History Q^i« 1rtfnn Cofombta Wltifomitp THE LIBRARIES JWebtcal iLttrrarp Digitized by the Internet Archive in 2012 with funding from Metropolitan New York Library Council - METRO http://archive.org/details/courseoflectOObrow COURSE OF LECTURES ^ ^ ON THE PHYSIOLOGY AND PATHOLOGY CENTRAL NERYO US SYSTEM. DELIVERED AT THE gopl tf Allege tf Snxpni of tfngtatr in pg, 1858. BY C. E. BROWN-SEQUARP, M. D., F.R.S., FELLOW OF THE ROYAL COLLEGE OF PHYSICIANS, OF LONDON J HON. FELLOW OF TOE FACULTY OF PHYSICIANS AND SURGEONS, GLASGOW J LAUREATE OF THE INSTITUTE OF FRANCE (ACADEMY OF SCIENCES) ; PHYSICIAN TO THE NATIONAL HOSPITAL FOR THE PARALYZED AND THE EPILEPTIC J EX-PROFESSOR OF THE INSTITUTES OF MEDICINE AT THE MEDICAL COLLEGE OF VIRGINIA, U.S.; FELLOW OF THE ROYAL MEDICO-CHIRURGICAL SOCIETY OF LONDON; EX-SECRETARY AND VICE-PRESIDENT OF THE SOCIETE DE BIOLOGIE, OF PARIS, ETC. PHILADELPHIA: COLLINS, PRINTER, 705 JAYNE STREET. 1860. Historical Collection Entered according to Act of Congress, in the year 1858, by E. BROWN-SEQUARD, M.P., in the Clerk's Office of the District Court of the United States for the Eastern District of Pennsylvania. TO HENRY J. FELTUS, Esq., OF PHILADELPHIA, U. S., JULES CHAUVIN, Esq., OF PORT-LOUIS, MAURITIUS. My Dear Friexds : — Had it not been for the assistance I owe to your extreme kindness, it is probable that the publication of the present edition of these Lectures, in book form, would have been much delayed; I therefore take, with great pleasure, this opportunity of publicly expressing to you my very best thanks. Your devoted friend, C. E. BROYYX-SEQUARD. London, September, I860. PREFACE. These Lectures contain the results of the work of almost all my life, since I began to study medicine. From the year 1838 to the year 1858, when I had the honor of delivering them at the Hoyal College of Surgeons, in Lon- don, and ever since, I have devoted all the time I could to the study of the great questions, the solution of which I have tried to give in these Lectures. If I have not suc- ceeded in my endeavors, I can at least have this consola- tion, that it is not because I have proceeded hastily. But, however prolonged my researches have been, I am afraid I must have come to erroneous conclusions on several points, because the questions discussed in these Lectures are as difficult as they are important, and also because many of these questions are quite new, and I had not, therefore, the views of other authors to guide me in their examination. I will be thankful to any one who will show me on what points I have erred. It is in the power of most medical practitioners to prove or to disprove the views I hold. Out of the millions of patients yearly treated by the medical men who may peruse this book, there are, indeed, many thousands whose cases may throw light, and often a decisive light, on the questions discussed in the following pages. As most of these questions are of the greatest VI PREFACE. importance, both in a practical and in a scientific point of view, I hope that those who will peruse this work will not let the cases pass unrecorded that may be the means of settling what is yet undecided in these questions, or of giving more strength to the proofs of the views held by myself or by my opponents. C. E. BROWN-SEQUARD. London, #1 "Wyiji/uui D/ki/ ji' . S. ^Cavendish Square, W. TABLE OF CONTENTS. LECTURE I. TRUTH OF SIR CHARLES BELL'S THEORY AS REGARDS THE EXISTENCE OF TWO DISTINCT SETS OF NERVOUS CONDUCTORS :— THE SENSITIVE AND THE MOTOR. Importance of comparing experiments upon animals with pathological cases ob- served in man. — Discovery of Sir Charles Bell ; removal of the last objections to his views in regard to the roots of the spinal nerves. — The pretended re- curring sensibility of Magendie. Causes of the pain produced by the irritation of the anterior roots of nerves, of the pain of cramps, of certain "contractures," of the spasm of the sphincter ani, and of the contractions of the uterus during par- turition, &c. — Are the sensitive nerve-fibres of muscles contained in the anterior roots of the spinal nerves ? — Theories concerning the transmission of the sensi- tive impressions in the spinal cord and the medulla oblongata . . page 1 LECTURE II. EXPERIMENTS SHOWING THAT THE TRANSMISSION OF THE SENSITIVE IMPRESSIONS, IN THE SPINAL CORD, TAKES PLACE CHIEFLY IN ITS CEN- TRAL PART— i. e., IN THE GRAY MATTER. Experiments and views of Longet. — Objections by Dr. R. B. Todd, Mr. Lockhart Clarke, and the Lecturer. — Causes of error in experimenting upon the spinal marrow. — Experiments proving that a part may be a conductor of the sensitive impressions, though not endowed with sensibility. — Experiments showing, 1st, that a transversal section of the posterior columns of the spinal cord, instead of causing anaesthesia, is followed by hyperesthesia ; 2d, that a transversal sec- tion of the whole spinal cord, except the posterior columns, is followed by a complete ansesthesia. Anatomical and experimental facts showing the relative share of the gray matter, and of the various columns of white- matter, in the transmission of the sensitive impressions ....... 13 Vlll CONTENTS. LECTURE III. PLACE OF DECUSSATION OF THE CONDUCTORS OF SENSITIVE IMPRESSIONS, IN THE CEREBROSPINAL AXIS. The celebrated experiments of Galen, which had been universally considered as showing that there is no decussation of the conductors of sensitive impres- sions, in the spinal cord, do not prove anything in this respect. — Experiments showing that the conductors of sensitive impressions from the various parts of the trunk and limbs make their decussation in the spinal cord, and not in the encephalon, as was admitted 29 LECTURE IV. ON VARIOUS QUESTIONS RELATING TO THE TRANSMISSION OF SENSI- TIVE IMPRESSIONS AND OF THE ORDERS OF THE WILL TO MUSCLES, THROUGH THE SPINAL CORD AND THE MEDULLA OBLONGATA. Most of the elements which are employed as conductors of the purely tactile im- pressions seem to pass by the same parts of the spinal cord as those which transmit the impressions which give pain. — The disposition of the conductors of the various sensitive impressions in the spinal cord is such that very deep alte- rations of this organ may not entirely destroy sensibility. — The gray matter of the spinal cord seems to have an important share in the transmission of the orders of the will to muscles. — The anterior columns of the spinal cord in the upper part of the cervical region have but a slight participation in voluntary movements, and the lateral columns, with the surrounding gray matter, in that part of the cord, are almost the only channels between the will and muscles 39 LECTURE V. CONCLUSIONS FROM THE FACTS MENTIONED IN THE PRECEDING LEC- TURES, AND PATHOLOGICAL CASES SHOWING THAT THE TRANSMIS- SION OF SENSITIVE IMPRESSIONS SEEMS NOT TO TAKE PLACE THROUGH THE POSTERIOR COLUMNS OF THE SPINAL CORD. Conclusions from the results of the Lecturer's experiments concerning the trans- mission of sensitive impressions and of the orders of the will to muscles, in the cerebro-spinal axis. — Agreement between the three principal sources of our knowledge concerning the spinal cord considered as a conductor of sensitive impressions and voluntary movements : i. e., anatomy, experimentation upon animals, and pathological cases observed in man. — Hyperesthesia or conserva- tion of sensibility after injury to the posterior columns . . . .50 CONTENTS. LECTURE VI. SOLUTION BY PATHOLOGICAL CASES, OF VARIOUS QUESTIONS RELATING S T0 ThE TRANSMISSION OE SENSITIVE IMPRESSIONS THROUGH THE SPINAL CORD. the evidence as regards the share of tlie gray matter in ^ ^ sitive impressions .'.***" LECTURE VII. PATHOLOGICAL CASES SHOWING THAT THE CONDUCTORS OE SENSITIVE IMPRESSIONS EROM THE TRUNK AND LIMBS DECUSSATE IN THE SPINAL CORdTnD NOT IN THE ENCEPHALON, AND THAT THE CONDUCTORS OE Te ORDERS OE THE WILL TO MUSCLES DECUSSATE IN THE LOWER ™RT OE THE MEDULLA OBLONGATA AND NOT IN THE PONS VAROLII. T Le dec— of the co— of -^^S^j^SJ - limbs , *. not t a,e plaoe »*. « -£. — ^ J ^ ^ h i the medu a ^f^ s 7 f S v ^taf y movements in one side of the body ^Tlts t^sTbity in the opposite side.-The decussation of the con- "of the cncepha P lon !aS regards voluntary movements and sensdnhty 93 CONTENTS, LECTURE VIII. CONCLUSIONS FROM THE PATHOLOGICAL CASES RELATED IN THE PRE- CEDING LECTURES AND FROM SEVERAL OTHER CASES, AS REGARDS THE DIAGNOSIS OF ALTERATIONS OF THE VARIOUS PARTS OF THE SPINAL CORD. Principal symptoms of the diseases of tlie spinal cord. — On a curious symptom which seems to belong especially to diseases of this organ. — Cases against the views of Bellingeri and Valentin, relative to the pretended motor functions of the posterior columns, and to certain symptoms of alterations of the anterior columns. — Differences in the degree of paralysis of voluntary movements, according to the extent of the alteration of the posterior columns. — Absence of paralysis, in cases in which these columns are entirely cut across, but not injured, in a great part of their length. — Causes and nature of the apparent paralysis observed when a great part of the length of the posterior columns is altered. — Alteration of the upper part of the anterior columns without para- lysis. — Decussation of the lateral columns ; their function and symptoms of their alteration. — Paralysis due to disease of the gray matter. — Alterations causing a loss of feeling a contact, a tickling, a muscular contraction, a painful impression, or a change of temperature. — Conclusions concerning anaesthesia. — When does anaesthesia exist without a notable paralysis. — Rarity of complete anaesthesia. — Referring of the various kinds of sensitive impressions to different parts of the body in cases of alteration of the spinal cord. — Absence of excita- bility of most of the conductors of the various kinds of sensitive impressions in the nerves and in the spinal cord. — Inflammation may render all these con- ductors excitable, and induce the production of all kinds of sensations, errone- ously referred to the periphery. — Groups of symptoms which characterize alterations limited to certain parts of the various columns of the spinal cord and of its gray matter 112 LECTURE IX. ON THE PHYSIOLOGICAL AND MORBID ACTIONS DUE TO THE GREAT SYMPATHETIC NERVE. Effects of a section of the sympathetic nerve in the cervical region. — Effects of the excitation of the same nerve, in the same region, by a galvanic or an electro- magnetic current. — Almost all the effects due to the section or galvanization of this nerve are owing to the condition of bloodvessels after these operations. — The sympathetic nerve originates chiefly from the cerebro-spinal axis. — Simili- tude between the effects of a section of the sympathetic nerve, and those of a section of a lateral half of the spinal cord. — Persistence of a contraction of bloodvessels due to irritation of the cerebro-spinal axis in certain diseases. — Two kinds of normal or morbid influences of the nervous system upon nutri- tion, secretion, &c. ; one upon bloodvessels, the other upon tissues . . 139 CONTENTS. XI LECTURE X. ON THE INFLUENCE OF THE NERVOUS SYSTEM UPON NUTRITION AND SECRETION; WITH REMARKS ON THE IMPORTANCE OF THE KNOW- LEDGE OF THIS INFLUENCE FOR THE TREATMENT AND THE EXPLA- NATION OF THE PRODUCTION OF MANY DISEASES. Distinction between the effects of the excitation of the nervous system and those of the absence of action of this system. — Three kinds of reflex actions : contrac- tion, secretion, and modification of nutrition. — Normal and morbid reflex secre- tions. — Normal and morbid reflex changes in nutrition. — Reflex influence of injuries of the trigeminal nerve upon the eye. — Reflex influence of one eye upon the nutrition of the other. — Sudden arrest of the heart's movements by a reflex action. — Cause of the rapid death after injuries of the abdominal sympathetic nerve. — Stoppage of the heart's movements by the application of cold to the skin, by the influence of cold drinks, and in some cases of death by chloroform. — Reflex influence of burns on the principal viscera. — Inflammation of the eyes, of the testicles, of the nervous centres, &c, by a reflex action. — Muscular atrophy due to an irritation of sensitive nerves. — Paralysis and anaesthesia due to a reflex action. — Disturbance of the functions of the brain and of the senses produced by irritation of centripetal nerves. — Other instances of reflex changes of nutrition. — Mode of production of the secretory and nutritive reflex actions. — Importance of the knowledge of the reflex secretory and nutritive phenomena for the treatment of disease. — Influence of the irritation of the nervous centres and of the centri- fugal nerves on nutrition and secretion. — Influence of the absence of nervous action on nutrition, repair and secretion 151 LECTURE XI. ON THE ETIOLOGY, NATURE, AND TREATMENT OF EPILEPSY, WITH A FEW REMARKS ON SEVERAL OTHER AFFECTIONS OF THE NERVOUS CENTRES. Artificial production of an epileptiform affection in animals. — Influence of certain injuries to the spinal cord as a cause of real epilepsy. — Existence of an unfelt aura epileptica in many cases. — Means of detecting the existence of an unfelt aura and its point of starting. — Seat and nature of epilepsy. — Principles of treat- ment of this affection. — Analogy between epilepsy and many other nervous affec- tions, as regards their mode of production and their treatment. — Curious case of convulsions and insanity, in illustration of some views advanced in this letter 178 Xll CONTEXTS, LECTURE XII. ON THE MEDULLA OBLONGATA, THE PONS VAROLII, AND SOME PARTS OF THE SPINAL CORD, IN THEIR RELATIONS WITH RESPIRATORY MOVE- MENTS ; WITH VERTIGINOUS OR ROTATORY CONVULSIONS ; WITH THE TRANSMISSION OF SENSITIVE IMPRESSIONS AND OF THE ORDERS OF THE WILL TO MUSCLES, AND WITH THE VASO-MOTOR NERVES AND ANIMAL HEAT.— GENERAL CONCLUSIONS OF THE COURSE. Medulla oblongata erroneously considered as the source or focus of life. — Causes of death in cases of sudden injury to this organ. — Respiration depending upon other parts of the cerebrospinal axis, besides the medulla oblongata. — Causes of the cessation of respiration in cases of a complete section of the medulla oblongata. — How are the respiratory movements produced ? — Parts of the ence- phalon and spinal cord that may produce rotatory convulsions. — Causes of the vertiginous or rotatory convulsions. — The auditory nerve and its power of pro- ducing partial or general convulsions. — The olivary and restiform columns of the medulla oblongata and their relations with various nervous disturbances. — Reasons against the view that the fibres which decussate all along the median line of the base of the encephalon are voluntary motor fibres. — Reasons for admitting that the anterior pyramids contain nearly all the voluntary motor fibres of the body. — Three kinds of paralysis due to lesions in three different parts of the cerebro-spinal axis. — Anaesthesia and hyperesthesia in their rela- tions with the state of bloodvessels and the degree of animal heat. — Condition of voluntary movements, sensibility, and animal heat, in different cases of alteration of the central nervous system. — General conclusions . . . 187 APPENDIX Part I. — Examination of objections that might be made against many of the views which are held in the preceding lectures 211 Part II. — Application of some of the facts and views exposed in the preceding lectures, to the treatment of disease 244 Part III.— Additional facts in proof of some of the views of the author . 2(33 THE CENTRAL NERVOUS SYSTEM LECTURE I. 1 TRUTH OF SIR CHARLES BELL'S THEORY AS REGARDS THE EXISTENCE OF TWO DISTINCT SETS OF NERVOUS CONDUCTORS ; THE SENSITIVE AND THE MOTOR. Importance of comparing experiments upon animals with pathological cases ob- served in man. — Discovery of Sir Charles Bell ; removal of the last objections to his views in regard to the roots of the spinal nerves. — The pretended re- cnrring sensibility of Magendie. Causes of the pain produced by the irritation of the anterior roots of nerves, of the pain of cramps, of certain " contractures," of the spasm of the sphincter ani, and of the contractions of the uterus during par- turition, &c. — Are the sensitive nerve-fibres of muscles contained in the anterior roots of the spinal nerves ? — Theories concerning the transmission of the sensi- tive impressions in the spinal cord and the medulla oblongata. Mr. President and Gentlemen: The subject of the lectures which I propose delivering here is a very vast one, as it includes, directly or indirectly, most of the principal questions concerning the Physiology and Pathology of the Nervous System. But vast as it is, this subject may be considered as composed of only three essential parts, which relate to the sensitive, the motor, and the vaso-motor nerve-fibres. In other words, I propose to examine successively the principal facts and views concerning the normal actions, and the consequences of the excess or of the absence of action, of these three kinds of nerve-fibres. 