. It would, per- haps, be more scientific to designate the earlier phase as the period of histogenesis, during which the tissues are being evolved, and the latter as the period of histolysis, in which the tissues are breaking down — degenerating. But, after all, though a great deal has been written and said, very seriously too, vipon the division of life into ages, the discussions have never, and can never, lead to much result beyond fixing upon a set of arbitrary terms, which will always be convenient, provided they are left sufficiently vague. The other matters which might be put under Age are to be found elsewhere, such as the determination of the age of a skeleton, the age at which the teeth are cut, etc. For the characteristics of infancy and childhood, ana- tomical and physiological, see the articles on these topics. For the changes in old age, see Senility. Oharles Sedgwick Minot. 1 Centralblatt fiir Gynakologie, 1883, vii., 72 to 78. AGORAPHOBIA {hyoph, a market-place, i^xiySo!, fear). [Ger., Platzsehwindel, Platzangst, Platzfurcht ; Fr., peur des espaces, peur du vide; It., agorafobia ; Dan., agora- iphoU; Rus., Mestoboyazin.'\ Etymologically speaking these names signify "fear of spaces," and are used to describe a peculiar emotional neurosis characterized by morbid fear of being alone in an open space, or under analogous circumstances. The name agoraphobia not having satisfied every one, its philological accuracy has been questioned, and such terms as isohphobia, eisophobia or autophobia, and kerurphobia have been proposed. How- ever appropriate these designations may be, the term agoraphobia is adopted in the current medical literature of all nations ; it is clear, concise, and elegant ; it has moreover, a certain element of fitness and admissibility' since ochlophobia is a prominent svmptom of the com- plaint, and one of the latest contributions to the subiect IS a paper in Greek that is to be found in the " Acts of the Congress of Greek Physicians, held in Athens in 88 1883." A better notion of the word may be given by detailing some of the salient phenomena that are found in a typical case of agoraphobia. Among the prominent somatic troubles are a sudden weakness and a tremor of the muscles, which render standing difficult. The tremor extends sometimes to the trunk, thence to the arm and to the lower jaw ; sometimes there is a wavy sensatioa going from the heart to the back of the neck. Chilly sensations in the back, stomach, breast, and limbs are fol- lowed by heat, redness of the face, profuse sweating, and violent palpitation. At the same time there is oppressioa and contraction of the pectoral muscles ; the speech is abrupt and anxious, and sometimes is momentarily im- possible ; intermittent pains of a sharp, rapid, and fatigu- ing character, following the trunk of the nerves, run along the legs, ascend the body, and extending to the arms, seem to lose themselves in the hollows of the hands ; there is formication, with numbness in different parts of the body ; f estination is observed in some cases ; in others sudden loss of motor power comes like a stroke of palsy, and the patient falls powerless with his face downward, in a state of waking nightmare. But these physical troubles are only the outward and visible signs of the moral trouble that is the true primi- tive phenomenon and the cause of all the others. That which is pathognomonic and constitutes agoraphobia, is terror, up to its extreme degree, and consequent motor impotence. The single primitive phenomenon, as the name indicates, is fear. Imagine looking down a deep mountain gorge, hanging over the brink of a burning cra- ter, crossing Niagara on a tight-rope, or falling from such a precipitous height as the Washington monument, and the sensation is not more fearful, more astonishing than that felt by a patient in an attack of agoraphobia. Ago- raphobic terror causes a patient to feel dumbfounded, thunderstruck, exhausted, and at the same time isolated from the entire world ; space seems to extend to infinity under his feet ; he feels persuaded that he will never ac- complish a given journey ; walk a certain distance with- out fainting ; hold out for a certain time without food, or support existence for a certain period without fresh air. He experiences fear and want of self-confidence when in a crowd, at theatre, church, or in a boat, omni- bus, or railway car. A case is related of an agrophobe who could not ride on a railway train without a brandy fiask in the left hand and a bible in the right, presuming that one counterbalanced the effects of the other. Fear to rneet acquaintances; fear of spiders, mice, and snakes; fear of apoplexy and of death come over the patient like the fear that seizes a timid child in the dark ; sensations like those of a swimmer deceived by false chances, or those of a victim to tantalizing hopes, cause the patient to be on the point of screaming or weeping, and he is, figuratively speaking, frozen with terror, motionless with fear, so great is the anguish that takes place during this psychical collapse. Agoraphobic symptoms are not new, Pascal having suf- fered from them, and Flemming says Brtick described them in 1832, and again in 1869, under the title of " Schwindel- Angst." It seems, however, that their sys- tematic observance and study are of recent introduction into science (1871). For convenience of study two forms of agoraphobia are spoken of, namely, primary and sec- ondary. The primitive form may occur suddenly in ap- parent good health and normal mental conditions, without other morbid symptoms than the usual somatic and psychical ones ; the secondary form occurs as an acces- sory phenomenon complicating a previous pathological condition : it is slow and progressive, and may coexist vnth other neuropathic conditions. Primitive agorapho- bia may come on suddenly without assignable cause amid varying circumstances, in a boat, during a lecture, or' while skating, at the sight of an extended horizon, or while looking at the summit of a high monument, as is the case with two of the writer's patients, who cannot look up to the dome of the Capitol or the summit of the Washington monument without being seized with agora- phobic symptoms. In one of the late St. Petersburg cases the patient could not look out on the sea without REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Age. Aiken. agoraphobic symptoms. There was also the " torment- ing fear of heights," the rooms on a second story being unbearable, and the patient in crossing a high bridge, al- ways did so in diagonal lines to avoid the sight of the space between him and the water below. Secondary agoraphobia comes on slowly, generally in patients whose neurotic antecedents are bad. Numerous prodromatic symptoms, more or less painful and persistent, are experi- enced, and at a certain time, while out alone in a public place or highway, or under analogous circumstances, there is added intense emotion and momentary suspension of motor power, which complete the attack. These symp- toms often disappear spontaneously, when the sufferer, in crossing a space, can fix his eye on some limited object, such as a carriage, a street lamp, a tree, or an open um- brella held over his head ; and often the companionship of a small child, or even the support of a cane will act as a preventive. Among the latest reported cases is that of a Russian officer, who escaped the agoraphobia brought on at the sight of carriages and pedestrians, by always taking an orderhr along and keeping on the least frequented streets. He did not have these symptoms outside of St. Petersburg, in a suburban village, nor did they come on when riding horseback through a crowded street at the head of his regiment. But little is known of the cause or of the precise nature of agoraphobia, and the numerous theories relative thereto are to be mentioned only as objects of medico-historic cu- riosity. Over-work, prolonged watching, early and ex- cessive sexual indulgences, venereal disease, alcohol and tobacco, excessive use of coffee, gastric disturbances, taenia, rapid decline of corpulency or a rapid change to corpulency, the gouty and the rheumatic diatheses, bad atavistic antecedents, and habitual indulgence in ground- less fears, may give rise to its development. In fact, one may become agoraphobic from moral weakness. The atrophy of will that allows imagination full career and gives rise to the superstitious fears, moral miseries, and morbid impressions that assail certain persons, may cause violent commotion of the organism with psychical sensa- tions of terror. By these facts, therefore, it is satisfac- torily established that in agoraphobia there is a kind of moral softening, a nervous adynamia, a psychic insuf- ficiency that may dominate the faculties of the individual and sterilize his acts. Whether the condition arise from organic insufflciencies, such as non-activity of the eye or of the ear, brain trouble resulting from anaemia, fatty heart, haemorrhoids, lesion of the cervix uteri, abscess of the liver, or from a morbid state of the ganglio-nervous ap- paratus, we are not prepared to say in the present state of our knowledge of the subject. But a consensus of med- ical opinion warrants the statement that the pathological change in agoraphobiai is a cerebral one, giving rise to a cerebro-spinal neurosis that should not be confounded with epilepsy, hypochondria, or the different forms of vertigo. Agoraphobia is said never to occur in hypo- chondriacs. A patient with hypochondria is constantly under the influence of the disease ; it is not so with agora- phobia. It differs also from vertigo caused by looking down from a height. The seeming impossibility to give a purely physical explanation of the disease arises from the fact that it is a purely mental trouble, and it is a curi- ous fact that none of the recorded cases have occurred in ignorant persons. Nor do any of the cases appear to have been accompanied by illu.sive transformation. Suicidal impulses are, however, reported to have occurred in sev- eral cases. The majority of them occurred in adult men of education and intelligence, who, in nearly every in- stance, kept the symptoms concealed from every one as long as possible for fear of being thought insane. The administration of drugs in agoraphobia is of less consequence than the removal of the cause, which is to be done mainly by moral treatment. The primitive form often disappears spontaneously, but the healing of the secondary form presents all possible and impossible difficulties, surprises, and uncertainties that the neurolo- gist is accustomed to meet. Among the therapeutic agents recommended are antispasmodics, the bromides, ergot, tonics, and iron ; cutaneous revulsives, cups, hydrotherapeutics, electricity to the cervical and to the sympathetic nerves, and electric baths. A case has been bettered after an operation for the removal of haemorrhoids ; in another the agoraphobic symptoms disappeared after aspiration of the liver and draining off a quantity of pus from an abscess. Two cases caused by taenia have been cured after removing the cause. Another case improved after a residence in the country, a course of hydrotherapeutics, and the avoidance of to- bacco. In addition to combating the functional and the physical alterations with proper medication, there must be a radical and complete change in the habits and surroundings, which should be as much opposed as pos- sible to the conditions in which the disease has originated ; and, above all, the physician should order and enforce a course of moral gymnastics that shall train the patient's imagination, and tame his terror by progressive and reg- ^1^^«*<^P«- Irnng 0. Basse. AGRIMONY {Agremoine, Codex Med. ; Agrimonia Eupatmia Linn. ; order, Mosacece) has been employed in Europe from the time of the ancient Greeks and Romans, by whom it was prized as a vulnerary. It is, however, now almost obsolete, excepting in domestic or country practice. Both herb and root have been used. It is a perennial plant, with slender, upright, leafy stem, from thirty to sixty centimetres high (one to two feet), bearing a wand-like spike of smallish yellow flowers ; leaves imparl- and interruptedly-pinnate, with adnate leafy stipules ; leaflets lanceolate, sharply serrate ; flowers perfect, polypetalous, stamens from five (seldom) to fifteen or more ; pistils, two or three, the ovaries buried in the receptacle, which becomes dry and woody in fruit, and is surmounted by a crown of rigid incurved spines. It is extensively distributed throughout the northern hemisphere, growing along roadside hedges and the bor- ders of cultivated fields in Europe, Asia, and America. The leaves, and especially the flowers, are rather agree- ably fragrant ; all parts, the root particularly, bitter and astringent. An essential oil has been obtained from the plant by distillation. It is a mild, stimulating astrin- gent, which has proved of some use as a vulnerary, as a gargle, a mild haemostatic, and an astringent in chronic diarrhoeas. More doubtful is its utility in jaundice and other indications of hepatic obstruction, or as so-called alterative. Dose, 4 to 8 grm. ( 3 j. to 3 ij.), in infusion. Botanical Connbctions. — Agrimony resembles the true roses in most details of botanical structure, but dif- fers from them in habit and general appearance, which are more like those of spirma ulma/ria. It is also bo- tanically connected with brayera anthelmintica (Kouso) Kunth., from which it also differs greatly in habit and the purpose for which the latter is used. Allied Deugs. — Astringency, bitterness, and aroma, with varying preponderancy of each, form one of the most common medicinal combinations of the vegetable kingdom. Alchemilla, sanguisorba, strawberry, poten- tillas, geums, blackberries, and spiraeas in the same bo- tanical family are instances, and numerous others might easilv be mentioned. For remarks on Bosacem, see Roses. W. P. Bolles. AGUE-CAKE. A chronic enlargement of the spleen following repeated attacks of intermittent fever, or ac- companying chronic malarial cachexia. (See Malarial Fevers.) To be treated with full doses of quinine and the local application of cold. M W. 8 AIKEN. [For detailed explanation of the accompany- ing chart, and suggestions as to the best method of using it, see Climate.] The village of Aiken lies not far from the western border of the State of Georgia, between the Savannah and Edisto rivers, but at a considerable dis- tance from either, and standing upon the elevated table- land or plateau forming the common watershed of both. 89 Aiken. Alnlium. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. From the Atlantic Ocean, Aiken is distant a little more than a hundred miles in a "bee line." The elevation of the town above sea level is five hundred and sixty-five feet. The soil is very sandy, consisting, indeed, of very little else than such absolutely pure and unmixed sand as is usually to be found only upon the very borders of the sea. Grass grows but scantily, and the vegetation of the sur- rounding country is that characterizing a region possess- ing a dry porous soil, and, in consequence, a dry atmos- phere. The yellow pine of the South finds here its congenial habitat, and in every direction the country about Aiken is covered with a dense, forest growth of these lofty evergreen trees, shading the ground from the rays of the sun, and filling the atmosphere with the de- licious balsamic odor exhaled from their leaves and trunks. Several varieties of oak are also to be found in the woods about Aiken, and not a few flowering vines and shrubs ; but the pine is the characteristic growth of the country, and it is to the soothing and purifying effect exerted upon the mucous membrane of the respiratory passages by the exhalations from this tree that the climate of Aiken owes much of its well-deserved reputation as a health resort for persons suffering from all forms of disease affecting the respiratory tract. The other chief factors in produc- ing the healthfulness of this now celebrated resort are the mildness and general equability of its winter climate ; the preponderance of bright sunny days, which enable the in- valid to pass much of his time in the open air ; the pro- tection against the wind afforded by the dense growth of forest trees ; and last, but by no means least, the remark- able dryness of the air, already alluded to, and depending upon the peculiar character of the soil and the distance from any large body of water. With the exception of certain stations lying in close proximity to, or west of the Rocky Mountains, no drier air is to be found in the whole United States, and, so far as present observations extend, none so dry as that which exists at Aiken. As might well be expected from what has been stated above, there are no marshes about Aiken, and Doctor W. H. Geddings, a well- known writer on climate and health resorts, and a prac- tising physician resident in the town, makes the following statement in a letter received from him a short time ago : " Malaria is remarkable for its absence. During a practice of fifteen years I have never known a case to originate here." From the dryness and warmth of its climate it may well be inferred that cases of gout and of rheuma- tism would also be benefited by a sojourn at Aiken. In support of the greatly beneficial effect produced by a resi- dence at Aiken upon cases of pulmonary phthisis, the fol- lowing statistics from the pen of Dr. Geddings are sub- joined Out of a total number of 113 cases of this disease treated at Aiken during a period of three years there were : Arrested, 17 cases, ci- 15.3 per cent. ; improved 50, or 44.6 per cent. ; unchanged 10, or 8.8 per cent. ; the number of patients who grew worse was 29, or 25.3 per cent. ; the number of those who died was 7, or 6.3 per cent. These statistics, which certainly speak well for the cli- mate of Aiken, were originally published in an article contributed by Dr. Geddmgs to the New York Medical Record (January 14, 1883). It is almost superfluous to call attention to the fact that inasmuch as cases of so grave a disease as pulmo- nary phthisis derive so much benefit, patients suffering from the less serious and less severe affections of the res- piratory system, such as laryngitis and naso-pharyngeal catarrh, may be expected to derive, and, as experience has proved, actually do derive an equal and even greater degree of such benefit from a resort to this favored spot during the colder, damper, and more changeable months of the year. To illustrate the comparatively small amount of varia- bility in temperature possessed by the climate of Aiken the following figures are quoted from •' Appletons' Hand- book of Winter Resorts. " The figures show the mean va- riation of temperature in twenty -four hours for the seven colder months of the year. The length of the period of ob- servation, whether for one year or for several years, is not stated by the writer in 'Appletons' Handbook," but the 90 figures were " compiled from reports on file at the Signal Office, Washington." Month. Sept. Oct. Nov. Dec. Jan. Feb. March. Daily variation 10.03° ir.OS" 18.26° 18.06°|l2.45° 19.14° 17.64° A table shovdng this same factor of dally mean variation of temperature during the year 1873, but which, unlike the former table, is based upon the tri-daily observations at the hours of 7 a.m., 2 p.m., and 9 p.m., instead of upon observations recorded from the maximum and minimum thermometers, is also given by Dr. Geddings on page 23 of the little pamphlet entitled, "Aiken, S. C, as a win- ter Resort." For further illustration of this same point these figures of Dr. Geddings are likewise herewith ap- pended. Obsebvations of 1873. Month. Jan. Feb. March. April. Sept. Oct. Nov. Deo. Mean diurnal range 12.96° 10.98° 13.45° 15.66° 10.46° 14.19° 12.45° 13.00° The following figures, showing the mean temperature at Aiken for each of the twelve months, for each of the four seasons, and for the year, are quoted from "Smithsonian Contributions to Knowledge," No. 377. The observa- tions upon which these figures are based were taken at 7 A.M., 2 P.M., and 9 p.m., (by Messrs. H. W. Ravenel, J. H. Cornish, and Newton), and extended over a period of seventeen years, from January, 1853, to December, 1869. January February... March April May ... 44.15° .. 47.83° ... 6.3.22° ... 61.49° ... 69.25° ... 76.08° July August September... October November. . . December. . . .. 78.f0° .. 77.19° .. 72.83° .. 61.80° .. 51.84° .. 45.48° Spring. Summer. . . Autumn.. . . Winter ... 61.32° ... 77.86° ... 61.96° ... 46.82° «1 «1» June The mean relative humidity for the year at Aiken, ac- cording to a footnote appended to his observations con- cerning the climate of that place, which are given by Dr. Geddings on pages 19 to 30 of " Aiken, S. C, as a Winter Resort, is fifty-eight per cent. The chart next following gives meteorological data of various sorts for the six months of the year during which Aiken is commonly resorted to by invalids, and for its careful filling out the writer is much indebted to Dr. Geddings, through whose kindness the proper figures were obtained. The water-supply at Aiken is chiefly derived from wells, which have to be sunk to a depth of about one hundred feet. In its character this water is pure and palatable, and it is said to be quite free, not only from all admixture of animal or vegetable matter, but also from any mineral ingredient except iron, a certain proportion of which is to be found in the water derived from some of the natural springs. The sandy roads leading in various directions through the pine woods afford ample facilities for driving and riding. HoTBLB, Etc. — Aiken is justly celebrated among the health resorts of the Southern States for the excellence of its hotels. The largest and best known of these is the Highland Park Hotel, which not only provides for its guests an abundant and well-supplied table, but also pos- sesses many other conveniences, and stands upon a reservar tion of ground extending over no less than two hundred and fifty acres of forest-land. The Park Avenue Hotel is under the same management and proprietorship as the Highland Park Hotel. Besides these two, the contributor of the article on Aiken, in "Appletons' Handbook of Winter Resorts," makes favorable mention of the Aiken Hotel, and of the Clarendon, and further states that " a group of neat cottages " exist, which are let to families, and that " there are many boarding-houses in the town, charging from ten dollars to twenty dollars a week." In repljr to an inquiry concerning the educational facilities existing at Aiken, Dr. Geddings informs the writer, in a letter bearing date of January 30, 1885, that " there is no first-class school for advanced pupils, but, on the other REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Aiken. Alnhum. hand, there are abundant opportunities for the best pri- vate instruction in English, classics, and music." In con- clusion, it may be added that, situated as it is upon the line of the South Carolina Railroad, Aiken is extremely easy of access to travellers from all parts of the United States. OUrmte of Aiken, S. G.— Latitude 33° 33", Longitude 81' Z4!'— Period of Observations, 1873 to 1884^JSl6vation of Place above the Sea Level, 565 feet— Name of Observer, W. H. Gbddings, M.D., Aiken, 8. O. January. . February. March.... April November December Winter'.'."! temperature of months at hours of 7 A.M. Denrees &.21 48.24 49.03 57.12 48.68 41.81 2 p.m. Degrees. 53.35 56.99 63.82 70,80 60.87 54.25 9 P.M. Degrees «.74 49.75 56.38 62.72 53.03 46.81 (Feb., March, and April. ) (Nov., Dec, and Jan.) II 1^ 48.01 49.93 58.40 68.34 53.88 47.42 56.55 49.77 Mean temperature for peiioa of ota- serration. Highest. Degrees. EB.OO 58.27 61.87 66.13 59.80 54.83 58.74 53.06 Lowest. Degrees. 41.38 45.85 .51.48 60.63 50.33 37.13 53.44 47.06 Degrees. 7S;54 78.41 84.00 76.72 70.45 D Degrees. 20.80 26.27 30;64 41.57 • 27.63 20.81 Absolute maximum temperature for period. Highest, Degrees. 82 84 89 81 75 Lowest. Degrees 66 74 71 61 Absolute minimum temperature for period. Highest. Degrees. 34 39 48 Lowest. Demrees. 18 23 40 22 03 H feg -I J P w January. . , . February... March April November. . December . . Spring Winter Degrees. 70 64 61 49 59 72 71 78 it si Per cent. 65.03 54.13 49.00 53 90 63.67 61.59 52.34 63.43 19X w 20)4 64M 59X Inches. 3.64 3.26 4.86 4.71 3.43 3.28 12.83 10.35 .9 From S.W. and W. S.W. S.W. S.W. S.W. S.W. and W. S.W. and W. S.W. .a ^ ■g I S3 Miles. 3.60 8.70 3.28 No obs. 2.46 3.49 3.09 NOTK— .Aiken being a voluntary station of the United States Signal Service, the hours of the tri-daily observations of temperature differ from those observed at the regular stations. The term " fair," in column L, is not employed in the purely technical sense adopted in the charts from reg- ular stations. Attention is called to the fact that in this chart Pabiuary is reckoned among the Spring months, and November among the Winter months. Huntington Richards. AINHUM, A disease, supposed to be a form of sclero- derma, occurring in one or more of the extremities, and resulting frequently in gangrene or spontaneous amputa- tion of the distal end of the affected member. It was first clearly described by J. F. da Silva Lima, a physician of Brazil, in 1867 ("Estudo sobre o ainhum," Gaz. Med. de Bahia, No. 1, 1867), although isolated cases had been previously reported by others. In the cases seen and studied by him, the disease was confined to the negro race, and the morbid process involved only the little toe of adults. It began as a slight depression on the plantar aspect of the metatarso-phalangeal articulation of the fifth toe, gradually increasing in extent until a distinct sulcus was visible, entirely surrounding the digit. The constric- tion growing deeper, the distal end was, in time, sepa- rated from the foot, retaining its connection only by a slender pedicle. The separated toe was sometimes un- changed in appearance and structure,.but more frequently the phalanges became atrophied, and in time disappeared, leaving only an oval-shaped fleshy knob, united to the foot by a fibrous pedicle. Finally, the pedicle itself was destrayed, and amputation of the toe was completed. The limitation of the disease to the fifth toe of adult ne- groes, as maintained by Silva Lima and other writers on the subject, in Brazil, is too narrow, for later observers have seen an identical process taking place in others than adult negroes, and involving different members. It may occur in any race, and at any age, and may be located in any one or several of the fingers or toes, or even in the legs. It may also take place in intra-uterine life, being probably the most frequent cause of congenital amputa- tions. The progress of the disease is usually very slow, and it seems at times to become arrested before any very serious changes have been produced in the distal portion of the affected extremity. The morbid process may even cease before the constriction embraces the entire circum- ference of the limb, so that the sulcus forms an imperfect ring of greater or less extent. In a case of ainhum examined by Guyot, the morbid process was found to be located in the deeper layers of the dermis, and to consist in an aggregation of fibrous bands, running in a direction at right angles to the axis of the limb. The band was thickest at the centre, becoming fradually thinned at each side until it was lost in the brous tissue of the integument. These fibres contract slowly, like cicatricial tissue, gradually constricting the Umb, as "would an elastic ligature, and by compressing the vessels and nerves, inducing degenerative changes, and, finally, death of the parts beyond. The affection arises independently of traumatism or other external causes, and is supposed to be due to a disturbance of the trophic nervous centres. If the disease is seen to be ad- vancing, and to threaten the function or the life of the limb, an endeavor should be made to arrest its progress by practising one or more incisions through the constrict- ing band in a line parallel to the axis of the limb. If this procedure do not suffice, the fibrous band should be dis- sected out. An incision is to be made on either side, parallel to the sulcus, and the intervening portion of in- tegument is then removed, care being taken to leave none of the transverse fibres. The gap remaining after the exsection of the sclerosed strip of skin is bridged over by direct approximation and suture of the edges of the wound. Only one-half of the circumference should be removed at one time, the remaining portion being excised at a subsequent operation. For a more extended description of this disease the reader may consult: Fox and Farquhar, " On Certain Endemic and other Skin Diseases of India," London, 1876; L. P. Despretis, "fitude sur Tainhum," Mont 91 Alnhnm. Air. REFERENCE HANDBOOK OP THE MEDICAL SCIENCES. pellier, 1873 ; P. Reclus, " Amputations congenitales et Ainlium " Paris, 1884 ; L' Union MMieale, October 18, 23, and 35, 1883 ; and other French, Spanish, and Portuguese periodicals of recent years. TTumas L. Stedman. AIR. The atmosphere, according to the chemist, con- sists of a mixture of two gases, oxygen and nitrogen. The former is active in its properties, combining with many susceptible elements, and especially with the carbon and hydrogen of devitalized organic matter, constituting, according to the rapidity of the process, either oxidation or combustion, and with the same elements in the living tissues of animals constituting one of the essentials for the continuance of life. The latter is passive, negative, and merely diluent. , Oxygen forms 20.96 per cent, by volume of the gaseous mixture ; and this proportion is preserved in all parts of the atmospheric ocean. Specimens taken from the sea level, and from the mountain-tops give practically the same percentages, a result due to the constant motion produced by cosmical forces, and especially to the power of diffusion or penetration into inter-molecular areas which gaseous molecules are known to possess. _ Ref- erence is here made only to the general constitution of the. air. Samples taken from enclosed localities where deteriorating agencies prevail, as in an unventilated and occupied school-room, church, theatre, etc., will, of ne- cessity, show a diminished percentage of oxygen. A certain small percentage of the oxygen of the air exists in the form of ozone, a peculiar modification of oxygen which, although much studied since first dis- covered by Schonbein in 1840, has yet to have its chemical and natural history fully written. Its nature is uncer- tain, but it is generally regarded as OjO. The quantity present in the air cannot be determined, and even its existence is at times indicated with doubt by the iodized starch papers which have been largely used for its detec- tion, as they are affedted by other matters, as nitrous acid and peroxide of hydrogen, occasionally present in the atmosphere. Iodized litmus papers have been shown by Dr. Fox to be of value as a qualitative test, and as indi- cating comparative quantities when known volumes of the air are aspirated over them. It is certain, however, that ozono has stronger affinities than ordinary oxygen, and that oxidation goes on more rapidly in its presence than in its absence. It undoubtedly destroys the volatile substances which are evolved during the putrefactive process. Where foul organic odors are present, ozone is absent. Hence, when the presence of ozone is indicated by the test-papers, the air is regarded as free from organic contaminations susceptible of oxidation. But there are grounds f oi supposing that the specific contagia are not destroyed by it. (See Malaria.) In the atmosphere, however, the chemist recognizes the existence of small and varying quantities of matters accidentally present, such as carbonic acid, ammonia, watery vapor, and organic matter. The ca/rbonic acid is produced by the oxidation of carbon in dead and living tissues, and its percentage varies with the local causes which determine its produc- tion. Thus it is greater in the alleys and streets of a city than in the open country ; and, as this gas is soluble in water, its proportion varies with the hygrometric and other conditions, being greater in a damp atmosphere, before rain has fallen, than in the air of the same locality after the watery vapor has been precipitated. The wind and the diiBEusive power of gases tend to equalize the percentage; but, as production is constant in certain localities, the air of these must always show a larger proportion of this gas than that of others remote from such sources. It is generally stated that 4 volumes of carbonic acid are found in 10,000 volumes of atmospheric air ; and this, according to the writer's experience, may be accepted as the average. In 1881, in connection with a report on the ventilation of the public schools of "Washington, D. C, he found in the air of the streets of the city, a little over or a little (inder 4 volumes in 10,000 ; but on one occasion 4.9 volumes were obtained, and on another 2.2 volumes. Two years before this he got similar results from the air of the Capitol grounds, while engaged in an investigation having reference to the ventilation of the House of Representatives ; and, in the spring of 1874, in a series of examinations into the ventilation of soldiers' quarters, at Fort Bridger, Wyo- ming Territory, he found a steady and gradual decrease, day by day, as the season advanced, from 4.5 to 2.6 volumes per 10,000. Some points have been determined concerning these tides in the carbonic acid volumes, especially by the ob- servations of De Saussure ; but, practically, no one can as yet predicate, from the experiment of one day, the prob- abilities as to the result of that of the next. Carbonic acid in the air of dwellings has, as will be shown here- after, an important bearing on the subject of ventilation. Ammonia emanates and is diffused from putrefactive processes in progress on the surface of the earth. It is also produced from the nitrogen of the atmosphere by electric agency, as during thunder-storms. Its quantity is variable, but 0.1 mm. in a cubic metre of air is a not unusual amount. This corresponds to a grain in about 33,000 cubic feet. In a series of analyses of the free ex- ternal air, preliminary to an investigation of its abnormal conditions, the writer frequently obtained this quantity. Rain washes the ammonia from the air to the surface of the earth, and in the rainfall it may always be detected and measured. Its quantity is increased during thunder- storms. It varies from less than 0. 2 to more than 0. 5 mm. per litre (one grain in from 84 to 86 U.S. gallons). In dealing with cubic feet of air the ammonia is necessarily a very minute quantity, but when the annual rainfall over a tract of country is made the basis of calculation, the subject becomes one of importance in agricultural chemistry. The ammonia of the air is condensed on exposed sur- faces, and R. A. Smith has suggested that the quantity of ammonia deposited on a given surface in a given time may be taken as an exponent of the sanitary condition of the atmosphere. A glass or other surface which has been exposed for some time in an unventilated bedroom, when washed with pure water, will show in the washings the presence of a readily determinable quantity of ammonia ; but the attempt to demonstrate the relative purity of atmospheres by the quantity deposited on equal and sim- ilar surfaces in equal periods of exposure meets with failure unless the temperature, the hygrometric condi- tion, and the air movement are the same in both instances. This concurrence of similar conditions is difficult, if not impossible, to obtain in practice. The writer failed by this method to show the presence of sewer air in an at- mosphere in which it was known to be present. Watery vapor is constant in its presence in the atmos- phere, but in such varying quantities that it is viewed by many as an accidental constituent. Its importance, how- ever, not only in the preservation of the purity of the atmosphere, but as a preservative of the vitality of all the organisms submerged in it, is so great that it must be regarded physiologically as an essential. The capac- ity of air for holding aqueous vapor is limited and varies with the temperature. When air of a given tem- perature is so permeated with aqueous vapor that no more can be taken up, it is said to be saturated for that temperature. Thus air at 0° C. (32° F.^ will take up and hold 4.875 grammes of aqueous vapor in one cubic metre (equivalent to 2.13 grains in a cubic foot). But It this same air is attenuated by increasing its temperature to 21.1° C. (70° F.) its capacity for holding the vapor of water will be increased and a cubic metre will not be saturated until it contains 18. 334 grammes (or 8.01 grains in the cubic foot). Precipitation of vapor occurs when the air is cooled to a temperature below that which is needful to enable it to retain the vapor which it contains. If a cubic metre of air at 21.1° C. holds only 4,875 grammes of aqueous vapor, precipitation will not take place until the air has been cooled to 0° C. The degree of temperature at which moisture begins to be deposited from air is called the dew-point. Wlien air is saturated, its temperature and the dew-point coin- cide. The quantity of vapor which air is capable of re 92 REFERENCE HANDBOOK OP THE MEDICAL SCIENCES. Alnliam. Atr. taining has been accurately determined for all ordinary temperatures. It is, therefore, only needful to ascertain the dew-point to learn, not only how much vapor the air contains, but, which is of more importance, how much more it is capable of taking up. As this latter quantity varies with the temperature and the difference between that temperature and the dew-point, medical climatolo- gists have endeavored to effect a uniformity in their records by expressing the results of such observations in terms of relative humidity, saturation being represented by 100. The dew-point may be obtained, after Regnault's method, by evaporating ether in a test-tube containing a sensitive thermometer, and noting the temperature when the surface of the tube becomes dimmed by deposited vapor from the air. But it is usually calculated from the difference between the dry and wet bulbs, and the relative humidity is obtained therefrom by the use of Glaishers' tables. The air constituents which have been mentioned must be regarded, from the scientific and sanitary point of view, as individually essential to the constitution of the atmosphere. The oxygen is vital to animals, its quan- tity being preserved by the evolution from vegetation and the equilibrium established between these two king- doms of nature. The carbonic acid is vital to vegetation, being the source of much of the carbon solidified in its tissues ; its quantity is preserved by the evolution from animals and by the retrogressive metamorphosis of the organic carbon of devitalized tissues. The ammonia is needful to the building up of organic structures by veg- etable life, which afterward figure in the life-history of the animal kingdom, and which, when ultimately over- taken by death, are returned to the ammoniacal condi- tion by the agency of microscopic organisms. The ni- trogen is primarily a diluent presenting the oxygen to the animal kingdom, and the carbonic acid to vegetation, in the strength best suited for their respective needs. Speedy death occurs to the animal organism exposed to an atmosphere of undiluted oxygen from exaggeration of the vital actions. Presumably a similar effect would be produced on the vegetation of to-day by a carbonic acid atmosphere, for, if we look back through the geo- logic eras to the time when a carbonic acid atmosphere enveloped the earth, we find the genera then living wholly different from those which are now their succes- sors under different conditions. But there is ground for supposing that the inorganic nitrogen of the air is a store from which the organic kingdoms may draw sup- plies. Nitrogen is transformed into ammonia and nitrous acid by electrical agency, and thus becomes susceptible of assimilation by the vegetable kingdom. The name asoie, originally applied to this gas by the chemists, be- cause animal life could not be sustained in it, is a mis- nomer. Without nitrogen there is no life. Some of the products of vital action, as the fats and starches, contain no nitrogen, but the active tissues of vitality which elab- orated these carbonaceous products are nitrogenous. Watery vapor prevents desiccation. Without a certain relative humidity life, vegetable or animal, would be an impossibility. As the fish dies when taken from the water, though in a medium which is richer in oxygen than is its natural habitat, so would all air-breathing organisms perish were the humidity of the atmosphere removed. But this water, by its absorption into and deposition from the atmosphere, under altered conditions as to temperature, exercises another and most important func- tion. Among what may be considered, in accordance with our present knowledge of vital actions, as the purely accidental substances found in the atmosphere, particulate matter in fine division, in other words, the dust of the earth, occupies a prominent place. As the earth is composed of organic and inorganic, living and dead matters, its dust is of similarly varied composition. Among the various species of the genus dust are some which, as will be shown hereafter, are exceedingly dele- terious to animal life ; but the greater number in the quantity usually present in the air are individually and collectively harmless. Nevertheless, without the aque- ous vapor, there is no provision of nature by which life may be preserved from suffocation by this otherwise harmless dust. With the reduction of the atmospheric temperature to a point below the dew-point, water is lib- erated and precipitated to the surface of the earth, carry- ing with it all particulate matters which would otherwise accumulate without end. The clearness of the atmos- phere after a rain-storm, which has been preceded by a period of dry weather, is a matter of common observ- ance, and can be readily understood. The impurities are washed to the surface. Rain-water is the sewage of the atmosphere. The matters occasionally or accidentally present in the atmosphere are gaseous or solid. Of the former, carbonic acid in excess of the average quantity must be regarded quantitatively as the most important. Its sources are or- ganic decomposition as occurring in the soil, animal res- piration, and the combustion of fuel. Hence it is found in excess or as an impurity at or near the surface of the ground in the narrow streets of closely built cities, and within the walls of occupied buildings. Carbonic acid is probably harmless per se, unless in very unusual quan- tities, but as its sources, in most instances, evolve also matters which are harmful, its presence is of much im- portance. Coming from the interstices of the ground or from the sewers, carbonic acid may be accompanied by specific miasms. In the former instance it may be sug- gested that the specific miasms, being particulate, are re- moved by the filtration which the air undergoes. It is well known to every experimenter that a plug of cotton- wool will protect a sterilized culture-fiuid from impreg- nation by the germs of putrefaction — that is, that the wool will act emciently as a filter when the air-current is only such as is caused by variations in temperature and barometric pressure. Professor Pumpelly has shown that asbestos, sand, and other dry filters are efficient against putrefactive agencies even when the air is drawn rapidly through them. Moreover, the writer knows, by experiments performed for the National Board of Health, and as yet unpublished, that the nitrogenous matters of sewer, garbage, and marsh airs are particulate and sus- ceptible of removal by filtration. But it remains to be proved that such nitrogenous particulate substances are removed by a filtration through the organic matrix, the soil, in which they are multiplying. Besides, in this ques- tion, evaporation from the surface is involved as well as filtration through the substance. The passage of air through and from the soil promotes evaporation from the surface, which carries with it the miasmatic exhalation. Hence may be inferred the inadvisability of furnishing cellar air, or air introduced by tunnels into a building for purposes of ventilation. In fact cellars, in default of an impermeable lining, should have a free circulation of air separate from the ventilation system of the superimposed building. Carbonic acid from the consumption of fuel and gas, while injurious by diminishing the proportion of oxygen in the air furnished for respiration, may be accompanied by other and more deleterious gases, such as carbonic oxide and sulphurous acid. One cubic foot of gas, ac- cording to Parkes, destroys in its combustion the entire oxygen of eight cubic feet of air. Carbonic acid as the result of animal