1 Although six lectures only were delivered at the Royal College of Surgeons, I will publish here twelve lectures, covering just the same ground as those of the College, but differing from them in this respect, that I give here details concerning experiments and pathological cases, which, for the sake of brevity, I was obliged to omit when lecturing. A Z THE CENTRAL NERVOUS SYSTEM. To try to solve the very important but complicated questions which are so numerous in both the physiological and the patho- logical history of the parts of these nerve-fibres which are in the nervous centres, it is necessary to make use of all the means that science may furnish, and particularly of the two best, which are: experimentation upon living animals, and observation of pathologi- cal cases. When employed together, these means of scientific re- search have allowed errors to be made; but, of course, the chance of committing errors is by far greater when either of them is em- ployed alone. The danger of making use of one of these means exclusively is very strikingly illustrated by the many errors, con- cerning the cerebellum, committed by experimental physiologists, who mistook the effects of certain circumstances of their experi- ments for the results of injuries or of the absence of the cerebellum. Had they taken the trouble of comparing the phenomena they saw with those observed by medical men in cases of disease of the cere- bellum, they would not have introduced in science a number of hypotheses which impede its progress. It is by so doing that ex- perimentalists have thrown discredit on the means of scientific in- quiry of which they have made so much use and abuse, and have given ground to many critics to blame their means of research, while the fault was in the men who employed those means, and not in the means themselves. If erroneous views have been arrived at by the exclusive use of one of the means of scientific research we have named, we find that, on the contrary, many great advances in the medical sciences are due to the combined use of vivisections and clinical observation. Perhaps I may be allowed to say that the lectures I am about delivering will afford some proof of the advantage of a comparison of pathological cases observed in man, with the result of experi- ments upon living animals. The great discovery of Sir Charles Bell gives a good instance of the importance of making use comparatively of clinical observation and vivisections. In fact, had Sir Charles had recourse to experi- ments upon living animals, he probably would have succeeded, at once, in proving the correctness of his theory concerning the roots of the spinal nerves. Before him, already, many physiologists had, more or less dis- tinctl} 7 , foreseen that the nervous conductors for voluntary move- ments and those for sensation form two distinct sets of nerves. Galen, Boerhaave, Lamarck, Alex. Walker, and others, had had this THEOEY OF SIR CHARLES BELL. 3 idea. To Alex. "Walker the credit is due of having first published this opinion, that there is a difference in the functions of the ante- rior and posterior roots of the spinal nerves, one set being employed for volition and the other for sensation; but he did not try to prove, either by experiments or by pathological facts, the correctness of his views; and, led by erroneous ideas concerning the function of the cerebellum, he imagined that the anterior roots of the spinal nerves are for sensation and the posterior for motion. (See the Archives of Universal Science for April and July, 1809.) It was only two years after the publication of this hypothesis of Walker, that Sir Charles Bell's first views received some publicity, in the celebrated little pamphlet, entitled, "An Idea of a New Ana- tomy of the Brain, submitted for the Observation of the Author's friends." 1 In this w r ork, as far as we know, he did not try to prove that the anterior roots of the spinal nerves are employed as con- ductors of volition, and that the posterior roots are the conductors of the sensitive impressions. He seems not to have yet had (at that time) the idea of this difference. He admitted that the posterior roots of nerves come from the cerebellum, which he considered as an organ employed for the organic or vital functions of the body, while the anterior roots are in communication with the cerebrum, which he thought to be the organ for both volition and sensitive perceptions. But, however erroneous may be some of these views, we look upon this first work of Sir Charles Bell on the nervous system, as an admirable production -of the genius of this great physiologist. The idea of the distinction between the nervous ele- ments employed in the different functions of the nervous system is there clearly and forcibly presented, and we may safely state that the greatest part of the recent progress of our knowledge of the nervous system, both in a practical and in a scientific point of view, has its source in this idea. There is another important thing in this little pamphlet; it is the result of Sir Charles Bell's experi- ments on the roots of the spinal nerves. He found, on a dying animal, that the irritation of the anterior roots caused muscular contractions, while there was no effect produced by the irritation of the posterior roots. Of course this experiment could not show what are the functions of these roots, but it was sufficient to prove 1 As only a few copies of this pamphlet were printed, it is now almost impossible to procure it. I speak of it after the numerous extracts published by Mr. Alex- ander Shaw and by Sir Charles Bell himself. 4 THE CENTRAL NERVOUS SYSTEM. that there is a notable difference between the anterior and the pos- terior roots. Long after this first publication, Sir Charles brought forward several facts, experimental and pathological, showing that the nerv- ous conductors for motion are distinct from those for sensation. He showed that the facial nerve is motor, and that the ganglionic root of the trigeminal is for sensation. But although these facts had given good grounds to the hypothesis that the posterior or gan- glionic roots of the spinal nerves are used for sensation, while the anterior roots are for motion, positive evidences of the exactitude of this distinction were still wanted. To Mr. Magendie belongs the merit of having furnished the proofs that were needed. He showed that the section of all the posterior roots of the nerves of one limb destroys the sensibility in the limb, while a section of the anterior roots of the nerves of a limb abolishes voluntary movements, leav- ing sensibility unaltered. He also found that strychnia, in this last case, does not excite convulsions in the paralyzed limb, while there are convulsions, in the limb deprived of sensibility, after the section of the posterior roots. So far as these experiments alone are studied, it seems quite certain that the anterior roots are motor and not sen- sitive, and that the posterior roots are sensitive and not motor; but Magendie tried other experiments, and, not being aware of a singular fact, which he discovered only in 1839, he arrived at conclusions which were quite different from those just exposed. The irritation of the anterior roots he found evidently to induce pain, though in a less degree than that of the posterior. On another side he found sometimes that local movements took place when he irritated the posterior roots. Here, then, are two facts which seem in direct op- position to the theory of Sir Charles Bell. In 1839, Magendie made a step forward, and discovered a very important fact, which has removed the objection against Sir Charles Bell's theory as regards the anterior roots of the spinal nerves. He found that these roots really cause pain when they are irritated, but that if they are divided (see Fig. 1), the distal end (d) alone may give pain. He ascertained also that if the posterior roots of any of the spinal nerves are divided, the irritation of the anterior roots of the same nerve no longer causes pain. He concludes, from these facts and some others, that there is what he calls, erroneously, a recurring sensibility, which, on the irritation of the anterior roots, manifests itself in this way : The nervous irritation which causes the pain goes, at first, from the parts of the anterior roots (see the THEORY OF SIR CHARLES BELL. b arrows in Fig. 1, a), in which it has begun, towards the trunk of the nerve, in which it goes to the periphery of the body, and then comes back towards the spinal cord, which it reaches in being conveyed by the ganglion (g) and the posterior roots (p); so that the current which proceeds from the cord along the anterior roots returns towards it and into it along the posterior ones. We must say that the name of recurrent sensibility is a very bad one, because sensi- bility is a vital property which cannot move from a place towards any other, and therefore cannot be recurring. It is the cause, what- ever it may be, of the painful sensation, which is recurring, and not sensibility. What is the channel of the nervous irritation generated when the ante- rior roots are excited? In the first place, we think it is necessary to repeat, that the current is not towards the spinal cord, inasmuch as Ma^endie has well Droved that after the section of the anterior roots of a spinal nerve, we may irritate the central part (Fig. 1, c) without causing the least manifestation of any kind of sensation. It results, therefore, and as positively as possible, that the anterior roots have not the property of sensibility in the same manner as the really sensitive parts. On the contrary, pain is caused by the irritation of the parts of the anterior roots in appearance separated from the nervous centres. (See Fig. 1, A, d.) But if the trunk of the nerve is divided, the irritation of the anterior roots on either end remains completely painless ; it results, therefore, that the current which causes the pain passes in this trunk. But how far does the current extend towards the periphery of the body, before returning upon itself in order to reach the spinal cord and the sensorium ? This has not been positively determined. It seems, however, already, from the experiments of Magendie, of Professor CI. Bernard, of Volk- mann, of Schiflf, and from my own, that the return takes place at the peripheric extremity of the nerve-fibres. Kronenberg and Pap- penheim have erroneously admitted that the current merely passes from the anterior roots to the posterior, at the place where they meet to form the trunk of the spinal nerves. The channel of the current which gives the pain when an ante- rior root is irritated, is, consequently, at first towards the trunk of the nerve; then in this trunk towards the periphery, where the recurrence seems to take place, and thence the current returns along the sensitive fibres of the nerve towards the ganglion of the poste- rior roots, and, at last, passes through the ganglion and these roots, and into the spinal cord. (See the upper roots in Fig. 1.) 6 THE CENTRAL NERVOUS SYSTEM. What is the cause of the pain produced hy the irritation of the anterior roots of nerves? According to Carus, the Dervous loops, which he thought existed in the muscles, give an easy explanation of the facts discovered by Magendie. Unfortunately for this explanation (which Mr. Flourens has again proposed quite recently), the exist- ence of nervous loops in muscles is now disproved. Indeed, even in the skin there is good ground to doubt the presence of many loops. Some experiments, which we have made, render it probable that the pain caused by the irritation of the anterior roots is exactly of the same nature as that of cramps, and that both the pain of cramps and the pain which we will call recurrent, to avoid circumlocutions, depend upon a peculiar kind of irritation of the sensitive nerves of muscles. The theory we will propose is also applicable to many pathological and physiological phenomena, which have puzzled for a long while both practitioners and physiologists, and which seem, indeed, to be very plain and natural now that we have the key to their explanation. Professor Matteucci, nearly twenty years ago, found that when a nerve going to a muscle (Fig. 2, m 2) is put upon another muscle, a contraction takes place in the first one when the second contracts. In this case the nerve receives an excitation at the time the muscle, upon which it lies, contracts. The cause of the excitation of the nerve, according to Professor Matteucci, is a galvanic discharge which accompanies the muscular contraction. Dubois-Reymond explains otherwise the excitation of the nerve, lie thinks it is due to a diminution of the galvanic current of the muscle when it con- tracts, and that the changes occurring, in consequence, in the nerve irritate it. But whatever be the right explanation, it seems certain that it is some change in the galvanic state of the muscle which causes the excitation of the nerve. \Ve will, therefore, call it a galvanic excitation. Now, I have tried to prove, in 184:9, that the sensitive nerve-fibres which are in muscles, receive that peculiar galvanic ex- citation which acts upon the motor nerves in the case of the pre- ceding experiment, so that there is a galvanic cause of sensation in muscular contractions. (See Figs. 3 and 4, and their explanations.) I have also tried to show, elsewhere, that our faculty of guiding our movements depends upon the sensations that we have of the state of our muscles, from the galvanic excitation which accompanies our muscular contractions. I cannot dwell at length here upon this explanation, which is only slightly connected with my subject; but THEORY OF SIR CHARLES BELL. 7 I will try, at least, to show that several experiments and pathologi- cal cases agree perfectly with this theory. If we fix a thread to the tendon of a muscle of a frog (see Fig. 2, t), and attach to this thread a weight, capable of entirely preventing the contraction of the muscle, which is fixed by its other extremity, we find that every time the muscle (Fig. 2, m) tends to contract, there is an excitation of the nerve (n) lying upon it, and a contraction of the muscle (m 2) to which this nerve is distributed. Hence it is not necessary for a muscle to contract in order to produce in nerves in contact with it a galvanic excitation. I repeat that it is sufficient that they tend to contract. Now, I have found that the greater is the resistance to the contraction of a muscle, the greater is the gal- vanic excitation that it gives to nerves in contact with its tissue. On the contrary, if there is no resistance at all, as already shown by Professor Matteucci, after the section of the tendon, then the galvanic excitation of nerves in contact with the contracting muscle no longer exists. If we compare these results with the following pathological facts, we find that the phenomena are much alike in the two series of facts that we compare, and, therefore, that they seem to depend on the same causes. I suppose a case of painful, contracture of the anterior muscles of the thigh; the pain is increased very much every time the contracted muscles are elongated, i. e., when the resistance to the contraction is augmented ; on the contrary, it diminishes when the resistance to the contraction is rendered less than it was, and, at last, it disappears entirely, or almost entirely, ichen the resistance is completely, or almost completely, destroyed, after teno- tomy. Surgeons, till our researches, had not been able to explain this apparently strange cessation of pain ; now it seems quite simple to understand that such should be the case. In cases of fissura in ano, it is very well known that the pain due to the spasm of the sphincter is increased when there is a re- sistance to the contraction, and that the greater the elongation of the muscular fibres, the greater also the resistance to their contrac- tion and the degree of pain. At last, when the muscular fibres can contract freely, and almost without resistance, the pain disap- pears, as is the case after the operation of Boyer (the section of the sphincter). Of course the pain depending upon the fissure persists, but that due to the muscular spasm disappears. In this case, also, surgeons could not explain the cessation of pain. We find here, O THE CENTRAL NERVOUS SYSTEM. as in the preceding case, that the excitation of the nerves due to the muscular contraction augments, decreases, and disappears in the same circumstances, concerning the degree or the absence of resistance, which produce analogous phenomena in the experiments above mentioned. In cases of neuralgia, when the sensibility of nerves in muscles is increased, there is pain produced or increased every time the muscles contract. The contractions of the uterus, which are the more painful the more there is resistance opposed to them, cause also pain in the same way as the spasm of the anus or the contraction of the mus- cles of the thigh. The relation between the degree of contraction of the uterus and that of pain is so evident, that the word " pains" is employed for that of "contraction." Every muscular contraction seems to generate a galvanic excita- tion of the sensitive nerves in the neighborhood of the muscular fibres ; and, the degree of excitation being in proportion to the degree of energy of the contraction, we have, in this way, an excel- lent means of judging of the state of the muscles. When the con- traction acquires the degree which it has in cramps, then it causes pain, which is also in proportion to the energy of the spasm. If we succeed when we have a cramp in making it cease by elongating the contracted muscle, we find that the pain often increases at first, and disappears only when the contraction has ceased. I regret not to be able to bring forward all the reasons which have led me to admit the views I have just proposed, but I must keep within my programme. If, now, we examine what takes place in the apparently para- doxical experiment of Magendie, we find that nothing is more easily explained. When the anterior roots of a spinal nerve are excited, a cramp is produced in the muscles in which the nerve- fibres of the roots are distributed, and the pain which belongs to a cramj) is generated. I think this pain is due, as I have said for cramps, to a galvanic excitation of the sensitive nerve-fibres exist- ing in the muscles which contract; but whether this theory be true or not is, in a measure, indifferent as regards the general cause of pain in the experiment of Magendie. In fact, there is then the same cause which exists in a cramp; and this cannot fail to be so inas- much as a real cramp is generated by the irritation of the anterior roots. So, then, we can conclude : 1st, that the recurrent sensation THEOEY OF SIE CHAELES BELL. 9 is only in appearance recurrent ; 2d, that the anterior roots of the spinal nerves cause pain when they are irritated, because they pro- duce a cramp : 3d, that, consequently, there is no sensibility of any kind in the anterior roots, and that it is because they are motor, and not because they are sensitive, that they cause pain ichen they are irritated. Therefore, the objection which has been urged against the views of Sir Charles Bell, and which was founded upon the fact that the anterior roots cause pain when irritated, is unfounded. "We will now say a few words of the objection originating from the fact that there are, sometimes, some local movements when the posterior roots are excited. These local movements are proved to be only reflex movements. In the first place, there is no contraction whatever when the distal part of a posterior root is irritated ; and, certainly, if there were motor nerve-fibres in this root, contractions should be produced. (See Fig. 1, d, g) In the second place, the irritation of the central part of a divided posterior root is sometimes followed by local contractions, a fact which implies that to reach muscles, the irritation passes through the spinal cord. In the third place, after having cut the anterior roots of the pair of nerves of which we irritate a posterior root, we do not see any local contrac- tion following this irritation. From these experiments it clearly results that, when a posterior root of a spinal nerve is irritated, if we see contractions of the muscles to which this nerve goes, they arise from the passage of the excitation to the spinal cord, and, from thence, to the muscles through the anterior roots. In other words, we must admit that it is only by a reflex action that the posterior roots act upon muscles. It would seem from what we have just said, and from the explana- tion above given of the recurring sensibility, that no further objection to the views of Sir Charles Bell can be made; but this is not the case. J. W. Arnold 1 has tried to show that the anterior roots of nerves contain the nerve-fibres which convey to the sensorium the impres- sions which give the knowledge of the state of the muscles. The chief fact on which he grounds his opinion is, that after the section of the posterior roots of the posterior extremities of a frog, it can make use of its hind legs almost as well as if nothing had been done to the posterior roots. This experiment is certainly of some value, 1 Ueber die verrichtnng des Rneckenmarksnerven, &c, Heidelberg, 1845. Ana- lyzed in the "British and Foreign Medical Review," April, 1845, p. 558, and p. 575. 