respiration is accompanied by organic exhalations which are well known to be deleterious, pro- ducing headache and febrile action when the exposure is of short continuance, and predisposing to pulmonary affec- tions, phthisis, and typhous conditions when the exposure is habitual. Specific miasms or contagia, if present, are generally concentrated in proportion to the percentage of expired carbonic acid in the air. Hence the examination of the air of an occupied building usually resolves itself into a determination of the amount of carbonic acid present in it ; not because this gas is of much importance in itself as compared with the organic matters which are eliminated with it from the human system, but because both being the result of the same vital processes, pul- monary and cutaneous exhalation, the amount of the one may be taken as an expression of the quantity of the other. These organic matters are susceptible of separa- tion into particulate and gaseous ; the vital qualities of 93 Air. Air. EEFERENCE HANDBOOK OF THE MEDICAL SCIENCES. the former may be examined microscopically by cultures and by inoculation, and the elementary analysis of both may be effected with the utmost accuracy ; but the col- lection of the organic matter for such quantitative ex- periments involves a tedious filtration, during which the character of the air to be examined may become ma- terially changed, and when collected the experimental proces'ses to which it must be subjected requires so much care, time, and experience in this special line of sanitary work that in practice the organic matter is seldom deter- mined. The carbonic acid, on the other hand, is quickly collected, readily and accurately estimated by any one who possesses experimental tact, and an experience of general volumetric analysis. It has therefore become the exponent of ths respiratory impurity of air ; the increase In its amount over that present in the external air being a measure of the respiratory use to which the air has been applied and of its fitness or unfitness for further use. In estimating the carbonic acid an alkaline solution of baryta or lime of known strength is used for its absorption, and the loss of alkalinity, as subsequently determined by some other acid, gives the figures from which the ab- sorbed carbonic acid may be calculated. The practical details are as follows : A solution of pure oxalic acid is made of such strength (3.864 grammes per litre) that one gramme will neutralize as much caustic baryta as may combine with one milligramme of carbonic acid. A baryta solution of equivalent strength, one gramme of the one neutralizing one gramme of the other, is then made and immediately transferred to bottles of from 50 to 60 c.c. capacity (two-ounce vials), each of which is corked securely and weighed, and the total weight of the bottle and its contents is marked upon the label. The air to be examined is collected in a clean and perfectly dry clear glass bottle or narrow-mouthed jar, the capacity of which is accurately known. Ten-litre bottles are large enough to give accurate results. A rub- ber tube and small bellows are conveniently used in fill- ing the jar with the air to be examined, but care must be taken that the air entering by the valve of the bellows is not contaminated by any direct respiratory streams from individuals present. As soon as the charge of air has been effected, one of the prepared baryta vials is care- fully uncorked and its contents poured into the jar, which is then closed by an accurately ground stopper, or preferably by a tightly fitting rubber cork. The baryta solution is then shaken in the jar, and made to flow all over its interior to promote its contact with the contained air ; but to insure thorough absorption of the carbonic acid the jar is usually permitted to stand until the follow- ing day before determining the loss of alkalinity. Mean- while the volume of the air operated on is ascertained from observations made at the time the air was collected. The height of the barometer and of the dry and wet bulb thermometers must be known, and the quantity of baryta solution introduced into the jar. The last is obtained by weighing the now empty vial in which it was stored and deducting this weight from the gross weight marked on the label. The quantity in grammes of the baryta solu- tion employed must be deducted as cubic centimetres from the known capacity of the jar. But in order that experimental results may be susceptible of comparison it is necessary to express the air-volume in the space which it would occupy when dry at zero Centigrade and under a pressure of 760 millimetres of mercury. In- creased pressure diminishes the volume of air, increased temperature expands it, and the pressure of the watery vapor present must also be taken into account. The temperature observations furnish the dew-point, and through it from the observations of Regnault the press- ure or tension of the aqueous vapor may be obtained. If p represents this pressure, t the temperature in Centi- grade degrees, * the barometric height in millimetres, and Fthe capacity of the jar, minus the number of cubic centimetres of baryta solution introduced, the corrected volume will be equal to V(b-p) 273 (273 + t) m Next day the liquid contents of the jar are transferred to a small beaked flask or alkalimeter, and the weight of the flask and its contents is noted, that, by again weigh- ing, the loss of weight may indicate the quantity used in the subsequent experiment. Ten grammes of the oxalic solution are weighed into a smpjl beaker and colored with a few drops of tincture of litmus. Into this the deteriorated baryta solution (after the carbonate present has settled) is dropped from the alkalimeter rapidly, until a haziness is developed, and after this more slowly until the last drop changes the color to a dark purple. The oxalic acid has been neutralized, and the weight lost by the alkalimeter gives the quantity of the baryta solution used in effecting the neutralization. Let it be supposed, for example, that 50 grammes of the solution were in- troduced into the jar, and that 25 grammes of it are now required to neutralize 10 grammes of the standard acid, the total of 50 grammes will suffice to neutralize only 20 grammes of the oxalic solution, while before absorb- ing the carbonic acid of the bottled air it was capable of neutralizing 50 grammes. There has therefore been removed by this carbonic acid as much baryta as would neutralize 80 grammes of the oxalic test, or, in other words, 30 milligrammes of carbonic acid were contained in the air which was the subject of the experiment. The weight of the carbonic acid in milligrammes when multiplied by the factor .50685 gives expression to its volume in cubic centimetres. It must be remembered, however, that this volume of carbonic acid is not all carbonic impurity, but includes that which is naturally present in the air. When the result of a cotempo- raneous experiment on the external air has been de- ducted, the remainder indicates the carbonic acid due to imperfect ventilation. An easily applied method of ascertaining whether a given air contains more than a certain number of volumes of carbonic acid per ten thousand is based on the turbid- ity caused in lime-water by the precipitated carbonate. If a half -ounce of this liquid is shaken up in an eight-ounce vial filled with the air to be examined, the appearance of turbidity indicates the presence of eight or more volumes of carbonic acid in ten thousand volumes of the air, and that the arrangements for ventilation in the apartments which furnished the air are not as satisfactory as could be wished. Bottles of various sizes are used by the opera- tor in conducting this, the Tvousehold method of sanitary air analysis, and from the capacity of the bottle in which a just visible turbidity is produced the volumes of car- bonic acid per ten thousand become known. In another method, the minimetric, air is Introduced in small quantitjr into a vial containing lime or baryta solution, which is well shaken, with gradual additions of the air, until the liquid shows a certain loss of transpar- ency, when the carbonic acid is calculated from the quantity of air needful to the production of this result. These, although pretty experiments, and described in full by most sanitary writers, have not come into gen- eral use, because they are not required. As they yield results which are only approximative, they cannot take the place of the accurate determination needful in a scientific inquiry, while, as rough and ready methods, their results convey no more Information of practical value than may be gathered unpretentiously by the sen.se of smell. A well-ventilated room should not have more than one or two volumes per ten thousand in excess of the external air, equalling a total of five or six volumes. When the carbonic acid amounts to seven volumes, a want of freshness is recognized on entering. When nine, ten, or more volumes are present, the organic odor be- comes manifest. Although the carbonic acid, as has been stated, is generally accepted as a measure of the respiratory im- purity. It is not an accurate one, for it is more readily diffused and carried off by ventilating currents than the organic exhalations which accompany it from the human system. Whence it comes that the continued occu- pancy of an apartment may give rise to organic odors in its atmosphere, although carbonic acid may not be present in large quantity. The writer has frequently 94 EEFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Air. Air. detected the organic odor in barrack-rooms some time after the men had quitted them, when the carbonic acid, on account of open doors and windows, was but little in excess of that found in the open air. The exhalation ap- pears to adhere to walls and other surfaces, and textures, and to require time for its dissipation. But, while the carbonic acid is not an accurate measure of the organic contamination in the air of occupied build- ings, its estimation affords the best means of testing the effieieTicy of the wntilation. Sanitary inspectors do not recognize this fact. Sanitary chemists have not brought it prominently into notice. When questions of ventila- tion are to be settled, Cassela's air-meter is used, and the air movement is calculated from its indications and the areas of inflow and exit. The inspector shows that go much air has entered or that so much has escaped, to be replaced of necessity by a corresponding volume of fresh air through the inflow ducts. But this is not enough. It must be shown that the air introduced has offected the purpose for which it was introduced. This may be done by a calculation based on the amount of car- bonic impurity found by experiment. It is needful to know the average, rate at which carbonic acid is elim- inated from the person. This evolution varies according to conditions of rest or activity. Professor Parkes states the yield at from twelve to sixteen cubic feet in twenty- four hours, or from .5 to .66 of a cubic foot per hour. Huxley gives three hundred and sixty feet as the volume f air expired daily, and, as the air of expiration is known to contain four per cent, of carbonic acid, this is equivalent to an hourly production of .6 of a cubic foot. Other experimenters have arrived at similar results. This is a convenient number for calculation, as it corresponds with .01 of a cubic foot per minute. The capacity of the room must also be ascertained, and in exact calcula- tions deduction should be made for the body bulk of the occupants and for the furniture. The time during which the deterioration has been going on is another factor en- tering into the calculation. The carbonic evolution, .01 cubic foot per minute per person, multiplied by the number of minutes, gives the amount of the carbonic impurity generated. When this is divided by the carbonic impurity found by experiment in ten thousand volumes of the air, the quotient multi- plied by ten thousand will express, in cubic feet, the vol- ume of the air with which the respiratory products have been diluted. But, as the air-volume in the room has con- tributed to the dilution, its capacity has to be deducted from the total to obtain the amount of the inflow. Thus, if the data consist of 50 persons, 50 minutes, 7,000 cubic feet, and a carbonic impurity experimentally found of 10 volumes : 01 X 50 X 50 = 35 cubic feet of carbonic acid expired. ,000 cubic feet of air requir 18,000'onbio feet of inflow. -- X 10,000 = 25,000 cubic feet of air required for the dilution. 25,000 - 7,000 — ^— — = 360 cubic feet of inflow per minute, 5U -— - = 5.1 cubic feet of inflow per minute per person. 51) The inflow being known, other questions which need only be suggested, may be answered. An experiment has been made on the air of a room which contained only fifty persons, although seated for one hundred ; what would have been the result had all the seats been occupied ? The occupation of the room at the time of the experiment had continued but sixty minutes ; what would have been the result had the occupation lasted six hours ? In practice it is often found that the inflow, as deter- mined by the anemometer, is much greater than that ob- tained from the chemical results. That the air enters is certain, and that it fails to be utilized in diluting the expired air, is equally so. A want of diffusion must be inferred in explanation. In one of the schools of Wash- ington, D. C. , 800 cubic feet per minute entered the room, while but 324 cubic feet contributed to the ventilation. The cause in this instance was manifest. The tempera- ture of the incoming air was so great that it rose immedi- ately to the ceiling, whence it was drawn oflE by the lowered windows and foul air-flues. Somewhat similar conditions prevail in the Hall of Representatives in our National Capitol. Although the floor is largely and gen- erally perforated for the inflow of fau-driven air, certain of the ducts leading to these perforations carry a large pro- portion of the incoming air, while others bring but little. Over some of the gratings there is a vigorous current, over others the inflow is small. The impetus in the one case carries the air upward until it reaches the area influ- enced by the aspiration of the louvres on the roof, whence it is carried through the perforations in the ceiling with- out having been distributed in the body of the hall. While the spaces in front of the Speaker's desk, and in the centre of the hall are well ventilated by this upward current, the air of the sides and galleries is more or less stagnant. The volume of air which enters is .suflicient to effect a satisfactory ventilation, but it is not dis- tributed. The galleries are close and stuffy, while cer- tain of the occupants below may feel chilly in the upris- ing current. The gaseous products of fuel and gas consumption contain traces of ca/rbonic oxide, if the oxidation is not complete. This gas is highly poisonous, entering the blood and rendering the red corpuscles incapable of per- forming their function, even though pure air be after- ward supplied. Death is the result of asphyxia. In rooms heated by stoves the headache, languor, and op- pression occasionally produced are due to the escape of this with other gaseous products through the open stove- doors and leaky joints. Some experiments of St. Claire Deville and Troost indicated that the carbonic oxide might even pass through the pores of cast iron when the metal became strongly heated. The French Academy, therefore, caused an investigation to be made of this sub- ject, and the conclusion was reached that carbonic oxide does pass through the metal when its temperature reaches a dark-red heat. Since these experiments air heated by furnaces or cast-iron stoves has been regarded as in- jurious. But doubt has been thrown upon the results of the French chemists by several later experimenters, and particularly by Professor Reinsen, of Baltimore, Md., who has shown some possible sources of error, and who, having guarded against these, has concluded that, while carbonic oxide may be present in the air of furnace- heated rooms, it must exist in quantities so minute that it is questionable- if it can act injuriously on the health of those who breathe it. Carburetted hydrogen and sulphurous acid are liber- ated during combustion, but in such small quantities that they need not be considered as influencing the health. The gases evolved during the putrefaction of organic matter, as in impure soils, manure piles, cesspools, vaults, .drains, and sewers, consist of carbonic acid, nitrogen, sul- phuretted hydrogen, ammonium sulphide, carburetted hydrogen, and organic vapors. The action of the sul- phur gases on the animal system has been demonstrated experimentally by Barker on dogs and other small ani- mals. Sulphuretted hydrogen produces vomiting and diar- rhcea, prostration and coma, which last, like the effects of carbonic oxide, persist after removal from the con- taminated atmosphere. The exhaustion and coma con- tinue, and death results if the impression fixed on the blood is sufficiently powerful. But, while this undoubt- edly occurred in the subjects of Dr. Barker's experi- ments, it is well known that men may breathe with im- punity for a time a sulphuretted atmosphere many times stronger than those employed by him. Sulphide of am- monium, according to this experimenter, caused vomit- ing and febrile action, quickly followed by the develop- ment of a typhoid condition. In fact, he considered the sulphuretted hydrogen similar in its action to the poison of typhus, and sulphide of ammonium to that of typhoid fever. Chronic poisoning by sulphuretted hydrogen mani- fests itself, according to some observations, by gi-adual prostration, emaciation, anri anaemia, with headache, foul tongue, anorexia, and the occasional eruption of boils, but it is not certain that these symptoms are due to this gas and not to organic miasms which may accompany it. 93 Air. Air. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. The action of the more complex organic vapors given off during decomposition has not been determined. 1 he dogs subjected by Dr. Barker to the cesspool air were all more or less affected, the symptoms being those of intes- tinal derangement with prostration, heat of surface, dis- taste for food, and those general signs which mark the milder forms of continued fever common to " the dirty and ill-ventilated homes of the lower classes of the com- munity." But the sulphur compounds already men- tioned contributed to these results. Even the constitution of these organic vapors is not known with certainty. Dr. Odling distilled half a gal- lon of the liquid contents of a cesspool until all alkaline matters had come over He treated the fetid ammoni- acal distillate with hydrochloric acid, and afterward pre- cipitated with platinum. The platino-chlorides of the organic alkalies were found to crystallize in well-deflned, flattened, orange-colored tablets, evidently not the platino- chloride of ammonium. Incineration of this platinum salt yielded 41. 30 per cent, of the metal, while the platino- chlorides of ammonium, methylamine and ethylamine gave respectively, 44.36, 41.64, and 39.40 per cent, of platinum. The salt formed from the carbo-ammoniaml vapors was analogous in composition to that formed with methylamine. But inasmuch as the crystals were more like those of the ethyl salt, and as a mixture of the ethyl- amine and ammonium salts would correspond in per-, centage composition to that obtained from the distillate, he supposed .that the sewage emanations were ammoni- acal and ethylic. A series of experiments made by the writer has shown that the volatile matters evolved during the fermentative changes in organic substances are of two different char- acters, the one vaporous and ethylic, but not containing nitrogen if separated from the ammonia with which it is volatilized and condensed, and the other volatile, car- bonaceous, and solid, concreting on distillation into white, soft, and greasy particles. The former has a dull, mawkish, not positively unpleasant, odor, the latter a strong and intensely disagreeable smell. The solid matters disseminated in the air consist, first, of minute particles of inorganic matter, such as soot, amorphous silicates, irregular fragments of hard mineral dust, and crystals of salts, many of which have not been identified ; secondly, of the detritus of decaying vegeta- tion, starch-cells, epidermal hairs, filaments from the pappus of the compositae, pollen grains, etc. ; thirdly, of fragments of animal tissues, epidermal and epithelial scales, woolly fibres, plumelets of feathers, butterfly scales, and other debris of insect life, etc. ; and fourthly, of micrococci, bacilli, the spores of fungi, and rarely the germs of infusorial life. It is probable that among the micrococci and spores are included the essence of many of the specific diseases which affect the vitality of the higher organisms. (See Bacteria.) The microscope has separated the organic matter of the air into the living and the dead, the animal and the vegetable, and biological experiment has determined the life history and function of many of these living forms. On the other hand, chemistry has done but little to per- fect the oi-ganic analysis of air. "With known methods of analysis the results obtained by the expenditure of much time and care are of small value. If an air-speci- men contains an unusual amount of the organic ele- ments, it may be correctly considered as impure, but the nature of the impurity is not defined. The. carbon esti- mated may have been a harmless particle of soot, or in part it may have been essential to the spread of a deadly disease. Nevertheless, analyses are made as a matter of official routine by sat''tary officers in England and France. The organic substani, ?s are absorbed by aspirating large volumes of the air thi ugh a small volume of distilled water, and the liquid menstruum is then investigated by the processes of water analysis. Professor Remsen, of the Johns Hopkins University, Baltimore, Md., endeav- ored to improve on this process by filtering the air through powdered and moistened pumice before pass- ing it in fine bubbles through the distilled water. He thus snowed that, so far as could be determined by chemical means, all nitrogenous matter was retained by the filter. But, as germs or microscopic organisms might have passed through without thus showing their pres- ence in the absorbing liquid owing to the necessarily minute trace of nitrogen in them, the writer planned and carried out for the National Board of Health a series of experiments which determined, first, that the nitrogenous matter of air, excluding ammonia from consideration, is particulate ; second, that it consists in large part of micro-organisms ; and third, that filtration through Aus- trian glass-wool effects their removal from the passing air. The experiments were conducted in a sterilized ap- paratus. The air was drawn through a short glass tube one centimetre in diameter, lightly packed for two or three inches of its length with the glass wool. From this it was passed in fine division through pure distilled water. After this it was mixed with pure steam gener- ated from a dilute solution of alkaline permanganate of potash, the mixture immediately entering the tube of a Liebig's condenser, where the steam was deposited, car- rying down with it, after nature's process of air purifica- tion by the rainfall, any micro-organisms which might have escaped removal by filtration or absorption. The ditficulties in the way of sterilizing th^ various parts of this apparatus were such that the first experiments, which gave speedy developments in culture-liquids tainted by the filter, the absorbing liquid, and the condensate, were regarded only as the practical expression of these difficul- ties. The experiments were repeated with precautions suggested as necessary by the previous experience, and- ultimately success attended them. The culture-liquids, tainted with portions of the filter, became turbid in from two to nine days. Those impregnated with a portion of the water in the absorbing flask generally remained un- changed at the close of the experiments, three months and ten days after the date of the first one completed. Those tainted with the condensate became hazy usually a few days later than the liquids containing the filter taint ; but in two instances there were no developments, and in two others the haziness did not occur until three and five weeks, respectively, had passed. In comparing the results of cultivation "in the case of the filters with the stability of the culture-liquids in presence of the water from the absorbing flasks, it is evident that germs were removed by the glass-wool ; but that this removal was not thorough is manifested by the fecundity of the con- densate. Germs escaped the filter and passed through the distilled water in the air-bubbles, to be subsequently deposited with the vapor in the tube of the condenser. Ammonia, in like manner, in part escaped absorption, and was condensed. Nevertheless, the efficiency of the filtration must, in general terms be admitted, since, in cer- tain instances, the condensate failed to induce change in the culture-liquid. The mass of the matters collected respectively on the filter, in the absorber, and in the condenser were sub- mitted to chemical examination, the result showing the absence of organic nitrogen on the distal side of the glass- wool. One of the processes of water analysis to which these matters were subjected involved the distillation of the ammonia which was present in the liquid, and its estima- tion by the calorimetric method with Nessler's solution. Ammonia gives, with this test solution, a faint straw- yellow color, which deepens, in proportion to the amount of ammonia present, to a dark sherry-brown, or to a dark haziness or distinct precipitate. But it not unfrequently happened that in testing for ammonia in the distillate from the pure water in which the glass-wool containing the organic matter of the air was suspended, as well as in that from the absorbing liquid which contained most of the ammonia, and in that from the condensate which con- tained but a trace, a citron-green color was produced which marked the ammonia reaction and rendered its es- timation impossible. Dr. Kidder, of the Navy, observed this interference with the ammonia coloration, and at- tributed it to the presence of substances evolved in the putrefaction of organic matter. He concluded from the few experiments he made that the amines are not neces' 96 REFERENCE HANDBOOK OP THE MEDICAL SCIENCES. Air. Air. sarily concerned in its production, as he found that buty- ric acid gave a somewhat similar interference to that met with in the experiments on air-washings. But the hazi- ness with which the presence of butyric acid masks the true ammonia color is not the citron-green coloration which so frequently occurs in the analysis of foul airs. This is due to the presence of an ethyl compound which is given off from the carbohydrates while undergoing change. It may be obtained free from the ammonia which ordinarily accompanies it and obscures its reac- tion by submitting the liquid containing both to the pro- cess of nitrification. It may also be obtained f fom am- monia and free glucose, and from starch, cane-sugar, tan' nin, salicin, etc., after treatment with heat and acids. (See Water Analysis.) In some of the experiments referred to, the air volume, 100 litres, was passed through the interior of a glass globe which contained liquid sewage and silt, garbage, or other foul and decomposing materials, and then through the glass-wool filter, absorber, and condenser to remove the matters with which it had become contami- nated. Culture experiments showed the satisfactory re- moval by the filter of all germs and nitrogenous matters, ammonia excepted and. chemical tests determined ap- proximately the quantity of organic matter thus removed. In some inst&nces a second air-volume of 100 litres was drawn over the organic matter in the globe, and the results obtained from the filter through which it was after- ward passed did not differ from those of the first experi- ment on the same organic matter. From these experi- ments the conclusion appears admissible that the volume of air which is contaminated by a certain decomposing organic mass is the volume which comes in contact with it. If no air is drawn through the foul globe, only that which is contained in it is rendered impure. This air has its oxygen in time replaced by the foul-smelling gases of decomposition. Evaporation takes place from the con- tained liquid until the stagnant and enclosed air becomes saturated. The ascensional force of the evaporation car- ries from the smeared and half -dried sides of the globe, and from the unsubmerged solids within it, some of the innumerable micro-organisms with which they are per- vaded, and the air becomes charged with organic particles to an extent proportioned to its temperature and hygro- metric condition. If a volume of air is drawn through the globe it will be contaminated by organic matters car- ried away by its own movement and by the increased ac- tivity of evaporation produced by it. If a second volume is drawn through, it will be contaminated in like manner, and to the same extent if the volume, rapidity of passage, temperature, and hygrometric condition are the same in both instances ; and so for a third, a fourth, or more vol- umes, until the decomposing mass has become changed by their agency. This is recognized practically in sani- tary work. The dead are buried that their decomposi- tion may not contaminate the atmosphere. For the same reason garbage is collected and removed. A receptacle for foul-smelling and fermenting matters is less of a nui- sance and less dangerous to health when fitted with an air-tight cover than when freely exposed to the air, for in the latter case every volume of air which comes in con- tact with it is a volume of air polluted. Sanitary of- ficials in growing cities protest against the continued ex- istence of small surface streams which of necessity pass into the condition of open sewers, tainting every volume of air which comes in contact with their foulness. These are bricked over and the air is preserved from the impure contact. But in the construction of regular systems of sewerage provision is made for this contact under the name of ventilation. The sewers are tapped at regular intervals along the streets for the exit of the contaminated air. From the present point of view this ventilation of the sewers is of questionable benefit. The volume of air rendered impure, and possibly dangerous, is proportioned to the thoroughness of the ventilation. Sulphuretted tases may be diluted, and the outflowing air be free from isagreeable odors, but the very air movement which ef- fects this may raise invisible clouds of fermentative and morbific agencies from the foul interior. Experiments Vol. L-7 on this point would be of value. Those mentioned above seem to indicate that the communication with the outer air should only be such as is needful to relieve tension and prevent the forcing of seals, and that these air-holes should be guarded by some filtering material. But since the volume of air which becomes contaminated is that which comes in contact with the fermenting material, it may be reduced as well by diminishing the extent of the impure surface as by cutting off the ventilation. Hence sewers of small size, as in what is known as the separate system, are to be preferred, on sanitary grounds, to the large ramifying caverns of the combined system ; while the Liernur system must be regarded from this point of view as the perfect method of sewage removal. The foul airs which arise from sewer apertures are matters of every-day observation. If well diluted with air they may not affect the sense of smell, but they rise, nevertheless, from the grated covers on our streets, and may be seen, by the vapor precipitated from them, as an uprising col- umn in weather which clouds the air of respiration thrown out from the lungs. With open streets and lively breezes it is probable that these exhalations are dissipated, or rather diluted, to harmlessness, but in enclosed spaces and stag- nant atmospheres the sewer-air, which is so carefully ex- cluded from living-rooms by intelligent plumbing, may enter as fresh air through open windows and apertures specially devised for its admission. The influence of these particulate organic matters of the air on the health of those exposed to them will be dis- cussed under the caption Miasms. Before leaving the consideration of air in its sanitary aspects, it is needful only to refer to the influence of cer- tain climatic factors, which operate in a great measure through its medium. These are heat, moisture, and move- ment. The influence of varying barometric pressures usually finds an expression in the temperature. Heat is of importance in the generation and evolution of miasms ; but aside from this the degree of temperature of the at- mosphere ,s of importance to the animal economy, ac- cording as it does or does not necessitate an unusual activity of the vital energies, for the preservation of the animal heat. Moisture acts chiefly by interfering with the natural cooling process effected by evaporation from the skin. But the principal factor in the determination of climatic influences is the wind. The absolute tem- perature as recorded by the thermometer gives but im- perfect information regarding climate, unless supple- mented by a cotemporaneous report of the air movement, and unless the medical climatologist is able to appreciate and express in definite terms the change made by this movement in the value of the temperature. Zero Centi- grade, with no wind blowing, is one set of climatic con- ditions ; the same degree of absolute temperature, with a steady breeze of ten miles an hour, forms a wholly different climate. What is manifestly required is a ther- mometer which will enable us to say now cold it is to the feel, or, in other words, with what rapidity the animal heat is carried away under a given set of atmospheric conditions. The amount of labor which has been expended in the routine work of keeping meteorological records in the past has been enormous. These have been compared with fragmentary records of sickness and mortality, and the concurrence of cold with certain diseases of the res- piratory organs, and of heat with disorders of the diges- tive system, has been repeatedly presented, while lines have been drawn showing the fluctuations in the annual course of many diseases which are influenced directly or indirectly by temperature. Nothing more is to be ex- pected from such work. If there were on the record as many and as continual observations on the temperature of the soil in miasmatic regions as there are of the air, our knowledge of the fermentative processes which are con- nected with the exhalation of disease-poisons, or with the manifestation of disease-causes, would be more advanced. There is a field for work in this direction, which sanitary observers might cultivate, since the Signal Service Bureau has relieved them from the labor of taking the meteoro- logical notes. Charles Bmart. 97 Air-Passages. Air-Passages. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. AIR-PASSAGES, Foreign Bodies in. Nose.— The presence of foreign bodies in the nose ' is of common occurrence. The list ' of them comprises extraneous substances introduced either through accident or design by infants or insane adults ; sequestra of dis- eased bone ; and parasites. The history is usually as follows : A child of about two, old enough to creep, but not sufflciently intelligent to know better, thrusts some small, rounded object, such as a bean or a shoe-button, which it has found upon the floor, into its nostril. If the child be not cauglit in the act the body may escape immediate detection. Soon symptoms of chronic inflam- mation are established. Tliese are confined to the nostril in which the body is, and continue until it is removed, the irritation often being severe and the discharge ex- ceedingly fetid. The mucous membrane adjacent to the foreign body is in a condition of superficial erosion. The body, if too firmly impacted to be dislodged by simply blowing the nose, remains fixed, usually in the inferior meatus, until removed by the surgeon. Removal should be attempted by means of a hooked probe or fine forceps. The sensitiveness of the nasal cavity should be borne in mind, and if, after two or three gentle and carefully directed efforts success be not attained, an ansesthetic (chloroform to a healthy child under six) should be given, and the removal of the body carefully acconiplished. Copious hsemorrhage, lasting two or three minutes, often follows, but is generally of little moment. The nostril should be washed several times a day with a weak disin- fectant, preferably a solution of potass, permanganate. In four or five days the membrane will often have healed so completely that no trace of trouble can be seen ; the discharge ceases entirely, and cure is complete. The possi- bility of the presence of a foreign body in all cases of fetid discharge confined to one nostril should always be remem- bered, and the nostril having been cleansed with a warm douche, examination should be made with probe and specu- lum. In simple cases a gentle stream of salt warm water carried through the free nostril and out of the other, or a sternutatory, will sometimes succeed. If the object be lodged far backward care should be taken in removing it not to allow it to fall into the larynx. Rhinoliths ' are merely calculi formed by an accumulation of the earthy salts of the nasal secretions around some foreign body or inspis- sated mucus. Their presence has given rise to such irrita- tion that they have been mistaken for cancer. Careful ex- amination and the history of the case will easily establish the diagnosis. If they are too large to be readily removed they should first be crushed by a lithotrite of proper size. Sequestra of bone, particularly in tertiary syphilis, some- times remain in the nasal cavity after their separation, thus acting as foreign bodies. They must be thoroughly removed preliminary to further local treatment. Parasites. — In tropical countries, seldom elsewhere, various kinds of flies, of the order muscidm, may enter the nasal cavity, preferably of a patient suffering from catarrh, and there deposit their eggs." These are quickly hatched, causing in succession irritability, tickling, and sneezing ; later, formication, bloody discharges, and epis- taxis, with oedema of the face, eyelids, and palate ; ex- cruciating pain, generally frontal, insomnia, and if the condition be unrelieved, convulsions, coma, and death. Sometimes the larvae are sneezed out. or may be seen on examination of the parts. This will, of course, establish the diagnosis. Destruction caused by the larvee may ex- tend to the mucous membrane, the cartilages, and even the bones of the head ; the ethmoid, sphenoid, and palate bones having been found carious. Where the maggots have entered the frontal sinus, or the antrum of Highmore, injec- tions of tobacco or alum, or insufilations of calomel for- merly used, will be of little use. Chloroform or ether,' pre- ferably the former, either inhaled or driven into the nasal recesses in the form of spray, is the sovereign remedy as under it the larvae are not killed, to remain in situ and tlius cause further trouble, but escape with all haste to the outer air. Meanwhile, opium should be given to allay pain, and the patient's strength carefully sustained. Leeches, ascarides, earwigs, and centipedes • have been 98 found in the nose, causing insomnia, frontal pain, sanious discharge from the nose, Tachrymation, vomiting, and, iq some cases, great cerebral excitement. Sternutatories are generally suificient for their expulsion. It may be necessary, however, to trephine the mastoid. Tonsils. — Three general varieties of foreign bodies may be found in the tonsil : 1, Foreign bodies proper, or substances which have become lodged in the tonsil during deglutition; 3, tonsillary concretions or calculi; 3, par- asites. The last two conditions are not common; the first will te described under Foreign Bodies in the Phar- ynx. Tonsillary calculi are formed in the lacunae of a chronically inflamed tonsil by a perverted condition of the natural secretions, and their retention in the lacuna by closure of its outlet. They vary in size, seldom at- taining a greatet diameter than three-fourths of an inch, and consist of phosphate and carbonate of lime, some iron, soda, and potassa, with varying proportions of mu- cus and water. Hence, they are not necessarily of gouty origin. The symptoms, generalljr not prominent, may be slight pricking of the throat with, occasionally, dyspha- gia. The presence of the calculus is sometimes directly irritating, and may give rise to quinsy, ulceration of the cavity, and abscess. Diagnosis, by ocular examination or the use of the probe, is usually easy, as is the removal of the calculus by means of a forceps. Sometimes, however, the mass is so completely covered that it is only seen upon removal of the tonsil. In most cases the latter operation will afford the most certain cure. Very rarely hydatids and trichocephali have been found in the tonsil. Phakynx. — The frequency with which foreign bodies are arrested in the pharynx, and their variety, are very great. Certain individuals seem especially liable to this accident, either from carelessness in eating, insensibility of the parts, or from some unusual irre^ilarity in the pharyngeal walls. Foreign bodies of large size generally lodge in the lower part of the cavity, where the cricoid and arytenoid cartilages project backward, or between the base of the tongue and the epiglottis. Small and sharp-pointed bodies may become fixed at any part of the pharynx, particularly in the tonsils, on account of their exposed portion and the irregularity of their surface. They may also be entangled in the pillars of the velum, or in the lateral folds of the cavity. A large body may be found stretching across the whole width of the phar- ynx. Symptoms.