10 THE CENTRAL NEBVOUS SYSTEM. and we must acknowledge that it is difficult to explain it otherwise than Arnold has done. Moreover, we have found that, after the section of all the posterior roots of the spinal nerves in frogs, the voluntary movements seem to be very nearly as perfect as if no operation had been performed, and that if the skin of the head is pinched on one side, the posterior limb on the same side tries to repel the cause of the pain as well as if no injury had been made. I have also ascertained that in frogs rendered blind, these experi- ments give the same results. It seems very probable, from these facts, that there is at least a part of the sensations giving to the mind the idea of the state of a muscle, which passes along the anterior roots to go to the senso- rium. But, although I agree so far with Arnold, I do not admit with him that it is only through the anterior roots that impressions are conveyed from the muscles to the brain. When a galvanic current is applied to the muscles of a limb of a frog, on which the posterior roots of the nerves of this limb have been divided, no trace of pain is produced, and all the other causes of pain are also unable to cause it, when applied either to the skin or to the mus- cles. When I examine, in another lecture, the correlation of pathological cases with experimental facts, I will speak again of the views of Arnold. I dismiss actually the subject, contenting myself in saying that, even if muscles have peculiar nerve-fibres, which go up to the brain along the anterior roots, to give there some special sensations in correspondence with the degree of con- traction, it seems nevertheless quite certain that the nerves of touch and those which convey painful impressions, do not pass by the anterior roots, and that, therefore, the theory of Sir Charles Bell, as regards these nerves, remains entire. In another lecture I will show, also, that all, or at least almost all, the motor nerve-fibres which go to the bloodvessels, pass in the anterior roots. But, if Sir Charles Bell's views concerning the roots of nerves are now based upon irrefragable experiments, it is not so as regards either of the views that he successively proposed concerning the columns of the spinal cord. We will prove by anatomical, expe- rimental, and pathological facts, that his ideas concerning the channels for sensation and volition are not exact. But, at the same time that we show the mistakes he has committed in this respect, we will bring forward a great many proofs of a theory of this eminent physiologist, which is by far of greater importance than the views THEORY OF SIR CHARLES BELL. 11 he held respecting the place of passage of the sensitive impressions, and the orders of the will in the spinal cord. The great theory of Sir Charles Bell was, not that volition and sensation have their conductors in this or that place, but that these conductors are dis- tinct one from the other, all along from the brain to the periphery. It is this principle of a complete distinction between the elements of the nerves and of the spinal cord, which are employed in motion and in sensation, which is the great thing that science particularly owes to him. Others had had this idea, but no one so powerfully as he had; and, also, no one tried to prove it, as he did. But, the principle being imagined, it remained to find out, first, positive proofs of its existence ; and, secondly, whether the conductors — though distinct one from the other — are congregated together in the same sheath (as in the trunks of the spinal nerves), or are sepa- rated in distinct bundles, as they seem to be in the roots of the spinal nerves. Now we must say that, had the various conductors been everywhere placed in contact one with the other, the theory could not have been proved. As regards the spinal cord, when we began our researches, the most positive facts amongst those that were known, seemed to be quite in opposition to the great view of Sir Charles Bell, as they seemed to show that the same part of the spinal cord is employed both in voluntary movements, and in sen- sations. I have tried to show that the same conductors cannot be the agents for both voluntary movements arid sensations, inasmuch as those for sensations make their decussation in the spinal cord, whilst those for motion decussate in the medulla oblongata. In this respect, then, instead of being in opposition to the great principle, to the demonstration of which Sir Charles had employed his whole life, I have brought a striking fact in proof of the truth of this principle. But I repeat that, as regards the channels of convey- ance of the sensitive impressions and the orders of the will in the spinal cord, Sir Charles has been completely mistaken. This will be fully demonstrated hereafter. The idea first proposed by Bell was, that the posterior columns of the spinal cord are the continuations of the posterior roots, and that they convey the sensitive impressions to the brain. He thought also that the anterior columns convey the orders of the will to muscles. This theory received no other support from its author than the following attempt at experimenting, which we record in the words of Sir Charles: "I found that injury to the 12 TIIE CENTRAL NERVOUS SYSTEM. anterior portion of the spinal marrow convulsed the animal more certainly than injury to the posterior portion ; but I found it diffi- cult to make the experiment, without injuring both portions." 1 The theory of Sir Charles Bell was opposed by Bellingeri, Schoeps, Kolando, Calmeil, Fodera, and several others, before it found a very ardent supporter in Mr. Longet. All the experiment- ers which we have just named, except Mr. Longet, agreed upon one fact, which is, that a section of the posterior columns of the spinal marrow is not followed by a loss of sensibility. Such was the state of science, when Longet undertook to prove that the theory of Sir Charles Bell concerning the columns of the spinal cord, was as exact as that concerning the roots of the spinal nerves. In the next lecture we will show how Longet has been mistaken. 1 The Nervous System of the Human Body. By Sir Charles Bell. Third edi- tion. London, 1844. Appendix, p. 443. IS LECTURE II. EXPERIMENTS SHOWING THAT THE TRANSMISSION OF THE SENSITIVE IMPRESSIONS, IN THE SPINAL CORD, TAKES PLACE CHIEFLY IN ITS CEN- TRAL PART— i. e., IN THE GRAY MATTER. Experiments and views of Longet. Objections by Dr. R. B. Todd, Mr. Lockliart, Clarke, and the Lecturer. Causes of error in experimenting upon the spinal marrow. — Experiments proving that a part may be a conductor of the sensitive impressions, though not endowed with sensibility. — Experiments showing, 1st, that a transversal section of the posterior columns of the spinal cord, instead of causing anaesthesia, is followed by hypersesthesia ; 2d, that a transversal sec- tion of the whole spinal cord, except the posterior columns, is followed by a complete anaesthesia. Anatomical and experimental facts showing the relative share of the gray matter, and of the various columns of white matter, in the transmission of the sensitive impressions. Mr. President and Gentlemen: Although extremely nume- rous, the theories concerning the transmission of the sensitive impressions in the spinal cord may be considered as mere varieties of two principal ones, according to which the transmission takes place chiefly, or exclusively in the posterior columns, or in the gray matter. Longet is the principal advocate of the first of these two theories. He thinks: — 1st. That all the nerve-fibres of the spinal nerves which are em- ployed in the transmission of the sensitive impressions, enter the posterior columns of the spinal cord, and go up to the brain in these columns, and, therefore, that the Sensorium receives sensitive impressions only from these parts of the spinal cord, and their pro- longations in the encephalon. 2dly. That in the medulla oblongata, the restiform bodies being the direct continuations of the posterior columns of the spinal cord, are also the only channels for the transmission of the sensitive im- pressions. 3dly. That the sensitive impressions going to the sensorium have to pass chiefly across the cerebellum, as the restiform bodies chiefly pass across this organ. 14 THE CENTRAL NERVOUS SYSTEM. Longet did not adduce any proof of the correctness of this theory. He merely tried to show that the posterior columns of the spinal cord are the only parts of this organ which are sensitive — i. e., which cause pain when irritated. We will show hereafter, that, even admitting this as true, it was wrong to draw the conclusion that the posterior columns are the only conductors of sensitive im- pressions. Before we pass to this demonstration, we must say, as we think that it may prove useful to do so, that, had the theory of Longet been criticized, even in taking notice only of the facts men- tioned by this physiologist, it would have been easy to show the utter impossibility of admitting this theory ; but science has no critics, and this imjwssible doctrine was received in France as per- fectly demonstrated, and was admitted in England, by almost every one, as being the theory of Sir Charles Bell, while Sir Charles had already repudiated it, five or six years before the first publications of Longet. It has been a curious spectacle to see men of great learning admitting that Longet had proved the truth of Sir Charles Bell's views, while, had Longet given real proofs, he would have demonstrated that Sir Charles was mistaken. In April, 1835, Bell read a paper before the Boyal Society, 1 in which he says: "Formerly I believed that the nerves of sensation — that is to say, the posterior roots of the spinal nerves, came from the posterior columns of the spinal marrow, and, consequently, from the cerebellum. Whilst entertaining this belief, I found my progress barred; for it appeared to me incomprehensible that motion could result from an organ like the cerebrum, and sensation from the cerebellum, for there was no agreement between them. They conformed neither in size, shape, nor subdivisions." In the same paper, Sir Charles tries to show that the lateral columns of the spinal marrow must be the parts transmitting sensitive impressions, because they go to the cerebrum, and because he thought that the posterior roots are united with them. There was, therefore, a complete disagreement between Longet and Sir Charles Bell, as regards the function of two out of the three columns of the spinal cord — the posterior and the lateral columns. We owe to Dr. K. B. Todd the first serious objections made in England against the views of Longet. 2 These objections are par- 1 Philosophical Transactions, Part I., 1835; and " The Nervous System of the Human Body," by Sir Ch. Bell, third edition, 1844, pp. 238, 239. 2 See his and Mr. Bowman's admirable work, " The Physiological Anatomy and OBJECTIONS TO LONGET's VIEWS. 15 ticularly grounded upon anatomical and pathological facts. Of these last facts we will speak elsewhere, and of the first we will say that they relate — first, to the size of the posterior columns, which are not, as they should be, according to the theory, larger and longer, the higher they are examined in the spinal cord; secondly, to the insertions of the posterior roots, which do not seem to be attached to the posterior columns. In 1851 and 1853, Mr. Lockhart Clarke published his important papers "On the Structure of the Spinal Cord," 1 in which he clearly showed, as Stilling and others had already done, that the posterior roots of nerves are in continuation with the gray matter, and not with the posterior columns ; and he tried to show — as had been already done by Sir Charles Bell and Dr. Todd — that the posterior columns, being united with the cerebellum, could not be considered as the only conductors of the sensitive impressions. As long as twelve years ago, I began to oppose the views of Longet. 2 I shall not here criticize at length this doctrine, as the very arguments which I shall give in support of the theory that I propose will be found easily, and without my showing it, to be decisive objections to the views of Longet. I will merely try to show the contradictions which exist between various parts of the system of this physiologist, and also try to explain how he has been mistaken. 1st Contradiction. — Mr. Longet thinks that the gray matter of the spinal cord cannot be a conductor of sensitive impressions, because it is not endowed with sensibility ; and his single argument to prove that the posterior columns are the sole conductors of the sensitive impressions is, that they are the only sensitive parts of the spinal cord. On another side, he admits that the cerebellum, which he rightly believes not to be sensitive, is the principal chan- nel for the transmission of the sensitive impressions. Of course, if the gray matter of the spinal cord cannot be a conductor, be- cause it is not sensitive, the cerebellum also cannot be a conductor; and if it is, the gray matter also can be. 2d Contradiction. — Longet admits that the extirpation of the cere- Physiology of Man," Part II., 1845, pp. 316-319; and the article "Nervous Sys- tem," in the Cyclopaedia of Anatomy and Physiology. 1 Philosophical Transactions, 1851, Part II., p. 607, and 1853, Part I., p. 347. 2 See my Inaugural Dissertation for the Degree of M. D. — Recherches et Exper. sur la Physiologie de la Moelle Epiniere. Paris, 3 Janvier, 1846. 16 THE CENTRAL NERVOUS SYSTEM. bellum does not diminish the sensibility of any part of the body, and he admits also that the cerebellum is the principal channel of the transmission of sensitive impressions to the brain. 3d Contradiction. — There are several pathological cases mentioned by Longet which show that an alteration of a lateral half of the pons Varolii produces a complete loss of sensibility of the opposite half of the body ; Longet, however, admits that there are but a small number of the sensitive nerve-fibres of the body which enter the pons Varolii. On another side, Longet relates pathological cases showing that the cerebellum may be altered very deeply without any diminution of sensibility, whilst he admits that most of the conductors of sensitive impressions pass through this nerv- ous centre. 4:th Contradiction. — Longet has proposed this view : that the pons Varolii is the centre for the perception of the sensitive impres- sions ; and he admits that most of these impressions do not reach this organ, and pass through the cerebellum going up to the brain. These contradictions are certainly sufficient to show the untena- bleness of the systematic views of Longet, and it might seem use- less to speak any more of these views ; but as they have, for a long while, been admitted as correct by almost every one in France and in England, we must say a few words on the causes of the errors committed by that able physiologist. There are two means of ascertaining by experiments the func- tions of a nerve, or of a part of the nervous centres. One of these means consists in exciting the part, and in finding out what action takes place in consequence of the excitation; the other consists in a section or the extirpation of the part, and in examining what are the actions then missing. The first one, therefore, may give the action of a part, whilst the other shows what is its action when we see what is missing. Of these two means, Longet has made use of the first one only, and he declares that it is impossible to employ the second on the spinal cord. We shall see, on the contrary, that the first one could not be employed alone with success ; whilst the second may very easily be employed, and furnish positive and direct facts. Causes of Errors in experimenting upon the Spinal Cord. — Longet declares that it is impossible to lay bare the spinal cord of a mam- mal without producing, at once, such a debility in the posterior limbs that they lose, more or less completely, both voluntary move- ments and sensibility. Of course, if mammals were always in this CHIEF CONDUCTOR OF SENSITIVE IMPRESSIONS. 17 condition after the opening of the spinal canal, it would be quite impossible to perform any valuable experiment on the spinal cord, to find out what are the parts employed in the two functions which are then lost. Fortunately, animals may not have any apparent diminution of either voluntary movements or sensibility after the exposure of the spinal cord to the air. They may walk about and run as fast as if nothing had been done to them, and, except the little change in the movements of the spine due to the section of some of its muscles, no difference may be observed between them and animals which have not been operated upon. As regards sensibility, it soon becomes increased, as I have stated in a paper read last year to the Royal Society. (See " Proceedings of the Royal Society," 1857, No. 26.) Longet has been mistaken, for the reason, that he opened the spinal canal in a considerable portion of its length, and in so doing produced a state of exhaustion by a great loss of blood and by the excessive pain. When the operation is made quickly, even if a very considerable part of the cord is laid bare, if the haemorrhage has not been great and if pain has been avoided by the exhibition of chloroform, there is no notable dimi- nution of sensibility, and there is no other diminution in the volun- tary movements, except that depending upon the section of the muscles of the back. 1 Another cause of error committed by some experimenters was in thinking that the absence of sensibility in the gray matter of the spi- nal cord is a proof that this matter is not a conductor of the sensitive impressions. A distinction between the property of conduction or transmission, and the property of being sensitive or impressionable, would have prevented such a mistake. The nerve-fibres of the cerebral lobes are conductors, but they are not excitable, not impres- sionable; and so is the gray matter of the spinal cord; when it exists alone, establishing the communication between two parts of the spinal cord, after a transversal section of the whole of the white 1 Animals usually survive after the laying bare of the spinal cord, while they usually die after the laying hare of the brain. Indeed, if the susceptibility to in- flammation is not greater in the spinal cord and its membranes in man than in animals, I think that Clive, Tyrrell, Laugier, and others, who have applied the trephine to the spine after fractures, should have imitators. In dogs, I have ascer- tained that the fracture of the posterior part of the vertebrae causes death, unless the broken pieces be removed and the effused liquid evacuated. Even in adult animals, the pieces of bone taken away are usually reproduced in a few months, and the injured spinal cord may also recover its functions. B 18 THE CENTRAL NERVOUS SYSTEM. matter, it conducts, it transmits to the brain the sensitive impressions made on impressionable organs behind the section, but when irritated it does not transmit anything because it is not itself impressionable. I have found that even the most sensitive nerve in the body, the tri- geminal, loses its sensibility, its impressibility, in a part of its length. It is well known that a very considerable root of the trigeminal nerve goes down in the medulla oblongata towards the nib of the calamus scriptorius, being there between the anterior pyramid and the resti- form body. Magendie has shown that a transversal section of one- half of the medulla oblongata dividing this root causes the loss of sensibility of the face, so that this root is positively a channel for the transmission of the sensitive impressions to the sensorium. Now, I have found that if a pin (even a large one) be introduced slowly and perpendicularly (see Fig. 5, p) through the restiform body and the root of the trigeminal nerve in the medulla oblongata, there is no sign of pain, so that the impressibility of this root in that part of its length is lost, or at least notably diminished. This fact proves that the power of conducting sensitive impressions may exist in parts deprived of sensibility. Even when we compare the various parts of the length of the roots and of the trunk of the spinal nerves, from the skin to the spinal cord, we find great differ- ences in the degree of sensibility, while the conducting power seems to be the same everywhere. (See my paper on this subject in my work, Experimental Researches applied to Physiology and Pathology, 1853, p. 98.) Of the means of experimenting, of which we have already spoken,- the one which consists in employing excitations is certainly un- able to give any decisive result, as regards the question of the channel by which the sensitive impressions are conveyed to the brain, in the spinal cord. All that may legitimately be deduced from the effects of the excitation of the various parts of the spinal cord is, that a certain part is sensitive, or seems to be, while others seem not to be. Another cause of error exists when we try to find out if a part is sensitive or not. If galvanism is employed, as was the case in the experiments of Longet, it is indeed impossible to have a current applied to the posterior columns, which will not pass by the posterior roots, and as the sensibility of the roots, par- ticularly at the place where they are in connection with the spinal marrow, is excessive, the signs of pain given by the animals do not prove that the posterior columns are sensitive. Experiments in which an irritation is made with the point of a needle or a pin may CHIEF CONDUCTOR OF SENSITIVE IMPRESSIONS. 19 be considered as insufficient, because the degree of pain, then, is not very great. However, so far as we may draw conclusions from this kind of experiment, it seems very doubtful whether the posterior columns possess any sensibility, and the causes of the mistake which has been made in this respect are, that the posterior roots have been irritated, and that the excitability for reflex action is very great in the posterior columns, and the movements due to the reflex faculty have been considered as signs of pain. 1 I pass now to the exposition of the facts upon which I ground the theory I have proposed concerning the channels of transmis- sion of sensitive impressions. The first fact I have to speak of is, that a transversal section of the posterior columns, instead of being followed by the loss, or even a diminution, of sensibility, seems to produce an increase in the amount of this property ; in other words, I have found that the section of these pretended only channels of the sensitive impres- sions, instead of preventing them from passing, allows them, on the contrary, to pass more freely, so that instead of anaesthesia there is hyperesthesia. In certain animals, and especially in rabbits and sheep, it is very easy to ascertain that there is a very great increase in sensibility in the various parts behind the section. Before the operation, in rabbits, the most energetic pinching of the skin pro- duces agitation, but no shrieking; after the operation, on the con- trary, the least pinching produces shrieking, and a much greater agitation. Sometimes the hyperesthesia is so considerable that the least pressure upon the skin makes the animal shriek. Whether the operation is performed in the lumbar, the dorsal, or the cervical region, the phenomena are always the same; that is, there is a manifest hyperesthesia in the various parts of the body which re- ceive their nerves from the part of the spinal cord which is behind the section. It has been so in all the animals I have operated upon, 1 Although, the reflex excitability of the posterior columns of the spinal cord is very great, the reflex movements observed when we irritate these columns alone, in a decapitated animal, are not so powerful as when we irritate at the same time the posterior roots and the posterior columns. But whatever may be admitted concerning this difference, it is quite certain, as first pointed out by the learned translator of Miiller (Physiol., p. 796), Dr. Baly, that the irritation of the posterior columns of the spinal cord produces more movement than the excitation of the anterior columns. In cases of tumours pressing upon the spinal cord there is also more spasmodic action when the pressure is on the posterior than when it is on the anterior columns. 20 THE CENTRAL NERVOUS SYSTEM. and I have already made this experiment upon animals belonging to more than twenty species. As long as the animals live after the section of the posterior columns, hyperesthesia continues to exist, except in the cases where reunion takes place between the two surfaces of the section ; but hyperesthesia is greater during the first week after the operation than it is after a month or many months. Laying aside the curious fact of the existence of hyperesthesia, a fact which is observed also in man, when the posterior columns of the spinal marrow are altered or injured, in a small part of their length, it results from the experiments consisting in a transverse section of these columns that the transmission of sensitive impres- sions to the encephalon does not take place only along the posterior columns. If a complete transverse section is made upon any part of the restiform bodies, sensibility becomes very much increased in every part of the limbs and trunk. Hyperesthesia is also, but in a less degree, one of the results of a transversal incision in the cerebellum, in the processus cerebelli ad testes, and in the tubercula quadrigemina. If we carefully dissect the two restiform bodies so as to separate them from the neighboring parts, and if we divide them trans- versely at their two extremities, and then remove them, we find that the animal, instead of losing its sensibility in the different parts of the limbs and trunk, becomes hyperesthetic. It results from these experiments, that the restiform bodies, which are the direct continuations of the posterior columns of the spinal cord, are not the only channels for the transmission of sensitive impressions to the sensorium. It seems certain, therefore, that the posterior columns of the spinal cord and of the medulla oblongata are not the only channels for the trans- mission of the sensitive impressions from the limbs and trunk to the sen- sorium. But we can go farther, and prove that the posterior columns do not seem to transmit the least part of the sensitive impressions to the encephalon. I have ascertained that after almost a complete transverse section of the spinal cord, leaving undivided only the posterior columns, the transmission of sensitive impressions from almost all the parts of the body behind the section does not take place. This experi- ment, performed by Stilling almost exclusively upon frogs, led him to affirm that sensibility is then entirely lost in all the parts behind CHIEF CONDUCTOR OF SENSITIVE IMPRESSIONS. 21 the section. Much more recently, M. Schiff, repeating this experi- ment, found, on the contrary, that sensibility is not lost in any of the various parts behind the section. Messrs. Vulpian and Phili- peaux, who made this experiment some time after Schiff, positively declare that sensibility is completely and definitely lost. I have ascertained that the differences in the results of this experiment de- pend upon various circumstances. At first, if the least quantity of the central gray matter of the spinal cord is left undivided, sensi- bility persists (although much diminished) almost everywhere be- hind the section. Besides, there are parts in the neighborhood of the section, and behind it, which always remain sensitive. I will explain afterwards what is the cause of this partial persistence of sensibility. Whatever is this cause, if we perform the following experiment, we may obtain the most decisive results: The spinal cord having been laid bare in a large mammal, in the dorsal region, I divide transversely the whole of it, except only the two posterior columns (see Fig. 8, d), and, after ten or fifteen minutes, or a little more, I find that all the usual means of exciting pain are applied in vain to the posterior limbs, so that these parts seem to be entirely deprived of sensibility. It results from this experiment, and from many others, in which the section was made nearer to the medulla oblongata, that the sensitive impressions do not pass along the pos- terior columns in their way to the encephalon. If the transmission of sensitive impressions does not take place along the posterior columns, it remains to be found what is the channel of this transmission. Is it the gray matter or some part of the lateral or anterior columns, or all or several, of these constitu- ents of the spinal cord? As regards the lateral columns, if we divide them transversely in the dorsal region, we find that sensi- bility, instead of being lost, seems to be increased in the two pos- terior limbs. But if, in performing this experiment, the knife goes farther than the limits of the lateral columns, and divides a part of the central gray matter on the two sides, sensibility is then dimi- nished in the two posterior limbs. From these experiments, and from another one, which consists in a transverse section of the whole spinal cord except one of the lateral columns, it results that these columns, like the posterior, are not the channels of transmis- sion of any part of the sensitive impressions to the encephalon. It is not so with regard to the gray matter, as the following ex- periments show: — 1st. A transversal section of the whole posterior half of the spinal 99 THE CENTRAL NERVOUS SYSTEM. cord is made, in the dorsal region, so that the posterior columns and the posterior half of the lateral columns and of the gray matter are divided, and then sensibility is found diminished in the two posterior limbs. Of course we cannot attribute this diminution to the section of the posterior or of the lateral columns, as we know that these divisions cause an increase of sensibility, and not a dimi- nution. 2d. A transversal section of the whole anterior half of the spinal cord, in the dorsal region, is made, so that the anterior columns and the anterior half of the lateral columns and of the gray matter are divided, and then sensibility is found diminished in the two pos- terior limbs. \V~e cannot attribute this diminution to the section of a part of the lateral columns, as we know that such an injury to the cord would increase, and not diminish, sensibility; nor can we admit that the section of the anterior columns is the only cause of diminution of sensibility, as, when these columns are alone divided, there is no marked alteration of sensibility. 3d. If the anterior, the lateral, and the posterior columns of the spinal cord are divided transversely, at the dorsal region, one set at one place, another at a distance of one or two inches, and the third also at the same distance from the second, so that the only channel of communication between the posterior limbs and the sensorium is the gray matter, of which, however, several parts have, unavoid- ably, been divided (such as the anterior and the posterior gray cornua, and also more or less of the central gray matter), we find that the posterior limbs are still sensitive, though evidently less than in the normal condition. 4th. If the section is made so as to divide only a small part of one of the lateral columns, and almost the whole of the gray matter, sensibility is very much diminished in the parts of the body behind the section. These facts prove that the gray matter is the principal conductor of the sensitive impressions in the spinal cord. But, amongst the white columns, there are some, besides the pos- terior ones, which have been considered, by two or three physio- logists, as organs of transmission of the sensitive impressions; I mean the anterior columns. Calmeil and Xonat thought that these parts share in this function. Although I admit their view, I believe they were mistaken in their experiments, which consisted in a transversal section of the whole spinal cord, except the ante- rior columns, as they state that immediately, or shortly after the CHIEF CONDUCTOR OF SENSITIVE IMPRESSIONS. 23 operation, they found sensibility persisting. This is not the case when the whole of the gray matter has been cut transversely, and it is extremely probable that they had left a good part of it undi- vided. But if the operation be made so as to leave no gray matter at all, sensibility, which at first seems to be lost, after a time reap- pears, and many hours after, it evidently exists everywhere, though in a slight degree only. 1 It is evident, therefore, that the anterior columns have a share, but only a small one, in the transmission of the sensitive impressions to the sensorium. From all the facts above related, it results that the transmission of sensitive impressions takes place chiefly by the gray matter, and, for a small part only, by the anterior columns, while the lateral and the posterior columns do not participate in the same way as the preceding parts of the cord, in this function. We shall see, in a moment, that they have a peculiar kind of share in this trans- mission. Which part of the gray matter is employed in the transmission of sensitive impressions t This substance is composed of parts surround- ing the central canal of the cord, of lateral masses, and of two anterior and two posterior horns, which separate the lateral columns from the anterior and the posterior ones. I call central gray matter the lateral masses, the bases of the anterior and posterior horns, and all the substance around the central canal, and I think that the transmission of the sensitive impressions takes place chiefly by this central gray matter. As regards the anterior horns of gray matter, I am not prepared to affirm that they have no share at all in this function; but I may state the posterior horns do not participate in it, in the same way as the central portion of gray matter. Which elements of the central gray matter are employed in the transmission of sensitive impressions? This difficult question has not yet received a positive solution; but it cannot be doubted, at least, that the transmission takes place by both cells and nerve- fibres united together, and not by cells alone acting at a distance upon their neighbors. Most of the nerve-fibres of the roots of the spinal nerves, after having reached the gray matter, attach themselves to the nerve-cells, and, as has been well demonstrated by K. Wagner, and by Bidder, and several of his pupils, these cells communicate with others in such a way that two kinds of transmis- sion are possible, one across the cord, and another towards or from 1 See my paper in the "Proceedings of the Royal Society," No. 26, 1357. 