— JuOC&X pain, dysphagia, occasionally in- flammation with ulceration or abscess of the pharynx, but generally localized inflammation and irritation. If an abscess be formed, the body may escape through a fistulous opening in the neck, or it may perforate some important blood-vessel, or even penetrate the interverte- bral substance and cause caries of the vertebral bodies. Inflammation of the pharynx may give rise to dyspncea, while a large foreign body may cause suffocation by ob- structing the entrance to the larynx. The diagnosis can generally be established by the his- tory of the case, and by inspection of the pharynx. Ner- vous patients often insist upon the presence of a foreign body in the throat, despite all assurance to the contrary, particularly if the pharynx be sensitive, or , as often happens when a hard substance may have caused a slight laceration of the mucous membrane while being swallowed. Treatment. — The patient's tongue should be well de- pressed, and the upper parts of the pharynx carefully ex- amined in a strong light. If the foreign body does not then appear, search should be made for it in the region of the base of the tongue, the glosso-epiglottic sinuses, and the upper portion of the larynx, with the tip of the finger, or, better still, by the aid of the laryngoscope. If present, it will generally be found without much difficulty, and should be removed by the finger or by a suitable forceps or probang. If dyspnoea be urgent, immediate surgical in- terference, of a nature suited to the special features of the case, either tracheotomy, thyrotomy, or, if possible, some form of sub-hyoidean pharyngotomy, may be required. The sensations of the patignt are often unreliable, and REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Air-Passages, Air-Passages. the sense of irritation caused by the presence of the body may continue for a long while after its removal. This is relieved by swallowing small lumps of ice, and later, if necessary, by the application of astringents and galvan- ism. Labtnx. — By reason of the danger to life which at- tends the lodgment of a foreign body in the larynx, this condition becomes one of the most important in surgery. The variety of objects found is infinite, and may be thus divided : Alimentary matters, introduced during mastica- tion, in the act of laughing or talking, in deglutition, or in inspiration during vomiting ; metallic bodies, such as coins, buttons, puff-darts,' etc.; teeth, artificial or natural, necrosed bone' from neighboring regions, as from the nose in tertiary syphilis, and fragments of the laryngeal car- tilages themselves, as thrown off in the late stages of syphilis, tuberculosis, and cancer of the larynx. Foreign bodies in the trachea may pass upward and become im- pacted in the larynx ; and, rarely, they may gain access to the larynx directly from without, by forcible penetra- tion of its walls, as in the case of bullets.' Again, the epiglottis may become incarcerated in the larynx,'" or oc- clusion take place from the so-called swallowing of the tongue." The symptoms vary with the size and position of the object. Thus a large body fixed in the rima glot- tidis may, unless dislodged, cause almost instant death. Again, small bodies lodged in out-of-the-way corners may remain indefinitely, causing nothing more than cough and discomfort. Dyspnoea may occur days after the reception of a foreign body, from inflammation and tumefaction of the soft parts of the larynx, and danger from the presence of a foreign body may suddenly become imminent from alteration in the position of the body. Great peril Some- times arises from violent spasm of the glottis, due to irri- tation caused by the foreign body. Mental anxiety and localized pain are prominent symptoms in cases in which the accident does not immediately threaten life, while ac- tive inflammation is speedily set up. A cautious prognosis must be given, even after removal of the body, as long as there are any symptoms of local inflammation. The dickg- rwsis is established by the history of the case, verified or otherwise by laryngoscopic examination. The greatest difficulties arise with children too young to express them- selves, in whom pain in the throat, and symptoms resem- bling croup, will often be the only indications obtainable. Here the laryngoscope will be indispensable. Treatment. — The offending body should, of course, be at once removed ; if possible, through the natural pas- sages and by means of the laryngeal forceps, aided by the laryngoscope, in case the symptoms are not urgent. If asphyxia threaten, tracheotomy should be done at once, and the foreign body afterward extracted as described above. Bodies at first immovable may sometimes be loosened by reducing the local inflammation. In rare cases, where the object has become firmly impacted, thy- rotomy Inay become necessary. A case is recorded m which a needle, transfixed in the larynx, was pushed through the anterior laryngeal wall, and thus removed." Tkachba and Bkonchi. — Any body which can pass through the rima glottidis may, of course, find its way into the trachea under the same circumstances described under the head of Foreign Bodies in the Larynx. Sharp objects lodged in the oesophagus, and even diseased bronchial glands, may work their way through the walls of the trachea, and into its cavity. Parts of instruments used in intra-laryngeal operations, and of tracheal canu- lae," laryngeal brushes, and even bits of solid nitrate of silver, occasionally, through accident or carelessness, drop into it. If too large to enter either main bronchus, the body will probably remain at the bifurcation. Otherwise it will pass into one bronchus or the other, preferably the right, on account of its anatomical position, in the propor- tion of five to three, and thence travel indefinitely into one of the more remote bronchial divisions. The symptoms will depend upon the nature of the body and its exact situation in the lung. Small objects have remained encapsulated with mucus for years with- out causing discomfort or serious results. Smooth, rounded bodies irritate less than irregular ones. Inflam- mation of the lungs from a foreign body may occur, the presence of the body being unknown. Large objects and fluids may cause death by instant suffocation, or death may result in the course of a few minutes, the symptoms presented being urgent dyspnoea, frantic efforts at relief on the part of the patient by thrusting the finger down the throat, rushing to the window for fresh air, and mak- ing great inspiratory efforts, while cyanosis quickly fol- lows, and if aid be not speedily afforded, death, with all the signs of asphyxia. Severe dyspnoea, followed by re- lief without extrusion of the foreign body, indicates that the body has probably dropped from the larynx into the trachea. Dyspnoea is, of course, more urgent when the trachea is occluded than when the foreign body only stops one bronchus. The body may change its position, pass- ing from one bronchus to that of the opposite side. A body, small when swallowed, may become more danger- ous through increase in size, either by swelling from im- bibition of water, or by forming the nucleus of a concre- tion. Physical signs from the preseuce of a foreign body in the lung may be altogether wanting, but are generally more or less distinct, the symptoms being whistling or flapping sounds at the point of lodgment, pain, and de- creased fremitus, with absence of respiratory murmur in the lung beyond. Diagnosis is often very difficult. At or about the bifurcation the body may be seen with the laryngoscope. The lodgment of a foreign body in the lung may result in pneumonia, tuberculosis, abscess, or gangrene. Or, it may become encapsulated and do no apparent harm. Rarely a body, generally an ear of bar- ley or other grain, havmg formed an abscess of the lung, has been discharged through the wall of the thorax, with complete recovery." Diagnosis. — The fact that some foreign body has been inhaled should be established if possible, and the site of the body determined. In children and incompetents, and in cases where the dyspnoea is urgent this may not be easy. The laryngoscope is useful m excluding the pres- ence of the body from the larynx, even if it be not visible in the trachea. The prognosis is serious, depending upon the nature of the body, the amount of dyspnoea, and the organic lesions which may result. The period of greatest danger is at the first, and although this diminishes in varying degree as time passes, it is never entirely absent. Even after expulsion death may occur from the organic disease set up. The expulsion of one object does not, especially with children, preclude the possibility of others remaining in the lung. Treatment. — Since the publication of Professor Gross's admirable article the necessity for operation in cases of for- eign body in the trachea has been an accepted law. Re- cently Weist has ably shown that the conclusions arrived at by Gross and Durham are, to some extent, misleading. His conclusions are based upon 937 cases of foreign body in the air-passages ; of these, 599 were not subjected to bronchotomy ; 460 recovered, or 76.79 per cent. ; 139 died, or 23.30 per cent. Bronchotomy was performed in 338 cases, with 345 recoveries, or 73.48 percent. ; 93 died, or 37.43 per cent. ; a difference in favor of non-interfer- ence of 4.31 per cent. Comparing the statistics with those of Gross and Durham, the former shows, in cases without operation, 11.03 per cent, more recoveries than those of Gross, and 19.39 per cent, more than those of Durham, and 7.34 per cent, more than the aggregate of the cases of both Gross and Durham. In cases operated on, Weist shows 12.31 per cent, less recoveries than Gross, 1.40 less than Durham, and 4.29 less than the cases of both combined. Of the whole number of cases studied, 1,674, there was one death in 3.5 cases without operation, and one death in 4 with operation. Bronchotomy, there- fore, has not shown such good results over non-interfer- ence as to justify unvarying recourse to it, so that the policy of awaiting spontaneous expulsion is often justi- fied. Since certain classes of foreign body, such as water- melon seed, corn, coffee bean, etc., are much more easily expelled from the air-passages than others, the nature of the substance, aside from other indications, must influence the decision as to the propriety of immediate interference. The conditions demanding speedy operation are : 1. Ur- 99 Air-Passages. Ajaccto. REFERENCE HANDBOOK OE THE MEDICAL SCIENCES. gent and dangerous symptoms, as progressive dyspnoea, or frequently occurring attacks of dyspnoea, or laryngeal spasm, when laryngoscopic examination fails to find the object or shows that its speedy removal by the natural passages is impossible. 2. Where a sharp and irregular body is impacted, as shown by the laryngoscope, in such a way that immediate extraction is impossible, and where acute inflammation, and especially osdema, are rapidly occurring, as evinced by increasing dyspnoea. 3. In the case of a foreign body of any nature, loose in the trachea, movements of which excite laryngeal spasm or cough of dangerous violence. 4. In case of a foreign body im- pacted in either of the primary bronchi, as ascertained by the rational and physical signs, particularly by ausculta- tion. Here low tracheotomy and immediate direct at- tempts at extraction are often successful. Direct exami- nation of the site, and demonstration of the foreign body in or at the mouth of a bronchus, by means of the fin- ger introduced quickly into the trachea, are possible, and this knowledge renders the subsequent instrumental re- moval of the body more easy. 5. Sharp-pointed, hard, and. irregular bodies within the air-passages will, as a rule, demand bronchotomy, provided they are not so lo- cated that they may be reached and removed by the nat- ural passages at an early momerft. The plan of treat- ment by inversion of the patient has of late years fallen into disrepute, and should seldom be practised, unless tracheotomy can be done at once it required. In em- ploying it, it should be remembered that the supine position will favor exit of the body, particularly if the glottis be in the condition of deep inspiration. In all cases the diagnostic importance of a thorough laryngo- scopic examination cannot be too strongly insisted upon, nor the great utility of the laryngoscope be overesti- mated. Bibliography. GroBs: Foreign Bodies In the Air-pafwages. Philadelphia, 1854. Bourdillat : Gazette de Paris, 1868. Nos. 7 to 16. Kuhn : Gi&nthers Lehre v. den Blut. Operat. v. Abtheil. Durham : Holmen's System of Surgery, vol, ii. Sanders: Foreign Bodies in the Air-passages, with Bibliography, Deutsch. Archiv. filr klin. Med,, 1875. Bd. xvi., Hefte 3. Johnson : Lancet, October 13, 1878. Leaming: Growths and Foreign Bodies in Air-passages, Diagnosis and Surgical Treatment, New York Med. Becord, 1879., xv., 808. Wagner : Ziemssen's Cyclopsediii, Holmes's System of Surgery. Morell Mackenzie : Diseases of Throat and Nose. London, 1880. I^lsherg: Archives of Laryngology, vol. iii., p. 275. Weist: Transactions American Surgical Association, vol. i. 188.3. Voltolini: The Operative Removal of Foreign Bodies and New Growths from the Air-pasaages. TraDsactions Eighth International Med. Congress. LcSerts ; Transactions Eighth International Med. Congress. D. Bryson Ddavan. "TUlanx: Soo. do Chirurg., January 26, 1876; also, Bron : Gazette Med. de Lyon, 1867, No. 36. I MoreU Mackenzie : Diseases of Throat and Nose.. London, 1880. = Sohmiegelow : Trans. Eighth Inter, Med. Cong., 1884. 4 Buchanan : Phila. Med. Times, October 30, 1875. = John Ellis Blake : Boston Med. and Surg. Journal, April 10, 1862. To Dr. Blake belongs the credit of having first discovered and reported this method of expelling larvie from remote sinuses. » Packard : Phila. Med. and Surg. Reporter, August 3, 1878. ' Bruce : London Lancet, February 18, 1863. * Lincoln : Archives Laryngology, vol. iii., p. 276. • Daly : Gunshot Wounds of the Larynx. Trans. American Laryn- gologlcal Association, vol. vi., p. 47. '» Cohen : Phil. Med. and Surg. Reporter, March 16, 1878. II Ingals: Trans. Araer. Laryngolog, Assn., vol. il., p 135 '2 Field : N. Y. Med. Record, March 10, 1877. '2 Cohen : Diseases of the Throat. New York, 1879. " Howell White: N. Y. Med. Record, September 10, 1881. AIX-LES-BAINS (a station on the railroad which runs from Lyons to Turin) is a small town in the Arrondisse- ment of Chamb^ry, in Savoy. It is charmingly situated on the brow of a hill, in close proximity to lofty lime- stone mountains (the Beauges), a spur of the Savoy Alps and not far from the eastern shore of the Lake of Bour- get Its elevation above the sea-level is about 900 feet and above the lake about 100 feet. Climate mild • air and ordinary drinking-water both pure. Hence critins and those affected with goitre are rarely seen here There are two thermal sources which, in chemical com- position and in the temperature of the water, differ only 100 very slightly from each other. These are the Source de Soufre and the Source d'Alun. According to Boniean the temperature of the sulphur spring is 45° C. (113 F.)' and it contains in 1,000 parts : ' ' Sodium sulphate 0,0960 Magnesium sulphate o!o352 Calcium sulphate oioififl Aluminium sulphate ; *[ 0.0548 Sodium chloride 0.0079 Magnesinm chloride 0.0172 Calcium fluoride. ( ' * Calcium and aluminium phosphate, J U.0024 Potassium iodide Traces. Calcium carbonate 0.1485 Magnesium carbonate 0.0958 Ferrum carbonate 0.0088 Silicon hydrate 0.11050 Organic matter Traces. Total of fixed elements 0.4176 The unstable elements in 1,000 cubic centimetres of the water are represented as follows : Hydrogen sulphide 27.24 c.c. Carbon dioxide 13.07 c'c! Nitrogen 25.46 cio! The alum spring has a temperature of 46.5° C. (115.8° F.), and its chemical composition is but little different from that of the sulphur spring. However, it is not so much to the chemical composi- tion of its waters that the hot springs of Aix owe their great celebrity, as it is to the systematic manner in which these waters are used. Durand-Pardel speaks of the es- tablishment of baths in Aix as pursuing a genuine sys- tem of thermal hydrotherapeutics. In this respect it may be compared with Aachen and Luchon. The principal form of bath employed is the douche, which is administered in a variety of ways, and usually in connection with massage and frictions. After the ap- plication of the douche, the patient takes a warm bath in the so-called " Bouillon," in which the water is kept in constant motion. The energetic and exciting methods employed at these baths render them especially efiBcacious in cases of rheu- matic or gouty exudations, m scrofulous swellings of the periosteum, or of the parts surrounding the joints, etc. They have also proved useful in cases of muscular atrophy, caries, contractures, etc.; in chronic affections of the skin, and in syphilis ; in affections of the larynx and pharynx ; in chronic bronchial catarrh ; and, finally, in quite recent times, in uterine affections. (Eulenburg.) Henry Fleisehmr. ALAP, a Hungarian village with railway connections, is divided into upper and lower Alap, each of which con. tains a remarkable spring of pure and very strong bitter- water ; in fact that of lower Alap is one of the strongest natural bitter-waters known. The waters of lower Alap are also used for bathing. In 1,000 parts, by weight, there are : Upper Alap, Lower Alap. Magnesium sulphate 3.13a parts. 4.094 parts. Sodium sulphate 5.711 " 18.149 '* Calcium sulphate ". 1.828 " o!260 '* Sodium chloride 4.186 " 14!486 " Totalsolids 16.549 parts. 37.6S5parts. S. F. ALBANY ARTESIAN WELL. Location, Ferry Street, Albany, N. Y. . j • Analysis. — One pint contains : „ Grains. Carbonate of soda 6.00 Carbonate of magnesia !'.!!'.*.".!'.'..!*.*.!...!*...*!" 2.00 Carbonate of lime ..!.!'.!!.....!!!!!!!!!!! 4.00 Carbonate of iron .'...'.".*.'.,...".''".''.".'!! 1.00 Chloride of sodium ......i !'.".!!!!.'.'!. 63.00 IBM Carbonic acid gas, 28 cubic inches. The well is 500 feet deep, and has a temperature of about 53° F. This is a saline-chalybeate water, very similar to the Congress, High Rock, etc., of Saratoga, and, undoubtedly, has the same general source as those springs. G. B. F. REFEEENCE HANDBOOK OF THE MEDICAL SCIENCES. Air-Passages. Ajacclo. ALBINISM. The condition which has been termed albinism consists in a congenital absence of the normal pigment. There are two varieties, the universal and the partial. The first of these is that which is best known. The skin is perfectly pigmentless and white, excepting where the blood-vessels coursing beneath it give it a rose tint. The general condition of the skin is normal, other- wise than as regards the absence of pigment. The hair is white or flaxen in color (in one case reported it was red), of a fine texture, and peculiarly silky sheen. The eye partakes of the anomaly ; the iris is colorless, so that its blood-vessels give it a red hue, excepting in some cases, when viewed obliquely, the interference of light-rays give it a blue color. As a result of the want of pigment in the iris, albinos suSer from photophobia and nystagmus, and are seen constantly blinking the eyelids and rolling the eyes involimtarily from side to side. They see best in the twilight. Albinos are usually of weak constitution, and are apt to be intellectually deficient. Exceptions are known, how- ever, to both of these conditions, and one of the best papers extant on albinism, so it is said, was written by a German albino named Sachs. The only etiological element known or suspected in the production of albinism is heredity, and even this is want- ing in the greater number of cases. It seems probable that the sisters in any given family are likely to be at- tacked rather than the brothers, if more than one indi- vidual is affected. Partial albinism is ordinarily met with in the colored race, the so-called " piebald negroes," and its existence in the white races has been denied. Lesser, however, has recently described a case, and it is believed that instances of congenital partial loss of pigment are not excessively uncommon among the lighter colored races, but that cases have escaped attention. Partial albinism over limited areas has been shown in one case at least by Lesser to fol- low the course of the cutaneous nerve-distribution, as is the case with the pigmented skin in the so-called " nerve nsevus. " One peculiarity of the pigmentless patches in this form of albinism is that the decolorized skin fades gradually into the surrounding integument, whereas in vitiligo the skin immediately surrounding the white patches is more deeply pigmented, giving a sharply defined boundary line. The hair growing over the pigmentless patches in partial albinism is white, although it is a curious fact that in the similar decolorization of the hair, apparently due to the same causes, called sometimes poliosis (see Calvities) the skin underneath may be of normal color. Arthur Van Harlingen. ALBUMINOID DEGENERATION, the term used by the English to denote what is ordinarily called amyloid degeneration, it being supposed that the amyloid material represented a modified form of albumen, an acid albu- men. This has been shown to be wrong. See Amyloid Degeneration. W. W. Gannett. AJACCIO. The town of Ajaccio is situated at the head of a beautiful bay, bearing the same name, which indents the western coast of the island of Corsica. At its mouth (the broadest part) the width of this bay is about ten miles from cape to cape, and it extends inland in a northeasterly direction for about the same distance, having in its general outlines the shape of a letter U or of a blunt-pointed V. At a distance of some twentjr miles from the shores of the bay stand the lofty mountains (six thousand to nine thousand feet high) constituting the backbone of the island, while the outlying spurs of these mountains come down to the sea in such a manner as to afford to the town of Ajaccio an all but complete protection from northwesterly, northerly, and easterly winds, leaving it exposed to the warmer winds blowing from the south and from the southwest. From this ac- count of its situation it would naturally be inferred that the climate of Ajaccio should be a warm one, and, as will presently appear from the statistics of temperature about to be quoted, this inference is entirely correct. In this feature of exposure to the south and shelter on the north, the town gi-eatly resembles many of the celebrated winter resorts of the Italian Riviera, while its somewhat lower latitude should iilsure Its being even warmer than these. Accordingly, it is no surprise to learn that the mean winter temperature of Ajaccio is more than 3.7° F. (1.5° C.) higher than that of the Riviera. The writer of . the article on Ajaccio in "Eulenburg's Real Encyclo- padie," from whose contribution the preceding statement is taken, mentions further that there is less variation in the mean temperature from month to month of the winter season at Ajaccio than is to be found at places lying along the Riviera. The relative humidity of Ajaccio is given by the same writer as varying between seventy and seventy- eight per cent. The average total number of rainy days oc- curring during the months of October, November, Decem- ber, January, February, March, and April, he states to be from forty to forty-flve. The annual rainfall, according to Doctor Hermann Weber in "Ziemssen's Handbuch. der AUgemeinen Therapie," is 24. 8 inches (630 mm.). Dr. Lombard states {Traite de Glimatologie Medicate, t. iv., p. 620) that the average number of perfectly cloudless days at Ajaccio is 136 ; of partly cloudy days, 89 ; and of days on which the sky is completely obscured by clouds, 51. He further remarks that the greatest proportion of cloudy days occurs during the spring months, only 43 cloudless days being observed at that season, on the average, against 49 cloudy ones. The mean temperature at Ajaccio for the year, for each of the four seasons, and for eight out of the twelve months of the year is shown in the following table : % 1 fB ^ 1 O i Izi 1 1 4 ^ 1 ai i a m 1 B fiS.IS SSR5 mm SO.Sfi 54.14 m.i» 59.36 Z 76.'!H fi6.6H 52.16 60,26 Ba.fio H 78.08 66.92 50.86 58.28 63.68 E., Eulenburg'B Real Encyclopadie ; Z., Ziemssen's Handbuch der AU- gemeinea Therapie (Weber) ; H., Hann's Handbuch der Eiimatologie, The dally variation of temperature is never great, not more than 9° or 10.8° F., even in November and Decem- ber ; the evenings are extremely mild, not colder than 50° F., even in February (" Eulenburg's Handbuch"). On the authority of the Drs. Versini, father and son, the climate of Ajaccio is said by Dr. James Henry Ben- net to be a healthy one, and no epidemic disease prevails there, save only malarial fever of a mild type, which visits the town only during the latter part of summer and in the early autumn, its attacks occurring chiefly when the wind blows across from the east shore of the bay, where the Gravone and Prunelli rivers empty into the sea. On the other hand, the writer in "Eulenburg's Handbuch " remarks that the health of the resident popu- lation at Ajaccio is not especially good, which circum- stance he is disposed to attribute to the imperfect hygienic conditions prevailing in the town itself. The soil at Ajaccio is granite, and the surface-water drains rapidly away. The air is free from dust at all seasons. "The vegetation of Ajaccio and the neighborhood indicates a climate at least as warm as that of Cannes and Nice, per- haps even a shade warmer ; the olive, the orange, the prickly pear thrive with great luxuriance. . . . The lemon-tree grows also, and bears fruit out of doors, but only, as at Nice, in very sheltered and very protected spots. . . . The botanical productions of Corsica assim- ilate, as might be presumed, to those of the countries that surround it. The north by its vegetation approximates to the Riviera, the east to the Italian coast, the west to Prov- ence and Spain, while the south, and I may say the en- tire island, shows decided African affinities" (Dr. J. H. Bennet in " "Winter and Spring on the Shores of the Medi- So far as its climate is concerned, the town of Ajaccio presents, in the estimation of the writer in "Eulenburg's Encyclopaedia," greater advantages than any point in Italy as a place of resort for persons suffering from any form of ptilmonary or cardiac disease, or from scrofula, 101 A]acclo. Alcohol. EEFERENCE HANDBOOK OP THE MEDICAL SCIENCES. as well as for invalids merely seeking a quiet and suit- able place of rest. He specifies the three months of February, March, and April as those which it is most desirable for the invalid to select for his sojourn at Ajaccio. The Cours Grandval is generally chosen by .foreigners for residence, lying as it does in the north- western portion of the town, which is the section most protected and best sheltered from the winds. Although it is now no less than twenty-three years since Dr. Ben- net first pointed out, in 1862, "that the exception- ally sheltered situation of Ajaccio, on the western coast, renders It a suitable residence for invalids requiring a moister climate than that of the Genoese Riviera," and that it appeared to him " thoroughly eligible as a winter residence," it is somewhat disappointing to learn from the fifth edition of his own book (1875), and from the abovfe- cited work of Eulenburg, that, despite certain improve- ments in this direction, the character of the hotel accom- modation and the facilities for social life existing in the town still leave something to be desired before the place can become as popular a resort for invalids as it is justly entitled to be. Up to 1880 good accommodations were only to be found at certain of the hotels and in villas (Eulenburg). "Biermann," says Dr. Weber in "Ziems- sen's Handbuch," "speaks favorably of the climate ; H. Bennet and Rohden, who also know the place from per- sonal experience, have high hopes of its future, when the accommodations and the means of communication with the continent shall have been still further improved. My own experience in four cases of pulmonary phthisis af- fecting the apex of one lung, and in two cases of chronic emphysematous catarrh is favorable ; in one case of chronic pneumonia of the right lower lobe, and in two of asthma, unfavorable." Dr. Pietra Santa (quoted by Lombard) describes the climate of Ajaccio as both tonic and soothing in its effect, and as being well suited to cases of scrofula, to chlorotic and anaemic persons, and especially to those suffering from certain forms of pul- monary phthisis ("surtout aux phthlsiques chez qui predomine le lymphatisme et la forme torpide ; il exerce egalement une influence prophylactique pour ceux qui sont predisposes a la tuberculose "). "One of the objects of my visit," say ^ Dr. Bennet, speaking of his exploratory trip to Corsica in the year 1862, "was to find a perfectly cool summer station for the EngUsh consumptive invalids who wish to pass the summer abroad. I found stations such as Arezza and the baths of Guagno, near Ajaccio, which would do very well for healthy persons anxious to escape from the ex- treme heat of Southern Europe during the summer months, but these localities are not sufficiently high and cool to be chosen as summer retreats by invalids. ... On crossing the granite chain on the way from Corte to Ajac- cio we came to a spot between Vivario and Bocognano, called Foci, the most elevated that is passed, which would no doubt do admirably for such a summer sanitarium. We were quite four thousand feet high. . . . The air was cool and pleasant, the sky clear, the mountains very beautiful ; but there was only a small, dirty roadside inn." Malarial fever does not prevail in Corsica, even in the' summer and early autumn seasons, according to Dr. Bennet, at any place having an altitude above sea level of five hundred feet. It is disappointing, after considering the evident desira- bility of the establishment of such a mountain summer resort and its entire feasibility, to judge from the above quoted remarks of Dr. Bennet, to read, as we do in Dr. Hermann Weber's contribution to Ziemssen's work (1880) that " the mountains of the island have not yet been made use of for the establishment of satisfactory places of sum- mer resort." " In the great primeval forests (of Corsica) are to be found wild boars and small game in abundance. In the higher mountains the native race of wild sheep called mouflons, are met with. Their presence in the mountains is a strong attraction to enthusiastic sportsmen. In the alluvial plains on the eastern coast game abounds and m the autumn and winter all kinds of water-fowl are met with in profusion. In the eariy autumn season how- ever, these districts are so very unhealthy that the pursuit 102 of the game would probably be followed by severe fever" (Bennet, op. cit.). Thanks to the good work done in Corsica by the French Government, excellent roads now intersect all parts of the island in every direction, and the entire suppression of the ' ' vendetta " has rendered every portion of the island a per- fectly safe residence for foreigners. For the latest information concerning hotels, etc., and concerning the various lines of steamers which bind Cor- sica to the continent of Europe, the reader is referred to the tourists' guide-books of Murray and Baedecker. A great deal of useful and entertaining information respecting the scenery, history, climate, etc., of Corsica may be found in the pages of the delightfully written work of Dr. Ben- net, from which such frequent quotations have been made in the penning of this article. (See also Gregorovius's "Wanderings in Corsica, its History and its Heroes;" "Notes on the Island of Corsica," by Miss T. Campbell; and several other similar works, all of which are recom- mended to his readers by Dr. Bennet.) Huntington Sicha/rds. ALBURG SPRINGS. Location and Post-office, Alburg Springs, Grand Isle County, Vt. Access. — By Central Vermont Railroad to Alburg Springs Station. Analysis (C. T. Jackson). — One pint contains : Grams, Chloride of sodium 1.095 Chloride of magneBium 0.627 Chloride of calcium and carbonate of lime 0.601 Sulphide of potassium and sulphate of potassa 1 ,2S7 Sulphate of soda 0.887 Insoluble matters 0.100 Organic acid of the soil (crenic acid) and loss 0.250 Total 4.797 Sulphuretted hydrogen, a large proportion. These springs are situated in the extreme northwestern part of Vermont, on Missisquoi Bay, an arm of Lake Champlain. The scenery round about is beautiful, em- bracing lake and mountain views. The climate is salu- brious. (Walton.) G. B. F. ALCOHOL. The term alcohol (Syn. : ethyl hydrate, spiritus vini), once used to signify ethyl hydrate, is now generally applied, as a generic term, to a series of organic compounds, having in common certain chemical charac- teristics, the representative of which class is ordinary alcohol. It is produced by (1) the fermentation of all saccharine bodies, (2) by synthesis in the laboratory. In composition it is a hydrate, i.e., the combination of a basylous radical with HO, and possesses the chemical properties of other hydrates, in forming salts with acids, etc. Pbepakation. — Alcohol is produced by a particular ferment (torula; cerevisise) acting upon saccharine sub- stances ; causing them to split up into alcohol and carbon dioxide, viz. : Glucose CeHisOs Alcohol 2C,H5HO Carbon dioxide. 2COs. Cane-sugar and milk-sugar undergo a conversion first into glucose and then into alcohol. Minute quantities of acetic and succinic acids, also traces of aldehyde, fusel oil (amyl alcohol), and glycerine are produced at the same time. It is an interesting and important fact that the fermentation gradually ceases as the alcohol produced nears eighteen per cent, strength, and when the latter is reached, further action ceases. In the grape-juice, when this strength is reached, if there still be unf ermented sugar, a " sweet " wine results ; if none, a " dry " wine. This is due to the action, on the ferment, of the alcohol itself ; the strength named above being just able to precipitate it. Pure wines, therefore, in moderate quantity will not precipitate the pepsine of the gastric juice, because not strong enough to do so immediately on taking, and in the stomach they are quickly diluted. In a diluted condition, under the influence of another ferment, alcohol is changed EEFERENCE HANDBOOK OP THE MEDICAL SCIENCES. Ajaccio. Alcohol. to acetic acid, by a process t)f oxidation ; thus, e.g., white wine vinegar is produced. Alcohol CHsHO + O, =r Acetic acid + Water. CsH^Os + HsO. When any of the fermented liquors are distilled, alco- hol mixed with water passes over into the receiver. Re- peated distillations free it from the greater proportion of higher alcohols and water. Its degree of concentration can then he determined by taking its specific gravity and comparing the result with a fixed table in which the strength for each specific gravity is worked out. The last amounts of water can only be gotten rid of with the great- est difficulty ; as, for example, by distillation over quick- lime out of contact with air (from which it rapidly ab- stracts moisture). Phtsical Phopertibs. — Absolutely pure alcohol is a colorless, limpid, pleasantly-smelling liquid having a sharp, burning taste ; boiling at 78.5° C. (173.3° P.), and, at 20° C, having a specific gravity of 0.7895. Its affinity for water is intense, even abstracting it from the air when the bottle is not securely corked. If it be mixed directly with water, heat will be produced, the volume of the mixture being less than the sum of the volumes of the components, thus showing that combination has resulted. It is a solvent of great power, advantage of which is taken both in the arts and in medicine, e.g., in the solutions of the fixed active principles of drugs called tinctures, or the solutions of the volatile active principles called spirits. It dissolves the alkaloids, essential oils, many resins, some fats, and COa freely. Chemical Pkopbrtibs. — Alcohol occurs in commerce and pharmacy in varjfing degrees of concentration. When absolute alcohol is required, it should be freshly prepared, that of the shops being often only ninety-eight per cent, strong. Alcohol (U.S. Ph.) has a specific gravity of 0.83, and contains ninety-four per cent, by volume. Alcohol dilutum (U.S. Ph.) contains fifty-three per cent, by volume, and is the ordinary proof spirit. Its distinguishing chem- ical properties are : (1) its affinity for water ; (2) its coag- ulating power on albuminoids, and (8) its antif ermentative power when stronger than eighteen per cent. Advantage is taken of the first, in the mounting of microscopical sections, to abstract all the water before immersing them in the oils and balsams ; of the second, in the hardening of the tissues for studj' and section ; of the last, in the preserva- tion in bulk of anatomical specimens, and those medicinal agents which undergo change in other media. Pure alcohol, properly diluted, will be understood to have been given, when we speak of its Physiological Action. — Locally: Prolonged contact with the integument produces a sensation of heat which, if continued, results in inflammation. It hardens the same by coagulation of its albuminoid constituents and abstraction of water, the rapidity, to a certain extent, depending upon its concentration. Hence, it is useful in a relaxed condition of the skin, in sweating, and in ulcers ; it acts here as an astringent, preventing the escape of leucocytes, and promoting the healing process. Stomach and IntesiiTml Tract. — The action of this agent upon the stomach and intestinal tract has been one of the bones of contention between the advocates of teetotalism and those who, knowing its virtues, can utilize them. To incorporate the arguments of both sides would be foreign to the scope of this article which is to give the present status of scientific opinion. Small quantities of alcohol, properly diluted, taken into the stomach, produce an agreeable sensation of warmth which soon diffuses it- self over the entire body. It is quickly absorbed. A tur- gescence of the capillary plexus of the mucous membrane occurs, which is speedily followed by a free secretion from the gastric follicles, due, in all probability, to (o) the increased supply of blood, and (fl) the stimulation of their glandular orifices. Here, just as in any other organ of the body, long-continued or excessive stimulation will give rise to a pathological secretion, and a gastric catarrh will result. Larger quantities of alcohol interfere with the digestive processes, partly by rendering the albuminoids less soluble, partly by producing a secondary constriction of the stomach capillaries, and thus a diminished secretion. Experimentally applied to the mucous membrane of the dog's stomach (through gastric fistulas) , increased secre- tion and peristalsis of that viscus are observed. This is probably true in man. Even a few drops of the stronger alcohol, applied to the base of the tongue, has been seen to cause an almost immediate flow of gastric juice. Poisoning by concentrated alcohol excites a burning sensation in the mouth, oesophagus, and stomach, soon followed by a gastro-enteritis, with its attendant symptoms of epigastric pain, fever, vomiting, and purging (some- times of blood). Post-mortem appearances of the tissues in contact with which the concentrated alcohol has lain, are such as are naturally to be expected from its chemical properties, i.e., abstraction of the watery constituents of the epithelial lining, cell-shrinkage, coagulation of the blood in the vessels of the mucosa, and hsemorrhagic softening. The circulatory system, like the other portions of the organism, is affected by alcohol, but not in so marked a degree. In small quantities, its first effect is to stimulate the heart, causing a slight increase in frequency and a marked increase m force, accompanying which is a dila- tation of the cutaneous capillaries, and probably also those of the brain. The intravascular pressure is increased. These phenomena are plainly visible in the flushed face, glistening eye, and animated expression of the person in the early stage of alcoholic influence. In poisonous doses, a lessening of the heart's power by one-twentieth and the blood-pressure by one-sixth occurs. Nothnagel ex- plains this as a reflex result, due partly to the severe irrita- tion of the vagus, partly to a direct affection of the heart- plexus and pheumogastric centre in the brain. He cites, in proof, the experiment of cutting the vagus in animals under the influence of alcohol, when the blood-pressure and heart's action again increase. The circulatory sys- tem is the last to succumb to the toxic effects of alcohol, for when all volition has ceased, and the voluntary muscles are paralyzed, the weakened heart continues beating, until, if the intoxication be severe, death results from paral- ysis of respiration. The long-continued use of alcoholic drinks, particularly in the more concentrated forms, in- duces a fatty infiltration of the heart-muscle and an atheromatous condition of the arterial walls. Brain and Nerwus System. — The primary effect of al- cohol (in small quantities) on the nervous system is a stimulation of the functional activity of the brain. This is a result chiefiy of the direct stimulation of alcohol upon the nervous tissue, though the increased force of the heart-beat, its increased frequency, and the greater activ- ity of the entire bodily functions undoubtedly assist its local action. A sense of well-being pervades the body, a greater activity of intellection, increased volubility, and a general exhilaration result, which, enduring for a time, are followed by no depression. Such quantities have little effect on the spinal cord. If the quantity be increased, we have an exaggeration of the foregoing conditions. Mental activity is at its highest, ideas flow rapidly, and thought finds ready expression. Later, the cerebellum and cord begin to show interference with their function, by the muscular incoordination, beginning usually in the tongue and lower lip. If in this condition the quantity of alco- hol be again increased, a general incoordination ensues. The tongue refuses to give correct expression, ideas are confused, mental hallucinations, and even a temporary in- sanity may result. This state is followed by depression, sleep, coma, and even death. The investigations of Schulinus reveal the fact that alcohol induces a distinct change in the contents of the nerve-cells, discoverable by the microscope, the exact nature of which, whether it be a change in the lecithin, fats, or albuminoids, is not posi- tively known. Such a change probably occurs in the lastruamed stage. Long-continued use of alcoholic drinks to intoxication causes an increase in the connective tissue, the neuroglia, and an atrophy of the nerve-cells. Pure alcoholic drinks, i.e., those which have been carefully freed from the higher alcohols, or aldehydes, produce far less textural, as well as psychical, disturbances, than those containing such impurities. The peculiar condition known as delirium Premens most frequently occurs. in 103 /Llcobol. Alder, Black. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. those addicted to liquors rich in fusel oil (amylic alco- hol). An interesting fact in this connection, to which attention was first called by Richardson, is this, that the administration of fusel oil induces a condition almost identical with that of delirium tremens. The tempera- ment of the subject under such conditions will modify the psychical manifestations ; those of a genial temper become merry, noisy, and hilarious, while those of an opposite disposition become morose, taciturn, or quarrelsome. The action, upon the peripheral nervous system, of alco- hol is slight, except in toxic doses, when the nerves of sensation are benumbed. (See Alcoholism, under the head of Insanity.) The sympatTietic system— fiaough. the increased blood- pressure, in the first stage ; the capillary dilatation, and the marked fall of pressure, in the later stages of alcoholic intoxication — shows its susceptibility to this agent. Its action upon the sympathetic in healthy and in inflamma- tory areas appears to differ, for Binz has shown that there is a contraction in the latter condition of the arterioles and a lessening of the migration of leucocytes. Temperature.— Small doses of alcohol frequently re- peated will cause a slight primary rise in temperature. It is now generally admitted that alcohol in liberal quan- tities lowers the bodily temperature. All carefully con- ducted experiments prove this. That large quantities will do so is a matter of almost daily clinical demon- stration, either in the healthy or in the feverish organ- ism, but practical use of this agent as an antipyretic has been limited, owing to the comparatively large amounts and the long-continued administration which are neces- sary. In toxic quantities it is not infrequent for the tem- perature to drop below the normal from two to four degrees Fahrenheit. On what this fall depends there is much dispute. The causes are multiple rather than single. 1. Since alcohol causes a superficial capillary dilatation, the volume of blood in the integument is increased, and since we have a radiation of heat from the body surface there will be a greater loss of heat than is normal. 3. The functional activity of the sweat-glands is thus increased; hence freer perspiration, increased evaporation on the surface, and cooling. 