24 THE CENTRAL NERVOUS SYSTEM. the encephalon. But, besides the nerve-cells and their nervous fibrils of communication, there are, in the gray matter, several col- lections of longitudinal nerve-fibres, forming very minute white columns, surrounded by the gray substauce. These white columns, first well described by Mr. Lockhart Clarke, and, after him, by Prof. Schrceder van der Kolk, cannot be considered as the only channels, in the gray matter, for the sensitive impressions or for the orders of the Will to muscles. The number of fibres they contain is too small for them to have these functions alone, but it is probable that they participate -in it. Are they emplo}*ed for a peculiar kind of sensitive impressions while the other impressions would be trans- mitted by nerve-cells and their communications? This is a ques- tion that experiments upon animals cannot solve. We will speak of it again when we give the history of the pathological cases re- lating to the subjects discussed here. We must now examine if the posterior and lateral columns have not a peculiar share in the transmission of sensitive impressions. As regards the posterior columns, the following experiments will show that there are conductors of sensitive impressions passing through them. Long ago I found that after a transversal section of the columns, the inferior surface of the section, that which seems no more to be connected with the encephalon, appears to be highly sensitive. I have since ascertained that the posterior roots in the neighborhood of that surface are the parts which then give the sensation of pain. But whether sensibility exists only in the roots or in the fibres of the posterior columns, it is a fact that pain is produced when this inferior surface is irritated. In 1852, I was led still more to admit that there are nerve-fibres coming from the posterior roots, and passing in two opposite directions in the poste- rior columns (see the arrows in Fig. 6), some going upwards and some going downwards, or, in other words, some going direct towards the encephalon and some going away from it. The follow- ing experiment was the first which led me to the conclusion that there are fibres of the posterior roots descend ing in the posterior columns: I introduced a very sharp bistoury between the posterior and the anterior parts of the spinal cord, and by cutting from above downwards, or in the opposite direction, I separate a part of the length of the posterior columns of the cord from the anterior parts of this organ. This being done, I divide transversely and in its middle the part of the posterior columns separated from the ante- ASCENDING AND DESCENDING CONDUCTOKS. 25 rior parts of the spinal cord, g so as to obtain (see Fig. 6) two seg- ments, one superior, the other inferior. The superior I will call cephalic segment, and the other caudal segment. Now, when there are some little parts of the posterior gray horns and some fibres of the posterior roots attached to these segments, we obtain this ap- parently strange and surely unforeseen result, that not only the caudal segment is sensitive, but that it seems to be more sensitive than the cephalic segment. But whatever may be the real amount of sensibility in these two segments, there is one capital conclusion to be drawn from this experiment, and this is, that a number of the conductors of sensitive impressions in the posterior roots pass in the pos- terior columns, in ivhich some go upwards towards the encephalon [cen- tripetal or ascending fibres), while others go in the opposite direction — i. e., dowmuards or bacJcivards (centrifugal or descending fibres). Now the question arises — What become of these ascending and de- scending conductors? By a great many experiments of various kinds, I have ascertained that they pass along the posterior columns only a little way, and leave them to enter the central gray matter. I will relate a few of the most striking experiments, which prove that such is truly the disposition of these conductors. If, after having ascertained that the roots attached to the upper or cephalic segment (see Fig. 6) are sensitive, I divide transversely the posterior columns at a very short distance above the extremity of the segment, I find that it loses its sensibility, which fact shows that the transmission takes place by these columns. Now if the section is made higher, sensibility persists, though diminished, showing that some of the conductors must, at this distance, have left the posterior columns and entered another part of the cord; at last, if the section is made far above the extremity of the segment, sensibility persists entire in the roots attached to that extremity, which shows that the con- ductors, at a certain distance from the point of their entrance into the posterior columns, leave these columns to pass into another part of the cord. This part is the central gray matter, as is proved by the fact that if we divide it transversely at four or five inches above the cephalic segment, this segment loses its sensibility. With the inferior, or caudal segment, analogous experiments show that the conductors coming from the posterior roots descend in the posterior columns, and, after a very short distance, pass into the central gray matter. There the transmission takes place towards the encephalon ; so that there are recurrent conductors in the spinal cord. 26 THE CENTRAL NERVOUS SYSTEM. An excellent experiment, showing the share of the gray matter in the transmission of sensitive impressions may be made after we have prepared two segments of the posterior columns, as we have said already. We ascertain that the caudal, or lower segment, is very sensitive, and then we divide gradually the laid-bare gray matter (see Fig. 6, g\ and we find that gradually, also, sensibility disappears in this segment. Experiments, which it is useless to describe, seem to show also that there are some fibres from the posterior roots which ascend, and others which descend, in the lateral columns, and in the posterior horns, both of which soon reach the central gray matter, by which part the transmission to the encephalon is at last performed. Their existence in the posterior columns, and also probably in the posterior horns and a part of the lateral columns, receives additional evidence from the following experiment: If the posterior half of the spinal cord is divided in two places, in one case very near, and in another very far, one from the other (see Fig. 7), we find that there is a loss of sensibility in the posterior roots which are be- tween the two sections, when they are very near one to the other ; while, on the contrary, sensibility remains, and seems to be in- creased, in the posterior roots which are between the two sections, when they are at a great distance one from the other. In admitting that before reaching the central gray matter the fibres of the poste- rior roots go up and down the cord along the posterior columns, and along the parts (gray or white) which are in the neighborhood of these columns, and which have been divided with them, we have the explanation of the loss of sensibility in the first case ; and in admitting that these conductors, after a short distance, enter the central gray matter, we explain the persistence of sensibility in the second case. With this knowledge of the mode of distribution of the sensitive conductors in the spinal cord, we may explain the differences in the results arrived at by different experimenters after the operation consisting in a transversal section of the totality of the spinal cord, except the posterior columns. If, for instance, this operation has been made at the level of the second or third lumbar vertebrae, very little above the place where the roots of the nerves going to the ab- dominal limbs begin to originate, we find that the extremities of these limbs seem to be completely deprived of sensibility, but that when the upper parts of the limbs are irritated, there are evident ASCENDING AND DESCENDING CONDUCTORS. 27 signs of sensibility. The reason of this difference is obvious, if we admit that the fibres from the roots of the nerves going to the ex- tremities of the limbs leave the posterior columns of the spinal cord below the section, and pass into the gray matter, and, also, in the anterior columns, which parts are divided; while some of the fibres from the roots of the nerves going to the upper parts of the limbs, pass into the posterior columns at the level where the other parts of the cord are divided, and still transmit the sensitive impressions. To prove that they pass only a short way in and along the poste- rior columns, I have performed the following additional experi- ment. In one case I divide transversely the posterior columns at a very short distance above the place where the antero-lateral parts of the cord have been cut, and I find, then, that sensibility is entirely lost in all the parts of the posterior limbs (see Fig. 8, d, s), in the other case I divide transversely the posterior columns at a great distance from the other section, and I find that sensibility of the upper parts of the posterior limb persists. There are many facts which I could mention, in addition to the preceding, which show that the posterior columns of the spinal cord afford passage to several of the conductors of sensitive im- pressions, but that, after a short distance, they leave- these columns to enter the gray matter. I refrain speaking of these facts, because I think that the above experiments are sufficient. It is useless to try to show that these experiments prove that the idea that there are sensitive fibres going to the encephalon in the posterior columns must be abandoned. As a general conclusion, we will say that the conductors of sen- sitive impressions, at their arrival in the r spinal cord, either enter directly the central gray matter, or go up or down a little way in the posterior columns, and also, most likely, in the posterior gray cornua, and in the posterior part of the lateral columns, and enter- ing afterwards the central gray matter, by, or in which, the impres- sions conveyed by these two sets ascend towards the encephalon. I will add, that many experiments, some of which are related in this lecture, prove that the restiform bodies, which are the con- tinuations of the posterior columns, seem not to give passage to any of the conductors of the sensitive impressions of either the various parts of the trunk and limbs, or of the head, and that, there- fore, the cerebellum, with which the restiform bodies are connected, does not receive from them any of such conductors. 28 THE CENTRAL NERVOUS SYSTEM. In another lecture, I will speak of the singular hyperesthesia which exists in so high a degree after the section of the posterior columns of the spinal cord, and also after a deep section of the following parts on the posterior side of the encephalon : the resti- form bodies, the cerebellum, the anterior crura cerebelli, and the tubercula quadrigemina. 29 LECTURE III PLACE OF DECUSSATION OF THE CONDUCTORS OF SENSITIVE IMPRESSIONS, IN THE CEREBRO-SPINAL AXIS. The celebrated experiments of Galen, which had been universally considered as showing that there is no decussation of the conductors of sensitive impres- sions, in the spinal cord, do not prove anything in this respect. — Experiments showing that the conductors of sensitive impressions from the various parts of the trunk and limbs make their decussation in the spinal cord, and not in the encephalon, as was admitted. Mr. President and Gentlemen: The question I am about treating has had a singular fate; considered as solved for a great many centuries, it has hardly been the object of the attention of scientific men in our days. Until 1849, when I first published the discovery I had just made, that there is a decussation of the con- ductors of sensitive impressions in the spinal cord, it had been uni- versally admitted that Galen had proved that there is no such crossing in the spinal cord, and that, therefore, these conductors must make their decussation in the encephalon. Physiologists and pathologists agreed in attributing to Galen the merit of having given a demonstration, in this respect, although he seems never to have tried to solve the question. In detailing his experiments on the spinal cord, 1 he does not say a single word concerning sensibi- lity, and it is upon the falsely understood results of these experi- ments, that, for a great many centuries, medical men have based their opinions that there is no decussation of the conductors of sensitive impressions in the spinal cord. Haller 2 also speaks of voluntary movements, and not of sensi- bility in mentioning the effects of a section of a lateral half of the 1 See his following works : " De Locis affectis," Lib. III. cap. xiv., et "De Ana- tomicis administrationibus," Lib. VIII. sect. vi. 2 " Elementa Physiologise," vol. iv. pp. 326 and 334. In one of these places he says just the reverse of what he affirms in the other, as regards voluntary move- ments. 30 THE CENTRAL NERVOUS SYSTEM. spinal cord. Lorry, Fode'ra, Flourens, Calmeil, and many other physiologists, have studied the effects of an injury to one half of the medulla oblongata, but none of them has directly examined if there is a decussation of the sensitive fibres in the spinal cord ; and in their experiments on the medulla oblongata they looked almost only at the effects on movements (paralysis and convulsions), and they hardly mention the state of sensibility. Sir Charles Bell is the first biologist who has tried to determine the real place of decussation of the conductors of sensitive impres- sions in the cerebro-spinal axis. He imagines that it is in a small part of the length of the floor of the fourth ventricle above, and near the crossing of the pyramids ; x but he does not give any rea- son in proof of his idea, except the results of a deceptive anato- mical dissection, quite in opposition with the results of the import- ant researches of John Eeid, of Solly, of Valentin, and other ana- tomists. Longet also has tried to show the place of decussation of the conductors of sensitive impressions. 2 He admits that the sensi- tive fibres, after having passed through, the cerebellum, go towards the tubercula quadrigemina, along the processus cerebelli ad testes, and that they make their decussation below the tubercles. The erroneousness of this view is pretty evident from the fact that the sensitive fibres do not pass through the cerebellum, so that the fibres, which really seem to make a decussation where the anterior peduncles of the cerebellum coalesce, below the tubercula quadri- gemina, cannot be the continuation of the sensitive fibres of the body. We will try to prove that the conductors of sensitive impressions make their decussation in the neighborhood of the place of inser- tion of the sensitive nerves, or roots of nerves, in the cerebro- spinal axis. As regards the sensitive fibres of the trunk and limbs, we will try to show that their decussation takes place in the spinal cord. The following experiments seem to be decisive in this re- spect : — 1st. The spinal cord of a mammal is laid bare at the level of the two or three last dorsal vertebrae, and a lateral half of this organ (including the posterior, the lateral, and the anterior columns, and 1 See the " Nervous System of the Human Body," 3d edition. London, 1844, pp. 231-40. 2 " Anatomie et Physiol, du Syst. Nerveux," 1843, vol. i. pp. 385 and 421. DECUSSATION OF SENSITIVE CONDUCTORS. 31 all the gray matter on one side) is divided transversely. (See Fig. 9, s.) The animal is left at rest for a little while, and then it is ascertained that sensibility seems to be much increased in the pos- terior limb on the side of the section, while it seems to be lost, or extremely diminished, in the posterior limb on the opposite side. There seems to be, therefore, hyperesthesia behind and on the side of a transversal section of a complete lateral half of the spinal cord; while, on the contrary, there seems to be anaesthesia behind the sec- tion, and on the opposite side. This experiment is one of the two made by Galen ; but he seems not to have looked at all at the condition of sensibility, and he simply states that there is a paralysis on the side of the section, and no paralysis on the opposite side. Sir Astley Cooper, under the suggestion of Dr. Yelloly, 1 has made a similar experiment, except that the section was higher ; the state of sensibility is not mentioned, and, as regards movements, there was paralysis on the side operated upon. Schceps, Yan Deen, and Stilling have observed that sensibility is not lost in the limb or limbs behind, and on the side of the sec- tion of a lateral half of the spinal cord ; but they have not remarked the most important fact, that on the opposite side there is ahgesthe- sia. They also do not mention this curious result of this experi- ment, the existence of hyperesthesia on the side of the injury. Fodera was very near discovering that there is a decussation of the sensitive fibres in the spinal cord. He says he has found in some cases, that a section of one of the posterior columns caused a diminution of sensibility in the opposite side of the body ; but he states that in other cases he has seen the reverse. He also has sometimes remarked that the section of one of the posterior columns causes hyperesthesia in the same side, and that a section of these two columns produces hyperesthesia in the two sides, but he declares, also, that he has seen the reverse. 2 Two explanations for some of the results of a section of a late- ral half of the spinal cord may be proposed, as regards sensibility. Either it may be imagined, as it has been by several German phy- siologists, that the gray matter has the power of transmitting sen- sitive impressions in such a manner that one lateral half of this substance is sufficient for the two sides of the body, or that the 1 Medico-Chirurgical Transactions, vol. i. p. 200, et seq. 2 See his paper in Magendie's Journal de Phvsiologie, vol. iii. p. 191-217. 32 THE CENTRAL NERVOUS SYSTEM. conductors of sensitive impressions decussate in the spinal cord, so that those which come from the left side of the body pass into the right side of the spinal cord, and vice versa. The hypothesis of the Germans may explain the fact that sensibility persists on the side of the section, but it is proved to be absolutely inadmissible by the fact that there is anaesthesia on the opposite side. We will see that the other experiments we have to mention are also in oppo- sition to the view of the Germans (Stilling, Schiff, and others). On the contrary, all the facts concur to prove the existence of a decussation. K - 2d. If, after having made a first section of a lateral half of the spinal cord in the dorsal region, on the right side, for instance (see Fig. 9, 5), and after having ascertained that the right posterior limb is hyperaesthetic, or at least extremely sensitive, we divide the left lateral half of the spinal cord in the cervical region (Fig. 9, s'), we find then that the right posterior limb loses entirely, or almost en- tirely, its sensibility. This experiment shows clearly that the sen- sitive impressions coming from the right posterior limb, after the first section, passed across the spinal cord from the right into the left side, along which they were transmitted to the encephalon. 3d. To obtain a very striking result from the experiment which consists in only one section of a lateral half of the spinal cord, it is better to make it after the posterior columns have been divided. We know that after this division there is hyperesthesia in the parts of the body which are behind the section ; if, after having ascer- tained this fact, the section of a lateral half is completed where the posterior columns have been divided (see Fig. 10, s $'), we find that the hyperaesthesia seems to increase on the side of the second ope- ration, while, on the opposite side, not only the hyperaesthesia, but sensibility entirely disappears. 4th. There is another mode of proving that the conductors of the sensitive impressions decussate in the spinal cord. In several points of view this mode of demonstration is superior to the pre- ceding. It consists in a longitudinal section of the spinal cord, an experiment already made by Galen, but the results of which, as regards sensibility, have been overlooked by him. The spinal cord is laid bare in the whole lumbar region, and a careful division of the entire extent of the part of the organ giving origin to the nerves of the posterior limbs, is made so as to sepa- rate the two lateral halves of the organ, one from the other. If this experiment could be executed perfectly well, nothing would DECUSSATION OF SENSITIVE CONDUCTOKS. 33 be divided in the cord except the commissures, which unite the right side with the left side of the cord, and all the longitudinal elements of this nervous centre would be left uninjured; but it is impossible not to cut more or less on either side. However, when the operation has succeeded well — i. e., when the two separated halves have been very little injured, a striking result is obtained. The voluntary movements still exist in the posterior limbs (though diminished on account of the injury to the muscles of the lumbar region), but sensibility is entirely lost in them. To those who know that injuries to the spinal cord, which cause a diminution of sensibility, always produce a greater diminution of voluntary movements, this fact will not be explained by the supposition that some injury has, then, been made to the two halves of the cord, and that it is, in consequence of this supposed injury, that the loss of sensibility is due. At least it will, I think, be easily admitted that if the two lateral halves of the cord had been injured enough to produce a complete and a lasting anaesthesia, there would be a notable degree of paralysis of voluntary movements. We repeat that snch is not the case: the animal has the use of his two limbs ; he moves about pretty freely, as Galen had already said. The loss of sensibility, therefore, must depend on the section of the commis- sures of the spinal cord, or, in other words, on elements of this organ which cross each other in the median line, or, rather, the median plane. If now we compare the results of this experiment with those of a transversal section of a lateral half of the spinal cord, we find that they agree perfectly in showing that the conductors of the sen- sitive impressions decussate in this organ. It is useless to stop to show that the longitudinal separation of the lumbar enlargement of the spinal cord would not produce anaesthesia, if the German physiologists were right in admitting that the gray matter has the power of transmission in every direction. It would be useless, also, to insist upon the disagreement between the results of a lon- gitudinal section of the spinal cord, and the views of the physiolo- gists who admit that the posterior columns are composed of sensi- tive fibres, coming from the posterior roots, and going up to the encephalon. These columns are left almost entire and uninjured, and, nevertheless, sensibility is lost. 5th. Another experiment, which is a combination of two of the preceding, gives a still better proof of the decussation of the con- ductors of sensitive impressions in the spinal cord. A longitudinal c 34 THE CENTRAL NERVOUS SYSTEM. section is made on the cervico-brachial enlargement of the spinal cord, so as to separate it in two lateral halves. I ascertain theu that sensibility is lost in the two anterior limbs, while it remains, and even seems to be increased, in the two posterior limbs. Of course, if the loss of sensibility in the two anterior limbs depended upon an injury to the two sides of the cord, and not upon a section of the decussating conductors of sensitive impressions, there would be a loss of sensibility, or, at least, a diminution of it in the poste- rior limbs. The admission of a decussation explains the two facts: loss of sensibility in one set of limbs, and conservation in the other set. (See Fig. 11.) If we divide transversely, in the same animal, the right lateral half of the spinal cord (see Fig. 11, s), we find then that the posterior limb on the same side becomes more evidently hyperaesthetic than before, and that the left posterior limb loses its sensibility. The transmission for this last limb there- fore took place by the right half of the cord, while that for the right posterior limb continues to take place by the left half of the cord. I think that the facts I have mentioned sufficiently show that there is a decussation of the conductors of sensitive impressions in the spinal cord. But several questions remain to be solved con- cerning this decussation. The first one we intend examining is, whether the decussation is complete or not. The fact that the loss of sensibility seems to be absolutely com- plete, after a longitudinal section of the whole length of the lumbar enlargement of the spinal cord seems to show that all the conduc- tors of sensitive impressions which reach the cord, coming from the posterior limbs, make their decussation in this enlargement. But if we admit that the decussation is complete, how do we ex- plain that there is an appearance of sensibility, and sometimes a well-marked degree of it, in a limb on the opposite side to that of a section of a lateral half of the spinal cord? In the first place, I must say that very often when we try to divide transversely such a part of the cord, being afraid of cutting too much, we leave un- divided a part of the gray matter and of the anterior column, so that the persistence of sensibility in the opposite side of the body is very natural, and not in opposition to our views. Yery likely this is what has occurred in many of the experiments of Mr. Chau- veau, who says that sensibility always persists in such a limb. If there is no notable diminution of sensibility anywhere, after an attempt to divide the lateral half of the cord, it is certain that the DECUSSATION OF SENSITIVE CONDUCTOKS. 35 operation is not complete, and that a part has escaped division. It is wonderful how smalliis the quantity of gray matter which, being left undivided, may transmit sensitive impressions! But even when the operation has been perfectly performed in certain animals, and especially guinea-pigs, in some cases, there seems to be a notable degree of sensibility remaining in the parts of the body which are behind the section, on the opposite side. I have ascertained that this appearance of sensibility is due to a very interesting cause. I suppose that the section has been made on the right side of the cord, above the origin of the nerves of the infe- rior limbs ; when the left inferior limb is irritated, the impression is brought to the spinal cord by the posterior roots (see Fig. 4, p), and, by a reflex action, the muscles of the right inferior limb have a spasmodic contraction, just as if the anterior roots of their nerves had been irritated, and in consequence there is a pain produced which is of the same kind as that which Magendie has attributed to a recurrent sensibility (see Lect. I.). The proof that the irritation travels, as we believe, is given by the facts, that if either the ante- rior or the posterior roots of nerves are divided on the right side, behind the hemisection of the cord, the appearances of sensibility disappear in the left inferior limb. Starting from the left limb, the irritation goes to the spinal cord; it is reflected to the muscles of the right inferior limb, along the motor nerve-fibres; it comes back again to the spinal cord, and then, following the normal channel of a sensitive impression, it passes from the right half of the spinal cord into the left side, in which it goes to the encephalon. Al- though the spasmodic reflex contraction in the right inferior limb is not very strong, it is able to give a painful sensation, on account of the hyperesthesia which exists in this limb. (See Fig. 4, and Lect. I.) As far as experiments go, it is very difficult to decide whether the decussation of the conductors of sensitive impressions is abso- lutely complete or not, but it seems to be very nearly, if not abso- lutely, complete. We shall see, by and by, that pathological cases seem to show that the decussation, in man, is complete. What is the place of decussation of the various posterior roots of a pair of nerves ? I have said, in the preceding lecture, that the fibres which enter the spinal cord, from the posterior roots, are distributed, in this nervous centre, in such a way that some are going upwards, some downwards, and some transversely. There are, therefore, ascending, descending, and transversal fibres. Now, 36 THE CENTRAL NERVOUS SYSTEM. all these fibres reach the central gray matter, after a short way, above or below their place of entrance, and almost at once they decussate. A great many experiments show that this must be the arrangement of the conductors of sensitive impressions. If we divide transversely a lateral half of the spinal cord in two places, so as to have three pairs of nerves between the two sections, we find that the middle pair has almost the same degree of sensi- bility as if nothing had been done to the spinal cord, while the two other pairs have a diminished sensibility, the upper one particu- larly in its upper roots, and the lower one in its lower roots : which facts seem to show that the ascending fibres of the upper pair, and the descending fibres of the lower one, have been divided before they had made their decussation. If there is only one pair of nerves between two sections, its sen- sibility is almost entirely lost, as then the transversal fibres are almost alone uninjured (most of the ascending and descending being divided), which fibres are employed for reflex action, and hardly for the transmission of sensitive impressions. After having divided transversely a lateral half of the spinal cord in the dorsal region, if we divide longitudinally this organ, so as to separate its two lateral halves one from the other, and at a right angle with the transversal section (see Fig. 12), we find that sensi- bility persists in the segment partly separated from the rest of the cord, if it is not more than two inches long, in a large mammal, whether the longitudinal section has been made below or behind the transversal one, as is the case in Fig. 12, or above or before this transversal division. If the longitudinal section is more than two inches long, it is not sensitive in all its length. When there are three pairs of nerves attached to it, the one nearest to the transversal section (see Fig. 12, 1), is hardly able to give slight sensations; the next (2) is a little more sensitive, but much less than in a normal condition; and the third is very sensitive, though not so much as the others on the same side and behind it. With a segment attached to the cord by its upper extremity, similar re- sults are obtained, and it seems certain, both from these facts and from many others which it is not necessary to mention, that the decussation of the conductors of the sensitive impressions in the spinal cord, whether they are, at first, descending or ascending, takes place at a short distance from the point of insertion of the posterior roots. Experiments upon the medulla oblongata, to decide if the cross- DECUSSATION OF SENSITIVE CONDUCTORS. 37 ing of the conductors of sensitive impressions, coming from the trunk and limbs, has taken place before they reach this organ or not, cannot give positive results, because the reflex movements are so energetic after a section of a lateral half of this nervous centre, that it is very difficult to know the degree of sensibility. But pathological facts, observed in man, will settle the question, as we shall show in another lecture. We have not, however, to regret that experiments on the medulla oblongata are useless, as it seems that the question of the decussation of the conductors of sensitive impressions, as far as the trunk and limbs are concerned, is clearly solved by the experiments on the spinal cord, mentioned in this lecture. There are some animals in which the decussation in the spinal cord is not so complete and so immediate as it is in mammals; such are reptiles and birds. This is one of the causes of some mistakes recently made by an able experimenter, Mr. Chauveau, of Lyons. He operated upon pigeons, and found that after a section of a late- ral half of the spinal cord, sensibility seemed to be much dimi- nished on the same side, and not at all on the opposite side. He concluded, therefore, that there is no decussation. I have ascer- tained that the results of the experiments vary with the place of the section. If it be made just above the lumbar enlargement, where Mr. Chauveau makes it, the decussation having hardly begun below this place, the results are as he says ; but if the section be made two inches higher, in the dorsal region, there is, as in mam- mals, though less marked, an increased sensibility in the posterior limb on the side of the section, and a diminution of sensibility in the opposite limb. The loss of sensibility is never complete, show- ing that the decussation is not complete. The same results are obtained in reptiles. As regards some other objections addressed to my theories by Mr. Chauveau, I do not think it worth while to mention them here. I have tried recently to show how little grounded they are, 1 and more decisive arguments than those founded upon vivisections will be given in my lectures on the pathological cases which prove the decussation in the spinal cord, and the power of transmission of the gray matter. In the preceding lecture, and in this one, I have tried to show 1 See my Journal de la Physiologie de l'Honime et des Animaux, Janvier, 1858, pp. 176-189. 