3. The value of alcohol in the economy is as a heat- producer ; but arguments based upon the theory that if it be burned up in the system, the body temperature should rise accordingly, are no more logical than to use the same reasoning for any of the other carbohydrates. Their combustion goes to the maintenance of the normal body temperature as the heat is lost by radiation. This is equally true with alcohol. But by the combustion of alcohol the fats — in part at least — escape oxidation, and are stored up in the tissues. The oxygen which, in the absence of alcohol, would have combined with them, com- bines readily with the more easily oxidizable alcohol, pro- ducing heat. Carbonic oxide + Water. CDs + mo. Now, Frankland has shown that a given weight of al- cohol, in. burning, produces but seven-ninths as much heat as the same weight of oil (cod-liver). A logical con- clusion then is that the temperature of the body, when supported chiefly by alcoholic combustion, will fall. 4. Alcohol in appreciable quantity diminishes cell activ- ity. Since the body -heat depends in part on their activity, anything diminishing the latter will lower the body tem- perature. According to a well-known law of physics, the separation of complex chemical bodies into ones of simpler composition results in the production of heat. Such changes, in all probability, take place within the cell. If alcohol, therefore, will diminish cell activity, it will lower the body temperature. The fact that a diminished quan- tity of COa is excreted does not militate against the idea that the alcohol has been burned up, because there is far less C in alcohol, in proportion to the other constituents, than in the fats. Moreover, experimenters have found an increase of the fats and sugar in the blood after imbibi- tion of alcohol, which fact would strengthen the theory that the alcohol is burned. Rude experience, as well as actual experiment, conclu. sively teaches us tjjat alcohol diminishes the power of resisting exposure to cold ; the explanation being plain enough when the action of this substance on the body-tem- perature is understood. On the secretions alcohol has considerable effect. To its action on the salivary and gastric secretions we have al- ready referred. The liver being the first to receive the blood freshly charged with alcohol, in a more concentrated condition than after dilution by the general circulation, is the first to feel its stimulating effect, and the first to un- dergo pathological changes. The liver-cells are stimulated, and as a result we have an increased flow of bile. The cells enlarge and become infiltrated with fat-globules. The stronger drinks, particularly if taken undiluted and if the practice be persisted in for any considerable period, cause an irritation of the connective-tissue cells in the liver sur- rounding the portal radicles. A proliferation of the same occurs, and, as a final effect, contraction of this newly formed tissue — as is the case with all newly formed con- nective tissues — ensues, producing the so-called cirrhotic or hob-nailed liver. With the primary new formation there is naturally an increase in the size of the organ, while the secondary contraction causes an atrophy of the liver- cells, (o) by direct pressure, and (i8) by diminishing their normal blood-supply. In those countries where the more dilute alcoholic drinks (wines and beers) are the national beverage, the cases of cirrhosis are unusual ; while, on the other hand, the contrary is true where the more con- centrated drinks (brandy, wMskey, gin, or rum) are largely consumed. Finally, the portal radicles become so narrowed by the contraction of the connective tissue in which they lie, that the portal circulation is interfered with, thus producing a mechanical congestion of the intestinal, peritoneal, and gastric capillaries, with ascites and watery stools. The remarkable investigations of Dujardin-Beaumetz upon the action of the various alcohols on the lower ani- mals, have developed, among other things, this very in- teresting fact, that after the continued use for thirty months of all varieties of pure and crude alcohols, neither intersti- tial hepatitis, thickening of stomach- wall, nor ascites was induced. The animals chosen for experimentation were pigs, because of the similarity between their digestive ap- paratus and food and those of man. Congestion of the liver and of the mucous membrane of the stomach and duodenum was induced to a slight degree when ethylic alcohol was used, but it was intense when the higher alcohols were used. When the dose of pure diluted ethyl-alcohol did not exceed one gramme (grs. 15) per kilo. (3 lbs.) of body-weight, no pathological changes whatever were induced I Kidneys. — The alcohol being in a much less concen- trated condition on reaching the kidneys than is the case with the liver, the effects, both physiological and path- ological, are less marked. The watery portion of the urine is increased ; the solid, at least so far as urea is concerned, is diminished. The increased amount of water excreted is a natural result of the increased blood- pressure ; the diminution of urea is due to the lessening of oxidation of the nitrogenous tissues. In these organs, also, the irritating results manifest themselves more slowly than in the liver, but in an exactly similar man- ner. Eventually the cirrhotic kidney is produced. Excretion. — Experimenters all agree in this, that not more than sixteen per cent, of the alcohol taken can he found in the excreta. The greater portion disappears in the system. As to its mode of destruction nothing is positively known. None of the intermediate products of its oxidation — aldehyde and acetic acid — have been found either in the blood or in the excreta. If it is de- stroyed by oxidation, as we have reason to believe, COj and HjO — both normal constituents of the blood — would be the final products, and could not be identified as de- rived from alcohol. Through the lungs a small percent- age escapes. The heavy odor of the breath after drinking is chiefly due, however, to ethers and higher alcohols which exist naturally in the fermented, and are always added to the artificial liquors. Pure dilute alcohol does 104 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Alcohol. Alder, Black. not taint the breath. As to excretion through the kidneys, Binz has shown that under the most favorable conditions not more than tliree per cent, of the alcohol ingested is excreted by them, thus exploding the theory once en- tertained that alcohol was entirely excreted unchanged in the urine. A small amount of alcohol is excreted through the skin. Administkation. — The physiological action of all pure liquors does not differ materially from that of alcohol of a similar concentration. Slight differences due to compo- sition will be spoken of in connection with the several liquors. The physical constitution of the patient, together with the state of health and the result to be acquired, must form the guide to the proper selection and dose. The carefully conducted experiments of Dujardin-Beaumetz, Richardson, and others, agree that one gramme (15 grs.) of absolute alcohol to every kilo (3 lbs.) of body-weight is about the daily limit that can be assimilated by the healthy adult without disturbance of digestion or other injurious consequences. It is true, however, that patients exhausted by the continued fevers can absorb amounts far exceeding the normal limits without injury, in fact, with benefit. A daily indulgence of two grammes per kilo induces Intoxication, and if continued for a few days, will cause loss of appetite, diarrhoea, vomiting of glairy mucus, etc. Finally, a dose of eight grammes per kilo will cause death within from twenty-four to thirty -six hours. In this connection it will be instructive to present the re- sults obtained by Dujardin-Beaumetz as to the average poisonous dose of the various alcohols per kilo of body- weight, sufficient to cause death in from twenty-four to thirty-six hours : Ethyl alcohol, 89 grm. concentrated ; propylic alcohol, 3.90 grm. concentrated, 3.75 grm. di- lute ; butylic alcohol, 2.00 grm. concentrated, 1.85 grm. dilute ; amylic alcohol, 1.70 grm. concentrated, 1.50 grm. dilute. From this it majr be concluded that the higher, the de- gree of concentration of the alcohol the more poisonous will it be. The two last are more poisonous when dilute, because more soluble and better adapted for assimilation. Hence, the importance of administering only pure unso- phisticated liquors should be particularly borne in mind. It may be generally stated that the stronger wines are indicated in the weakened conditions occasioned by long- continued fevers, chronic suppurative processes, ai>d anaemia from frequent haemorrhages, and for convales- cents generally. The red wines, by reason of the tannic acid which they contain, are serviceable where we desire also an astringent effect ; hence their use in diarrhoeas, locally to ulcers, as gargles, or not infrequently as an in- jection in gonorrhoea. The sparkling wines, from the COa which they hold in solution, often are efficient in re- lieving such irritable conditions of the stomach as occur in seasickness, vomiting of pregnancy, or in true cholera. Brandies, whiskeys, etc. (of good quality), are indicated, undiluted, in cases of sudden weakening of the heart's action. Given after a full meal they certainly aid its digestion. This group of alcoholic drinks, when not abused, take the place, with the poor, of the costly con- diments of the rich, improving the appetite and aiding di- gestion. Diluted they can be used where wines are indi- cated, but not as efficiently. Externally they are fre- quently employed as alcohol is, to check sweating, as a counter-irritant for bruises, etc. The beers, ales, and porters are valuable because of the nutritive material which they contain. They are readily assimilated, and are pleasant to the taste, and the bitter principles contained in them, together with the alcohol, cause an increased flow of gastric juice. They are, there- fore, prescribed, together with food, as a dietary measure. The diastase which exists in the beer is present in suffi- cient quantity to aid in the conversion of the starchy foods. Their effect upon the brain is not so pleasant as that of wine, due (according to Rossbach) to the oil of hops, which resembles, in physiological action, oil of turpentine. They are desirable for those who cannot stand the cerebral effects of wines. Since one gramme of absolute alcohol per kilo (2 lbs.) of body -weight is the average limit per diem that cannot safely be exceeded, a list of the strengths of the more com- mon alcoholic drinks seems here appropriate. From it may be calculated the maximal dose, which it is not desir- able to exceed. The following table shows the average strengths of the ordinary liquors, as given by several authorities, with the extremes of variation : Per cent. Brandies, gin. and whiskeys 48to56 Sherries and port 20 to 33 Clarets and hoclc Stoll Sweet Spanish and Italian ._ 13 to 17 Ales and porter .' 6 to 10 - Beers 4 to 6 Stout 4 Kumyss 1 to SJ The pure natural wines, of course, vary in strength, from year to year, according as the season has produced a very sweet or a sour grape. Sherries and port are fre- quently fortified by the addition of brandy, which explains their being stronger than the usual eighteen or twenty per cent, strength. Lewis L. McArthur. ALDEHYDE. The aldehydes form a genus of chemical compounds ; but acetic aldehyde being the commonest member thereof, the word aldehyde, when used singly, is always understood to mean that substance. Acetic alde- hyde, CjHjO, is, from the point of view of chemical com- position, the first outcome of the oxidation of common — ethylic — alcohol. It very closely resembles alcohol in physical and physiological properties, being a thin, color- less fluid of pungent smell and taste ; inflammable, miscible in all proportions with water, alcohol, and ether ; antiseptic, irritant, and narcotic. It is not used in medicine. Edward Curtis. ALDER, BLACK (Ffrinos, U. S. ; Ilex vertidllata Gray ; PHtws verticillatus Linn. ; order, Aquifoliacic^, a medium- sized shrub, with gra3rish bark, alternate, short, petioled, pointed, and serrated leaves, and small clusters of axillary, minute, whitish flowers ; fruit a glossy scarlet, six-celled, six-seeded, persistent berry, in small close clusters along the branches. This plant is common in most parts of the United States, growing along roadsides and moist by- ways and in swamps, and forms, in the autumn, a striking and characteristic portion of our country landscape. The bark is smooth, grayish or whitish ash-colored, and when dried for medicinal use is in "thin, slender frag- ments, about one millimetre thick {^g inch), fragile, the outer surface brownish ash-colored, with whitish patches, and blackish dots and lines, the corky layer easily separat- ing from the green tissue ; inner surface pale-greenish or yellowish ; fracture short, tangentially striate ; nearly in- odorous, bitter, slightly astringent" (tj. S. Ph.). No important or definite proximate principles have been found In this drug, which resembles the other hollies in its general properties. Like most bitter barks and woods, black alder has been considered to be tonic and anti- periodic, also, perhaps, slightly astiingent ; this latter quality has recommended it as a local applicatfon to in- dolent and foul ulcers, and, like most other medicines without definite active properties, it has been used as an alterative in the treatment of various chronic skin and other diseases. The utility of black alder for any purpose excepting a mild astringent tonic is very doubtful, and where it may be serviceable there are better drugs to select from. It is at present, in regular practice, almost obsolete, but in some demand for domestic use. Dose, internally, from 2 to 4 grm. ( 3 ss. ad 3 j.). There is no officinal preparation, but it may be given in the regular ten percent, decoction; dose, 25 to 50 c.c. (f 3 vj. ad f 3 xij,), two or three times a day. Botanical Rblations.— PKjios is, by Bentham and Hooker and Gray, included in the extended genus Ilex, which comprises about one hundred and forty five species, mostly of tropical America, a few in Europe and Asia, and is the principal genus of the order. Ilex aquifoUum Linn., the common holly of Europe, grows there both wild and cultivated, and is occasionally 105 Alder, Black. Algiers. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. cultivated in the United States as an ornamental or hedge- plant. It has similar tonic properties to those of black haw ; is also diaphoretic, and has been occasionally used as a popular remedy in digestive derangements, diarrhoea, etc. The berries are emetic and cathartic. A bird-lime was formerly prepared from the bark. The leaves, which are bitter, contain ilicic acid, ilexanthin (a yellow coloring matter), and the bitter principle ilicin, none of which are obtained in complete purity. The latter has been used as an antiperiodio, in doses similar to those of quinine, but has fallen into disrepute. Ilex opaca, American hoUy, a good-sized tree, has • qualities similar to the above. lUx vomitaria Linn., and other species act as bitter cathartics or emetics. Ilexparaguaiensis Lambert, contains caffeine (see Mate). Allibd Drugs. — The number of bitter drugs which in moderate doses may act as mild tonics, and in large ones certainly derange the digestion, is very large ; of these, too, a considerable proportion have been proposed as sub- stitutes for quinine ; none of them have held their place as antiperiodlcs ; most of them, it must be confessed, have a little value as tonics ; but while there is an abun- dance of typical bitters, like the gentians and quassias, it is hardly worth while to use them. If a laxative astrin- gent or stimulant is needed in addition to the bitter, it can easily be added to the pure bitters. For list of bitter tonics see Gentian. W. P. Bolles. ALEPPO EVIL. (Synonyms : Delhi boil, oriental sore, impetigo annua, mycosis cutis chronica, lupus en- demicus ; Fr., JBouton d'Alep, bouton du Nil, houlon du Caire, bouton de Biskra, bouton de Bagdad, bouton du Scinde, bouton de Bombay ; Ger., Beule mn Alep, Delhi- Beule, Jemen-Beule, Biskara-Beule ; It., gavoceiolo d'- Aleppo; Arabic, liabab el seneh , one-year ulcer ; Turkish, dous el kourmati, date disease ; Persian, salek.) Defini- tion : A non-contagious, indolent, and very intractable sore, commencing as a papule, terminating as an en- crusted ulcer, and producing a permanent cicatrix like that of a burn ; found chiefly on the skin of the face, neck, and dorsal aspect of the forearm, hand, and foot, and affecting both natives and foreign residents in many parts of Asia and Africa. The lesion is either single or multiple, usually multiple. Among the natives of places where it is endemic, it generally occurs during childhood, and it has even been seen in children at the breast ; it may occur in persons of any age. In Aleppo, where the disease was first observed (by Richard Pococke, in 1745), it is said that not one of the native inhabitants escapes. It maybe reproduced by inoculation ; it attacks dogs, and perhaps horses, as well as men. Etiology. — Nothing at all definite is known as to the cause or causes of this, as yet, imperfectly understood disease. Drinking-water (as in the case of the water of the Koweik River at Aleppo), parasites, bites or stings of insects, the influence of climate and of particular seasons, general insanitary conditions, lupus, and syphilis, have all in turn been held to blame for its causation. Geographical Distribution. — An exanthematous af- fection, more or less like the original Aleppo evil, ob- served and described by Pococke and the brothers Rus- sel, in the middle of the eighteenth century, has since that time been noted by various authors as prevailing en- demically in Egypt, in the Arabian Peninsula, in the Valley of the Euphrates, at Bagdad and Mosoul in the Valley of the Tigris ; at Basra, near the Persian Gulf ; at Ispahan, in Persia ; in India, especially its north- western portion ; in Algeria, Morocco, the Sahara, and the Island of Cyprus ; perhaps in China, and, according to Rigler, even in Hungary, Siberia, the Polynesian Archipelago, and New Zealand. Whether it be one and the same disease which prevails in all these localities, many of them so widely separated the one from the other, seems reasonably open to doubt, especially in view of the conflicting statements of authors ; and it is equally evident that, until Aleppo evil, or oriental sore, has been more accurately observed and more carefully differ- entiated as a special form of disease, no adequate or satis- 106 factory account can be given, either of its nature, etiol ogy, or appropriate.treatment. Symptoms. — Leaving out of discussion, so far as pos- sible, the points of dispute in the descriptions of this malady, it would appear that its chief characteristics are as follows : There are no prodromal symptoms. The initial lesion characteristic of the first stage of the disease is a small, reddish papule appearing on the skin of the face, neck, or extremities, and increasing slowly in size for several months, desquamation of the cuticle over the papule occurring after a time. During the second stage, or period of softening, a vesicle (or vesicles) appears on the surface of this now enlarged papule ; the vesicle bursts and discharging its contents, of a sero-purulent nature, a scab or crust is produced. This scab is of varying thick- ness and color, sometimes adherent, sometimes non-ad- herent. Under it is an ulcer, having a diameter from several millimetres up to eight centimetres in length ; the ulcerated surface may be excavated or not excavated, it may be smooth or be covered with prominent ^anula- tions. One writer (A. Barralier, in "Nouveau Diction- naire de Medecine et de Chirurgie ") describes the bouton d'Alep as surrounded, during this stage, by a narrow areola, dotted over with little tubercular prominences, and he quotes Dr. Suquet, of Beyrout, as testifying to the existence of ansesthesia in this areola ; he also states that at times the ulcer reposes on an indurated base, having an extent greater than that of the ulcer itself. Sir Joseph Payrer (in Quain's " Dictionary of Medicine") speaks also of induration in his account of Delhi boil. In this connection it may be of interest to state that Virchow regards the various forms of oriental sore as belonging to the syphilides, while Hirsch considers them as a variety of lupus. The duration of the stage of softening or disintegration is usually about five or six months. The third and final stage is that of cicatrization. The cicatrix varies, of course, according to the severity of the preceding ulcerative stage ; it is not generally depressed; the process of cicatrization occupies usually about two months. As a rule the whole duration of the disease is about one year ; it may not be so long, it may be much longer. The natives in Arabia and Syria call the disease ' ' one-year ulcer. " There is a general tradition that it can occur but once in a lifetime. When the lesion is single, the name male has been applied to the button or papule ; where several large papules have appeared, each sur- rounded by a number of smaller ones, the name female button has been used to designate the variety. (In one case, of unusual severity, reported by Guilhou, seventy- seven of these female buttons existed.) Aleppo evil is, for the most part, a painless affection, and is not necessarily accompanied by any febrile movement, or other evidences of general constitutional disturbance. The prognosis is good ; the cicatrices are, however, sometimes very disfiguring. Treatment. — There is, of course, no specific treatment for a disease so ill-defined as is the oriental sore. Tonics, change of climate, the use of caustics, and of the actual cautery and the knife, and many ointments and lotions, etc., have all been used with varying success. BiBLIOGBAFHT. Richard Pococke : A Description of the Bast and some other Countries, vol. ii,, part i., chap. xv. Alex. BUssel : The Natural History of Aleppo, etc. 1756. Volney : Voyage en Egypte et en Syrie, etc. 1787. ' Lewis and Cunningham : The Oriental Sore as observed in India, Cal- cutta, 1877. F. Zimpel: Die Beule von Aleppo (Jenaische Annalen d. Phys. und Med., 1848, S. viii.). Requin ; Du Bouton d'Alep (Saz. Mod., 1832), and Elements do Patholo- gie Interne, vol. iii. 1853. Pfenner : Krankheiten dos Orients. Erlangen, 1847. Gober, in Eulenburg's Real Encyolcpjidie, vol. Iv. 1880. A. Barralier (de Toulon), in Nouveau Dlctionnaire de M6d. et de Chirurgie, vol. V. Sir Joseph Fayrer, in Quain's Dictionary of Medicine. Hurvtington Richards. ALEXISBAD is situated in a deep valley on the south- eastern slope of the Hartz Mountains; altitude 408 metres REFERENCE HANDBOOK OP THE MEDICAL SCIENCES. Alder, Black, Algiers. (1,338 feet). It can be reached in two hours' time from either Quedlinburg or Ballenstedt, stations on the line of the railroad. It possesses two chalybeate springs, the " Alexisbrunnen " and the " Selkebrunnen." A chemical analysis shows that in 1,000 parts of the water of the Alexis spring there are 0.5118 of solid constituents, of which carbonate of iron represents 0.044, and carbonate of manganese 0.025 parts. This water, which possesses no very great therapeutic properties, is used only as a drinking-water. The water from the " Selkebrunnen" contains sulphate of iron (0.056 in 1,000 parts), chloride of iron (0.104), and sulphate of manganese (0.025), and is used for bathing purposes (temperature 11.8° C. — 53° F.). The climate may be described as a mild mountain climate, with protection against the raw easterly and northeasterly winds. (Eulenburg.) H. F. ALGIERS. Algiers, the largest town and capital city of the French colony of Algeria, lies almost due south of Marseilles, upon the Mediterranean coast of Afiica (Lat. 36° 47' 20" N., Long. 8° 4' 32" E.). The population in 1866 was 52,614. As seen from the deck of an approach- ing steamer, the appearance of the city is exceedingly pic- turesque and striking, its compact mass of dazzlingly white houses, having the form of a triangle, whose base rests upon the western shore of the bay, while its apex climbs almost to the summit of the range of hills shutting in the bay on that side, and culminates at the Kasbah, or former palace of the deys, some five hundred feet above the level of the sea. Running along the water-line of the city is a well-built quay, backed by a series of stone arches which support a wide and handsome promenade terrace, or boulevard. The Place du Gouvernement and the neighboring streets constitute, together with this quay and esplanade, the newer part of the town built by tiie French, and occupied by public buildings, warehouses, and the residences of some of the foreign inhabitants. Mustapha Superior, a very pretty suburb lying on the hillside east of the city, contains many villas, and is probably the most desirable place of residence for invalids intending to pass a win- ter at Algiers.. Another suburb, lying also to the east of the town, is known as Mustapha Inferior, just be- yond which, at a distance of two miles from Algiers, is situated the great Jardin d'Essai, an experimental garden under the management of the French government, wherein many varieties of palms and other tropical plants are to be seen growing in the open air. Ste. Eugenie, another sub- urb of Algiers, also contains villas, but of a residence in these Dr. Bennet (" Winter and Spring on the Shores of the Mediterranean") speaks unfavorably, stating that " they are decidedly objectionable, being at the extremity of the western promontory that contributes to form the bay of Algiers, and exposed, consequently, both to the north- west and northeast winds." As to that portion of the city proper, the old quarter, which climbs the hill back of the French quarter previously described, it is not for a mo- ment to be thought of as a residence for invalids, consist- ing, as it does, of a compact mass of low, flat-roofed whitewashed houses, intersected by the narrow, crooked, dark, and dirty streets characteristic of an oriental town. Picturesque, indeed, this portion of the city may justly be considered, and a ramble through its dingy streets will well repay the traveller for whom the tjfpical scenes of eastern life possess a fascination, but with its picturesque- ness its attraction for the visitor certainly ends. From its low latitude and its situation within the great Mediterranean basin, as well as from its proximity to the desert of Sahara, the climate of Algiers is necessarily a mild one in winter and a hot and very dry one in summer, having its rainf ul confined almost exclusively to the colder mont& of the year, as is the case with all places lying in the sub-tropical region of the Old World. The greater mildness of its winter climate, as compared with that of the Genoese Riviera, is ascribed by Dr. Bennet in large measure to the higher temperature of the hours be- tween sunset and sunrise, the temperature along the Riviera being lowered at night "by down-draughts from the mountains that protect it from the north, the Mari- time Alps." Another element in producing this more equable temperature at Algiers is probably the fact that winds blowing from the north must pass over the warm waters of the Mediterranean before they can reach the African coast, whereas on the northern shores of this sea all such winds partake of the character of continental winds, and, notably in the case of the much-dreaded mistral of the Rhone Valley and of the bm-a of the upper Adriatic, they are accompanied by sudden and most un- comfortable depression of the atmospheric temperature. The following data, representing the climatic features of Algiers, have been collected from various sources: The mean annual temperature is 66.5° P., according to' the writer in the " Encyclopsedia Britannica ; " 67.89° P., according to Martin and PoUey, quoted by Dr. H. C. Lombard, in his "Tralte de Climatologie Mddicale;" 64.58° P., according to Angot, quoted by Dr. Julius Hann, in his ' ' Handbuch der Klimatologie ; " 69. 13° F. , ac- cording to the author of the article on " Climate," in the " Nouveau Dictionnaire de M^decine et de Chirurgie " (Jules Rochard) ; and, finally, about 68° P., according to Dr. Hermann Weber. The mean of all these figures would .^ve us 67.22° P. as the mean annual temperature of Algiers. On page 448 of his work above cited, Dr. Hann states as follows: "Entirely erroneous mean tem- peratures have hitherto (1883) been given for Algiers, which showed especially a winter temperature by far too high. The figures of our table are quoted from a recently published work by Angot, and relate to the period be- tween 1860 and 1879." For the eight months of August, October, November, December, January, February, March, and April the figures of Dr. Hann are as fol- lows : Aug. , Oct. Nov. Deo. Jan. Feb. March. April. 77° 67.46° 60.44° 64.68° 53.78° 54.68° 67.02° 61.34° The mean absolute minimum temperature, he states (on the authoritjr of Angot) to be 38.48° P, Deducing from the above given figures the mean temperature of the three winter months, we find it to be 54.88° P., while that of the seven colder months of the year (October to April) is 58.48° P. The duration of the season for invalids ("Kurzeit"), according to Weber, is from November until the end of April ; for this period of six months the average temperature of Algiers, calculated from these same figures, is 56.99° P. There appears to be much dif- ference of opinion respecting the degree of variability of temperature exhibited from day to day. Thus, the writer in Eulenburg's " Encyclopadie " remarks that the changes in temperature during the course of a single day, from one day to another, and from one month to another, are considerable in their amount, and frequently sudden in their manner of occurrence (sind sehr bedeutend und fallen oft sehr plotzlich ein). Weber (loc. cit.) says the daily variations are from 10.8° to 14.4° P. (6° to 8° C). Rochard (loc. cit.) states that the annual mean of the vari- ation from day to day does not exceed 11.34° P. (6.8° C), while the difference between the day and night tempera- tures (variations nycthemerales) is given by him at from 5.4° to 9° (3° to 5° C). Lombard remarks that the former (variations diurnes) are not extreme, not exceeding 1.45° P. in winter, 2.03° P. in spring, 2.66° P. in summer, and 1 . 6° P. in autumn. The absolute minimum temperature ob- served at Algiers during a period of twenty years was 35.6° P. , according to the author last quoted. The following figures for the relative humidity are given by Dr. Hann : Nov. Dec. Jan. Feb. Mar. Winter Mean. Dec— Feb. 68 73 73 72 69 73 The extreme figures representing this factor of climate during the whole year are given as 16 per cent, and 80 per cent. (Mitchell, quoted by Rochard). The annual rainfall at Algiers is about 36 inches ; Lom- 107 Allmeut. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. bard puts it at from 31.49 to 33 7 mches and gives the following extreme quantities. 21.9 and 42 3 inches As illustrating the seasonal distribution of the rainf al , the following tables, quoted by Dr. Bennet, will be of interest to the reader : A.— Mean Rainfall at Alqiees, 1839-1S45. May If to*- June Oi July ° „ August "I j^ September 1 October aiinchea. Xotal 5 inches. November 5 inches. December 8 '^ January 6 February 5 March 3 April 4 Total 31 inclies. B.— Ndmbeb of Days and Nights in 1843 on which Bain FEtL. DavB. Nights. . Days. Nights. : l(t 10 May 3 1 . B 2 June 3 " . 10 7 July , 9 7 August . 9 fi September 2 . 1 2 October 3 1 November : 10 December 5 January 10 February 9 March 9 April 1 Total 44 It will be observed that the mean rainfall for October given in Table A is but little less than that for March, thus bearing out the statement made by Dr. Hann tliat the duration of the dry season for places lying on the Algerine coast is but five months. The average number of fair days in the course of a year at Algiers is 233. The prevailing wind for the year is the northwest, which fre- quently blows with great violence. The west is the rain- bearing wind, and is the one which is of commonest occur- rence in the winter season. North and northeast winds are those which blow most frequently during the spring' and summer months. The sirocco, tailing its origin over the heated sands of the great Sahara desert, is most com- monly felt at Algiers during the hot season, at which time it is greatly dreaded. This wind, blowing from the south- east, occurs somewhat less frequently during the colder months, at which season it is far less oppressive, and is more easily borne. The sirocco at Algiers is always a dry wind ; it is accompanied by clouds of dust, a portion of which, consisting of extremely fine particles of sand, it brings with it from the great desert. Dust, it may be re- membered, is one of the pests of the Algerine climate ; in great part it is of purely local origin, the character of the soil and the heat of the sun, together with the almost con- stant prevalence of wind, favoring rapid evaporation of the rainfall, and the rainfall itself occurring chiefly in the form of lieavy and not very protracted showers. A fall of snow at the city of Algiers itself is an extremely rare phenomenon ; in the elevated country back from the coast, known as the Hants Plateaux, snow falls quite fre- quently, and at times to a considerable depth. The water- supply of the city of Algiers is abundant. Concerning the character of the water, the writer has no exact informa- tion ; but from the absence of adverse comments in the works of the various authors consulted, he deems it.prob- able that it possesses no deleterious qualities. The mildness of its winter climate, together with the moderate percentage of relative humidity in the atmos- phere and tlie great preponderance of clear sides and of hriglit, sunny weatlier, which it enjoys at all seasons, combine to render Algiers a desirable, pleasant, and beneficial place of residence during the winter and early spring montlis, for invalids suffering from pulmonary phthisis and from certain other affections of the respira- tory system. For such cases its climate is recommended by Lombard, Rochard, and "Weber. The last-mentioned writer speaks of the climate as exercising also a benefi- cial influence upon chronic diarrhoeas and upon the sequelae of dysentery.' Lombard specifies chronic bron- chitis, asthma, and phthisis as diseases likely to be bene- fited by a sojourn at Algiers, and he calls attention to the remarkable immunity from pulmonary phthisis en- joyed by the native population as well as by the soldiers of the French army stationed in Algeria. This immun- ity is greater upon the sea-coast tlian it is on the higher ground lying further mland. The writer on Algiers in " Eulenburg's Encyclopaedia" speaks, on tlie contrary, in very unflattering terms both of the climate of the city and of its desirability as a winter residence for invalids. He lays great stress upon tlie variability of the climate and its liability to sudden changes of weather, and warns all invalids who are unpleasantly affected by sucli changes, all asthmatics and persons subject to attacks of diarrhoea, rheumatism, and intermittent fever, that they would do well to avoid the place. How far the unfavor- able comments of this writer may be justified, the writer is not in a position to know from personal experience ; but, judging from the meteorological data quoted from reliable sources in the present article and from the favor- able comments made by Lombard and other writers of repute, he deems it not improbable that the contributor of the article in Eulenburg has overestimated the un- pleasant features of the Algerine climate. Huntington Bieha/rds. I Chronische Bronchitis, besonders mit Reizhusten, Emphysem, TJeber- reste von Pneumonic und Pleuritis und Phthisis im ersten Anfang bflden das geeignete Material ; auch Chronische Diarrhoen und Folgezustiiiide ^'on Dysenterien sind geeignet (Ziemssen's Handbuch der allgemeineQ Therapie, Band ii., S. 80). ALHAMA D'ARAGON (Lat. 41° 13' N.; elevation above the sea, 1,880 feet), a Spanish village on the Saragossa & Madrid Railway ; a spring of moderately high tem- perature (93.2° F.), and of slightly mineralized, almost tasteless water. Total solids 6.1 per 1,000. The place is frequented chiefly by rheumatic patients. The bathing estabhshments are on a grand scale. (Eulenburg.) KF. ALICANTE. Tlie city of Alicante lies upon the shore of the bay bearing the same name, on the eastern or Med- iterranean coast of Spain, and about forty miles south of the middle point of that coast (Lat. 88° 30' N., Long. 0° 30' W.). The population of the town is 31,500. Ex- tending in the form of a crescent along the northern sliore or head of the bay, and nestling at the base of a rocky eminence some 400 feet high, the town is tolerably shel- tered from north and northwest winds. The streets near the port are wide and clean. The water supply, accord- ing to Dr. J. H. Bennet ("Winter and Spring on the Shores of the Mediterranean," fifth edition, 1875), is de- rived from one large spring and from rain-water tanks. " Lippincott's Gazetteer " (1864) states that in its characttr the water is not good, being impregnated witli the sahs of magnesia, but in the point of abundance it would ap- pear to be suflicient for the needs of the town. Up to the time of Dr. Bennet's visit, in tlie spring of 1869, no ho- tel existed at Alicante which came up to tlie standard of comfort and convenience desirable for invalids in searcii of a good sanitary resort. Perhaps this defect may have since been remedied. The climate of Alicante is a mild and a very dry one. The annual rainfall is only 16.98 Inches ; of which (according to Lorenz and Rotlie, quoted by Dr. Weber in Ziemssen's " Handbuch der Allg. 'Thera pie") 20.7 per cent, or the extremely small quantity of 3.5 inches, falls during the winter months. From the other percentage figures given by these authorities, the average rainfall during the spring at Alicante would be 5 inches, during the autumn 6.4 inches, and during the hot summer months only 1.9 inch ! The percentage of clouds prevailing in the sky of that portion of Spain in which Alicante is situated is much lower than is found in any other part of Europe, Italy and Greece being in- cluded. The neighboring province of Murcia bears the name among the Spaniards of "el reino serenissimo," a title justly bestowed upon it for this reason (Hann's " Klimatologie "). Figures for the relative humidity of Alicante itself the writer has not been able to find, but at Valencia, lying some eighty-flve miles north of Alicante, the mean relative humidity of the year is 66 per cent., and it varies but little from season to season (Weber, loc. cit.). The mean annual temperature of Alicante is 64.4° P.; the mean temperature of the winter season nearly 53.5° F. ; according to the same author, who quotes these fig- ures from Francis. For Murcia, lying about fifty miles southwest of Alicante, the yearly extremes of tempera- 108 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Algiers. Ailment. ture are_ 26.5° P. in winter, and 106.5° F. in summer; the mean temperature of January being 48.7° F., that of April 60.3° F., that of July 79° F., and tliat of October 64.5° F. These latter figures are quoted from Hann's " Klimatologie." The east wind, or "Solano," is the rain-bearing wind for the eastern coast of Spain. The "Leveche," a very dry, hot wind from the Sahara, reaches the southeast coast between the Cabo de Gata and the Cabo de Nao. Dr. Weber says (1880) that there is good accommoda- tion to be found at Alicante. He speaks favorably of the efEect of the climate upon certain cases of phthisis ("einzelne FaUe von apyretischer, ruhender Phthisis"). "Alicante," says Dr. Bennet, "appears to me decidedly the most favorable health station that I have seen on the southeastern coast of Spain. . . . There is a Hu&rta, or irrigated valley, it is true, connected with Alicante, but it is situated at some distance north of the town, . . . and there are no rice grounds to produce ma- laria as at Murcia and Valencia." On account of its greater dryness. Dr. Bennet questions whether Alicante would be as beneficial to certain classes of patients as the Riviera of France and Italy. Huntington Bichards. ALIMENT. Food or aliment is matter which, in con- junction with the air, supplies the elements necessary for the maintenance, growth, and development of the organ- ism, and is thus the source of the power on which the vitality of the organism is dependent. Hence, in the broadest sense, true aliment is a mixture of food-stuffs and drink, together with the air from which comes the oxygen necessary for the oxidation of the former and by which force is produced. Again, physiologically con- sidered, true aliment, especially in the animal kingdom, is to be distinguished from so-called "food "as being only that portion of the food which is either itself di- rectly soluble and diffusible, or convertible by the diges- tive juices of the body into soluble and diffusible prod- ucts, and thus capable of being absorbed by the blood. The aliment of vegetable organisms is quite different from that of animal organisms. Moreover, the nature of the processes involved is likewise quite different.' The vegetable organism by a synthetical process — a building up of more complex bodies from simpler ones — derives its nourishment from the inorganic world ; its cells ap- propriate such of the inorganic principles as are needed for its growth and convert them under the influence of the sun's rays into organic compounds which enter into its own structure. The animal organism, on the other hand, does not pos- sess this power, and thus we look to the creative power of the vegetable kingdom as the source, either directly or indirectly, of the aliment of animals. Moreover, the veg- etable matter which thus serves as food, not only fur- nishes the material necessary for the growth and life of the organism, but it contains in addition, stored up with- in its molecules, a certain amount of latent force derived from the solar force originally used in its construction. Animal prganisms, by a process of transformation quite the reverse of synthetical, convert the preformed animal or vegetable organic matter into allied or simpler forms which are absorbed into their own tissues. Ani- mal food approximating more closely in composition with the body to be nourished by it, is more easily ap- propriated, and probably with less expenditure of energy, than vegetable products. Animal food, moreover, pos- sesses stimulating properties, due without doubt to the crystalline nitrogenous bodies contained in muscle-serum. Organic matter once entered as a part of an animal organ- ism and applied to the purposes of life is decomposed or broken apart, and its decomposition products are ulti- mately reconverted into inorganic principles. There is thus a complemental relationship between vegetable and animal life and the inorganic world. The plant by a selective action appropriates as an element of nutrition certain kinds of mineral matter, together with nitrogen in the form of ammonia and nitrates, from the soil in which it grows, at the same time drawing from the air carbon in the shape of carbonic acid, while hydrogen and oxygen are supplied to an unlimited extent in the form of water. The vegetable products thus formed serve in turn as the food of animals, while the latter at every breath pour forth carbonic acid and water, which ultimately find their way again, more or less modified, into the tissues of plants. These, together with the nitrogenous excreta, products of the metabolism of life, and the post-mortem decompositions which follow, continually serve in their variously modified forms as agents by which the conser- vation and transference of energy is accomplished. The alimentary products found in nature can be sepa- rated by chemical analysis into several well-defined sub- stances, none of which are usually found free in nature. These chemically distinct substances arc termed the ali- mentary principles. Many of them are found in both animal and vegetable foods, as, for example, certain fats, casein, and some forms of albumin, although in the case of the tw^o latter examples there would appear to be some few minor points of difference both in percentage composition, and in chemical reactions. Others are to be found only in one kingdom, as starch in the vege- table, or collagen, the gelatin-forming substance, in the animal. Now since food is the source from which the various elements of the body are supplied, it is evident that to ful- fil its purposes food must contain all of the elements present in the body. These are of course not free, but in a state of combination, for it is only in the latter case that they are of service as food, and as Pavy remarks, "the combination must have been formed by the agency of a living organism — the combination must, in other words, constitute an organic product." Aside from the elements which appear as inorganic salts, there are in the body at the most but six elements, two of which are present only in small quantity and are apparently much less important. These six elements are carbon, hydrogen, nitrogen, oxy- gen, sulphur, and phosphorus. Any substance which as food is to satisfy the requirements of life, must contain at least the first four of these six elements, in addition to in- organic salts and water. Various classifications of food have been from time to time proposed, based mainly either upon physiological or chemical groimds. Popularly, aliment is frequently divided into food and drink, without, however, any suit- able reasons, since the mere fact of a food being in solu- tion does not preclude the possibility of the presence of even a large amount of solid matter, as for example in the case of milk, while, on the other hand, butcher's meat contains on an average sixty to seventy-two per cent, of water. Hence, food should be considered as including both liquid and solid matter. The most natural and com- prehensive classification of foods is that based primarily on chemical composition and origin, viz., organic and in- organic — that is, chemical combinations of elements pro- ducible only through the agency of living cells, and sec- ondly, inorganic compounds absorbed from the mineral kingdom, and thus intimately mixed with the. former. The inorganic portion of food consists simply of water and various saline compounds. The organic portion may be advantageously subdivided into two groups, nitro- genous and non-nitrogenous, based simply on the pres- ence or absence of the element nitrogen. The nitrogenous alimentary principles contain carbon, hydrogen, oxygen, and nitrogen combined in varying proportions, and gener- ally also small quantities of sulphur and frequently of phosphorus. The non-nitrogenous principles contain only the three elements carbon, hydrogen, and oxygen. These are in turn further subdivided according to the relative proportion with which the carbon and hydrogen unite with oxygen, viz., into fats and carbohydrates; the for- mer consisting of carbon and hydrogen united to only a small amount of oxygen, as in the case of tripalmitin, CsiHbsO,, the latter of carbon vfith the hydrogen and oxygen always in such proportion as to form water, as in the case of cane-sugar or saccharose, CiaHsjOu ; hence the name carbohydrates. These two divisions of the non- nitrogenous principles not only differ in percentage com- position, but they are likewise widely divergent both in 109 Ailment. Ailment. KEFEBENCE HANDBOOK OF THE MEDICAL SCIENCES. chemical and physical properties. Following is a partial classification of foods : . water. b. Baits. calcium sulphate and phosphate. ?'„Suroh;?SaShospliate, and oarbo.j.te. sodium chloride, phosphate, and carbonate, iron salts, silica, fluorine. a. non-nitrogenous. b. nitrogenons. fats. carbohy- drates. 'tristearin. ■ tripalmitin. triolein. amylaceous. gelatinous principles. albuminous principles. L saccharine. collagen, chondrigen. gelatin, albumin, fibrin, canein. syntonin. globulin. , vitellin. animal and vegetable. ' starches. gums, dextrins. _ cellulose. ' grape-sugar. cane-sugar. milk-sugar. muscle-sugar. 1 anittial and vegetable. Examination of this classlflcatlon leads us first to notice the importance of water' as food. According to Voit the body of a fully developed man contains 63 per cent. of water, while the body of a growing child contains nearly 66.5 per cent. Any great alteration in the content of water in the animal body is always attended with dis- astrous results ; thus, in diarrhoea, cholera, etc., such large quantities of water are lost as to render the blood quite thick, and even the muscles may lose as much as six per cent, of water. Such loss, if long continued, soon results in loss of vitality and consequent death. It is noticeable, moreover, that a certain proportion of the water contained in the tissues of the body can be removed with- out difficulty, while a smaller, residual portion, apparently more closely united to the organic matter, can be separated only with great difficulty ; this is well illustrated in the simple drying of dead muscle-tissue. Removal of the water from low forms of animal life by drying them at the ordinary temperature, or at a temperature below the coagulating point of their body protoplasm, causes them to lose all appearance of life, but in such condition they will again absorb the water lost, and return to their for- mer appearance and vitality. Increase of water in the organism beyond the normal amount is usually associated with an unhealthy condition of the body. Various inves- tigators have likewise demonstrated that there is a close connection between the percentage of water in the body and the diet, irrespective of the water taken as drink. Thus Voit has shown that a bread diet continued for some time renders the body more watery than normal. In one experi- ment with a cat the amount of water in the brain and mus- cles was increased three to four per cent. Increase of fat in the body is usually attended with a diminished per- centage of water.* A vigorous, well-nourished man pos- sesses organs much poorer in water than a badly -fed per- son. Forster ' has figured that under normal conditions a person living on an average diet takes dally 3,315 to 3,538 grammes (about 6.5 pounds avoirdupois) of water. It is easy to see, however, that a great variety of circum- stances, of diet, exercise, temperature, etc., may excite a modifying influence on the amount of water taken into the system during the twenty -four hours. The figures just given do not, however, represent all of the water, since a variable amount is formed within the body by ox- idation of the hydrogen contained in the organic alimen- tary principles. Thus, according to Volt; in the case of a hungry man, 33 grammes of hydrogen in the form of or- ganic matter were oxidized to 388 grammes of water dur- ing twenty-four hours. It is thus plainly evident from the foregoing that water is a necessary constituent of the body, and as one of the alimentary principles is a decidedly important one ; yet we need to understand its true significance. It does not itself undergo any chemical change, and is thus not con- cerned in the production of force, though it aids chemical change in supplying, by its presence, a condition abso- lutely necessary for its occurrence in other bodies. The inorganic salts, as Pavy remarks, " stand, if not to the full extent, nearly so, in the same position as water, as regards the non-possession in itself of force-producing properties." The mineral matters are more closely con- cerned in the structure of the organism than in the devel- opment of power, and this is true both of the animal and ' vegetable organisms. They are particularly necessary in the developing animal body, and of all the forms of mineral matter none is so important and so widely distributed as calcium phosphate. This salt is seldom, if ever, absent from any stnictural element of the body, and its intimate union with many of the nitrogenous principles, particu- larly the albuminous bodies, is so decided that only with the greatest care can this salt be completely removed without changing the nature of the albuminous body;' indeed in many cases there would appear to be a chem- ical combination between the proteid body and inorganic salt Mineral matter is needed, not only for the growth and nutrition of the skeletal portions of the body, but it is also needed in the structure of the softer tissues as well as in the formation of secretions ; thus the acid of the gastric juice has its origin in the chlorine of sodium chloride or common salt, while the alkalinity of the pancreatic secretion, as well as that of some of the other fluids of the body, is due to sodium carbonate. Moreover, the removal of carbonic acid by the lungs, through the agency of the venous blood, could hardly be accomplished were it not for the alkalinity of that fluid. In many juices of the body, inorganic elements are held not only in solution, but quite firmly united with the more characteristic organic matter, as in the sodium salts of the bile acids, and in some instances they can be removed only by decomposition of the compound. The excess of salts taken into the body, by the food or other means and that which becomes free by decomposition within the body, is easily removed through the urine and faeces. There is still other evidence that the various inorganic salts of food serve definite purposes in the body. The two alkalies, potash and soda, so widely distributed and so closely allied in their chemical properties, cannot be made to replace each other in the living organism, while the same is likewise true, to a certain extent, of the alkali earths, lime and magnesia. Thus a qualitative, and also a quantitative selection of inorganic matter is noticeable in the body, particularly in the blood, where the corpus- cles contain the greater portion of the potash salts and phosphates, while in the serum, soda salts and chlorides are in excess. Again, it is quite noticeable that potash salts predominate in the formed tissues of the body, while soda salts are characteristic of the fluids. Porster's ' experiments on pigeons with food poor m salts, and on dogs with powdered meat from which the greater portion of inorganic matter had been removed by extraction with hot water, fat and carbohydrates being afterwards added, showed that these animals could not bear the loss longer than four to five weeks without great suffering, and, finally, death. In fact, it is evident from physiological experiment, that an organism supplied witli all organic food-stuffs and water can live only for a lim- ited time without mineral matter. For a time the body draws upon the inorganic matter stored up in its own tissue ; « but this failing, and that naturally present in the organic foods being removed, death soon results from lack of inorganic aliment." In the ordinary diet of men and animals, sufficient salts are generally contained in the fat and proteid foods to furnish the required amount ot mineral matter. As to the actual quantity of inorganic matter needed to counterbalance that withdrawn from the body in twenty-four hours, we can hardly say. IM content of ash contained in the smallest amount of food necessary to keep up the vitality of an organism would give an approximate answer to this question. This liis- chofE and Voit attempted to ascertain by experimenting with a dog weighing 31 kilogrammes (68.3 pounds), the daily food in this case containing 6.5 grammes (lOO.d grains) of ash. The excretion of ash, however, as Voit has pointed out, is quite different in the hunger condition 110 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Ailment. Ailment. from what it is during a plentiful diet ; for, in the case of hunger, the inorganic matter of the organs is drawn upon, the salts passing into the excreta, thus keeping the per- centage composition of these fluids for a time constant. The importance of iron, or iron-salts, as aliment, is hardly second, certainly not in the case of the higher animals, to lime salts. The position which it occupies in the haemoglobin molecule, on which the blood depends for its power of carrying oxygen, would alone indicate this. Boussingault '" has determined the amount of iron in a sheep of 32 kilogrammes weight to be 3.38 grammes, = 0.151 per cent." Of the non-nitrogenous foods, the fats or hydrocarbons which, according to Liebig's classification, come under the head of elements of respiration or calorifacient prin- ciples, are particularly applied to the production of heat and other forms of force. They also appear to be con- cerned, to a certain extent, in tissue development. The neutral fats alone are important as foods. The free fatty acids and glycerine are seldom present in sufficient quan- tity to have any significance. The more important fats are tristearin and tripalmitin among the solid, while among the more easily melting fats triolein alone occurs. These are simply neutral compounds, formed by the union of a triatomic alcohol, glycerine, with three molecules of a monatomic fatty acid. The fluidity of a fat depends on the amount of olein present ; thus, beef -fat, which contains more palmitin and .stearin, melts at 41° to 50° C, while goose-fat, which contains large quantities of olein, melts at 34° to 26° C. The following table gives some idea of the amount of fat contained in a few common foods : Fer cent, of fat. Fat-tisBue of swine 92,21 Fat-tissne of beef 88.88 Fal>-ti8Bue of mutton 87.88 Butter 85. to 90.0 Eggs 12.0 Fat meat B.O to IS.O Milk 3.0 to 4.0 Clieese 8.0 to 30.0 Vegetables to 3.0 Nuts 53.0to66.0 All animal fats show a remarkable uniformity in elemen- tary composition, containing on an average 76.5 per cent. C,,11.90 per cent. H, and 11.60 per cent O. The chemical composition of the fats indicates the importance of these principles as heat-producing agents. In the carbohydrates and other allied principles, the hydrogen and oxygen are present in such proportion as to form water (starch CeHioOe), while in the fats, as in tripalmitin (CsiHoeOa), only 12 atoms out of 98 have their combining equivalent of oxygen contained in the compound, and hence the re- maining hydrogen atoms, as well as all of the carbon, are ' free for oxidation. And since the quantity of heat produced is dependent upon the amount of chemical action or oxida- tion, it follows "that a given "quantity of fat will have the power of appropriating about 2.4 times as much oxy- gen as the same quantity of starch, or, in other words, iWill develop about 3.4 times as much heat in the process of oxidation, and hence has about 2.4 times as much value as a heat-producing agent " (Pavy). But while the fats are especially important for the production of heat, and for forming the basis of adipose tissue, they are likewise essential for tissue development generally. The great importance of fat in food and of that deposited in the body is to be found in the aid which it furnishes to the hungry organism in developing its wasted tissue. A purely proteid diet to a person poor in fat necessitates a large amount of the former to sustain the weight of the body, indeed more than the intestines are capable of ab- sorbing. But a mixture of fat with the proteid matter diminishes both the amount of circulating albumin in the body and the proteid metabolism. The proteid food is needed to sustain the bodily wants, and at the same time to prevent the loss of fat. Still, it is not possible to convert a poor body into a body rich in fat and proteid ma- terial by a simple albuminous diet ; fats or carbohydrates are needed, admixture of which diminishes the work of the organism. The energy of the active cells of the body is then only in part used for the decomposition of albumin, the remaining energy being applied to the decomposition of fatty matter. This is well illustrated by the increased metabolism of fatty matter during muscular exertion. In the words of Voit, "muscular work renders the cells capable of decomposing more material, and, after the use of the disposable albumin, the fat is brought into requisi- tion. Thus nothing is of greater influence upon fat metamorphosis than work." (See Nutrition.) The carbohydrates being especially found in the vege- table kingdom, belong essentially to a vegetable diet. A few, however, occur in animal food, as glycogen and sugar in the liver, lactose in milk and the sugars, as ino- site present in small quantities in muscle-tissue. In composition, the carbohydrates are all alike in containing hydrogen and oxygen in such proportion as to form wa- ter, but the exact chemical constitution of the bodies is not known. As a class they constitute very easily de- composable material, readily breaking down into carbonic acid and water, and as food-stuffs they are especially prominent in causing an accumulation of glycogen in the liver. They are, moreover, without doubt the source, in part, of the fat in the body. Sugar or starch is always present in fattening foods, and although it is doubtful whether the fat is formed directly from the carbohydrates, still the association of fat and glycogen in the hepatic cells, and the fact that the former is increased by such diets as tend to increase the latter, would in itself tend to indicate a connection between carbohydrates and the pro- duction of fat. (For a discussion of this question see Nutrition.) Carbohydrates, like the fats, tend to dimin- ish proteid decomposition, and even more decidedly ; and as they are likewise able to prevent the withdrawal of fat from the body (according to Voit 175 parts of carbohy- drates accomplish as much as 100 parts of fat) it is evi- dent that they possess the power, in a high degree, of taking the r61e of the fats. Moreover, while the carbo- hydrates are being oxidized, the fat formed from albumin is spared, and Voit '" considers that in both carnivorous and herbivorous animals the main action of carbohydrate food (so far as its connection with fat is concerned) is to protect the fat already formed, and that in no case does the fat itself have its origin in the carbohydrates, but in the carbon surplus of proteid food. (See Nutrition.) Carbo- hydrates differ from fats in that they contain, weight for weight, less potential energy than the latter. They diflrer likewise in being more easily 'digestible. The nitrogenous or albuminous and gelatinous princi- ples, are all very much alike in general composition, showing, however, some decided differences in their con- tent of nitrogen. Most of the nitrogenous principles oc- cur in the solid form, both in the animal and the vegeta- ble kingdom, though a few are to be found dissolved in the fluids of the organism. Voit" has estimated from analyses by Bischoff, that in a fully developed human body weighing 68.65 kilos (151.3 pounds) there would be contained when dry (at 100° C), 33.4 per cent, of albu- minous matter, and 14.8 per cent, of collagenous tissue. The excretory products of animal organisms contain such a large percentage of nitrogen, it is evident that the nitro- genous principles must play an important part in supply- ing the needs of the body. Of these the albuminous principles are the most important, and for man and ani- mals albumin, in its various forms, constitutes a vital food-stuff, without which life cannot be long sustained. As the content of albuminous matter in the body is large, and as all the active cells of the body are protoplasmic, it follows that albumin must be supplied in considerable quan- tity to take the place of that used up in the ordinary pro- cesses of life. It is, however, widely distributed through both the animal and vegetable kingdoms ; notably in the casein of milk, egg-albumin, and myosin of muscle in the animal kingdom, and in the coagulable albumin, vegeta- ble casein, legumin, and congluten of the legumins, and gluten of wheat and rice, etc., in the vegetable kingdom. The albuminous principles, moreover, in view of their containing all of the or^ganic elements necessary to life, are capable, when used in conjunction with the inorganic principles, of supplying alone all the needs of the body ; still such a diet would not be an economical one for the system, owing to the large amount of proteid matter 111 Aliment. Alimentation. REFERENCE HANDBOOK OP THE MEDICAL SCIENCES. which the system would be obliged to work over, to- gether with the subsequent removal of the nitropn, in order to obtain the requisite amount of carbon. This is easily seen from the composition of pure egg-albumin with its 53 per cent, of carbon, when compared with a fat, as tripalmitin with 76 per cent, of carbon, or with a carbohydrate as saccharose with 43 per cent, of carbon and 51 per cent, of oxygen. It is evident, from these fig- ures, that a judicious mixture of an albuminous food- stuff with a carbohydrate or fatty food-stuff, would give a food containing the required carbon and nitrogen, as- similable with less expense to the body. Liebig's theory, that nitrogenous food is used wholly in building up al- buminous'tissues, as the muscle, and other forms of pro- toplasm, and that the nitrogenous excreta are formed wholly from the metabolism of the above tissues, is now known to be incorrect, and that in reality proteid food- stuffs may, in one sense, be respiratory and also give rise to the storing up of fat as well as the production of force. In fact, in the decomposition of proteid matter within the body, into the ultimate product, urea, which is excreted, there results a complementary hydro-carbonaceous resi- due, apparently applicable to the production of force. At the same time, the chemically distinct oleaginous and saccharine principles which are together especially con- cerned, either directly or indirectly, in the production of heat, are likewise of use in force-production, and thus any classification of the alimentary principles based on the physiolorical grounds advanced by Liebig, is wholly untenable. The view now taken regarding the produc- tion of force within the body is that the combination of muscles and nerves is to be considered as a form of appa- ratus especially adapted to transform the force liberated by chemical action into those other forms of force termed muscle and nerve force. This being the case, any easily oxidizable organic matter will answer the purpose. Hence, to a certain extent, the two groups of nitrogenous and non-nitrogenous alimentary principles are qualita- tively alike, in that both may be concerned in the pro- duction of force, in the development of heat, and the stor- ing up of fat, although the non-nitrogenous are not distinctly provocative of metabolism. The nitrogenous principles are, however, indispensable to the growth of the tissues of the body, and are likewise indispensable in the production of the nitrogenized ferments, on the pres- ence of which the digestive juices of the body depend for their special action. Collagenous tissue, comprising the gelatinous principles (organic basis of bone, cartilage, tendons, and connective tissue), cannot supply the place of the albuminous princi- ples ; still. Volt'* has found that nitrogenous equilibrium is established at a lower level of proteid food when gela- tin is added, and Foster " apparently considers that in the metabolism of gelatin it rapidly splits up into a urea and a fat moiety, but is unable to imitate the other function of proteid matter, or to take part in the formation of living protoplasm. (For nitrogenous metabolism see Nutrition.) There are a number of crystalline nitrogenous sub- stances occurring in both the animal and vegetable king- doms which are present in greater or less quantity in food, such as creatin and other like proteid decomposition- products, contained, for example, in some quantity, in Liebig's extractum carnis; also the vegetable alkaloids. None of these, however, are of any value as food ; the majority of them pass quickly out of the body, but little if any altered, although one or two, as asparagin," are said to slightly diminish proteid metabolism. The more highly complex lecithin, present in the yolk of the egg, in the brain, etc., may possibly be placed among the true foods, though no direct experiments have been tried to demonstrate its action. The main action of the alka- loidal substances, as the caffein of coffee, is that of a stimulant, acting especially upon the fatigued nervous system though many of the common alkaloidal infusions made from roots, leaves, and berries may be somewhat nutritious from the albuminous and fatty matters which thCT contain, as is the case with cocoa. The drinks commonly used as food may be divided aside from water, into the alcoholic, acidulated, saccharine! 112 gaseous, and infusions of various substances, such as tea. The alcoholic drinks contain from about sixty per cent. of alcohol, as in rum, brandy, and whiskey, to from two to ten per cent. , as in beer and light wines. Malt liquors con- tain, perhaps, the largest number of constituents, among others there being sugar, dextrin, gluten, and various substances from the hops. The exact influence of alco- hol, or its value as a food, is uncertain. It is, without doubt, decomposed in great part within the body," and split up into simpler substances ; but its main action is doubtless that of a local excitant to the mucous membrane of the alimentary canal, possibly thereby stimulating di- gestion, and as a stimulant upon the central nervous sys- tem and upon the circulation. Food, as eaten by man and animals, is a natural mixt. ure of the various alimentary principles described. Sel- dom are the isolated principles eaten . by themselves, other than in the case of sugar and salt, or pure fat. It is the function of digestion to separate the individual principles from this natural mixture, by which means they are separately absorbed. The behavior of animal and vegetable food is quite different in the alimentary canal, which difference is dependent more upon the quality of dry substance contained in the latter food than upon its quantity. Vegetable food yields a much larger percentage of indigestible residue, and is in itself much less easily digestible, owing to the fact that it is more or less enclosed in the diflBcultly soluble cellulose, while animal food is free. Moreover, vegetable food, as a rule, is less easily absorbed, and, as it contains a less percentage of nitrogen, a much larger quantity is needed to furnish a certain amount of this element than in the case of animal food. Again, the large quantities of starch contained in a vegetable diet tend to produce an acid fermentation in the small intestines, with formation of butyric acid, together with marsh gas and hydrogen, which causes the frequent intestinal excretions of her- bivorous animals. The following tables give the percentage amounts of the alimentary principles contained in several of the natural animal and vegetable foods. It is to be borne in mind, however, that the nutritive value of a food depends not only upon its composition but also upon its digestibility. ANiMAii Foods. Water Solids Albuminous. . , CoUageuous... Fatty Carbohydrates. Extractives . . . Ash « li n C* ,. "lO S £ A h" & ■6 75.90 6^.93 75.S4 73.90 87.41 72.33 24.10 37.07 24.75 as.io 12.59 27.67 18.36 23.93 18.53 14.10 3.41 2U.10 1.64 0.00 12.81 6.16 10.90 3.66 4.82 5.58 0.45 1.90 1.30 1.33 1.06 0.70 1.64 Ii6.0» 34.00 S.7U 26 70 2.80 Vegetable Foods. Water Solids Albuminous Woody fibre (cel- lulose) Fatty Starch Sugars, gums, etc. Ash m n t" i ! 1 jl 1^ 74.00 13.00 15.00 14.00 12.60 26.00 87.00 86.00 86.00 87,60 2.50 6.30 12.60 11.10 30.80 1.04 3.00 O.U 0.70 5.60 8.10 1.90 1.09 79.6 0.60 63.80 65.10 48.30 8.00 1.70 3.50 16.42 0.99 5.17 7.78 0.81 1 BischofE and Voit : Gesetze d. Krntihrung des Fleischf ressers, 1860, p. .304. » W. O. Atwater : Bericbte d. deutsch, chem. Gesell., 16 Jahrgang, p. 1844. ' Voit J Hermann's Handbuoh d. Physiologie, 6, 460. 4 J. IConig: Hermann's Handbuch d. Physiologie, 6, 463. * According to Payen. « Dr. Letheby'fl Tables. ' According to Payen. ^ Letheby's Tables. " Payen. ^^ Voit. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Alfment, Alimentation. In studying the composition of animal substances, with a view to determining their Mod-value, the percentage amount of nitrogen is the most important point to be ascer- tained, inasmuch as this element is an index of the amount of albuminous matter present: At the same time it is to be remembered that proteid food-stuffs alone do not con- stitute an economical diet. A rational diet is to be found only in a judicious mixture of proteids, fats, and carbo- hydrates. Even milk is not a properly constituted food for a working man, for though it contains both fat and carbohydrate it has too large a percentage of nitrogen (albumin and casein) for the carbon. It has been found by repeated experiment that an aver- age working man, in order to prevent loss of nitrogen and carbon, requires daily about 18.03 grammes of nitrogen (= 118 grammes of dry albumin), and at least 328 grammes of carbon ; and as the 118 grammes of albumin contain but 63 grammes of carbon, it is plain that there would be required 265 grammes in the form of fats or carbohy- drates. '^ The following table gives the number of gi-ammes of several common foods necessary to furnish the daily requisite of carbon and nitrogen : For 18.3 grammes Nitrogen. For 328 grammes Carbon. Gm. 538 Lard Gm. . 450 796 Corn 801 EggB (18j 905 824 989 1,868 2,905 4,675 4. TOR Rice 896 Bice Milk Potatoes Eggs (48) Lean meat Potatoes Milk 2,231 2,620 3,124 .. 4fiB2 It is thus evident that no one of these substances is in itself a proper food. Lean meat, for example, must have added to it fat or carbohydrate, or both ; while potatoes, as an example of a carbonaceous food, require an admixture of nitrogenous matter. Hence a judicious mixture of all the alimentary principles from both the animal and vege- table kingdoms constitutes the food best adapted to the wants of mankind. jB. E. Chittenden: 1 Wurtz : Chimie Biologique, chapters 1-2. 1884. 2 Hoppe-Seyler : Ptiysiologische Chemie, p. 28. 8 Hermann's Handbuch der Physiologie, vi., 347. 4 Philosophical Transactions, 2, 494. ' Zeitschrif t fur Biologic, ix., 387. " Aronatein : Pfliiger's Archiv fiir Physiologie, viii., p. 75. Alex. Bchmidt : Pfliiger's Archiv, xi., p. 1. ' Zdtsohrift fur Biologie, vol. ix., 1873. ' Weiske : Zeitschrif t fur Biologie, vol. vii., pp. 179 and 333. ^ Forster : Zeitschrif t fiir Biologie, vol. xil., p. 464. >» Comptes Rendos, 1872, 64, p. 1353. 11 Compare Hamburger; Zeitschrift fiir Physiolog. Chem., vol. ii, 191. 13 Hermann's Handbuch der Physiologie, vi,, 260. IS Ibid., vi., 888. » Zeitschrift fur Biologie, viii., 297. 1= Text-Book of Physiology, p. 467. 1^ Zeitschrift fiir Biologie, xv., 261. 1' Pfluger's Archiv fiir Physiologie, vol. xxxii., 398. 18 Voit : Hermann's Handbuch der Physiologie, vi., 497. ALIMENTATION, RECTAL. The literature of this subject does not date back very many years. Dr. Austin Flint says that Samuel Hood, in 1822, was the first in this century to write concerning this form of nourishing ; the next writer was Steinhausen, in 1845. It is recorded, however, that an Italian physician employed this method successfully two centuries ago (Dr. Bodenhamer : " Rec- tal Medication "). In the discussion of this subject the topic of rectal medication will be included. In almost all cases of nourishing by the rectum it is found necessary or convenient that the nutritive material or the drugs should be either in fluid form or in suspension. (The sub- ject of suppositories will not be discussed in this article.) In many instances rectal alimentation has been used al- ternately with feeding by the natural method or by the use of the stomach-tube, for a longer or shorter period ; indeed it is rare to find an instance where rectal nourish- ing has been carried on exclusively for a great length of time. The rectum is freely supplied with lymphatics and Vol. I.— 8 blood-vessels ; its glandular supply is abundant, there being both the follicles of Lieberkiihn and lymphoid fol- licles, similar to the solitary glands of the small intestine. Dr. Flint thinks that digestion and absorption may be due to the presence of the follicles of Lieberkiihn, which may take on a vicarious action when stimulated by the presence of digestible material; also that the presence of food in the large intestine may stimulate the glands of the stomach and small intestine, the secretions passing into the large intestine. Rectal alimentation has been used in the following dis- eases and injuries : in spasmodic constriction of the oesophagus, cancer of the oesophagus, cancer of the pylorus, ulcer of stomach, "encephaloid disease of uterus with sympathetic stomach disturbance," phthisis, anaemia, dyspepsia, pyaemic abscess and sloughing of the parotid gland, inflammation of mouth, fauces, oesophagus, and stomach due to swallowing strong ammonia water, and in lacerated wound of pharynx and trachea. The long- est period during which this form of nourishment has been kept up is fifteen months (Dr. Flint in Ameriean Practitioner). In another case (reported by Niemeyer) this method was kept up for three months ; in a case of carcinoma life was prolonged forty-two days ; in several cases this method has been kept up for twenty-eight days. In most cases feeding by the stomach was resumed grad- ually and carried on in connection with rectal alimenta- tion. Kauflman (Lancet, 1877) reports nine cases, seven of cancer of oesophagus, one of cancer of pylorus, and one of ulcer of the stomach, in which this method was used ; all lived nine or more months under this treat- ment. In the report of the Therapeutical Society (New York, February, 1879) there is the following analysis of sixty- three cases which were nourished by enemata of deflbrin- ated blood : in thirty-eight cases of phthisis, eight did not bear the treatment well, ten were not benefited, twenty were benefited, one case of diarrhoea was made worse ; in nine cases of ansemia, one received no benefit, eight were improved or cured ; in five cases of dyspepsia all were cured ; in four cases of exhaustion all were im- proved ; in three cases of neuralgia, one was not bene- fited, two were improved ; in two cases of gastric ulcer, one was not benefited, the other recovered when appar- ently moribund. The indications for the employment of this form of alimentation may be stated as follows : "Whenever from any cause it is impossible to convey food to the stomach by the natural passages ; whenever the stomach is too irritable to retain food or too much diseased to digest it ; whenever the presence of food in the stomach or small intestine causes trouble, or when there is great exhaustion from any cause, then rectal alimentation is clearly indi- cated. Except when the difficulty is obstruction of the oesophagus or disease of the stomach, this method is used in connection with feeding by the natural method. The process of nourishing by the rectum is quite sim- ple. The rectum is prepared for the nutrient enema by first administering an enema of lukewarm water. It is not always necessary to do this, but it should be done if there has not been a passage since the last nutrient enema, or if any portion of this has not been absorbed, although it almost always is entirely taken up. The mechanical means employed is similar to that used in_ giving an or- dinary injection : a syringe with a screw-piston is safest, but an ordinary barrel-syringe, or Davidson's syringe, may be employed, care being taken not to use too great force. After withdrawing the tube of the syringe a towel should be pressed against the anus until the desire to void the contents of the rectum has passed away. The quantity to be injected should not exceed six ounces at a time, and this may be repeated every four or five hours ; not less than three hours and not more than six should intervene between any two injections. Various substances have been employed in this method, as raw beef, beef-soup, chicken-broth, beef-tea, defibrin- ated blood, milk, cream, eggs, and coffee. (Leube was of the opinion that eggs and milk were not absorbed by the rectum, but this seems to have been an error.) LieWg's 113 Alimentation. Alkanet. EEFEKENCE HANDBOOK OF THE MEDICAL SCIENCES. extract of meat has been used with success. In the report of the Therapeutical Society deflbrinated blood is recom- mended for the following reasons : Patients thrive on it ; in quantities from two to six ounces it is all absorbed ; it causes constipation in but very few cases for a few days only ; it causes no irritability of the bowels except m very few cases ; it gives an impulse to nutrition, and it is wholly unattended by danger. Brown-S^quard {TMncet, 1878) has used the following formula : Two-thirds of a pound of raw beef, one-third of a pound of fresh pancreas ; this was injected twice a day. This was followed by the pas- sage of well-formed faeces. The fat and cellular tissue should be rejected. Kauffman, in his cases, gave one pound of finely divided beef, and one-half pound of minced pancreas every morning ; half this quantity was given at noon and at nighty A solid stool followed every day. The patients were able to walk about. In one case good results were obtained from the use of two teaspoonf uls of Liebig's extract in a teacupful of milk, about every four hours. Dr. J. H. Beech nourished a patient with uterine trouble and sympathetic stomach trouble for five weeks with enemata of chicken-broth, cofiee and cream, beef- broth and milk and eggs ; he found that coffee and cream seemed best to relieve the thirst. Dr. J. O. Davis (Medical Record, 1878) nourished a patient with ulcer of the stomach by lukewarm enemata of beef-tea, or chicken-broth, for six weeks. Dr. McLane nourished a patient exclusively by enemata of unsalted beef -tea for' twenty-eight days, eggs and milk being resorted to only three times ; a little brandy and tincture of opium (ten drops) was added to each "injection. Later, feeding by the stomach was partially resumed. The patient lived one year. Dr. "W. T. Chandler (Louisville Medical News) reported a case of ulceration of the oesophagus, from swallowing strong ammonia water, in which rectal in- jections of eggs and milk were the only nourishment taken for twelve days ; feeding by the stomach was re- sumed gradually. In a case of sloughing of the parotid gland, following a pysemic abscess, the patient, a woman, sixty-five years old, was nourished solely by enemata of beef-tea for four weeks, followed by recovery (Woman's Hospital). In a case occurring at Bellevue Hospital in 1878, a patient was nourished by enemata of eggs and milk, together with a little brandy and a few drops of the solution of morphia (IT. 8. Ph.). The prepara- tion known as Leube's Pancreatic Meat Emulsion has been recommended for use in this form of alimentation. It is prepared as follows ; Five to ten ounces of meat free from fat and chopped very finely ; half this weight of fresh minced pancreas (of pig or . ox) is added to the meat, and the whole rubbed up with five ounces of luke- warm water. When administered the enema should be tepid. It may be mentioned here that when water cannot be administered by the stomach, thirst may be relieved by bathing the body. In many cases it has been found necessary to overcome the irritability of the bowels by the use of some prepara- tion of opium. In one case, from twenty to thirty drops of laudanum were added to the enema whenever it seemed necessary. Solutions of morphine have also been used successfully for this purpose. If the necessary amount of nutriment has been con- veyed to the system by this method there will be the usual feeling of comfort experienced after a meal, with- out, of course, the sensation of fulness in the epigastric region. Diarrhoea is very seldom caused, and the func- tions of the skin and kidneys do not seem to be affected. Patients not only thrive under this treatment, but actu- ally gain in flesh and strength. The subject of medication hy the rectum is very closely associated with that of feeding by the rectum. In al- most all cases of prolonged rectal alimentation, drugs are combined with the enemata, either for their general effect on the system or to assist in the process of nourish- ing. There are many cases, however, in which drugs have been administered alone. The indications for this method of medication are the same as for alimentation by the rectum ; this method is especially useful in irrita- bility of the stomach. It is quite common to add a small amount of brandy or whiskey to a nutrient enema in cases where a stimulant is needed. One writer says that in using stimulants it is well to add cream to the enema. He says, also, that tincture of the chloride of iron may be given in this vehicle. Quinine has been given in this way quite frequently. In a case of peri- tonitis following ovariotomy (Woman's Hospital, New York), quinine was administered in enemata to re- duce the temperature ; thirty grains were given in milk every four hours ; the rectum became irritable after the first few injections, and this method had to be given up. Dr. Flint cites a case of violent hsematemesis whieli was controlled by injecting three drachriis of the fluid extract of ergot into the rectum ; rectal alimentation was carried on for some time subsequently;. Thirty-grain doses of chloral hydrate have been administered in this way in cases of neuralgia, in cases of acute mania, and also in the vomiting of pregnancy. The ethereal tincture of iodine has been injected" in five-drop doses, and also the balsam of copaiba in two-drachm doses. In all cases it is necessary to add a vehicle in sufficient quantity to make about a four-ounce mixture. The use of simple enemata of warm water or warm water and soap, to cause an evacuation of the bowels, is of such common occurrence in domestic practice that it is hardly necessary to speak of it here. Several medi- cines, as castor-oil, oil of turpentine, and assaf CBtida, may be added to these simple enemata. Willia/m R. Murra/g. ALKALIES. The alkalies are inorganic substances, possessed usually of a caustic "alkaline" taste, which unite readily with acids to form salts. They will restore the blue color to litmus paper reddened with acids, turn syrup of violets and red cabbage infusion green, and tur- meric yellow a reddish brown. Properly speaking, only those substances answering to the above description, whose carbonates are soluble In water, are called alkalies, viz., ammonia, lithia, potassa, and soda ; but in medicine twf of the alkaline earths, lime and magnesia, are also in- cluded under this term. The carbonates of these sub stances possess many properties in common with their bases, and exert a similar therapeutical action when in- ternally administered. The acetates, citrates, and tar trates resemble in their remote effects the carbonates, and may therefore for our present purposes be classed among the alkalies. External Uses. — Potassa, soda, and lime, when ap- plied in concentrated form, are powerful escharotics. Po- tassa is the strongest and is the one to be preferred when extensive and complete destruction of tissue is desired. It penetrates deeply and widely, and the skin about the part to be destroyed should therefore be protected by cerate or a ring of adhesive plaster. It is employed to destroy malignant pustule, epiUielioma, and other morbid growths, to establish healthy action in sloughing and pha- gedenic ulcers, and to cauterize the bites of reptiles and rabid animals, and other poisoned wounds. It was for- merly used also to open abscesses or cysts of the liver. Its action causes intense pain, and the slough formed is of a dirty grayish color. When the destructive action has proceeded as far as desirable, it may be arrested by washing the parts with vinegar or some other dilute acid. Caustic potash abstracts the fluids from the tissues, and, uniting with them, forms a liquid which exerts an es- charotic action wherever it may flow. In order to absorb this fluid, and thus limit the extent of the caustic action, an equal quantity of unslaked lime is added to the potash and formed into a pa.ste with alcohol. This is the well- known Vienna paste. Caustic soda is milder than po- tassa, and is seldom used as an escharotic. A mixture of soda and lime, rubbed up with alcohol into a consistent mass, is called London paste. It is employed for the same purpoises and in the same way as "Vienna paste, than which it is milder. Alkaline lotions are used to allay itching, as an application in various skin affections, and to correct the fetor of bromidrosis. Liquor potassse, or a solution of the carbonate of potash, is generally selected for this 114 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Alimentation. Alkaaet. purpose. Liquor potassse is also used to soften the edges of the nail In ingrowing toe-nail. Bicarbonate of soda is one of the best applications for burns and scalds of the integument ; in burns of the first or second degree its im- mediate application in strong solution will almost in- stantly relieve the pain and prevent inflammation. This is a remedy superior to the mixture of lime-water and linseed oil, known as carron oil. Ammonia is much em- ployed as a rubefacient and counter-irritant, in the form of liniment. If strong aqua ammoniae be applied to the skin and covered by a glass to prevent evaporation, vesi- cation is produced. It is used likewise in the bites of venomous reptiles, because of its repute as an antidote to snake-poison, but the better plan is, when possible, to thoroughly destroy the parts with potassa or the actual cautery. The irritation resulting from the bites of insects is relieved by ammonia. Solutions of the lithia salts are sometimes applied to the affected joints in chronic rheu- matic arthritis. Intebnal Uses. — Potassa and its salts, when given in large doses, act as cardiac depressants and paralyzers of the spinal cord. In medicinal doses the acetate and citrate increase the quantity of urine, and render this se- cretion alkaline. For the former purpose the acetate is to be preferred, and for the latter the citrate. Liquor po- tassse in small dose, given before meals, stiniulates the se- cretion of the gastric juice, and thus promotes digestion. Given after meals it neutralizes an excess of acid in the stomach, but magnesia and bicarbonate of soda are pref- erable as antacids. The former is also a laxative, and is to be selected when the action of the bowels is sluggish. When the opposite condition prevails, carbonate of lime or chalk may be prescribed with advantage. It is es- pecially in the acid diarrhoea of infants that chalk mixture is valuable. Lime-water relieves gastrodynia and vomiting, and is added to milk to prevent the formation of caseous masses in the stomach. The treatment of rheumatism by alkalies was formerly much in vogue, but these are now fenerally superseded by other more efficacious remedies, 'he alkalies promote the absorption of fat atod induce an- aemia, and hence they leave the patient in a weakened con- dition after the rheumatism has been cured,' and convales- cence is thereby unnecessarily prolonged. When alkalies are to be used, the lithia salts should by preference be se- lected. Ammonia is a diffusible stimulant, and is seldom employed as an antacid. The carbonate and muriate are excellent stimulant expectorants, and are very frequently given in bronchitis and in the resolving stage of pneu- monia. In cases of sudden and profound depression the intravenous injection of ammonia has answered an ex- cellent purpose. Ammonia is also given internally as an antidote to snake poisons, but its efficacy in this respect is doubtful. Thomas L. Stedman. ALKALINITY. Oxidation of organte substances in the human economy, as in the chemical laboratory, occurs best in alkaline media. Many organic substances require the presence of alkalies to render them oxidizable at the body temperature. Thus alcohol, in the presence of a free alkali, is easily burned up at body heat, and glycer- ine, ordinarily resistant to such influences, will readily