38 THE CENTRAL NERVOUS SYSTEM. that the sensitive impressions follow, in the spinal cord, quite a determinate course, and I think that the facts I have mentioned to establish what this course is, are positive evidences that there are fixed channels, and that some of them cannot compensate for the absence of others. It is, therefore, useless to show the untenable- ness of the theory of the Germans (Schiff and Stilling), that the gray matter has the power of transmission in any direction, and that any small part of it may act for the whole, without any dimi- nution of intensity. It may be thought that experiments on animals can show only what relates to painful impressions, and not to impressions of touch, of cold, of warmth, &c. I will try to show, in the next lecture, that the channel for impressions of touch, at least, seems to be the same as that of painful impressions, in the spinal cord. 39 LECTURE IV. ON VARIOUS QUESTIONS RELATING TO THE TRANSMISSION OF SENSI- TIVE IMPRESSIONS AND OF THE ORDERS OF THE WILL TO MUSCLES, THROUGH THE SPINAL CORD AND THE MEDULLA OBLONGATA. Most of the elements which are employed as conductors of the purely tactile im- pressions seem to pass by the same parts of the spinal cord as those which transmit the impressions which give pain. — The disposition of the conductors of the various sensitive impressions in the spinal cord is such that very deep alte- rations of this organ may not entirely destroy sensibility. — The gray matter of the spinal cord seems to have an important share in the transmission of the orders of the will to muscles. — The anterior columns of the spinal cord in the upper part of the cervical region have but a slight participation in voluntary movements, and the lateral columns, with the surrounding gray matter, in that part of the cord, are almost the only channels between the will and muscles. Mr. President and Gentlemen : I hope I shall be able to show, in one of the succeeding lectures, that the various sensitive impres- sions — of touch, of pain, of temperature, of muscular contractions, etc. — are transmitted by conductors which are quite distinct from one another, and so much so that the conductors of painful impres- sions, for instance, are not more able to convey other kinds of im- pressions than to transmit the orders of the will to muscles. This view appears to be positively established by pathological cases ob- served in man. I hope I shall now be allowed to make use of this view as if it were proved, and I will examine if the conductors of tactile impressions follow the same course in the spinal cord as those of painful impressions. I will, at first, relate experiments which seem to solve the following question: Do the conductors of tactile impressions proceed to the encephalon along the posterior columns, or do they pass into the gray matter as the conductors of impressions of pain ? After having divided transversely the two posterior columns of the spinal cord in the dorsal region, in a dog, we cover its eyes and wait until it has lain down in a state of quietness. When it seems to be perfectly quiet, we find, if we gently touch the skin of one of 40 THE CENTRAL NERVOUS SYSTEM. its hind toes, that it lifts up its head and tries to see what is the cause of the irritation. It is certainly difficult to decide what kind of sensation this dog has felt, but I think I may show that it is a tactile sensation. Before discussing this point, however, I must say that it is not in consequence of a local reflex movement, shaking the whole body, that the animal looks anxiously around it. If it were so, the movement of the head would not take place imme- diately after the irritation and at the very same time that the irri- tated leg is withdrawn. Besides, after a complete transversal sec- tion of the spinal cord, when reflex movements are much stronger than after a section of the posterior columns, the head of the animal does not move at the time we touch the under part of its hind toes. Therefore the dog, in our experiment, moves its head because the touching of its toes has directly given a sensation. When we think that there is a real hyperesthesia in these toes, it seems possible that the simple touching of the toes is painful; but the hyperses- thesia, I think, is not of a sufficient degree for the production of pain from such a trifling cause. Still more, the touching of other parts of the skin of the posterior limbs, which are endowed with the same morbid power of causing pain as the skin of the toes, is not followed by a movement of the head; so that it becomes very probable that the effect following the touching of the toes depends upon the propagation of a tactile impression to the encephalon, the skin of the toes being endowed with more tactile sensibilitv than that of the legs. The posterior columns, therefore, seem not to be the only channels of the tactile impressions. Another experiment goes farther, and seems to prove positively that the posterior columns do not transmit directly any part of the tactile impressions to the sensorium. If we divide transversely, in the dorsal region, the whole of the spinal cord, except the posterior columns, the touching of the sole of the foot is not followed by any sign of feeling, and the head, if the eyes are covered, remains quiet. At times, however, it happens that the animal moves its head and its anterior limbs, because it has been shaken by the strong reflex movements which are produced in the paralyzed limbs. In this case reflex movements are always more energetic than after a complete section of the cord, and very much more than after the section of the posterior columns. From the above facts it seems to result that the transmission of tactile impressions to the encephalon does not take place along the posterior columns. Other experiments, useless to be mentioned, CONDUCTION, ETC., OF TACTILE IMPRESSIONS. 41 show that the gray matter of the spinal and probably also the anterior columns are the channels of conveyance of the tactile im- pressions to the encephalon. We shall not insist upon the demon- stration of these conclusions now, as we shall again have to ex- amine their value when we compare the results of experiments with the results of pathological alterations of the spinal cord in man. We will then try to show the disagreement between these results and a theory recently proposed by Mr. Moritz Schiff, according to which the posterior columns of the spinal cord are the channels for tactile impressions, and the gray matter the conductor of painful impressions. 1 We will now say a few words on the decussation of the conduc- tors of tactile impressions. If a lateral half of the spinal cord has been divided transversely in the dorsal region, we find that when we touch the sole of the foot of the posterior limb on the side ope- rated upon, the animal raises its head and tries to look at the place irritated (in which attempt it cannot succeed, as its eyes are covered). On the opposite side the touching of the skin of the toes does not produce the least effect. It seems therefore that the conductors of the tactile impressions decussate in the spinal cord, as well as that of pain- ful impressions, so that the right side of this organ transmits to the sensorium the impressions which come from the left side of the body, and vice versd. We will add that the experiments which show that the conductors of these two kinds of sensitive impres- sions decussate in the spinal cord are in opposition to the view that the posterior columns are the channels for both these kinds or for either of them, as it is well known that these two columns have no communication one with the other unless it be through the other parts of the cord. The question relative to the place of passage in the spinal cord, of the impressions of temperature, and of some other kinds of im- pressions, cannot be solved positively by vivisections. We can say, however, that after a transverse section of the whole spinal cord, except the posterior columns, in the dorsal region, the application of ice or of fire to the toes, seems not to be felt, and that also spasms may be induced in the muscles of the paralyzed legs with- out causing a sensation. It seems, therefore, that the posterior columns are not the channels of transmission of these impressions. 1 Untersuolmngen zur Naturlehre des Mensclien und der Thiere. Von J. Mole- schott. Vol. iv. pp. 84-87. 1858. 42 THE CENTRAL NERVOUS SYSTEM. Some experiments also seem to show that the conductors of these impressions decussate in the spinal cord. But pathological facts observed in man will teach us much more concerning all the sensi- tive impressions which are not purely painful, than experiments upon animals. In consequence, we shall postpone also, till we come to pathological facts, what relates to this question: Is it possible to recognize the place upon which an impression is made, when the posterior columns of the spinal cord are divided or altered ? We will merely say, at present, that animals, after a section of the posterior columns or of a lateral half of the spinal cord, seem to discover the point irritated, as, although their eyes are covered, they try to bite near the place upon which a painful irritation has been produced. I pass now to another and capital question, the solution of which will explain a great many mysterious pathological cases observed in man: How is it that sensibility is not lost and is only more or less diminished, although the spinal cord is deeply altered? This question seems to be solved by the following experiments : If we divide transversely the posterior columns in the upper part of the lumbar region in a mammal, we find that there is hyperesthesia everywhere behind the section ; if, then, we divide the posterior parts of the lateral columns and the posterior gray horns, we find that the hyperesthesia increases also everywhere behind the section. If the section is carried farther, so that the whole posterior half be divided transversely, the posterior part of the gray matter, behind the central canal, being cut, the hyperesthesia remains excessive everywhere behind the section. When another section is made, cutting a little more of the central gray matter, the hyperesthesia disappears from everywhere at once, and a certain degree of anes- thesia appears also everywhere behind the section. At last, if the whole of the central gray matter be divided, with also a good part of the basis of the anterior horns, sensibility is very much diminished everywhere behind the division, and it disappears entirely everywhere at the same time when the section has left only the anterior parts of the anterior columns. 1 The general result of this experiment is, 1 I must say that it is absolutely impossible to know, while we make a section of parts of the spinal cord, what is the precise depth of the injury ; it is mere guess- work. But if we study well the phenomena, and then, after having killed the animal, if we put the spinal cord in alcohol, we render it hard, and we can ascer- tain exactly what is the extent of the incision. This is the means that I always ARRANGEMENT OF SENSITIVE CONDUCTORS. 48 that any change that takes place in the state of sensibility — either an increase or a diminution — shows itself everywhere, at the same time, behind the section. If we now examine what might be the disposition of the con- ductors of sensitive impressions, in the spinal cord, we find that either they might be scattered without any order at all, or they might have one or the other of these two kinds of arrangements: 1st. They might be disposed in such a manner that the anterior parts of the body, the middle parts and the posterior parts, would each have a peculiar place in the cord. 2d. They might be arranged so that each small portion of the conducting part of the cord would contain conducting elements from the anterior, the middle, and the posterior parts of the body. Now, if we take the results of the above experiments, we find that they agree with this last supposi- tion, and not with the others. If there was no order in the dispo- sition of the elements conducting sensitive impressions, in the spinal cord, we should not have found changes taking place exactly in the same measure in all the parts of the body behind the section — i. e., in the skin, in the trunks of nerves, in muscles, and in the viscera of the abdomen. If the anterior parts of the body had their con- ductors of sensitive impressions crowded together, as well as the posterior and middle parts also, we should have found that certain sections produced anaesthesia in certain parts, and not in others, while on the contrary we find anaesthesia, when it first appears, be- ginning everywhere at the same time, and when it increases, and also when it becomes complete, we find that it is so everywhere. We must, therefore, admit that elements representing the various parts of the body exist in the various portions of the spinal cord from behind forwards in the conducting zone of this organ. This explains clearly why a complete loss of sensibility is so rare in dis- eases of the spinal cord. What we have said of the various parts of the body considered from the posterior to the anterior surface, we can say also of the various parts of the body considered transversely. We have shown that the left side of the spinal cord is the conductor of sensitive impressions coming from the right side of the body, and vice versa. Let us now examine what takes place in the right posterior limb employ in my experiments, and it is also the means employed by the Committee appointed by the Societe de Biologie, in 1855, for the investigation of my researches on the spinal cord. 44: THE CENTRAL NERVOUS SYSTEM. when we divide the left side of the spinal cord. We find that, after a division of a part of the left lateral column, there is no diminu- tion of sensibility anywhere in the right limb; if the section is deeper, and involves a part of the gray matter, with the whole of the left lateral column, sensibility is diminished everywhere in the right posterior limb; if the section is still deeper, so that there re- mains only a very slight part of the central gray matter, or of the anterior column on the left side, sensibility is then much more diminished everywhere in the right posterior limb, and, as in the preceding case, the same degree of diminution exists in all the parts of this limb. At last, when the whole of the left side of the cord has been divided, there is only in the right limb the false appear- ance of sensibility which has been explained in the preceding lec- ture. It results from these facts, that the various parts of this limb, the outside parts, the inside parts, and the middle parts, are not represented in the left side of the spinal cord by conductors of sen- sitive impressions disposed in distinct layers; because, had it been so, the diminution of sensibility, instead of being gradual every- where, and appearing in all the parts at the same degree, would have taken place in one part more than in another, after some of the sections. It seems, therefore, that transversely, as well as in the direction from behind forwards, the spinal cord, in the various parts of the conducting zone, contains fibres or other elements, conductors of sensitive impressions coming from the various parts of the body, one lateral half of the cord, however, being the agent of transmission for the opposite lateral half of the body. If, for instance, we imagine that there are a thousand conducting elements coming from a small part of the right side of the body, in the left half of the spinal cord, they are scattered in all the parts of the conducting zone of this half, so that to divide them all, a section must divide the whole of this zone. In other words, we can saj r , that every small portion of the conducting zone in a lateral half of the spinal cord contains conductors of sensitive impressions coming from all the points of the body on the opposite side, which are behind the place of this small portion. We can say, also, that the sensitive impressions made on any point of a lateral half of the body are transmitted to the sensorium by conducting elements, distributed in all the parts of the lateral half of the spinal cordon the opposite side. This view, which explains the so frequent persistence of sensi- bility in cases of disease of the spinal cord, is entirely different from that of Stilling and others who admit that a part of gray matter in TEANSMISSION OF THE OKDEES OF THE WILL. 45 one half of the cord is sufficient for the transmission of sensitive impressions from both sides of the body. We pass now to the transmission of the orders of the will to muscles through the spinal cord. It is by far very much more difficult to determine what are the parts of this organ employed in voluntary movements than to find out what are those through which the sensitive impressions are transmitted. I have long been in doubt in this respect, and even now, after having carefully watched a great many animals, on the spinal cord of which certain altera- tions had been made, and after having read a great many patholo- gical cases, I still hesitate as regards various points. I will try in this lecture to show what seems to be positive, and I will also point out some of the questions that seem not to have yet been solved. It is very well known that Sir Charles Bell did not give any proof of the idea that he seems to have entertained all his life, that the anterior columns of the spinal cord are the only channels by which the will exercises its power on muscles. Most of the physio- logists who have experimented on this subject admit that a trans- versal section of the anterior columns is a cause of paralysis. Stilling alone does not admit the exactitude of this assertion. Various experiments which I will relate show how difficult it is to decide most of the questions on this subject. If we divide transversely, in the dorsal region, the two posterior columns of the spinal cord in a mammal, we find that its voluntary movements seem not to be at all disturbed or diminished. If in another mammal we divide transversely the whole of the spinal cord, except the posterior columns, we do not find the least appear- ance of a voluntary movement in the muscles which receive their nerves from the parts of the spinal cord which are behind the sec- tion. So far, therefore, as the posterior columns alone are con- cerned, we arrive at a positive, and, I think, undeniable conclusion, which is, that the posterior columns of the spinal cord are not directly employed in the conveyance, of the orders of the will to muscles. If we compare this conclusion with this well-known fact, that there are several, I may even say many, pathological cases, showing that in man an alteration of the posterior columns has caused nothing but a loss or a diminution of voluntary and reflex move- ments, we find an appearance of contradiction which in reality, how- ever, does not exist, as I will show in another lecture. After having divided transversely the two posterior columns as in the preceding experiment, if we divide a part of the lateral 46 THE CENTRAL NERVOUS SYSTEM. columns and the posterior gray horns (see 1, Fig. 13), we find that there is an evident, although very slight diminution of voluntary movements. But now, if instead of dividing this part of the spinal cord, we divide the whole of this organ, except this part, we find that voluntary movements are completely lost. It seems, there- fore, that there are some conductors for voluntary movements in either the posterior horns or the posterior part of the lateral columns, or in both ; but it appears also that there is but a small number of such conductors in either of these parts. If we divide transversely, in the dorsal region, the whole pos- terior half of the gray matter, and a part of the lateral columns, besides the posterior columns (see 2, Fig. 13), we find that the voluntary movements are much diminished in the abdominal limbs. If the division is carried farther, so that the whole of the central gray matter be divided (see 3, Fig. 13), the animal can hardly move its abdominal limbs; and if we add to this section that of the anterior horns of gray matter, the loss of voluntary movements seems to be complete. These experiments seem to lead to the conclusion that the ante- rior columns of the spinal cord are not at all employed in voluntary movements; but now, on the other side, if we divide only the ante- rior columns in the dorsal region, we find voluntary movements almost entirely lost, in the abdominal limbs — a fact which seems to prove that the anterior columns are the principal channels for the orders of the will to muscles. Besides, if we compare the results of the two experiments represented in Fig. 13, at 3 and 4, we find in the case of a section of little more than the posterior half of the spinal cord, that voluntary movements are almost entirely lost : while, in the case of a section of less than the anterior half (see 4, Fig. 13), voluntary movements seem to be entirely lost. We do not see any other way of explaining these various results except in admitting, what seems to be proved by thousands of pathological cases and vivisections, that voluntary movements require very powerful excitations from the nervous system upon muscles, and that when one-half or one-third of the normal amount of excitation is missing, what remains is insufficient. If we add to the preceding experiments that any injury to the central gray matter, and that a deep injury to the lateral columns. in the dorsal region, always produce a diminution of the voluntary movements, we are led, by all the facts we have mentioned, to the conclusion that, in the dorsal tegion, the various ^ar/s of the spinal DECUSSATION OF VOLUNTARY MOTOR CONDUCTORS. 