be oxidized. Life, which is dependent upon a constant succession of oxidation processes, takes advantage of this fact by maintaining that menstruum (the blood) in which its important chemical changes occur, in a con- stantly alkaline condition. No indubitable examples of acidity of the same have ever been recorded as existing during life ; though some cases of leucocythsemia, sun- stroke, and cholera have been reported, in which, soon after death, the blood was feebly acid. Moreover, attempts to render it acid have signally failed, death occurring be- fore such a condition could be induced. Witness the ex- periments of Hoffman, who, in attempting to render the blood of pigeons acid by the administration of foods yielding acid oxidation products, induced toxaemia before acidity (of the blood). Besides favoring oxidation pro- cesses, the alkaline salts aid in maintaining the albu- minoids in a soluble condition, and increase the power of absorption for gases of the blood-serum. The amount of alkaline matter in the blood is comparatively constant, though subject to slight fluctuations. The blood owes its alkalinity chiefly to the sodic bicarbo- nate (NaHCOs) and sodic phosphate (NasHP04), though partly, too, to the alkaline albuminates. In health its re- action is subject to variations intimately dependent upon the digestive processes ; the chemical nature of the foods taken determining the extent of change. During the absorption of the foods there are always being taken into the circulation organic salts of the alkaline bases, and often small quantities of the alkaline phosphates. The former, in the presence of ozone and an alkaline serum, are easily converted into the alkaline bicarbonates. Hence increased alkalinity of the blood. This is the more marked when the organic salts have been introduced either incidentally to the preparation of the foods, or for medicinal purposes. Thus the "saleratus," "cooking soda," and "baking powders" now so extensively used to lighten our breads, biscuits, cakes, and pastries, by their liberation of COs, are converted at the same time into organic salts (acetates, lactates, or tartrates), which, on entering the circulation, are burned up into the alka- line bicarbonates with distinct effect upon the blood re- action. Or again, the so-called "lemon" treatment, when it is desired to induce an increased alkalinity, is thoroughly scientific. The lemon-juice, which already contains potassium and calcium citrates, being added in large excess to a small quantity of sodium bicarbonate, converts the latter into a citrate, at the same time making a pleasantly acid effervescent drink. This, on being al> sorbed, increases the blood alkalinity, as do the other or- ganic salts. It is just to this absorption and conversion of organic salts that the daily changes in the urine reaction are due. Just before the meal hour the urine (in health really an index of the alkalinity of the blood) reaches its maximum acidity ; at the same time the blood is least alkaline. In a short while, when absorption and conver- sion of the organic salts has begun, its alkalinity steadily increases, until finally (particularly after the consump- tion of the "soda-raised" foods) the urine becomes neu- tral, or even distinctly alkaline, from the excretion of the excess of alkaline matter. When the organic salts have been converted into bicarbonates, and the excess has been excreted through the urine, the latter begins again to resume its normally acid reaction from the oxidation products of the nitrogenous tissues chiefly. It is not probable that, as some authors suggest, the normal alkalinity is maintained by the excretion of ex- cess of alkaline matter by the salivary, biliary, and pan- creatic glands, and excess of acids by the gastric follicles ; because it has been Repeatedly demonstrated that when one secretion withdraws from the blood acid matter, other secretions .increase decidedly their alkaline constitu- ents. Thus the withdrawal from the blood of alkaline and acid matter at the same time would not alter its rela- tive alkalinity. When the stomach is pouring out its acid secretion, the salivary, biliary, and pancreatic secre- tions become unusually alkaline. The kidneys, assisted by the lungs and integument, serve as the chief exits for the excess of alkalies or acids from the blood. Lewis L. MeArihur. ALKANET (Oreanette, Codex Med. ; Alkanna tinctoria Tausch. ; Anohusa tinctoria L. ; lAthospermum tinctoriwn D. C, etc. ; order, Borraginacem) is a small perennial hairy herb, with straggling forked stems, simple spatu- late or lanceolate leaves, and one-sided cymes of tubular, nearly regular flowers. It is a native of the southern and eastern part of Europe and Asia Minor, and is also cultivated. The fleshy root, which is the part employed, is one or two centimetres (two-fifths to four-fifths of an inch) in diameter, branched above into several stem-bearing heads, usually simple below, soft and stringy in texture. The dried root of commerce is sometimes entire, with a purplish-red external surface, a soft, easily separable and exfoliating bark. It is of a dull, deep red color within, and has a pinkish or whitish, hard, but easily-sjilitting wood. More often the roots are twisted and^incom- 115 Alkanet. Allevard. EEPERBNCE HANDBOOK OP THE MEDICAL SCIENCES. pletely split into coarse shreds ; in the better grades, the woody cylinder is removed, and they consist of the tough and flexible bark. Alkanet has no odor, but a sweetish, afterward bitter- ish and slightly astringent taste, coloring the saliva when chewed. Its only valuable constituent is its coloring matter, alkannin, or alkanna red, which was first separated by Pelletier, and named adde anchuaigue. To obtain it, the root, first treated with water, is exhausted by slightly acidulated alcohol, the tincture so obtained is evapo- rated to a thickish, turbid extract, and the alkannin pre- cipitated with water. It is then re-dissolved in ether, the ether mostly washed out by shaking with successive portions of water, and, finally, the thick solution evap- orated to dryness (Huseman, Bailey, and "Wydler, " Ann. Chem. Pharm.," 141). It is a dark brownish-red, resinous mass, or powder, insoluble in water, but soluble in the liquids above named ; neutral in reaction. Its red color is intensified by acids, and changed to bluish-green by alkalies. Alkanet has no physiological action and no medical use. It is, however, used in elegant pharmacy to color oils, cerates ("rose lip-salve "), and tinctures, and occasionally in making test-papers which maybe prepared either red or blue. Allied Plants. — The order Borragmaoem comprises a number of bland, hairy herbs with no distinctive medici- nal qualities. (See Borage.) Allied Dkttgs. — For a list of the pharmaceutical col- oring matters see Saffron. W. P. Bolles. ALKEKENGI {Alkekengi coqueret, Codex Med. ; Physalu alkekengi L. ; order, Solanacece ; ground plum). This little genus of annual or perennial, spreading, sometimes prostrate, herbs dltCers but little, botanically, from Holanum or Lycopersicum (the tomato) excepting that the calyx loosely envelops the fruit in a miniature, usually five-angled papery, balloon-like bag. One species, with fragrant yellow edible fruit, is cxiltivated in, this country, now and then, under the name of " strawberry tomato." Physalis alkekengi is a perennial weed of Central and Southern Europe, bearing a round, shining scarlet-red berry, about as big as a cherry, enclosed in its calyx- bag, four or five times as large. The fruit is two-celled, with numerous kidney-shaped, flat seeds embedded in a fleshy, pulpy pericarp ; odorless, with mawkish sweet tasto, sometimes bitter, and, dried, forms the commercial drug. It is then brownish red, much shrunken, and generally bitterish. It is reputed to be diuretic and lax- ative, and is an ingredient of some European preparations, but is not entitled to rank as a medicine. The berries are also pickled and eaten. The calyx, which is not used, contains an abundant bitter principle, which has been Tiam.eA physalin. For allied plants and drugs see Belladonna. W. P. Bolles., ALLANTOIS. In this article is given an account only of the origin and morphology of the allantois ; for its metamorphoses and functions see Placenta. The allan- tois is a hollow outgrowth from the ventral wall of the posterior extremity of the digestive canal ; morphologi- cally. It is a modification of the bladder, lasting till the end of foetal life. The bladder appeared early in the evolution of vertebrates, being constant in the amphibia and all higher forms. In the fcetus of all reptiles birds and mammals the bladder is modified by being greatly enlarged and projecting beyond the body proper! so as to be a true appendage, the allantois, the possession of riiifJ^i '^1°^""''^'/''^ ^"^^^yo^ of the three classes named. The same classes also have an amnion, a struct- ure not found m the lower vertebrates. The terms al- kmtoidea, and amnwta are therefore strictly synonymous iftract'^thp"*^'*-' ^^":^ ^'§!'^' "^^^^'"^"^ vertebrates. Wp nSfat?^'^ °'i^l °^ *H ^"'^°*°'« ^e find a remarka- ble illustration of change of function ; the organ which ^SE^''''^ '' ^^ "" urinary vesicle is precocioSsly devel- oped and enormously enlarged in the embryo ; and has 116 acquired respiratory functions in the reptiles and birds and later nutritive functions in the mammalia. In 35! cordance with its new duties the vesicle is furnished with a greatly increased vascular apparatus. The aorta forks at its caudal extremity, and each fork again divides ; one branch goes to the leg (iliac artery) and one branch runs up along the side of the bladder and ramifies upon its outer portion ; the main stem is known as the hypogag. trie artery. The blood is collected from the allantois by two veins (umbilical or, better, allantoic) ; in man and other mammals, however, one of these veins; the right early disappears, so that during most of the f cetal life there is only one vein, the left. The exact origin and growth of the allantois in the embryo can be understood only in connection with the history of the germ-layers, and is treated of under Fcetus. In form the allantois varies greatly ; in birds and reptiles it is a large sac which protrudes from the abdomen ; in the higher (placental) mammals this sac is still further modified to constitute the essential part of the placenta ■ indeed the placenta may be best defined as an allantois so specialized as to establish a direct nutritive relation be- tween the mother and offspring. The following brief account will suffice to elucidate the comparative morphology of the allantois. It will be remembered that during the very early stages of the em- bryo, the body cavity is not closed but open ; the external abdominal walls (somatopleure) extend down for a short distance, and then bend outward and upward on all sides so as to completely arch over the back of the embryo ; that part of the somatopleure which thus encloses the embryo is a thin membrane, long known as the amnion. On the other hand, the walls of the intestinal canal (splanchnopleure) likewise extend beyond the embryo, making a contracted stalk at the end of which is the yolk- sac. These relations are shown in the accompanying diar Fio. 74.— Diagram of a Young Allnntoidean Embryo Chick, sft, calcore- onsegg-BheU; sji, air-space; oto, amniotic cavity ; ys, yolk-sac or iim- biljoal vcBicle ; w, remnant ol the white of the egg ; al, allantois ; al', dotted imes representing the later nearly maximum extension of the allantois. gram. It will be observed that the body-cavity is continu- ous with a large space around the embryo, lying entirely outside the closed amnion and inside the chorion. Into this space pows out the allantois, appearing first as a small diverticulum, but rapidly enlarging to an ample vesicle. As the embryo grows the yolk-sac, except when modi- fied as a secondary respiratory organ (rabbit, etc.), di- minishes while the allantois enlarges still more rapidly, and thus soon becomes the principal appendage of the embryo. In this stage it is readily identified in birds and reptiles ; the actual relations are well indicated by the admirable diagram here given of a hen's egg after about ten days' incubation ; the figure is copied from Allen Thompson. If the walls of the vesicular allantois be examined, they are found to consist of two layers, 1, a stratum of epithelium which is directly continuous with the epithelium of the digestive tract, and therefore rep- resents the innermost germ-layer or entoderm ; 2, a stratum of connective-tissue (so-called mucus) cells lying externally and representing the middle germ-layer 01 REFERENCE HANDBOOK OP THE MEDICAL SCIENCES. Alkanet. AUevard. mesoderm. Now the placenta of mammals Is formed mainly by the developments which take place in the outer (mesodermic) layer of the allantois. There arise, namely, irregular outgrowths or villosities, richly supplied with blood-vessels ; these force up the chorion and so project beyond the general surface of the ovum ; the projecting villi fastened by their tips to the irregular surface of the uterine wall. This combination of foetal and maternal tissues constitutes the placenta. In the majority of mam- mals the allantois retains its vesicular character ; the various classes are distinguished from one another by the form and distribution of the villi over the allantois. They are diffusely scattered in the horse, pig, etc. ; in the ruminants they are collected into patches or cotyledons; in the carnivora and elephants they are gathered into a distinct mne ; in the rabbit they are restricted to a circular dish. In man still further modifications occur ; the cavity of the allantois remains always exceedingly small, and the epithelial lining is, of course, correspondingly re- duced ; the mesodermic layer, on the contrary, under- goes an excessive enlargement and produces a circular villous area, which enters into the formation of the pla- centa ; the term metadiscoidal is employed to distinguish the human placenta from the discmdal of the rabbit. For the early; history of the human allantois, which is in reality quite unlike that of the bird, see Foetus, Development of ; for the details of its structure and con- nection with the uterine wall, see Placenta ; for a state- ment of the manr>er in which it is enclosed to form part of the umbilica' cord, see Amnion ; compare also IJm- bilical Cord. CJui/rles Sedgwick Minot. ALLEGHANY SPRINGS. Location and PosUOffice, Alleghany Springs, Montgomery County, Va. Three and one-b»if miles from Shawville station, on the Norfolk & Western Railroad, and about eighty miles west of Lynchburg. The geological character of the neighbor- hood is "magnesian limestone of the lower Silurian pe- riod; Intercalated with argillaceous slates of the same age." The spring at present in use is a moderately-flowing one, dis'/harging about four hundred gallons per day. As an- alyzed by Dr. F. A. Genth, the composition and general rhiaracter of the water are as follows : Limpid ; tempera- 'tire, 53° F. ; taste, slightly alkaline, but pleasant ; faint \cid reaction, when fresh, from free and partially com- iined COa. On standing, the water deposits a small Quantity of lime carbonate, magnesium carbonate, and tninute traces of silicic acid, aluminium silicate and phos- phate, etc. — in all about 4.704 grains to the gallon. Analysis. — One gallon (70,000 grains) contains : Grains. Sulphate of magnesia... 50.884290 Sulphate of lime 115.294098 Sulphateof Koda ;.„ 1.717959 Sulphate of potassa 3.699081 Carbonate of copper 0.000359 Carbonate of lead 0.000569 Carbonate of zinc 0.001713 Carbonate of iron 0.157049 Carbonate of manganese 0.060617 Carbonate of lime 3.61.3209 Carbonate of magnesia 0.362362 Carbonate of strontia 0.060636 Carbonate of baryta 0.022404 Carbonate of lithia 0.001679 Nitrate of magnesia 3.219562 Nitrate of ammonia 0.559412 Phosphate of alumina 0.025549 Silicate of alumina 0.207399 Fluoride of calcium •. 0.022858 Chloride of sodium 0.274676 Silicic acid . . 0.882782 Crenioacid 0.001921 Apoorenic acid 0.000192 Other organic matter ." 1.999121 Carbonate of cobalt, V Trawn Terojtide of antimony,! i.races. 183.069321 [Solid ingredients by direct evaporation gaVe 184.072000.] Halt-combined carbonic acid 1.885526 Free carbonic acid 5.455726 Hydro-sulphuric licid 0.001339 Total amount of ingredients 190,411912 Therapeutic Pbopbrtibs. — The presence, as in this water, of both the lime and magnesium sulphates is very unusual, and especially in such large proportions. As regards the effect upon the bowels it would be imagined that these two ingredients would counteract each other, and such, to some extent, is the fact. Taken in large quantities the water is purgative and diuretic, but in smaller doses the effect is tonic. The reputation of the spring is firmly established as of great efficacy in many forms of digestive disorders, those especially associated with chronic diarrhoea, constipation, and torpid liver. It is doubtful whether any of the other numerous iugre- dients are of any medicinal value. The accommodations for guests are upon a liberal scale, and consist of a large and well-appointed hotel, and about one hundred and fifty outlying double cabins or cottages. Pure spring water is freely distributed, being brought from the mountains through pipes, thus affording hot and cold bathing in every part of the establishment. The ordinary drinking water is of two kinds — limestone and freestone. There are churches and school accommoda- tions on the grounds. Situated on the eastern slope of the Alleghanies, the highest point between the eastern seaboard and the Rocky Mountains, and on the headwaters of the Roanoke River, these famous springs offer unusual attractions in point of scenery and healthful climate. Oeo. B. Fowler. ALLEVARD, a watering-place in the Department of Isere, France, near the border of Savoy; latitude, 45° 34' N. ; altitude, 475 metres (1,558 feet). From Lyons it may be reached by taking the railway as far as Mont- mSlian, and then driving a distance of twenty-four kilo- metres (about fifteen miles). The town is situated in one of the most beautiful valleys of that region, which is also celebrated for the wine which it produces. The climate, however, is very variable. There is but one spring, whose copious waters have a temperature of 24.3° C. (76° F.). Several analyses of the water have been made, but their results — in harmony with the varying composition of the water itself — vary so considerably that no reliance can be placed on any one of them. This, however, is not an uncommon experience in saline springs containing an abundance of earthy matter. There were found from twelve to twenty-two parts of solids in ten thousand parts of water, magnesium and sodium sulphate furnishing the largest proportion. A little iodine was also found. ■ Of the gases, hydrogen sulphide is the most prominent, and is indeed present in large amount, perhaps to the extent of 0.31 in ten thousand parts by weight. The water is taken at the spring at its natural temperature. Patients suffering from chronic pulmonary and bronchial affec- tions drink it heated to 36° C. (96.6° F.). Taken in small doses,- the water seems to produce no appreciable effects, but in large draughts it is a powerful circulatory stimu- lant. Aside from the use of the water as a beverage, it is employed in the form of baths, and particularly is it advisable to use these in combination with whey, at a temperature of 36° C. (96.6° F.). The proportion of whey to water should be as three to two. In this way a power- ful tonic and sedative effect is produced, which forms an important element in the course of treatment. In the bathing establishment there are seven large inhalation chambers, in which the temperature is of a pleasant degree of coolness. Then there are, in addition, two inhalation-rooms of various degrees of saturation with watery vapor and hydrogen sulphide, heated to a tem- perature of from 80° to 83° F. The air in these may contain hydrogen sulphide in the proportion of one to one hundred thousand parts. The effect of inhaling the air in the large cool chambers is at first, in the case of a healthy person, somewhat soothing, but after a time it begins to produce some excitement of the respiration and of the heart's action, which, however, is soon suc- ceeded by a period of comparative quiet. A protracted stay in the inhalation-chamber may produce serious symptoms, such as bronchial irritation, a condition sug- gesting intoxication, pain in the stomach, loss of appetite. 117 Allevard. Almonds. EBFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Pjo. 75.— Pimenta OtScinalis, Fruit (entire). persistent constipation, or a diarrhoea characterized by black stools, disturbed sleep, etc. The treatment should therefore be pursued under the guidance and advice of a physician who is familiar with the methods of the establishment and with the effects to be expected in dif- ferent diseases. Beneficial effects may be expected from the inhalations in cases of simple bronchitis, in the bronchial catarrhs of old people, in bronchial catarrh as- sociated with emphysema, in nervous cough, in asthma (except during the paroxysms), in simple laryngitis, and in chronic' pleuro-pneumonia. In cases of herpes, rheu- matism, gout, and pulmonary tuberculosis, the water should be administered internally and in the form of baths, as well as by inhalations. In diseases of the skin, generally, the baths of Allevard will be found to be too irritating. Henry Fleischner. ALLSPICE {^Pimenta, U. S. Ph. ; Pimenta officinalis Lindley ; Eugenia Pimenta, D. C. ; order, Myrtaoea), whose unripe fruits constitute "allspice," is a handsome, evergreen, fragrant tree, about ten metres (thirty feet) in height, with opposite dark-green, shining leaves, and small *hite flowers. The leaves are oval, with tapering bases, thick, coriaceous, and punctated, like the others of the family, with semi-transparent dots, indicating oil- glands in their substance. The flowers are in axillary cymes near the ends of the branches — tetramerous, witid numerous stamens and a two-celled inferior ovary. The fruit is a rather dry, stony berry, from one-half to one centimetre (one-fifth to two-fifths inch) in diameter, nearly spher- ical and crowned with its four-parted calyx and short cylindrical style. The allspice tree is a native of the West Indies, South and Central Ameri- ca, and Mexico. It is abundant in the island of Jamaica, both wild and culti- vated, and has been introduced into Asia and other tropi- cal places. This spice has been used in Europe for more than two centuries, and is still in great demand, both there and here, as a domestic condiment. It comes almost entirely from Jamaica, where it is obtained in enormous quan- tities from both wild and cultivated trees. The fruits — like those of pepper and cubebs— are collected just before they are ripe and dried in the open air. When fully ripe a portion of the fragrance is lost. The dried fruits are slightly smaller than the fresh, round or nearly so, finely wrinkled or tuberculated upon the surface, of a brown or grayish- brown color, and having a strong, agree- able, aromatic, clove-like odor. The limb of the calyx is usually rubbed away, leaving a circular projecting margin, or crown, at the apex of the fruit, enclosing a shallow, saucer-shaped calyx cup, from the middle of which rises the style, usu- ally broken off at the top. They are two- celled and two-seeded (sometimes one- seeded by suppression). Seeds brown, flattish, exalbuminous ; embryo spirally coiled. A sec- tion of the fruit reveals, just below the surface, numerous large oil-cells, some of which projecting outward form Uie small corrugations to be seen upon the outside These cells contain most of the oil ; in the seeds are also fewer and smaller oil-cells. The oil of allspice (O^mto Pimentm, U. S. Ph Br Ph ) which is its only valuable constituent, can be obtained to the extent of two to four per cent. It is a heavy yellow, thickish essential oil, having the odor and taste ol Its source ; specific gravity, 1.037. It consists of two parts, one lighter than water, a hydrocarbon, and one heavier, probably Eugenol, the same as in oil of cloves Action AND tJsE.-Similar to that of other aromatics. (Bee Cloves.) Not often used as a medicine, occasionally as fm adjuvant, probably inferior to cubebs for the special purposes for which they are used ; as a stomachic the choice between allspice, cinnamon, and cloves is merely a matter of taste, all being equally good. All- 118 Fio. ■Loni?itu- diiml section oC same (enlarged). Fio. 77.— Primus Amyg- daluB, Leaves and Bud. spice Is not often taken in substance, but might be il desired. A dozen berries or a gramme (gr. xv.) of the powder would be slightly stimulant to the stomach. The oil is to be preferred and might be given in doses of from two to four centigrammes (Tf|_ iij. ad vj.). It is an ingredient in the officinal bay rum {SptritiM Myrcvs, U. S. Ph.), and Syvv/pus Bhami (Br. Ph.), also there is an Aqua Pimenim (Br. Ph.). For allied plants and allied drugs, see Cloves. W. P. BolUa. ALMONDS, BiTTBR and Sweet (Prunus Amygda- lus H. Bn. ; Amygdaliis communis Linn. ; order, So- sacece, Prunes). The almond tree is a small, gra'cefal tree, inhabiting the countries bordering the Mediterranean Sea, Greece, Asia Minor, Syria, Algeria, as well as Abys- sinia and other Eastern lands. It has been cultivated also in many of these places from time immemorial. It is very similar in size and appearance, as well as leaf and flower, to its near ally, the peach, growing from five to ten metres in height (sixteen to thirty -two feet), with graceful branching top. The leaves are ob- long, lanceolate, finely serrated, simple, and give when bruised a peachy odor. The flowers are large, pale-rose colored, almost exact coun- terparts of those of the peach. But the fruit, although structurally similar, develops diflerently; that part (the sarcocarp) which in the peach becomes juicy and edible, in the almond dries up, splits, and falls away, leaving the stone (putamen) attached to the tree. This is then gathered and makes the almond of commerce. It is an oblong ovate, pointed, jrellow " nut," somewhat flattened, with blunt or sharp- ish borders, and a roughish surface, perforated with nu- merous pores and depressions. The shell is variable, usually hard enough to require a light hammer to break it ; in some varieties easily crushed between the thumb and forefinger. The seed is sometimes, in some varieties always, imported without the shell. It is solitary and exalbuminous. ' Long cultivation has produced many horticultural varieties of almonds, depending mostly upon their size, shape, and thickness of shell ; but the most important distinction is that of taste and coinposition, in re- spect to which these varieties fall into one or another of two series, namely, those with bitter, and those with sweet or bland seeds. The trees pro- ducing them do not differ from each other much, excepting in the character of the I'"'- ''P.-Prunns Amygdalus, Flowers. seeds, but yet appear to be distinct, both existing in the wild state. 1. Pruwas Amygdalus amara Benth. and Hook {Amyg- dalus communis amara L.) grows wild and is culti- vated in the localities given above, but is more especially cultivated in Northern Africa and the Mediterranean Islands, the rather small Barbary almonds being pre- ferred. This variety yields : Bitter Almonds (Amygdala Amara, U.S. Ph., Br. Ph. ; Amygdalm amarm, Ph. G. ; Amandes amires. Codex Med., etc.). They are smaller and thicker than some kinds of sweet almonds, but are of several sorts them- selves, and vary. They are thus described : " About one inch (twenty-five millimetres) long, oblong lanceolate, flat- tish, covered with a cinnamon brown scurvy testa, marked by about sixteen lines, emanating from a broad scar at REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Allevard. AlmondjBi the blunt end. The embryo has the shape of this seed. Is white, oily, consists of two plano-convex cotyledons, and a short radicle at the pointed end ; has a bitter taste, and when triturated with water, yields a milk-white emul- sion, which emits an odor of hydrocyanic acid" (U. 8. Ph.). A magnified section of the seed shows the scurvi- ness of the surface to be due to a layer qi large project- ing blunt hairs, easily broken away ; the embryo consists of parenchymatous tissue, with occasional vascular bundles, the former filled with aleurone and other al- buminous granules and drops of oil. The most abundant constituent of almond, whether bit- ter or sweet, is the Jwed oil, which is the same in both {Ole- um amygdalcB expreasum, U. 8. Ph.), although usually for commercial reasons obtained from the former, in which it is present in from forty to forty-five per cent., by sub- jecting the seeds, after being ground and gently warmed, to high pressure. It is a pale yellow or almost white limpid oil, with slight, if any, odor, and a bland, pleas- ant, nutty taste, recalling that of almOnds. It consists of nearly pure olein, and does, not congeal until cooled to a point below zero. Keeps pretty well, but finally becomes rancid. Almond oil has no medicinal proper- ties, but is adapted to any use where a simple liquid fat is desired. According to Hager (" Pharmaceutische Praxis "), the oil expressed from bitter almonds is not so food and does not keep so well as that of the sweet, [oreover the commercial oil is largely expressed from the so-called "peach-meats," as well as the seeds of other JPruni. The most interesting constituent, although less abun- dant, in bitter almonds, is amygdalin, a remarkable crys- talline glucoside contained in them to the extent of from one and a half to three per cent. It was discovered in 1830 by Robiquet and Boutron Charlard, and its peculiar decomposition lq 1835 by WOhler and Liebig. Amyg- dalin m.ay be prepared by exhausting the cake left after pressing out the fixed oil, with boiling alcohol, evaporat- ing and precipitating with ether, washing the impure precipitate again with ether, and then crystallizing it from boiling alcohol. It is in fine pearly scales, or yarger transparent, colorless, orthorhombic prisms, ac- cording to the amount of water of crystallization con- tained. Soluble in twelve parts of water at ordinary temperatures, and in all proportions of boiling water. Nearly insoluble in cold, but freely soluble in boiling al- cohol. Ether does not dissolve it at all. Its taste is in- tensely and purely bitter ; it has no odor, and alone is not poisonous, and probably a simple bitter tonic ; as much as four grammes ( 3 j. +) having been taken at one dose with impunity. Half-gramme (gr. xxxj.) doses, three times a day, have been continued without ill effects, but once an odor of prussic acid was noticed in the eructations. Besides the above substance, bitter almonds also con- tain, in common with sweet almonds, an uncrystallizable albuminoid ferment, emuldn, which exerts a peculiar power over amygdalin. This was discovered by Wohler and Liebig in 1835, and is prepared by a rather compli- cated process of treating sweet almonds with water, separating the other albuminous substances in the solu- tion by acetic acid, acetate of lead, or fermentation, and finally precipitating the emulsin. It is an amorphous, whitish or pinkish powder, by no means chemically pure, as it contains at least one-third of its weight of ash, insoluble in alcohol, freely so in water, from which a portion is separated upon boiling, both portions thereby losing their power. It is closely related to the casein and albumen of the almonds, of which it is probably a modi- fication, is not poisonous of itself, but it has the property of determining the disintegration of the amygdalin under certain circumstances. If solutions of each of these sub- stances in water are made, and one poured into the other, after a few seconds the odor and taste of the mixture is altered and the presence of priusic acid and bemaldehyd (oil of bitter almonds) is easily proved, while the amyg- dalin has disappeared ; with the addition of two equiva- lents of water it has been completely resolved into the above-named substances and glucose. The emulsin is not decomposed, but, in common with other ferments, there appears to be a limit to the amount of change it can produce. The same reaction takes place in the bitter al- mond seeds whenever they are ground and moistened. Advantage is taken of this reaction in the preparation of the commercial oil of bitter almonds (Oleum AmygdaXx Amwrm, U. S. Ph.). The mash left after expressing the fixed oil is reground, moistened and macerated to de- compose the amygdalin, then distilled from water after the manner u^d in the extraction of volatile oils. The benzaldehyd and prussic acid, which together constitute the " oil," pass over and are condensed. It is a colorless, or light yellow, thin, volatile liquid, having a "peach- meat " odor, distinct from, but recalling that of prussic acid, and a sharp, burning taste. Specific gravity, 1.050 to 1.060. It is soluble in alcohol and ether in all propor- tions, and in 300 parts of water ; on long standing it deposits crystals of benzoic acid. It must not, in conse- quence of its name, be associated with the numerous hy- drocarbons and their allies, which constitute most of our aromatic stimulants, and with which it has neither chem- ical nor therapeutic affinity. In its ordinary state it is a preparation of prussic acid, and should only be used with that fact in mind. It is not difficult to separate the acid from the oil, and the latter when so freed has a pleas- anter, purer odor, and may be used freely as a flavor ; in- deed, it is largely so prepared for culinary and confec- tionery uses. 3. Sweet Almonds {Amygdala BuMa, U. S. Ph. ; Br. Ph., Amygdalm dulees, Ph. G. ; Amandes douoes, Codex Med.). The treatment of bitter almonds leaves little to be said of these. They are often larger and longer than the pre- ceding, but cannot be distmguished from them by the eye alone. They have a sweet, bland, oily taste, free from bitterness or odor. Their composition resembles the others in most particulars ; they contain the same ficed oil in slightly larger proportion (up to fifty per cent.), emulsin also in larger proportion, similar albuminoids, but no amygdalin. As the amount of emulsin in bitter almonds is not quite enough to fully decompose the amygdalin, it is usual, in its manufacture, to mix in some sweet almond seeds. Action and Usbs. — Sweet almonds have no physio- logical action beyond that of an oily, agreeable, rather indigestible food, and are only used for two officinal preparations, whose office is that of agreeable vehicles. 1. Mistura Amygdalm, U. S. Ph. ; strength ^. Almond mixture is an emulsion made by rubbing six parts of al- mond with one of gum arable and three of sugar into one hundred parts of water. It is a white, opaque, milk-like liquid, with sweetish taste and nutty flavor. It may be used freely internally or as a lotion, but does not keep well, and should be freshly made. It is pharmaceutically incompatible with acids and alcohol, which will curdle it. A few bitter almonds may be added in making, for the sake of flavor. 3. Byrupus Amygdalm, U. S. Ph. (Syrup of Almonds, Syrup of Orgeat); strength -ts sweet, and tou bitter (sweet almonds, 10 ; bitter almonds, 3 ; sugar, 50 ; orange flower water, 5 ; water enough to make 100). A thicker, sweeter, and more elegant vehicle than the preceding ; useful in cough and antispasmodic mixtures. The expressed oil (see above) is an ingredient in " cold cream" {Ungwntum Aqum Bosm, U. 8. Ph.), of which it comprises one-half ; the other ingredients being, sperma- ceti, 10 ; . wax, 10 ; rosewater (from which it takes its name), 80. A pleasant, cooling, unirritating, widely-used, cosmetic ointment. The essential oil (see above) is used in the preparation of bitter almond water {Aqua Amygdalm Ama/rm, U. S. Ph. ) , of which it comprises the one-thousandth part. Dose of the oil, fifteen to sixty milligrammes (0.015 to 0.060 grm. = gr. i to j.) This would allow for an active dose of the water from fifteen to sixty grammes (15 to 60 c.c. = 3 iijss. to I ij.), but it is in fact only used as a flavor, and should be restricted to this, as there is a distilled water in the market often much stronger ; from five to ten or twelve grammes ( 3 j- to 3 iij.) is as much as it is safe to give. The action of the oil in full doses is that of prussic acid, which see. 119 Almonds. Aloes. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Botanical Relations. — The order Bosacem is so large, and its members have such disconnected qualities, that it -will be most instructive to study its different tribes sep- arately. (See Rose, etc.) The tribe Pmnem is a well- marked division, comprising Bosacem with solitary free carpels, containing a one-seeded drupe. The principal genus is Prunus, with eighty-three species scattered over the north temperate zone. Several species are cultivated for ornament, and many for their edible fruits, which have been much improved by cultivation. A strong bitter almond flavor pervades the genus, especially in leaves, bark, and seeds, which are often used. They occasionally poison cattle. A gum consisting of almost pure bassorin (cherry-tree gum) exudes from the bark of a few species. Aside from the hydrocyanic possibilities the gum is not poisonous. In its present extended limits, Prunus Includes at least five old genera of familiar domestic plants, as follows : 1. Sub-genus AmygdaXua. — Drupe with velvety surface, stone rough pitted ; sarcocarp hard, leaves conduplicate in the bud. Ten species, including the almonik and Prunus nana Jess., a European and Eastern almond, yielding the so-called "peach-meats," which are exten- sively used in making the almond oils. Europe and Asia. 3. Sub-genus Armeniaca. — Fruit velvety, fleshy ; ver- nation convolute; peaches and apricots, species two — one Asia, one America. 3. Sub-genus Prunvs. — Fruit smooth, often glaucous ; seed oblong, compressed ; vernation convolute ; species twenty, widely distributed. Plums, etc. _ 4. Sub-genus Oerasus.— Emit smooth, rounder ; verna- tion conduplicate; twenty species, widely distributed. Cherries, etc. 5. Sub-genus Zaurocerasus.-^FloweTa in racemes ; fruit smaller, oblong, or globose ; stone smooth or rough • vernation conduplicate ; thirty species ; temperate and tropical regions. Cherry laureb. (See also Cherry, "Wild and Prune.) Medical Relations.— Amygdalin, or something hav- ing the same power of producing prussic acid, exists in minute quantity in a number of neighboring genera of tribes Pomel ':*™*7 ^'^'■"est '^°o^''> is. singularly LnH oL T'' ^^''''^ '^.'f'll considered the best il Eng snmp Sh ^T""^* ^""^ ^l nominally obtained from tlfe same little, obscure, out-of-the-way island that Alexander L??n?''^ *° ^^^ peopled with fereeks, in order to pro- tect and improve its production. From Socotra the di-u2 Ifexandrif^ A^^^.L '"^^ ^"™P^ ^^ ^he Red Sea anf the Caoe of ^1^^ ^IT^^^ "^ ^"^"^ ^'ite around meroe ?n th«t rt?v ^°^' " f°^^°^"''^ ^^-^ '=°"'-se of com- merce m that direction ; at present, Socotrine aloes inm Fortior, Stronger "Water of Ammonia- This is an aqueous solution of ammonia, containing twenty-eight per cent. , by weight, of the gas. It presents itself as a " colorless, transparent liquid, of an excessively pungent odor, a very acrid and alkaline taste, and a strongly alkaline reaction ; specific gravity, 0.900 at lo" C. (59° F.). It is completely volatilized by the heat of a water-bath. On bringing a glass rod dipped into hydro- chloric acid, near the liquid, dense, white fumes are evolved" (U. 8. Ph.). From the volatility of its contained ammonia this preparation is directed to be kept in " strong glass-stoppered bottles, not completely filled, in a cool place." Aqua Ammonim, "Water of Ammonia : " An aqueous solution of ammonia, containing ten per cent., by weight, of the gas." This weaker solution has the properties of the stronger, only not to so intense a de- gree. Its specific gravity is 0.959, at 15° C. (59° F.). It also should be kept cool, in glass-stoppered bottles, but the precaution to avoid filling the bottles completely is not here necessary. Spiritus Ammoniw, Spirit of Am- monia : " An alcoholic solution of ammonia, containing ten per cent. , by weight, of the gas. " This solution is pre- pared by subjecting stronger water of ammonia, in a still, to a gentle heat, and conducting the ammonia gas thereby volatilized to a receivef containing freshly distilled alco- hol. The product is assayed and brought to standard strength by the addition of alcohol. Spirit of ammonia is a " colorless liquid, having a strong odor of ammonia, and a specific gravity of about 0.810" (U. S. Ph.). It should be kept in glass-stoppered bottles, in a cool place. Spiritus Ammonim Aromaticus, Aromatic Spirit of Am- monia : This is a composite preparation, containing in 1,000 parts, carbonate of ammonium, 40 ; water of am- monia, 100 ; oil of lemon, 13 ; oil of lavender flowers and oil of pimenta, each, 1 ; alcohol, 700 parts ; and the rest distilled water. It is a " nearly colorless liquid when freshly prepared, gradually acquiring a slightly darker tint, of an aromatic, pungent, ammoniacal odor, and hav- ing a specific gravity of about 0.885 " (U. S. Ph.). This spirit, like the other ammonia solutions, should be kept glass-stoppered, in a cool place. But in spite of this pre- caution, the fact obtains generally with ammoniacal solu- tions that they lose strength upon keeping, so that a sam- ple a year or more old may be almost wholly without ammoniacal odor. Ammoniacal solutions are incompati- ble with acids, acidulous salts, and many salts of the 135 Ammonia. Ammoniac* BEFERENCE HANDBOOK OF THE MEDICAL SCIENCES. metals and earths ; ammonia, however, does not decom- pose calcic salts, nor, except partially, magnesic. _ Ammonia is chemically a powerful alkali, and, physio- logically, is in gaseous form intolerably pungent, its fumes, if strong, exciting vigorous spasm of the larynx. In strong solution, it is intensely irritant. Either of the officinal waters of ammonia, or the simple spirit will, it of standard strength, excite severe irritation upon incau- tious inhalation of the fumes, and, if applied to the skm upon cloths so covered as to prevent evaporation, will very speedily cause burning pain and redness, and, after a few minutes, blistering. Prolonged application may lead to ulcerative inflammation or gangrene. Internally, in proper dilution, ammoniacal solutions are locally alka- line so far as the contents of the stomach and bowels are concerned, and also, because of the pungency and vola- tility of ammonia, they tend to allay nausea and to expel flatus. Ammonia, being of high diffusion power, is read- ily absorbed, whether taken by swallowing or by inhala- tion, and then quickly but evanescently exerts the pecu- liar effects of the ammonic compounds upon the heart, respiration, and motor tract of the cord as already set forth. Undiluted, the three first named pharmacopoeial solutions of ammonia are so irritant as to be practically corrosive to the mucous membrane of the stomach and bowels. Large doses are, therefore, violently poisonous, capable of causing speedy death, with all the usual symp- toms of corrosive irritation. In some cases death results in so short a time as a very few minutes, probably from suSocation through rapidly developed cedema of the glottis. So small a quantity as about a teaspoonf ul and a half of a strong solution of ammonia, swallowed undi- luted, has killed. Dangerous, and even fatal, poisoning has also resulted from inhalation of strong ammoniacal fumes. The therapeutical uses of ammoniacal solutions are lo- cal and general. Locally, according to strength of applica- tion, ammonia may be made to serve as a vesicant or ru- befacient. To blister, a pledget of lint, steeped in a strong solution, is covered with a watch-glass or wooden pill-box to prevent evaporation, and then directly applied. In such way the stronger water of the Pharmacopoeia has been used, but this solution is unnecessarily and, unless very carefully manipulated, dangerously strong. If em- ployed, the application should be held in contact with the skin for only three or four minutes, or until the part is well reddened, and should then be removed and a hot poultice applied until the blister rise. It is safer to di- lute the stronger water with one-half its volume of addi- tional water. Ammonia is rarely selected as a blistering agent, unless the need for the blister is urgent, when the quickness with which ammonia acts makes it preferable to cantharides. For rubefacient purposes a dash of the stronger water is a very common addition to composite liniments, and there is officinal in the U. S. Pharmaco- poeia Idnimentwm Ammonice, Ammonia Liniment, or as it is commonly called, volatile l^nimeni. This prepara- tion is made by mixing three parts of water of ammo- nia (not the stronger water) with seven of cotton-seed oil. An ammonia soap results, which partly dissolves and partly remains emulsified in the fluid, forming a white viscid mixture. The preparation is saponaceous, yet possesses mildly the irritant qualities of ammonia, and makes a capital liniment for rubef action. Still a third local purpose of ammonia is to relieve the pain or itching of bites of insects. For this purpose a drop or two of the weaker water, clear or diluted, may be applied to the part. Internally, ammonia may be used, first, to cor- rect the gastric malaise that attends a fit of acid indiges- tion, or to allay nausea from any cause. For such pur- pose the aromatic spirit is specially devised, to be given in doses of from one-half to one teaspoonful, diluted with three or four volumes of water. Secondly, ammo- nia may be given for the constitutional effects of reviv- ing the heart in faintness, of supporting it in chronic conditions threatening heart-failure, of stimulating flag- ging_ respiration, as in dyspnoea from lung disease, or respiratory failure in poisoning by paralyzing agents, of allaying mild spasmodic seizures, and of opposing gen- erally the action of narcotics and paralyzers. For all in- ternal medication the stronger water is entirely too strong, and the weaker water or the spirits are preferred Of this water or simple spirit from ten to thirty drops may be administered at a dose, largely diluted. If swal- lowing be impossible, as in case of unconsciousness from a faint, the effects of ammonia may be obtained by in- halation, but ^reat caution is necessary lest dangerous, or even fatal, irritation of the air-passages be set up by too strong inhalation during complete or semi-unconscious- ness. None of the pharmacopoeial ammoniacal solutions should be applied close to the nostrils. Acid ammonic carbonate, NH4HCOS. Upon sublim. ing a mixture of chalk and ammonic chloride or sul- phate, double decomposition ensues, and a sublimate is obtained which consists of acid ammonic carbonate and ammonic carbamate, represented by the symbol, NHjHCOs.NHiNHjCOs. This composite salt is of- ficinal under the title Ammonii Carbonas, Carbonate of Ammonium. It occurs as '_' white, translucent masses, consisting of bicarbonate (acid carbonate) of ammonium and carbamate of ammonium, losing both ammonia and carbonic gas on exposure to air, becoming opaque, and finally converted into friable, porous lumps, or a white powder (acid carbonate of ammonium). The salt has a pungent, ammoniacal odor, free from empyreuma, a sharp, saline taste, and an alkaline reaction. Soluble in 4 parts of water at 15° C. (59° F.), and in 1.5 part at 65° C. (149° F.).* Alcohol dissolves the carbamate and leaves the acid carbonate of ammonium. When heated the salt is wholly dissipated, without charring. If the aqueous solution is heated to near 47° C. (116.6° F.), it begins to lose carbonic acid gas, and at 88° 0. (190.4° F.) it begins to give off vapor of ammonia. Dilute acids wholly dissolve the salt with effervescence" (U. S. Ph.). This salt must be kept in well-stopped bottles in a cool place. Ammonic carbonate behaves, physiologically, like am- monia itself, but is a little less rapid and evanescent in operation. In concentrated solution it is locally irri- tant and, taken internally, dangerously poisonous. The salt is used for the constitutional stimulant and sustain- ing effects of ammonia, being for such purpose often preferred to solutions of ammonia because of the slightly longer duration of the action. It is given internally in frequently repeated doses of from 0.30 to 0.60 gramme (five to ten grains) in aqueous solution, with the acri- mony disguised by gum arable or sugar, or some agree- ably flavored aromatic addition. Large single doses should be avoided, since they easily over-irritate the stomach and may excite vomiting. Ammonic carbonate is also much used to get an ammoniacal effect by inhalation. For this purpose it is coarsely bruised, treated with half its bulk of strong water of ammonia, and flavored witli a little oil of lavender or bergamot, such mixture con- stituting what is known as smelling salts. Ammonic acetate, NH4CaH80a. This salt is used only in the aqueous solution in which it results from the procedure of neutralizing with ammonic carbonate the diluted acetic acid of the Pharmacopoeia. Such so- lution, commonly called spirit of mindererus, is officinal as Liquor Ammonii Acetatis, Solution of Acetate of Am- monium. It is " a clear, colorless liquid, free from em- pyreuma, of a mildly saline taste, and a neutral or slightly acid reaction ; specific gravity, 1.023. It is wholly volatilized by heat. "When heated with potassa it evolves vapor of ammonia, and when heated with sul- phuric acid it gives out vapor of acetic acid. It coii| tains about 7.6 per cent, of acetate of amnionium" (U. S. Ph.). It should be freshly made for use, smce like other solutions of alkaline salts of the common organic acids it tends to spontaneous decomposition on keep- ing, Ammonic acetate is a bland, mawkish salt, which upon absorption may prove feebly diaphoretic or diuretic, according to circumstances, and may to a slight degree exert the characteristic effects of the ammonic com- * According bo Squibb the salt begins to deoompoBe at mucli less than this temperature. 136 REFERENCE HANDBOOK OP THE MEDICAL SCIENCES. Ammonia, Ammoniac. pounds generally. It is used to allay headache, espe- cially the headache of pyrexia, to quiet an uneasy stomach, or to promote gentle diaphoresis or diuresis in fever ; but it is at best a feeble medicine. One or two tablespoonfuls may be given at a dose, clear or diluted, sweetened and aromatized. If diluted, carbonic acid water makes an excellent addition. (Df) Ammonie {ortfio-) phosphate, (NH4)aHP04. The salt is offlciml as Am/monii Phoaphas, ifhosphate of Am- monia. It occurs in "colorless, translucent, monoolinic prisms, losing ammonia on exposure to dry air, without odor, having a cooling, saline taste, and a neutril or faintly alkalme reaction. iSoluble in 4 parts of water at 15° C. (59° F.), in 0.5 part of boiling water, but insoluble . in alcohol. When strongly heated the salt fuses, after- ward evolves ammonia, and at a bright red heat is wholly dissipated " (U. S. Ph.). Ammonic phosphate is a bland saline without any marked physiological proper- ties, and has been used on theoretical grounds in rheu- matism, gout, and diabetes, by a few practitionui:;, with- out very startling results. It may be given in doses of from 0.65 to 2.00 gm. (ten to thirty grains) three or four times a day in solution. Ammonic nitrate, NHjNOs. The salt is ofllcinal in the TJ. S. Pharmacopoeia as Ammonii Nitras, Nitrate of Ammonium. It is not used in medicine, but inasmuch as one of its pharmaceutical uses may need to be availed of by the physician himself — namely, the making from it of nitrogen monoxide gas — the pharmacopoeial de- scription and also tests for purity are here appended : " Colorless crystals, generally in the form of long, thin, rhombic prisms; or in fused masses, somewhat deliques- cent, odorless, having a sharp, bitter taste, and a neutral reaction. Soluble in 0.5 part of water and 30 parts of alcohol at 15° C. (59° F.) ; very soluble in boiling water and in 3 parts of boiling alcohol. When gradually heated, the salt melts at 165° to 166° C. (339° to 331° F.), and at about 185° C. (365° F.) it is decomposed into nitrous oxide gas and water, leaving no residue. The aqueous solution of the salt, when heated with potassa, evolves vapor of ammonia. On heating the salt with sulphuric acid it emits nitrous vapors. The aqueous so- lution, when acidulated with nitric acid, should not be rendered cloudy by test solutions of nitrate of silver * (chloride), or of nitrate of barium* (sulphate) " (U. S. Ph.). Normal ammonic sulphate, (NHi)sS04. The salt is of- ficinal in the U. 8. Pharmacopoeia as Am/monii Sulphas, Sulphate of Ammonium. It is used only in the phar- maceutical making of ammonia and iron alums. Edward Curtis. AMMONIA, POISONING BY.— The first symptoms of poisoning by ammonia, when the drug has been swal- lowed, are those due to the local action of the drug upon the mucous membrane of the mouthy throat, and stomach. There is intense pain in the oesophagus and abdomen, and the lips, tongue, and pharynx are swollen and reddened. Vomiting occurs soon, and the vomited matters often consist largely of blood. Purging sets in, and blood is passed also in the stools. There is a considerable degree of dysphagia. The pulse becomes rapid and weak, and respiration is greatly accelerated. There is cough, with increased secretion from the trachea and bronchi, and oedema of the glottis sometimes occurs. The intellect may be preserved to the end, or stupor may arise, pass- ing into coma and death. The symptoms of gastro- enteric and bronchial inflammation are manifested al- most immediately, and increase in intensity, reaching their maximum in the course of a few days. When poisoning has been produced by inhalation, there is spasm of the glottis, and consequent dyspnoea, often with aphonia. CEdema glottidis very commonly occurs, and all the respiratory symptoms are intensified, but those of the gastro-enteric system are absent, or very insignificant. The diagnosis of poisoning by ammonia presents no difiiculty, owing to the characteristic odor of this sub- stance. Poisoning has been caused by the ingestion of * Five per cent, aqueous solution (distilled water). carbonate of ammonia, as well as of the aqueous and alcoholic solutions of the gas, but the chloride (muriate) of ammonium is practically of no toxicological impor- tance. Treatment. — The stomach-pump should never be used after poisoning by ammonia, for fear of doing further in- jury to the gastric mucous membrane. Dilute vegetable acids, vinegar, or lemon- juice, should be given at once, and then oily or mucilaginous drinks may be taken. The resulting bronchitis and gastro-enteritis are then to be treated on general principles. When the poison has been inhaled simply, the inflammation of the respiratory passages only will demand attention. In the dyspnoea resulting from osdema glottidis, tracheotomy may be necessary to preiserve the patient's life. Thomas L. Stedman. AMMONIAC (Ammoniacum, U. S. Ph., Br. Ph., Ph. G-.; Oomme armnoniaque. Codex Med.; Borema Ammoniacum Don). The source of the above is a large, weird-looking umbelliferous plant, growing abundantly in the wastes of Persia and Beloochistan. fi has a fleshy, turnip-shaped, perennial root, nearly thirty centimetres (one foot) in length, which is itself an article of com- merce in the East, and known as "Bombay sumbul." The flowering stem does not appear until the plant is five or more years old ; it is thick and coarse, two metres or more (over six feet) in height. There are a few large compound leaves at its base, but above it is leafless. It terminates in a large, close raceme, along the branches of which the minute flowers are clustered m small globular heads. The plant is filled with an abundance of milky juice, contained in both stem and roots, which exudes either spontaneously or from punctures made by a beetle which feeds upon it. The sap, as it escapes, hardens and dries upon the stem, and flows or drops to the ground. It is col- lected in July and August, partly from the stems, partly from the ground, by Persian peasants, and exported to India, and from there to Europe. Ammoniac consists of these hardened drops, or tears, as they are technically called. In the best qualities they are separate, or only loosely stuck together in porous masses ; in inferior grades they are imbedded in a dark-brown resinous matrix. Fine specimens consist of rounded pieces from one millimetre to a centimetre or two (one-twenty-fifth to three-quarters of an inch) in diameter. They are brown- ish, cream-colored externally, darkening to cinnamon- brown with age, creamy white, or pure white within They break with a conchoidal fracture, disclosing a waxy, but shining surface. The odor is peculiar, rather disagreeable, but faint, excepting in masses or upon warming ; the taste bitter and rather acrid. Inferior specimens are those having a large proportion of the darker homogeneous resins and extraneous substances, such as dirt, sticks, chaff, etc. It is a difficult drug to powder, unless very cold or very dry (dried over quick- lime, Hager). When heated it softens, but does not melt. Alcohol dissolves about three-fourths of it. Water disintegrates it, and forms with it a milky emulsion. Ammoniac consists of about seventy per cent, of resin, fifteen to eighteen of soluble gum, and the rest is insoluble gum, water, and a trace of essential oil. The latter, according to Fliickiger, does not contain sulphur, and, therefore, is not similar to the oil of assaf oetida. Ammoniac is stimulant, expectorant, and to a slight extent said to be antispasmodic, but is scarcely used now internally. The dose is stated to be half a gramme to two grammes (gr. viij. ad gr. xxx.) three or more times a day. An emulsion would be an eligible form, al- though a tincture would probably contain all that v^as active in it. The only officinal preparation is Ammoniac Plaster {Emplaatrum Ammoniaei, U. S. Ph.), made by softening the ammoniac in diluted acetic acid, and evap- orating to a suitable extent. It is a stimulating and rube- 137 Fia. 85. — Dorema Ammoniacum, Fruit. Ammoniae. Amnion. REFEKENCE HANDBOOK OF THE MEDICAL SCIENCES. facient, sometimes blistering application, useful as a mild counter-irritant. Allied Plants.— One other species of Dorema, ac- cording to the "Pliarmacographia," yields ammoniac. Bentham and Hooker only include two species m the genus. The ammoniac of Dioscorides and Pliny, and other ancient writers, was obtained in Africa, and is a different article, namely, a gum resin obtained from Fm-ula Tingitana Linn. It is rarely found in European markets. Sagapenum is an obsolete product of a similar nature. See Assafoetida ; also see Anise, for a notice of the order. Allled Drugs.— See Assafoetida. W. P. BoUes. AMNION. The amnion is a thin, pellucid membrane, which is the innermost of the envelopes enclosing the fcEtus while in utero. Morphologically it is an extension of the body- walls (somatopleure) of the foetus itself, and, therefore, consists, histologically, of two layers, one epi- thelial, continuous with the ectoderm (seu epidermis) of the embryo, the second of loose connective tissue continuous with the outer leaf of the mesoderm, which, after the splitting of the middle-germ layer, unites with the ecto- derm to form the somatopleure. The epithelial layer is turned toward the embryo, and the connective tissue con- sequently lies upon the outside of the amnion, away from the embryo and toward tlfe uterine wall. The usual descriptions of the development of the am- nion in mammalia are erroneous, in that the process is described as essentially the same as in birds, whereas it is essentially different, as has_ been recently demonstrated for the rabbit and bat by Edouard van Beneden and Charles Julin (" Arch, de Biologie," tome v., p. 369), and has been rendered very probable for man by Wilhelm His (" Anatomic Menschlicher Embryonen"). In birds and mammals, according to the tradition which has come down to us from Von Baer and Von Bischoffl, the amnion arises in the same manner as in reptiles ; we now know that, this is true only of birds. In the sauropsida (birds and reptiles) the amnion grows up around all sides of the embryo ; in the rabbit it grows up over the posterior end, and gradually presses forward until it covers the whole, or nearly the whole, embryo ; in man it is supposed by His to grow up over the head and advance backward, but it must, in view of Van Beneden's and Julin's discoveries, be surmised that, when actual knowledge replaces supposition, the devel- opment of the f CBtal envelopes in man will be found to conform more closely to the process in other mammals than now appears to be the case. In this article it has been deemed best to give a short account of the origin of the amnion, 1, in the chick ; 3, in the rabbit ; 3, In man, according to His's theory. 1. Amniok in the Chick. — The middle germ-layer di- vides very early into an outer leaf, which unites with the ectoderm to make the somatopleure, and an inner leaf, which unites with the entoderm to make the splanchno- pleure ; the space produced by the splitting of the me- soderm is the future body-cavity (coelom), and is gener- ally known as the pleuro-peritoneal space. The split extends beyond the region of the embryo proper over the surface of the ovum, hence there is a distinct so- matopleure in the area around the germ, and this it is which gives rise to the amnion in all cases, both in birds and mammals. In the hen's egg, at about the twentieth hour of incubation, there appears around the anterior end of the primitive groove, which is the only embryonic structure distinguishable by the naked eye at that period, a large arch. Fig. 86, i>Af; this semilunar fold is pro- duced by the arching upward of the somatopleure. Somewhat later a second, but smaller, fold appears around the caudal extremity of the embryo, and this is soon followed by lateral folds, one on each side. Mean- while the head fold has greatly increased in extension, and partly covers over the anterior end of the embryo, which has also advanced rapidly in its development. By the fusion of all the folds the embryo becomes en- closed in a thin somatopleuric duplicature, which forms a continuous wall all around it. The folds increase in height and are gradually drawn over the dorsal aspect of the embryo, and at last meet and completely coalesce, all traces of their junction being removed. Beneath these united folds there is, therefore, a space, within which the embryo lies ; this space is the cavity of the amnion. Fig. 86. — Area Pellucida of a Ohick; Twenty Hours' Incubation. vAf, anterior amniotic fold ; Pr, primitive groove in the area pel- lucida, .^p. (Alter Kolliker.) The accompanying diagrams will serve to elucidate these changes ; they are taken from Allen Thompson. In these figures the parts of the embryo, and those near it, are represented larger than natural in proportion to the rest of the egg. Fig. 87, A, represents a longitudinal sec- tion of a hen's egg and, therefore, a transverse section of the embryo ; sh, is the calcareous shell, etc. ; sp, the air- space at the larger end ; vm, the vitelline membrane ; y, the yolk partially covered by the spreading layers of the blastoderm, viz. , ep, somatopleure, and hy, entoderm ; of the mesoderm only the splanchnopleuric portion, me, is Fio. 87. indicated ; the embryo, e, is black ; the rising lateral folds of the somatopleure are seen on either side of the em- bryo. Fig. 87, B, is a longitudinal section of an embrjro of the same stage, to show the large size of the cephalic amniotic fold and its extension backward ; also the lesser proportions of the caudal fold. Fig. 88 represents the suc- cessive steps in the development of the amnion ; -4, at the beginning ; B, at the end of the second day of incuba- tion ; C, on the third day ; D, on the fourth day. The embryo is black ; the lettering is the same as on Fig. 87. The manner in which the meeting and the final coalesc- ence of the folds is accomplished, is here very well shown. Another important point is likewise made plain by thesa 138 REFEBENCE HANDBOOK OF THE MEDICAL SCIENCES. Ammoniac. Amnion. diagrams, viz., that the amniotic folds consist of two leaves, an inner and an outer leaf ; so that after their co- alescence there appear over the embryo two membranes. Fig. 88, D, the inner of which is the true amnion, am^ and lies close about the embryo ; from the mode of its formation we understand why the epithelium of the am- nion, being the continuation of the embryonic epidermis, faces toward the embryo. The outer membrane, D, ep, passes outside the true am- nion and over part of the surface of the yolk ; it goes by the name of the f filse am- nion, or membrana serosa of Von Baer ; according to the text-books, it is vaguely said to participate in the forma- tion of the chorion, and, in- deed, current opinion is ex- tremely confused in regard to the whole history of the chorion. In fact, however, the relations of the mem- brane and its homologies ar6 quite evident and easily un- derstood : the false amnion is the equivalent of a part of the cJwrion of mammals ; the remainder of t|ie mammalian chorion being represented by the layer of ectoderm and subjacent mesoderm on the external surface of the yolk. This interpretation, which is here published for the first time, appears to me incon- trovertible. 2. FtETAL Envelopes of the Eabbit. — Yeiy differ- ent is the arrangement of the amnion iu the rabbit ; it is shown in the accompanying very admirable diagram, after Van Beneden and Julin. In the higher mammalia, it will be remembered, the yolk substance has almost entirely dis- appeared. (In the monotremes, according to Caldwell, Fio. 88. Fio. 89.— Fcetal Envelopes of a Rabbit ; Embryo of Eleven Days. A.pl.^ area placentalls; P/., placenta; Al.^ allantois; CA., churion; Am,, amnion; am^f portion of the amnion united with the walls of the allantois; As, Av', area vasculosa; T, T', sinus terminalis; C 821 gms. ; CS-assner ' the average of 35 cases, 1,730 gms. ; but as Gassner's results seem to deserve less confidence, we may safely conclude that at full term there is usually under one htre of amniotic fluid, while it must be remembered that the amount is extremely variable. The amount during development gradually increases, but no exact proportion exists between the stage of devel- opment of the ioetus and the amount of fluid. Fehling attempted to show a relation between the length of the umbilical cord and the quantity, but Krukenberg ' demon- strated from Fehling's own figures ■* that this conclusion was untenable. Composition. — The liquor amnii has the character of a serous fluid. Levison ' found its specific gravity to vary from 1.0005 to 1.0070, while, according to Prochownick," it varies from 1.0069 to 1.0082. The latter found it to contain between 1.07 and 1.60 per cent, dry solids, giving 0.51 to 0.88 per cent. ash. With the increase of quan- tity there is no constant diminution of the percentage of solids. The following table, compiled from Vogt ' and Scherer,'" indicates the little that is known concerning the changes in composition during gestation : 3 months. 4 months. 5 months. 6 months. 10 months. Water 983.47 9.26 979.45 10.77 3.69 B.09 975.84 7.67 7.24 9.25 990.39 6.67 034 2.70 991.74 Albumen and Mucin Extract Salts 0.82 0.60 7.06 It is clear that there is a, great diminution in the amount of albumen, especially toward the last month, and there is apparently a small diminution in the percentage of salts. The salts are such as are usually contained in se- rous fluids. In connection with the albumen, it may be remarked that the fluid contains no fibrin-forming ma- terial, as has been shown by Gusserow." There is a small quantity of urea, but not more than is found in other serous fluids ; hence, the presence of urea is no argument in favor of the view that the amniotic fluid is an excretion of the foetal kidney. Early in gestation the amount is small, but it gradually increases, until the ninth month, 0.030 per cent., and tenth, 0.045 per cent. (Fehling). The figures of various authors differ greatly — sometimes no urea being found (cf. Preyer, " Specielle Physiologic des Embryos," p. 289). Finally, we have to note the pres- ence of lymph-corpuscles, but whether they are always present, and, if so, in what numbers, is unknown ; in a few cases they have been found in large numbers. Ongin. — It is a hypothesis of long standing that the Uqum- amnii is an excretion of the foetus, and opinion has inclined to regard it as the product of the foetal urinary apparatus. There is, however, no satisfactory argument of any kind in favor of this view, but, on the contrary, there are many forcible objections to it ; while there is strong evidence to show that it is derived from the mother by direct transudation. It is to be considerfed, firstly, that the liquor has the composition of a serous fluid, trans- uded from the blood-vessels, and does not resemble urine ; like other serous fluids it contains a small amount of urea, but this is no indication whatsoever of the uri- nary origin of the fluid ; secondly, that the foetal penis is completely closed during the greater part of embryonic life, because after the closure of the raphe on the stalk, the glans remains long imperforate, so that in the male, at least, the direct discharge of the urine into the amni- otic cavity is impossible ; unless, therefore, we are ready to attribute the formation of the fluid to different sources in the two sexes, we cannot as.sume the kidney to be the source of the fluid in either sex ; thirdly, that the fluid is not excreted by the epidermal glands is proved by the very late development thereof, and the early and abundant formation of the fluid ; fourthly, that the amniotic fluid appears very early, being certainly present in the third week, at which time the enibryo is entirely without ex- cretory or glandular organs of any kind, and all its tissues are still undifferentiated ; lastly, that it seems improba- ble that the foetus, which constantly requires water for its own use, should excrete a large quantity only to swal- low it again. That the liquor transudes directly , from the uterine wall or from the chorion through the amnion into the amniotic cavity, is indicated, first, by the composition of the fluid ; second, by experimental evidence that certain salts can pass directly from the mother into the fluid without passing through the foetus, at least during the latter part of pregnancy. Zuntz '* was the first to make such an experiment ; he injected an aqueous solution of sulph-indigotate of sodium into the jugular vein of a pregnant rabbit ; the liquor amnii showed a distinct blue color, while no trace of blue was found in any part of the foetus. Wiener", repeated an^ extended this observa- tion, , and G. Krukenberg ' made similar experiments, with like results, with iodide of potassium. All the facts taken collectively, point, it seems to the writer, to the theory that the liquor amnii is a product of the osmotic function of the amnion ; that, during the ear- liest period, the osmosis takes place from the fluid in the space between the amnion and chorion; that, during a certain interval, namely, while the superficial capillaries of the chorion maintain an active circulation in that mem- brane (cf. Chorion), the fluid may come from the chorion, and, therefore, indirectly from the foetus ; and flnally, that during at least the latter half of pregnancy, the transfusion occurs from the decidua through the chorion and amnion both. This theory, as far as known to the writer, is new ; that the amnion itself produces the liquid it encloses, is highly probable, but the exact source of supply upon which the amnion draws is much more un- certain. LiTEBATUEB. 1 William Harvey : Exercitationes de generations animalium, 1651. ^ Forster : Meconium. Wiener med. Wochenschrift, No. 2, 1858. ^Zweifel: TJntersuchungen iiber das Meconium, Arch. f. G-yneek., vii., 475. 4 Fehling: Physiologische Bedeutung des Fruchtwassers, Arch, f. Gynaek., xiv., 221. s Levison: Frnchtwasser, Virchow-Hirsoh, Jahresber. fiir 1873, ii., 650 ; see also Arch, f . Grynsekol., ix,, 517. " Gassner : Die Menge des Fruchtwassers, Monatschr, f. Geburts- kunde, xix. 7 G. Krukenberg : Kritische nnd experimentelle Untersuchungen tiber die Herkunft des Fruchtwassers, Arch. f. Gynsek,, xxii,, Hft. i. * Prochownick : Das Fruohtwasser und seine Entstehnng, Arch. f. Gynffik., xi., 304, 661. 8 C. Vogt : Untersuchungen zweier Amniosflftssigfceiten, Miiller's Arch., 1837, 69-7.3. i» Jos, Soberer : Chemische TJntersuchung der Amniosfliissigkeit des Menschen in- verschiedenen Perioden, Zeitschr, f. wisa. ZooL, i., 88. Ct. also Verhandl., Wurzbnrg Phys.-med. Ges., 1862, ii., 2. >«GuBserow: Stoflaustausoh zwischen Mutter und Frucht, Arch. t. Gynsek., xiii. '2 Zuntz: Quelle nnd Bedeutung des Fruchtwassers, Pflilger's Ar- chiv, xvi., 548. " Wiener : TJeber die Herkunft dee Fruchtwassers, Arch, t Gynsek., xvii,, 24, Charles Sedgwick Minot. [Note. — Since the preceding article went to press an interesting paper, by Richard Haidlen, has been received, entitled, " Ein Beitrag zur Lehre vom Frnchtwasser," in Arch. f. Oyrmkologie, Bd. xxv., pp. 40 to 50. He gives a table of forty-three observations of the amount of the amniotic fluid determined according to Fehling's method, mde supra, and has recorded also for each case the sex, length, and weight of the child, the weight of the after 141 Amnion. Ampntatlon. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. birth, the length of the umbilical cord, etc. Combining his observations with those of Fehling (thirty-four cases),. he is still unable to detect any constant relation between the amount of the fluid and the weight of the child, the weight of the afterbirth, or the length of the umbilical cord. Haidlen's method of tabulation, however, hardly corresponds to the requirements of rigid statistics, and it is possible that a reworking of his figures will give difEer- ent results. I find the average of his observations to be 714 c.c. of fluid ; taking out two isolated extreme observa- tions, one of 50 c.c., and one of 7,000 c.c. (hydramnios), the average of forty-one observations is only 577 c.c. Haidlen also failed to find any proportion between the per- centage of solids and the amount of the fluid. Haidlen also repeated Krukenberg's" experiment of giving women iodide of potassium in the early stages of labor, and also small repeated doses for several days before labor ; in each case he found the salt in the amniotic fluid, and also in the first urine of the child. This experiment, there- fore, does not show whether the diffusion takes jilace from the uterine wall or the foetus into the amniotic cavity.] AMPUTATION. Amputation (amputare, to cut away) is a term generally used to designate the removal by surgical operation of a portion or the whole of an ex- tremity. In a wider application the word is still used with reference to separations of other prominent or pro- jecting portions of the body, such as the mamma, penis, and cervix uteri. In this article amputations of the ex- tremities alone will be considered. Older writers, and many of the present time in Germany and France, still further restrict the term amputation to the operative removal of a limb in its continuity, as in amputation through the forearm or thigh, while they designate as "disarticulations," "enucleations," the removal of a member in its contiguity {i.e., through the joint). This distinction is properly ignored by English and American writers, since many operations present combinations of the two procedures. (Syme-Pirogofl.) HiSTOBiCAii Skbtch. — The helplessness of surgeons of ancient times to cope with profuse hsemorrhage is gener- ally accepted as the sole admissible explanation, of the fact that, for nearly two thousand years, from the time of Hippocrates to that of Parfi, amputations were prac- tically limited to the removal by cutting through the dead tissues of gangrenous extremities. The only reference to amputations in the Hippocratic writings is as follows : "In case of fractures of the bones, when strangulation and blackening of the parts takes place, at first the separation of the dead and living parts quickly occurs, and the parts speedily drop oft', as the bones have already given way ; but when the blackening (mortifica- tion) takes place while the bones are entire, the fleshy parts in this can also quickly die, but the bones are slow in separating at the boundary of the blackening, and where the bones are laid bare. Those parts of the body which are below the boundaries of the blackening are to be removed at the joint as soon as they are fairly dead and have lost their sensibility, care being taken not to wound any living part ; for ifi the part which is cut off give pain, and if it should prove to be not quite dead, there is great danger lest the patient swoon away from the pain, and such swoonings are often immediately fatal" ("Hippocrates," Sydenham, vol. ii., p. 639). The anatomical labors of the Alexandrian school could not have been without influence on the status of surgery. This we see illustrated in the surgical writings of Celsus, who unquestionably was the first to suggest amputations in the living tissues above the line that separates them from the sphacelus. While he admits that patients frequently succumb during the operation from haemor- rhage, there can be no question but that Celsus was ac- quainted with the great usefulness of the ligature. In his chapter on wounds, he advises that,'" "if these (plugging the wound, compression, and mild caustics) do not prevail against the hfemorrhage, the vessels which discharge the blood are to be taken hold of and tied in two places, about the wounded part, and cut through, 142 that they may both unite together and nevertheless have their. orifices closed." It seems scarcely possible that the theory, if not the practice, of surgery could have developed to the position designated, unless a less difficult procedure for the liga- tion of a bleeding vessel in an open wound had been like" wise perfected, particularly in view of the facts that Archigenes had introduced the tourniquet, that every writer of the Greek and Arabian schools makes repeated reference to the use of the ligature for the relief of hsemorrhage, and that torsion of bleeding vessels was advised under certain circumstances by Galen, Rhazes and Paulus .^Eginfeta. ■ It is quite certain, therefore, that the proper management of haemorrhage was not entirely lost sight of even in the darkest period of the history of medicine. Indeed, the indications for amputation seem to have been more elucidated for a time after the labors of Celsus. Thus Archigenes enumerates, among the circumstances which require amputation, "the presence of intractable disease, such as gangrene, necrosis, putre- faction, cancer, certain callous tumors, and sometimes wounds inflicted by weapons " (Syd. " Paul ^gin.," vol. ii., p. 410). Nevertheless, the advanced position occu- pied by this writer was soon receded from. For a thou- sand years from the time of the latter authority retro- gression was the fate of amputations as of surgery in general. Where recourse to amputations was unavoid- able, the most barbarous methods were resorted to. The Arabians operated with red-hot knives. Through- out the dark ages the actual cautery was applied to the bleeding stump, or this was covered with boiling oil, or molten pitch, or sulphur. More cruel than any other was the practice of Guy de Chauliac, who in the four- teenth century bound a cord with sufficient force around a limb to insure its removal by gangrene. While ampu- tations were thus dreaded, until within the last three centuries, alike by surgeons and patients, it is certain that this operation was not called for so frequently as it is now. Lacerations as terrible as those produced by machinery and firearms, which for the most part force the amputating knife into the surgeon's hands, could hardly have been often encountered prior to the dis- covery of gunpowder and steam. While Gersdorff, of Strassburg, probably had used the ligature in amputation wounds for some years, it re- mained for the genius of Par6 to give to amputations a comparatively firm position among surgical operations. After nearly thirty years of experimentation and practical test of the ligature, he published results which should at once have revolutionized the surgical practice of the time. With the retraction of the skin and soft parts above the site of operation, to insure sufficient tissue to cover the divided bone, and the use of a constricting band, Parfi had adopted all the preliminary means which are deemed necessary to-day by many for making a cir- cular amputation. Grasping the open mouths of the arteries with curved forceps, he closed them with a double thread, and the wound with three or four sutures. Likewise was Pare the first who clearly taught the value of the ligature en masse in refractory hfemorrhages. " Inspired by God with this good work," it would seem that Par6 should have speedily moulded the practice of his contemporaries. That this was not the case is evi- dent from the great opposition encountered by him, and that it required nearly two centuries for the ligature to supplant the actual cautery as a hsemostatic measure. Although Fabricius Hildanus, in Germany, Dionys, in France, and Richard Wiseman, in England (last half of seventeenth century), make mention of the ligature, they in nowise recommend it. It is not remarkable, there- fore, that in the seventeenth century, Botal did not hesi- tate to perform amputation by means of two hatchets, one placed immediately below the member and the other loaded with leads let fall upon it (Velpeau, " Operat. chir."), and that even as late as 1761 W. Sharp saw cause for complaint at the restricted practice of ligaturing bleed- ing vessels. Indeed, it is questionable whether the liga- ture of vessels in amputation wounds could even then have obtained u firm foothold without the assistance BEFERBNCB HANDBOOK OF THE MEDICAL SCIENCES. Amnion. Amputation. given to it by the tourniquet. The origin of the latter is enahrouded in mystery. There can be no doubt that H. V. GersdorfE made use of constricting bands. It ap- pears that the idea of provisional compression of the artery, as now practised, was introduced Independently by two surgeons of different countries at about the same time. Morel, in France, and Young, in England, each devised a tourniquet for the arrest of the. circulation. It remained, however, for the great J. L. Petit (1718) to elaborate the principles of arterial compression and to construct an instrument from which those now in use differ but little. Finally, with the introduction of digi- tal compression and the use of the Esmarch bandage, the appliances for the control of haemorrhage appear as perfect as human ingenuity can make them. The most dangerous feature of an amputation being controlled, attention could be directed toward the secur- ing of a more rapid cure and a useful stump. When in ancient and mediaeval times an amputation terminated well, a year elapsed before the wound had healed, and a conical stump usually resulted. In 1678 a friend of Thomas Young expressed his great surprise that larger extremities could be removed in such a manner that the wound was firmly cicatrized by first intention in three weeks. The circular incision for amputations being the one most quickly accomplished and intuitively resorted to by the earlier operators, was the one generally adopted. Although Celsus clearly indicates the necessity of com- pletely covering the ends of the bone with the soft parts, by dividingituponahigherlevel, yet it was but rarely ac- complished. This will not appear remarkable when we consider how the operation was described as late as the sixteenth century by Hans v. Gersdorffl, the great bar- ber-surgeon of Strasbourg: "And when you, will cut him, order some one to draw the skin hard up, and then bind the skin with your bleeding-tape tight. Next tie a simple tape in front of the other tape in such a way that a space is left between the twq tapes of one finger's breadth, so that you may cut with the razor between them. In this way the cut is quite reliable, goes easily, and makes a perfect stump. Now when you have done the cut, take a saw and separate the bone, and after that undo again the bleeding-tape and order your assistant to draw the skin over the bone and the flesh, and to hold it hard in front. You should have a bandage ready of two fingers' breadth ; it should be moistened beforehand, so as to be wet through, then bind the thigh from above downward to the cut, that the flesh may protrude in front of the bone, and then bandage this too." ' Amputation by a single circular incision down to the bone has since been revived by Louis and Briinninghausen in the begin- ning of our century, and has been advised by Esmarch recently in emaciated and exhausted subjects.' Early in the last century J. L. Petit originated the first decided improvement upon the ancient method of prac- tising the circular incision. With the first circular in- cision he divided the skin and subcutaneous cellular tis- sue alone, and after reflecting them divided the muscles upon a higher level by a second circular sweep of his concave knife. Cheselden and Sharp in England, and Heister in Germany, independently devised and became adherents of this improved operation, by which the end of the bone could be completely covered. To still fur- ther improve tho stump Edward Alanson, after the cus- tomary circular incision through the skin, sought to give the wound a funnel-shape by applying the knife ob- liquely and dividing the muscles in the form of a hollow cone. Subsequent operators finding, however, that the wound thus made was not conical, but spiral, and that it entailed conditions unfavorable to primary union, this modification failed to get a permanent foothold among recognized operations. A better and simpler means to produce a conical wound was produced by Desault, who, after division of the skin, divided the superficial and deep muscles on different levels by two separate sweeps of the knife. Meanwhile flap operations had been devised. Al- though, according to Velpeau and Lacauchie, Helio- dorus had described amputation of superfluous fingers by the double flap operation, the knowledge of this method was entirely forgotten."" R. Lowdham, of Ex- eter, in 1679, introduced the flap operation for amputa- tion of the leg by making a lateral flap on one side, a semicircular incision on the opposite side completing the operation. The incision was made from without, and in- cluded the skin and muscles of the calf of the leg. Al- though, as already indicated. Young (currus triumphalis) most highly lauded the results achieved by the new method, it was ignored until Peter A. Verduyn, of Am- sterdam (1696), practised a similar amputation, transfix- ing the soft parts with a double-edged knife. Sabourin and Garengeot adopted the method by transfixion. Other modifications rapidly followed the first steps of the new method. H. Ravaton (1750), and Vermale (1767), sur- feons of the Palatinate, recommended the formation of ouble flaps, while Charles Bell (1807), and the elder Langenbeck (Gottingen), again practically returned to the older operation of Lowdham. On the other hand, S^dillot, in 1841, and Teale, in 1858, greatly improved the double flap operation. S^dillot formed two musculo- cutaneous flaps, in which only a small part of the flesh was included, and divided the remaining soft parts by a circular incision. A number of operators advised that the flaps be of unequal size, lest the cicatrix become ad- herent to the divided end of the bone. Finally, Thomas Teale, of Leeds (1858), devised the antero-posterior rect- angular musculo-cutaneous flaps. Scoutetten, of Metz, in 1827 combined into what is termed the oval method, a number of operations which had been previously em- ployed by the older Langenbeck, Larrey, Guthrie, and others. According to Scoutetten, this method, which is best adapted to disarticulations, is supposed to possess the advantages of both flap and circular operations. While, on the continent, this operation has found a small band of followers, it has never met with general favor. Indications. — Amputation has been termed the "last resource " and the " opprobrium " of the surgeon. Re- course to this radical measure signifies the surgeon's un- belief in his e:^orts to restore to usefulness an injured limb ; it is his concession that, in the combat with dis- ease, he has been conquered, or that his ability to rectify a congenital deformity is limited. To recognize the limits of his powers to save a part reqiflres ihe keenest judg- ment of the surgeon, and it is remarkable how, in the history of amputations, this has swayed between the ex- tremes of radicalism and conservatism. It is, of course, not remarkable that, prior to the introduction of the ligature, amputations were, for the most part, confined to the removal of parts which were all but removed by an accident itself, or were already the seat of gangrene. On the other hand, the multiplication of methods of am- putation, during the last and the early part of this' cen- tury, went hand in hand with the most reckless con- demnation of limbs. The voices of Gervaise* and Boucher, ° which were raised in defence of conservatism, were unheard, and even the remarkable reports of Bilguer were unable to stay the useless sacrifice of limbs. Bilguer,* the father of conservative surgery, and surgeon to Frederick the Great, could report, in 1763, 169 com- pound fractures successfully treated by conservative methods. Among these were 9 of the femur, 42 of the leg, 19 of the ankle, 9 of the head of the humerus, 16 of its shaft, 33 of the elbow, 9 of the forearm, 3 of the wrist, and 3 of the hand. The distinction which these statistics brought to Bilguer was materially dimmed by the fact that he published his successes alone, and that for a while he denied amputations a place among justifiable opera- tions. The incredulity of surgeons in these results and extreme views was one of the causes which prevented them for many decades from restricting the indications for an amputation. Faulty methods of treating wounds and an insufficient appreciation of the dangers attending major amputations were likewise potent factors in so frequently forcing the amputating-knife into the hand of * The importance of covering the end of the bone was patent to many —Earth, Maggi, among others. (Von K. Sprengel: Gesoh. der Chir., vol. i., p. 408, Halle, 1805.) 143 Ampntatlon. Amputation. BEFERENCE HANDBOOK OF THE MEDICAL SCIENCES. the surgeon. The introduction of immovable dressings, the startling statistics of Malgaigne, published in 1842 and 1848, the favor with vrhich excisions were received, and, above all, the advantage of antiseptic treatment in the widest sense, were the chief causes in finally deter- mining the indications for amputations as they are now generally accepted. In general terms, it is proper to resort to amputation when the sacrifice of a part, which is hopelessly diseased, is necessary to the preservation of life or the enjoyment of its various functions and duties. It is well to remem- ber that " the vast majority of people would prefer living with three extremities to being buried with four." While in each individual case the danger and advantages of an operation are to be carefully balanced, conditions may arise which may make an operation imperative which but a few days before seemed uncalled for. Contra-indications to amputation, either temporary or permanent, should also be clearly recognized. Among the former, particularly as to amputations for injury, should be, considered extreme shock and exhaustion from ex- cessive hsemorrhage. As permanent contra-indications, such conditions should be recognized as will preclude the possibility of attaining the object of all operative pro- cedure, viz., the restoration of the patient to health. Such indications are, first, so extensive an involvement, by disease, of a limb and contiguous parts that amputa- tion will not suffice for its complete removal, and, second, complications on the part of important internal organs from injury or disease, under which circumstances an amputation would not only be useless, but would prob- ably curtail life. While it is an axiom that amputation should be resort- ed to only under circumstances where no other means will avail, there is no little diflBculty in determining the conditions that ca,ll for this extreme measure. They may be most readily investigated by considering them under the three general headmgs of injuries, non-traumatic lesions, and deformities. (as) Injuries. — When, from accident of any kind, a limb is entirely severed from its connection, or the soft parts so mutilated that it is attached by skin alone, or by it and pulpified flesh, an amputation is absolutely indicated. Wounds from circula!r-saws, railroad accidents, extensive gun-shot lacerations, afford numerous instances in which the amputation consists in nothing more than trimming off the ragged edges of the wound, levelling the inequal- ities of the protruding fleshy masses, and placing the stump in the best condition for speedy repair. To this class of injuries belong those cases, caused by railroad trains, heavily loaded wagons, entanglement in machin- ery, etc., in which the soft parts are extensively torn from the bone, the muscles being pulpified, the blood- vessels and nerves lacerated. It is remarkable that in in- stances of this character the skin itself may remain un- broken, while all that it covers has been practically crushed. The shock attending the tearing off of a leg or an arm is usually so excessive that a formal operation with attendant loss of blood must be dispensed with. On the other hand, it is a well-established fact that fingers, portions of the nose and ear which had been almost completely and even totally separated by an in- cised wound uncomplicated by contusion, have been per manently replaced by the careful use of sutures. 0) Extensive burns and circumferential lacerations of only the skin and subcutaneous cellular layers may, in rare cases, require the sacrifice of a limb. When, from the depth of a burn, it becomes evident that the repara- tive process must be suppurative in character, and com tinue for many months, and when finally ended leave a disfigured and practically useless member, it is usually better at once to amputate than to expose the life of the sufferer to the dangers of septic infection, amyloid de- generation, or exhaustion. Extensive stripping of the in- tegument from a member may likewise impel the surgeon to operative interference. A most interesting case of this character is recorded by M. Schede (Billroth und Pitha, vol. n. , Heft ii. , 3 Abth. , p. 19), in which an entire arm was caught m a cogwheel and stripped of its integument, the 144 muscles of the arm and forearm bein^ laid bare as in a careful dissection. Although amputation at the shoulder was successfully re.sorted to and the acromion removed, the integument was insufficient for the closure of the wound (c) The simultaneous injury of the main artery and vein of an extremity has usually been considered an in. dication for amputation, since it almost invariably results in its mortification if conservatism is practised. This has applied particularly to wounds of the femoral artery and vein. The advisability of an operation in all such cases must, however, be seriously questioned, since in- stances are multiplying in which, with neoplasms, several inches of the main vessels of the limb have been removed without resulting in its death. When the vein alone is slightly injured, it is far preferable to trust to a properly applied lateral ligature, or if completely divided, an at- tempt to save the limb should be made by ligation of the accompanying artery. Quite recently a case has been recorded by Pilcher in which an incised wound of both femoral artery and vein was successfully treated by double ligation of both vessels.' On the other hand, am- putation may be required for the relief of traumatic aneurisms or those of spontaneous origin which have become diffused. Particularly may ablation of the thigh be preferable to other plans of treatment of aneu rism of the popliteal and of the deep arteries of the leg in persons of advanced years. In cases of subclavian aneurism exarticulation at the shoulder has likewise been successfully performed as a modified distal ligation. Finally, secondary haemorrhage after injuries from what- ever cause, when other measures have failed, can be re- lieved alone by the sacrifice of the limb. Since after ligation in continuity of an artery the secondary haemor- rhage most frequently comes from the distal end of the vessel, it is apparent why amputation is often successfully practised. (d) Compound fractures and dislocations are the con- ditions which most frequently call for amputation in all communities where manufacturing interests are largely developed and where railroads furnish employment to large numbers. Not very long ago, the presence of a compound comminuted fracture was deemed sufficient cause for an amputation, even if unattended by exten- sive laceration of the soft parts. In no field of surgery have greater triumphs been recorded than in the con- servative treatment of these compound fractures. There can be no question but that to-day all surgeons of twenty years' experience save limbs which in their earlier ex- periences they would have doomed. For these results we are in the main indebted to the principles of antiseptic treatment, which, although first promulgated in 1865 in Glasgow by Mr. Lister, were first extensively practised on the continent, especially in Germany, by Bardeleben, Volkmann, and Nussbaum. It is immaterial for our purpose which of the numer- ous antiseptic agents be preferred, or whether the open method of wound treatment with thorough drainage he employed. Such remarkable results have been achieved in the conservative treatment of compound fractures that ordinary cases may be said to present no indications for am- putation. Nearly a year ago a lad of eighteen had his left arm caught in the belt of a machine-shop. When brought to the Good Samaritan Hospital, in Cincinnati, an hour after the accident, there was detected a double fracture of the humerus, one of which was compound, a simple dis- location backward of the elbow, a compound fracture in the middle third of the radius with two inches of fragment protruding, and a compound dislocation of the ulna at the wrist. An amputation was strenuously advised, but, fortunately, rejected by the parents. The boy, after con- finement for nine months, recovered after two inches of the radius and six inches of the ulna were removed. The hand and forearm are almost useless, but infinitely preferable to the best artificial limb. Statistics of the advantages of conservatism in the treatment of these accidents are rapidly accumulating. Thus Volkmann was enabled to report 75 compound fractures of the larger long bones without a single death, although in 8 cases he was compelled to resort to secondary REFEBENCE HANDBOOK OF THE MEDICAL SCIENCES. Amputation, Amputatloo. amputation. Sir Joseph Lister, with rigid adherence to the antiseptic method, lost 3 out of 97 cases. In the treatise of Billroth and Luecke* is a most exhaustive compilation of 354 cases which were treated by the Lis- terian method. Of 334 of these cases which were treated conservatively only 14 died. But it remained for our own countryman. Dr. Fred. S. Dennis, to record the most brilliant and, indeed, unique successes ever ob- tained in this field.' Of 144 cases of compound fracture treated in the New York Hospital, not one died from septic infection, and 100 cases were treated without a death from any cause. Extensive splintering of bone and laceration of soft parts can, therefore, no longer be considered an excuse for the sacrifice of the limb. If amputations still form a considerable percentage of the operations performed in large hospitals, it is because of the more extensive employment of heavy machinery, and the great extent of railway travel. Most of the primary' amputations thus practised are indicated by the condi- tions above detailed. (Siib. a.) (e) Closely allied to compound fractures in their re- lation to amputations are compound dislocations. Since the more general appreciation of the value of primary excision of joints, amputations for these injuries are now less frequently resorted to than formerly. Indeed, all formal operations for compound dislocations should be greatly restricted. Cooper '" and Nelaton " already leaned toward conservatism. The latter advised reduction of the dislocation, closure of the external wound, and antiphlo- gistic measures. What has been accomplished in this way in recent years, and particularly by immobilization, could be demonstrated by a stately array of cases of com- pound dislocations of large joints in which the limb was saved, and often with perfect motion. Compound disloca- tions of shoulder, wrist, hand, and elbow, unless the dam- age of the soft parts is such as per se to call for amputa- tion, should always be treated without operation, or by excisions. A com^pound dislocation of the elbow, with laceration of the brachial artery, was successfully treated without operation by McCarthy, and Davis '* reports an- other such dislocation of the knee, in which all the func- tions of the joint were retained. On the other hand, amputations for compound disloca- tions of the foot and ankle are more frequently indicated, since excision and conservative measures often leave the parts useless, if not positively a burden, and the dangers of primary amputations are at least no greater than those which attend milder methods of treatment of these cases. if) Gun-sfiot Wounds. — These are of sufficient frequence in civil practice to often call for amputation. Here, on account of suitable accommodations and facilities for proper treatment, conservative means may be adopted, where in the field a part must be sacrificed for the benefit of the whole. A recent writer thus enunciates the con- ditions which caU for amputation:" "1. When there has been great destruction of soft and hard parts, as in a crush by Targe shot, or when the limb has been almost completely or altogether carried away. 3. When the fracture is associated with laceration of the main vessels or nerves of the part. 3. When acute, infective osteo- myelitis has been developed. In the chronic form of this disease, when the entire length of the bone has become af- fected, it may or may not be necessary to amputate, ac- cording to the general condition of the patient, and the particular bone that is diseased. 4. When there is severe secondary haemorrhage from an eroded vessel, or from a ruptured traumatic aneurism. 5. When traumatic gan- grene has supervened." (g) Mortification. — The presence of mortification, as a se- quel of trauma or of the application of the extremes of heat and cold, offer an unmistakable indication for the ablation of a part as soon as the evidences of the limita- tion of the gangrene are made manifest. Nor is it always advisable to wait for this in the case of traumatic gan- grene, which often extends with such rapidity that a few hours will rob the sufferer of his only chance. The mor- tification which follows the ligation of an arteij, or upon an embolism, is a condition calling for operative interfe- rence. On the other hand, this is rarely permitted by the Vol. I,— 10 general condition of the patients in cases of senile gan- grene. {h) Tetanus. — Amputation may be said to be one of the most successful measures for the relief of traumatic tet- anus. According to the latest experiences an equal pro- portion of good results follow this method and nerve- stretching. The latter should be given the preference in every case, when, in the event of failure, amputation should be resorted to as a dernier ressort. NoN-TEATJMATic AFFECTIONS. — (o) Inflammation. — Severe and extensive inflammations of the skin, subcu- taneous cellular layer, and intermuscular layer, as they are frequently encountered in phlegmonous erysipelas from injuries which in themselves are most trivial, and which from septic infection or protracted suppuration would lead to death, are conditions that may necessitate an am- putation. While with free incisions, the permanent water-dressing, and irrigation, many limbs thus affected may be saved, amputation must always be resorted to in a certain small proportion of especially aggravated cases. The presence of septicaemia and pyasmia should not be deemed a contra-indication unless the want of vitality of the patient will preclude the possibility of surviving the shock resulting therefrom. Billroth, Volkmann, Fayrer, Weinliichner, Luecke, and numerous other surgeons cite cases in which amputation was successfully practised after a varying number of rigors had placed the presence of the gravest constitutional infection beyond doubt. By removing the primary seat of the septic changes, the gen- eral manifestations of pysemia may frequently be caused to disappear. (i) Inflammatory conditions of the bones and joints which cannot be relieved by less radical measures often make an amputation imperative. Acute spontaneous osteo-myelitis, when unrelieved by trephining, and when affecting only a single bone, must be considered a condi- tion requii'ing this radical interference. Necrosis which involves the entire thickness of the shaft of the bone, when this is single on the part of an extremity (humerus, femur), and when repeated necrotomies have been una- vailing, occasionally requires the sacrifice of a limb. In extensive caries of the articular ends of the long bones, or of the carpus and tarsus, when from the depraved con- dition of the patient excision is unfeasible, amputation is compulsory. The improved methods of dealing with suppurative and destructive affections of joints by im- mobilization, and, if need be, by resection, have happily reduced the number of cases calling for amputation from these causes to a minimum. (c) Extensive circumferential ulcerations of the leg, which sap tlje strength of patients through haemorrhage or profuse suppuration, or which unfit the patient for the vocations of life, not unfrequently render amputation advisable. This also applies to cases of true and spurious elephantiasis, in which milder measures have proven of no avail. (d) Tumors of benign and malignant character, when from their size they destroy the usefulness of a limb or endanger life, are well-recognized indications for am- putation. The neoplasms most frequently demanding the latter are carcinomatous degenerations of chronic ulcers or epitheliomas developing around a sequestrum, or an osteo-sarcoma of the articular ends of the long bones. Under all these conditions amputation offers a better chance for permanent recovery than excision. The rule which applies to the management of neoplasms generally, that an operation must be refrained from unless all of the diseased tissue can be removed, is particularly to be re- membered before an amputation is determined upon for the relief of a tumor of an extremity. The bearing of amputation to certain traumatic affections of the blood- vessels and special spontaneous aneurisms has already been referred to. Congenital telangiectases likewise exact amputation when rapidity of growth endangers life or when other plans of treatment have been unsuc- cessful. Defobmities. — (a) Supernumerary fingers and toes are proper cases for removal, and the operation may be safely practised six months after birth. This early re- 145 Amputation. Amputation. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. moval assures a better form of hand or foot and a di- minutive scar. Cases of club-foot which have been alto- gether neglected or badly managed, and vrhich, from extensive ulceration or inflamed bursee, entail great suf- fering upon patients, not infrequently can be relieved by amputation only. But in early life no case of talipes is of sufficient severity to warrant the removal of the foot. (b) Cicatricial contractions of the joints, associated with great wasting of the muscles, from extensive burns ; great deformity and uselessnesa of a limb from neglected dislocation (foot or ankle), may call for an amputation. For these and similar cases, amputations of expediency may occasionally be required, but the surgeon should care- fully weigh all factors in the case before subjecting his patient to the risks of an operation for the relief of a condition which in itself is only a burden and not a source of danger. Time for Amputation. — When, in consequence of an injury, an amputation is indicated, the proper time for performing it must be considered. While the patient is still suffering from shock, collapse, or even exhaustion from excessive haemorrhage, it would be sealing his fate to resort to an operation. At least moderate reaction must invariably be awaited, irrespective of its early or late appearance. When reaction has once been estab- lished, with the aid of restoratives, the most appropriate period for an amputation has arrived, since, for a period varying from twelve to seventy-two hours, the injured part remains in apparently the same condition that it was in immediately after the accident. After this interval, there may be expected to supervene those local and sys- temic manifestations which belong to severe inflamma- tory changes in the injured part. All amputations prac- tised prior to the advent of these changes are designated primwy amputations. Since the time when these changes supervene varies from one to three or four days, ac- cording to a multitude of circumstances, foremost of which are the constitution of the patient and the character of the wound, no absolute limit can be fixed to the time when an amputation should no longer be classed among the primary amputations. With very few exceptions, sUrgeons of the present day recognize the necessity of immediate amputation in every instance where conservatism cannot be practised. The diversity of opinion which has prevailed on this subject has been great. Among the advocates of primary ampu- tation may be enumerated Du Chesne, Wiseman, Pott, Percy, J. Bell, Larrey, and Guthrie ; among its oppo- nents, Faure, Hunter, and, within the last quarter of a century, J. NeudorfEef, Paul, and Gross. The extensive experiences of Guthrie and Larrey have finally con- vinced surgeons of the advantages of early, as compared with late, amputations. Of 291 primary amputations, 107 recovered, 24 died, and 160 remained under observa- tion. Of 551 secondary operations, 170 recovered, 265 died, while 116 remained under treatment (Guthrie). The accumulated experiences of the Crimean and Franco- Prussian wars, and the vast statistics of our civil war, indorse the prevailing practice of resorting to early am- putations. In the statistics of Otis, there were in 3,259 primary amputations of arm, 602 deaths, 18.4 per cent, mortality ; in 902 intermediary amputations of arm, 302 deaths, 33.4 per cent, mortality ; in 411 secondary ampu- tations of arm, 114 deaths, 27.7 per cent, mortality ; in 1,914 primary amputations of lower third thigh, 927 deaths, 48.7 per cent, mortality; in 676 intermediary amputations of lower third thigh, 459 deaths, 67.9 per cent, mortality ; in 207 secondary amputations of lower third thigh, 100 deaths, 48.3 per cent, mortality. The obvious reasons for the better results which follow early operations are that they are made at a time when the constitution has not yet been exhausted by pro- tracted suppuration and high temperatures, and that they leave wounds which can be kept free from septic infection. The second date at which an amputation might be forced upon the surgeon is that during which the severe.st local and general signs of inflammation present them- selves. The damaged limb has become red, cedematous, 146 and painful. From the wound there issues a sanious malodorous fluid, and a more or less extensive slougliin? of the tissues adjacent to the wound ensues. Associated with these local conditions are an acceleration of pulse elevation of the temperature, often to a dangerous degree '• headache, dry tongue, scanty urine, and muttering delir! ium. Unless the patient succumbs to the paralyzing in. fluences of excessive temperatures, his condition becomes gi-adually ameliorated in from five to fifteen days. As the discharge of scant/ serum is followed by a free secre- tion of pus, the gangrenous parts are exfoliated, and the swelling largely subsides ; the fever and acceleration of pulse are reduced ; the tongue regains its normal moisture and color, and a comparative degree of comfort is enjoyed. Amputations practised during this stormy period of the clinical history of an accident have, after the designations of Boucher and Alcock, been called intermediary. Since they are made at a time when the damaged part and the system at large are in the very worst condition for operations, it is not remarkable that- sucli amputations offer the worst prospects for recovery. Although the mortality following such amputations must therefore be very much greater than that following primary or lata amputations, cases will arise in which the very gravity of the local and general phenomena, such as recurrent hsemorrhage, impending gangrene or septicsemia, will ne- cessitate the speedy removal of the limb,' as the last hope of deliverance. With the subsidence of the grave constitutional symp- toms and the advent of profuse suppuration, begins that period when if amputations are performed, they are termed secondary. It has already been seen that the pros- pects of recovery after amputations in this period are less promising than alter those of an earlier period. An equally strong objection to waiting for this period is that more of a limb must generally be sacrificed than by an early operation. Thus Guthrie observes that, "When an am- putation is delayed from any cau.se to the secondary period, a joint is most frequently lost ; for instance, if a leg be shattered four inches below the knee, it can fre- quently be taken off on the field of battle and the joint saved. Three or four weeks after, the joint will in all ' probability be so much concerned in the disease that the operation must be performed in the thigh ; the same in regard to the forearm and hand, and the upper part of the arm with the shoulder." Notwith- standing the drawbacks attending sec- ondary amputations, certain circum- stances frequently make them impera- tive. Continued fever, impending ex- haustion from excessive and protracted suppuration and evident uselessness of the limb, even if saved, may force the knife into the hand of the surgeon, after much valuable time has been lost ihrough an error of judgment on his part, or a procrastination on the part of friends. Pkbpabatiojts. — Before beginning an amputation it is essential to make such preparations for it as are required for every major operation. If possible, this should be made in the early part of the day, in order that if there be much hemorrhage subsequent to the operation its source can be looked for without artificial illumination. It can be most satisfactorily performed on any operating table, or in the absence of this on two kitchen tables placed end to end. The instruments necessary for major amputations are : 1. An Es- march elastic bandage and strap for the production of anaamia of the part to be removed. 2. A suitable tourniquet. 3. Amputating knives of various lengths and widths, with at least one double-edged blade (Fig. 53) (catling). 4. One large and one metacarpal am- putating saw. 5. From six to twelve haemostatic forceps. 6. A bone-cutting forceps, and a lion-jawed forceps. 7. Via. 93. REFERENCE HANDBOOK OP THE MEDICAL SCIENCES. Amputation. Amputation. Cartolized animal and silk ligatures, drainage-tubes, nee- dles, and an abundance of hot water. The preparations which are to be made for the after- treatment, although they are necessarily a preliminary to the operation itself, will vary according to the plan to be adopted, and will be considered at some length hereafter. While a finger or toe can be removed by a surgeon with only such aid as a layman can give, at least three assist- ants are required for every larger amputation. The duties of these should be first clearly defined by the operator, lest valuable time be lost during the operation. The undivided attention of one must be given to inducing and maintaining anaesthesia. The second is to support the part to be removed, after which he can be entrusted with the ligation of the vessels. The duty of the third should be confined to controlling the circulation of the limb above the seat of operation and eventually to retract the flaps. Where there is a fourth assistant, it should be his duty to hand the instruments to the operator as he may require them. This assistant is dispensable, since when the instruments are placed on a table near the operator, the latter can help himself quite as expeditiously as when assisted to them. These details arranged, the patient is anaesthetized and brought into such a position that the limb to be removed is everywhere accessible. The part to be removed must now be carefully wrapped in towels, the entire limb thoroughly cleansed with soap and brush and the hair removed , from the part where the incision is to be malde. The surgeon is then ready to take the final and most im- portant preliminary measure for the amputation, that by which he in- tends to control the circulation of the limb and reduce the loss of blood to a minimum. There are various methods by which the circulation may be more or less controlled during an amputa- tion, and they are of sufiioient im- portance to justify a detailed con- sideration. To prevent haemorrhage the surgeon can choose between tour- niquets, digital compression, and the Esmarch elastic bandage, or combine the latter with one of the other two. From the time of Morel the ingenu- ity of surgeons has been taxed to de- vise an instrument which will safely compress the main artery of a limb above the point where an amputa- tion is to be practised. Of the many instruments introduced, only a few have been able to gain general recognition. The oldest of these is the Spanish windlass or garrdt of Morel, which consists of nothing more than a wide band (g) of an unyielding material (muslin or linen), firmly drawn around the limb and tied. Over the main artery and at a point diametrically opposite, there are inserted underneath it compresses of linen, a piece of thick leather, or a piece of paste-board (p). At a point opposite the artery a firm rod (« s) is introduced underneath the encircling band and turned in such a manner as to shorten the latter, and thus the compression of the main ar- tery is effected (Fig. 94). Ovring to the simplicity of its construction the garr6t of Morel stands without a peer in cases of emergency in civil as well as military practice. It has, however, one great detraction which renders its use a matter of necessity rather than of choice. Notwith- standiog the use of the pads of linen or leather already referred to, veins, arteries, and soft parts are compressed to an almost uniform degree ; hence extensive venous haemorrhage and insuflScient retraction of the muscles follow. A great improvement on the windlass is the tourniquet of Petit which is now so generally in use. It consists of two metal plates, the distance between which can be regulated by a screw, and which are connected by a strong linen band supplied with a buckle, by which the limb is encircled (Pig. 95). To apply it properly, the limb should be surrounded by a few turns of a roller, while Fig. 94.— Morel's Tour- niquet. Fig. 95. — Petit's Tonmiquet. the body of the bandage (p) is placed over the artery (a). Over this bandage the lower metallic plate is then placed, the band and buckle are fastened, when, by turning the screw, compression of the main vessel can be regulated at pleasure. The objection has been raised to the tourni- quet of Petit that it compresses not only the artery, but also its accompanying vein, and thus induces venous stasis, and enhances the dangers of thrombosis. While this is doubtless true, it is an insurmountable defect common to all tourniquets ; and based more on theoretical than on clinical data. When properly applied the tourniquet of Petit is not apt to slip or yield, and its safety is such that in case of emergency the management of the screw might be entrusted even to a layman. In order to limit the compression to the main vessel alone, complete or in- complete metallic rings have been devised which, while they surround the limb more or less completely, make com- pression at only two points, i.e., over the artery and at a point diametrically opposite. The best known tourniquets constructed on this principle are the horseshoe tourniquet of Signorini and Dupuytren, the arterial compressor of the late Professor Gross, and the abdominal tourniquet of Pancoast and Lister (Pig. 96). While with these the compression can be limited to the main vessels of the limb, and the circumferential constriction of the latter is thus avoided, they are more liable to slip than the tourniquet of Petit, and are far less reliable than digital compres- sion. For certain amputations, however (of the hip and shoulder), the instrument of Petit is inapplicable ; it is then that one or other of the horseshoe tourniquets or dirftal compression will be found indispensable. Digital compression, when made by trustworthy hands, is admirably suited to control temporarily the circulation. If compression of the artery alone is anatomically possi ble, it can be best accom- plished by the finger. To be practicable, the vessel must be contiguous to a bone against which it can be pressed, as the femoral upon the OS innominatum, the bra- chial upon the humerus, the subclavian against the first rib, or the abdominal aorta against the vertebrae. Since only a few minutes are re- quired for the amputation of a limb, and the ligation of Fia. 96.-HorBeshQe Tourniquet, tj^g larger arteries, the endur- ance of the assistant entrusted with the duty is not severe- ly tasked. In digital compression, associated with the use of the elastic bandage, we have a combination with which' the circulation of a limb can be completely con- trolled, and by which parts, the compression of which would be useless or even harmful, are protected. Not- withstanding the advantages of this method, the surgeon should never resort to it unless he can absolutely rely upon the ability and skill of his assistant. Elastic C'onyw«««4()«.— Notwithstanding the precautions against haemorrhage after amputations, these were invari- ably associated with very great loss of blood until twenty years ago. The blood thus lost was venous in character, and came from the veins of the amputated member. Through the practices of Grandesso Silvestri," an Italian surgeon, and particularly of Esmarch, "of Kiel, the blood contained in the part to be removed is saved, and that this is not an inconsiderable quantity has been demonstrated by experiment. '8 The apparatus of Esmarch consists of 147 Ampntatlon. Amputallon. REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. an elastic bandage and an elastic tube or flat band with chain or clasp attachments. Commencing at the fingers or toes, the bandage is applied by spiral turns until the limb is covered to a line at least four inches above the point where the bone is to be divided. Above the last turn of the bandage, the elastic band or tube is rather flnfily and repeatedly wound around the limb, and secured by clasp or hook and chain (Fig. 97). When the bandage is then removed, a condition of ischeemia is observed in the limb, which will permit its amputation without a more than appreciable loss of blood during the operation proper. When the elastic strap is ^removed, the integu- ment of the stump rapidly assumes a bright-red color, and in the wound there appears free, persistent, and often em- ban-assing, capillary oozing. It is generally accepted now that the source of this haemorrhage is from the dilated capillaries, the walls of which have been paralyzed in consequence of the pressure exerted by the strap on the vaso-motor nerves. When in from twenty to thirty min- utes the vessel- walls regain their tonicity, the hsemorrhage ceases. To check this capillary oozing, a number of remedies have been suggested. That of Riedinger," to apply the faradic current, while very serviceable, is not always practicable. Esmarch relies upon closure of the wound and elevation of the stump before the strap is en- tirely removed. Hot water (150° to 180° F.), applied with sponges, often acts admirably in these cases. Since com- pression of the vaso-mo- tor nerves, caused by the bandage, is the cause of this parenchymatous haemorrhage, this can best be obviated by completely substituting digital compression for the elastic strap, or, if the latter be used, by preventing, the ingress of blood by the use of a tourniquet until the vessels have regained their natural tone. The latter plan, as practised by Ashhurst,'* is "to place a tourniquet in po- sition, but not screwed down over the main artery of the limb, and then to apply the Es- march tube a few inches above the point at which it is intended to ampu- tate. As soon as the principal vessels have been secured, the tourniquet plate is screwed down, and the tube removed. No bleeding follows, and by the time that the remaining arteries requiring ligatures have been tied, the vessels will have regained their tone, and the tour- niquet can be removed without any risk of bleeding fol- lowing." In amputations near the trunk, the elastic strap or tube should not be used in the ordinary manner. (See Special Amputations.) In an amputation of the shoulder, and another of the hip, I have seen it loosen or slip over the stump immediately after the disarticulation was effected, and in both instances the hasmon-hage was most alarming. In amputation at the shoulder, when by the use of the bandage, the blood in the extremity has been returned to the economy, it is better to rely upon compression of the main artery against the first rib with the tinker or a padded key. In amputations of the hip the main artery can be compressed against the pubic bone or even the circulation in the aorta can be controlled "y one 01 the many compressors already referred to Methods of Ampdtation.— Every amputation con- . sists ot three steps : 1. Division of the soft parts ■ 2 di- vision of the bone, or disarticulation ; 3, ligation of' the vessels and closure of the wound. According to the method adopted for the division of the sott parts, amputations are classified as circular or flap 148 Fig. 97. — Esmarch's apparatus. operations, and in the choice of the method the surgeon must be guided by the condition of the soft parts about the bone, the ease vrith which the joint can be opened in a disarticulation, the probable position of the cicatrix and form of the stump, and, above all, the desire to save as much of the limb as possible. Of the circular and flan operations all methods of amputation may be said to be but modifications. By the circular method it is at- tempted to give to the stump the form of an inverted cone or funnel, the apex of which is occupied by the di- vided end of the bone, the base or margin of wMch is represented by the cutaneous margin of the wound. In the flap operation the soft parts are so divided as to inake one or more flaps, the bases of which are on a level with the divided bone, And the free margins of which are so adapted to each other as to completely cover the bone and admit of the ready closure of the wound. Whatever plan of operation is adopted, the surgeon should stand in such a po- sition that he grasps the stump with his left hand, and that the amputated part therefore falls toward his right side. Ovrcular Method. — All modifications of the circular method have a similar incision through the skin and sub- cutaneous cellular layer, which is made around the en- tire circumference of the limb and at a right angle to its axis. According to the depth to which the incision is carried, the method is subdivided into that by single in- cision and that by double incision. Single incision : This, as already remarked (see His- tory), is the oldest method of amputation, and is gener- ally known as the Celsian operation. After retraction of the soft parts a long amputating knife is swept around the limb, and all of the soft parts are divided down to the bone. This is then divided on a slightly higher Fio. 98. level by the retraction of the soft parts. While this operation yields the smallest wound, and is the most rapid in its execution, its manifest disadvantage is in the insuflicient covering which it affords for the bone. It is admissible only in greatly emaciated subjects. Brun- ninghausen," in the beginning of the century, reintro- duced this method, but, after the amputation of the limb was completed, made a second section of the bone sev- eral inches above the point at which it was first divided. Double incision : This operation, of which those of Petit, Cheselden, B. Bell, Desault, and Alanson, are but unimportant modifications, has received its name from the fact that the skin, underlying fascia, and muscles are divided upon different levels, and, therefore, by at least two circular incisions. It is made as follows : The surgeon, firmly holding the limb with the left hand, car- ries his right hand, in which he firmly holds a large am- putating-knife, underneath and around the limb until the heel of the cutting edge is over the uppermost part of _ the line of the proposed incision. Giving the knife this position forces the operator into a more or less stoop- ing posture, from which he raises himself as the incision is completed. This is commenced with the heel of the knife, which, by a single sweep, is carried around the entire cir- cumference of the limb, severing the skin and adipose layer down to the deep fascia (Fig. 98). Two incisions, the ends of which meet, will answer as well as the di- vision by a single sweep of the knife. As soon as the REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. Amputation. AmpDtation. integument is divided tlie wound gapes. Tlie upper mar- gin w raised by tlie tliumb and finger of the left hand, and gradualljr detached from the fascia by repeated long incisions carried perpendicularly to the axis of the limb. This operation of detachment is continued until the skin and adipose layer can be reflected like a cuff, the length of which should be equal to half the diameter of the limb (Fig. 99). Where the latter rapidly increases in circumference, or there is a thick subcu- taneous layer, or this has been, infiltrated, the reflection of a cufl is often impracticable. Pig. 99. Then two longitudinal incisions, diametrically opposite each other, will materially facilitate this part of the operation, although by this means the amputation is in a manner converted into a flap operation. The in- tegument having been reflected to the required extent, the muscles are next divided close to the line of reflection by one steady cir- cular sweep of the knife, which should cut through every thing do wn to . the bone (Pig. 100). C'^ Where there is Fio. 100. but one bone to be divided, the surgeon is now prepared to use the saw. Where there are two bones, the interos- seous tissues remain to be divided. Whereas this can be accomplished with an or- dinary amputating-knife, it is safer to use a double- edged instrument (catling) for this purpose. By using it in the manner indicated in Fig. 101, there is no dan- ger of cutting the blood- Vy "% vessels twice, and thus one danger of troublesome haemorrhage is avoided. To protect the soft parts from injury by the saw, j^iq jqj they must be well retracted by the hands of an assistant, or by the use of a band of muslin (retractor) divided into two or three slips, accord- ing to the absence or presence of an interosseous space (Fig. 103). When it is deemed advisable to save sufficient perios- teum to cover the divided end of the bone, this can now be readily effected with the back of the knife or the han- dle of the scalpel. The utility of this procedure must certainly be questioned, since in a number of instances it has interfered with the ready drainage of the medullary cavity, and has thus been -the indirect cause of a fatal issue.™ The movements of the saw can be greatly facilitated by guiding them with the nail of the left thumb (Fig. 103). The to-and-fro movements of the saw should be slow, lest the heat developed by its too rapid use endanger the vitality of the bone. Where there are two bones of the same diameter (fore- arm), they should be divided simulta- neously. In the leg, the tibia is to be almost entirely divided before the sec- tion of the fibula is commenced. Un- less this precaution is adopted, splinter- ing of the bone is not easily avoided. For the same rea- son, the assistant in charge of the part to be amputated should hold it hori- zontally, allowing i it neither to drag by its weight nor to be raised in a manner to interfere with the movements of the Fia. 108. saw. Should splin- tering of the bone nevertheless occur, the splinters and sharp margin of the latter must be removed with the cut- ting bone-forceps. Oval Method. — Holding an intermediate position be- tween the circular and flap operations is the oval method, which, although practised by the older Langenbeck and Pio. 103. others, was first generalized by Scoutetten (1837). The essential feature of this amputation in the continuity of the limb is, that the incision, instead of being made per- pendicular to its long axis, is carried at an angle of forty- five degrees, and in such a way that the soft parts m front of the bone are divided upon a higher level than those on its posterior as- pect. At the same time the upper portion of the wound is converted into an acute angle, whereas its lower portion is given an oval outline. The upper extrem- ity of the wound is placed at the point where the bone is to be divided. The operation i s commenced by two incisions, in the form of an inverted V, the lower ends of which are united by a transverse cut Fig. 104. on the posterior surface of the limb (Blasius). Here, as in the circular amputation, by a single incision all the 149 Amputation. Amputation. REPEKENCE HANDBOOK OF THE MEDICAL SCIENCES. Fio. 106. soft parts are divided at once on each side of the bone and then those on its posterior aspect. This operation has heen senerally discarded for amputations m the continuity, although for disarticulations at certain joints it presents advantages which are worthy of consideration (see J