47 cord, except the posterior columns, seem to be employed in the conveyance of the orders of the will to muscles. Now, as regards the question, which of these parts of the spinal cord is the principal channel for the orders of the will ? we cannot give a very positive opinion. We can, however, state that of these three parts — the lateral columns, the anterior columns, and the gray matter — each of the last two seems to have a greater share in this function than the first. Besides, the gray matter appears to have as great a share as the anterior columns, and in the gray matter the most important parts seem to be those in the anterior half of the cord. In the upper part of the cervical region of the spinal cord, near the crossing of the anterior pyramids, the results of experiments on the various parts of the spinal cord are very different from those of the same experiments in the dorsal region. In that part of the cervical region it is the section of the lateral columns, and of the part of the gray matter placed between the anterior and the lateral columns, which produces the most decided effect on voluntary movements — viz., a complete paralysis. The section of the anterior columns alone, when it has been made without a notable injury of the neighboring parts, causes a diminution of voluntary move- ments, which is by far not so considerable as after a section of these columns in the dorsal region. The section of the posterior columns and of the posterior parts of the gray matter in the cervi- cal region hardly causes a diminution in the energy of the volun- tary movements. From these results we conclude that in the upper part of the cervical region of the spinal cord, near the medulla oblongata, most of the conductors of the orders of the will to muscles are in the lateral columns and in the gray matter between these and the anterior columns. Is there any decussation of the voluntary motor conductors in the spinal cord? The celebrated experiments of Galen, which we have already mentioned, seem to answer positively that there is no such decussation. Haller (Elem. Phys., vol. iv. p. 326) says: "Alte- rius demum lateris musculi resolvuntur, si climidiam medullam spinalem dissecueris." It is probable that his assertion in this case was not grounded upon any experiment made by himself. He quotes as his authority Galen, who had said the reverse, and Oribase, who seems to have copied Galen. In the same volume of his great work {loco cit., p. '334), Haller gives the very opposite assertion. He says: "Id latus corporis resolvitur in quo ea medulla vulnus 48 THE CENTRAL NERVOUS SYSTEM. passa est aut pressionem." In the experiment already quoted, which was made by Sir Astley Cooper on the cervical part of the spinal cord of a dog, the section of a lateral half of this organ produced a loss of voluntary movements in the corresponding side of the body. Most of the living experimenters agree upon this fact that such a section causes paralysis only on the side injured. I have ascer- tained, a great many times, that this is not entirely right. There is always, even in mammals, after a transversal section of the whole of a lateral half of the spinal cord, at least some appearance of voluntary movements in the side of the injury, and always also a diminution of voluntary movements in the opposite side ; so that, in animals, there seems to be in the spinal cord a decussation of a few of the voluntary motor conductors. As there seems to be no such decussation in man, at least according to several pathological facts, we shall not insist on its existence in animals. We have now to say a few words on a theory which was first proposed by Bellingeri, 1 and had the good fortune of being accepted by an eminent physiologist, Professor Valentin, of Bern. 2 Accord- ing to these experiments, the motor nerve-fibres which go to the extensor muscles pass in the posterior columns, while those which go to the flexor muscles pass in the anterior columns. AYe have already said that a section of the posterior columns does not pro- duce any kind of paralysis, so that they are not more for extension than for flexion. But the question remains whether the other pos- terior parts of the spinal cord are, or are not employed for one of these kinds of movements more than for the other. To solve this question, we divide, in the dorsal region, the posterior half of the spinal cord (see 2 and 3, Fig. 13) in a mammal, and nearly the whole of the anterior half of this organ in another (see 4, Fig. 13); and we find that all the muscles seem to be almost completely paralyzed in the abdominal limbs, the flexors as much as the ex- tensors, in the two animals. If some pathological facts observed in man, and of which we will speak in another lecture, appear to be different from these facts, we will show that there was in them an irritation, and not a destruction or a section, of certain parts of the spinal cord or of its nerves. As regards the place of passage of the voluntary motor conduc- tors in the medulla oblongata, I will now say only a few words. 1 De Medulla Spinali Nervisque ex ea Prodeuntibus, &c. Torino, 1823. 2 De Functionibus Nervorum Cerebralium, &c. 1839. DECUSSATION OF MOTOR CONDUCTORS. 49 The crossing of the anterior pyramids I shall try to prove by and by to be very nearly the only one for the conductors for voluntary movements. I will merely state now that if a section is made longitudinally just at the place of the decussation of the anterior pyramids, so as to divide entirely all the decussating elements, we find that, although the animal lives some time after the operation, it has no voluntary movement at all in any of its limbs, which are almost always the seat of convulsions. A section of the two ante- rior pyramids is followed by the same results, while a section of the olivary columns, which are chiefly the continuation of the anterior columns of the spinal cord, does not seem to produce a notable paralysis ; so that the greatest difference exists between the spinal cord and the medulla oblongata, as to the place of passage of the voluntary motor conductors. From the facts we have related, concerning voluntary movements, we think it may be concluded that the idea that there are two columns of the spinal cord (the anterior) alone employed in the. production of these movements, must be completely abandoned. It is extremely probable that the voluntary motor conductors pass in the anterior pyramids, and, after having made their decussation, pass chiefly in the lateral columns of the spinal cord and in the gray matter near these columns, and, at last, that, after a short dis- tance, a number of these conductors leave the lateral columns to pass into the gray matter and into the anterior columns. As regards the practical deductions from the various facts we have related, concerning the channels of sensitive impressions, and of the orders of the will to muscles, they will be discussed in the future lectures. 50 LECTURE Y. CONCLUSIONS FROM THE FACTS MENTIONED IN THE PRECEDING LEC- TURES, AND PATHOLOGICAL CASES SHOWING THAT THE TRANSMIS- SION OF SENSITIVE IMPRESSIONS SEEMS NOT TO TAKE PLACE THROUGH THE POSTERIOR COLUMNS OF THE SPINAL CORD. Conclusions from the results of the Lecturer's experiments concerning the trans- mission of sensitive impressions and of the orders of the will to muscles, in the cerebro-spinal axis. — Agreement between the three principal sources of our knowledge concerning the spinal cord considered as a conductor of sensitive impressions and voluntary movements : i.e., anatomy, experimentation upon animals, and pathological cases observed in man. — Hyperesthesia or conserva- tion of sensibility after injury to the posterior columns. Mr. President and Gentlemen : In the preceding lectures I have related a great many experiments which have given results, or which may lead to conclusions, some of which I have already mentioned, while there are others of which I have hardly spoken. It will be useful now to give, together, most of these conclusions or results, before I relate the pathological cases which seem to con- cur with ray experiments in proving the exactitude of these facts or deductions. I will mention most of them without discussion, and say only a few words in the way of explanation about two or three of them. 1st. The laying bare of the spinal cord, and its free exposure to the action of the atmosphere, instead of being a cause of loss or diminution of sensibility, as has been said, seems to be followed by a marked increase of sensibility in the parts of the body which are behind the point where the cord is exposed. 2d. The laying bare of the spinal cord, even in mammals, is very rarely followed, even after a number of days, by any kind of accident (meningitis, myelitis, &c.) producing a diminution of sensibility. 3d. The posterior columns of the spinal cord are not, as has been imagined, a bundle of fibres, from the posterior roots of the spinal nerves, going up to the encephalon. CONCLUSIONS IN REGARD TO THE SPINAL CORD. 51 4th. The restiform bodies are not a collection of fibres, chiefly from the sensitive nerves of the various parts of the body, going up to the encephalon, and, therefore, the cerebellum is not the recipient, through the restiform bodies, of most of the sensitive fibres of the trunk and limbs. 5th. The hyperesthesia which appears in all parts of the body, behind deep injuries to the posterior columns of the spinal cord, is always more marked than that which is due to the mere laying bare of this nervous centre. 6th. All parts of the encephalon which are situated in its pos- terior or superior side are like the posterior columns of the spinal cord, in this respect — that a marked degree of hyperesthesia always follows a transverse section upon any of them. (If a complete transverse section is made upon any part of the restiform bodies, sensibility becomes very much increased in every part of the trunk and limbs. Hyperesthesia is also, but in a less degree, one of the results of a transversal incision in the cerebellum, in the processus cerebelli ad testes, and in the tubercula quadrige- mina.) 7th. A section of either the anterior or the lateral columns is followed by a certain degree of hyperesthesia. 8th. The hyperesthesia is greater after a section of the posterior columns and the posterior horns of gray matter and the neighbor- ing parts of the lateral columns and central gray matter, than after a section of any other part of the spinal cord. 9th. The power of transmission of a nervous excitation, for either sensation or movement, may exist in parts of the nervous system which are not excitable. 10th. The posterior columns of the spinal cord are much less sensitive than they are said to be, and it even seems that their apparent sensibility depends upon the fact, that when they are irritated, the posterior roots, which are very sensitive, are also more or less irritated. 11th. The restiform bodies seem to be deprived of sensibility to mechanical excitation. 12th. Of the fibres sent to the spinal cord by the posterior roots, some go transversely, which do not seem to be employed for the transmission of sensitive impressions. Others go upwards and others downwards, both of which are conductors of sensitive im- pressions. These two sets of conductors, the ascending and the descending, seem to go ultimately into the central gray matter of 52 THE CENTRAL NERVOUS SYSTEM. the cord or into the anterior columns, after having, for a short dis- tance, passed through the posterior columns, and most likely also through the lateral columns and the posterior gray horns. 13th. The transmission of sensitive impressions to the encephalon takes place chiefly in the central gray matter of the spinal cord, and for a small part in the anterior columns. 14th. The decussation of the conductors of sensitive impressions, coming from the various parts of the trunk and limbs, does not take place in the upper part of the pons Varolii nor beneath the tubercula quadrigemina, nor in the medulla oblongata, as it has been imagined. It takes place in the spinal cord in the case of sensitive impressions conveyed by the posterior roots of the spinal nerves. 15th. The decussation of the conductors of sensitive impressions in the spinal cord takes place very near their place of entrance into this organ, some above and others below this place. 16th. The transmission of sensitive impressions through the spinal cord takes place in certain definite directions, and not, as several German physiologists have thought, in almost every direction. 17th. Every small portion of a transverse section of the conduct- ing zone, in a lateral half of the spinal cord, contains conductors of sensitive impressions coming from all the points of the body, on the opposite side, which are behind the place of this small portion. 18th. The sensitive impressions made on any point of a lateral half of the body are transmitted to the sensorium by conducting elements, distributed in all the parts of the lateral half of the spinal cord on the opposite side. (This conclusion and the preceding explain why the transmission of sensitive impressions is so rarely lost in pathological alterations of the spinal cord, and also why the degree of diminution of sensi- bility in those cases is nearly in the same degree in almost all the parts where it exists.) 19th. Most of the elements which are emplo} 7 ed as conductors of the purely tactile impressions, seem to pass by the same parts of the spinal cord as those which transmit the impressions which pro- duce pain. 20th. The posterior columns of the spinal cord are not directly employed in the conveyance of the orders of the will to muscles. 21st. The gray matter of the spinal cord seems to have an im- portant share in the conveyance of the orders of the will to muscles. 22d. The lateral columns of the spinal cord have a notably greater share in the conveyance of the orders of the will to muscles CONCLUSIONS IN REGARD TO THE SPINAL CORD. 53 in the upper parts of the cervical region than in the dorsal and lumbar regions. 23d. The anterior columns of the spinal cord everywhere except in the upper part of the cervical region have a great share in voluntary movements. 24th. The decussation of the conductors for voluntary movements in animals seems to take place chiefly, but not entirely, where the anterior pyramids cross each other. "When we compare the conclusions above mentioned with the results of recent microscopical researches on the structure of the spinal cord, we find that they agree very well as regards several of the main points. We shall not insist upon this subject here, but we must say a few words on the descending fibres which enter the cord with the posterior roots, and we must also speak of the decus- sation of the conductors of sensitive impressions. As regards the descending fibres, the existence of which we had been led to admit nearly six years ago, 1 we will refer our hearers to the second of the important papers of Mr. J. Lockhart Clarke, 2 in which these fibres are described and represented (Plates XXIII. and XXIV.). Vivisections show that there is but a slight decussation of the conductors for voluntary movements in the spinal cord in animals, while pathological cases seem to show that there is no decussation in man of these conductors in this organ at all. Anatomy, how- ever, teaches that the anterior roots send a large part of their fibres transversely across the cord, so that many fibres of the anterior roots of the left side decussate with as many fibres of the anterior roots of the right side. The teachings of experimentation and of pathology are both opposed to our admitting that these decussating fibres are all voluntary motor conductors. It seems extremely probable that many of these fibres are employed for reflex move- ments. How is it that there is not an evident decussation of many, if not all, the fibres of the posterior roots in the spinal cord ? Vivisec- tions, and, as we shall show, pathological cases establishing posi- tively the necessity of admitting the existence of such a decussation, it seems certainly strange that we do not see a manifest and con- 1 See Boston Med. and Surg. Journal, Nov. 1852. 2 Transactions of the Royal Society, 1853. See also my Journal de Physiologie, No. I., Janvier, 1858, Plate I. 51 THE CENTRAL XERVOUS SYSTEM. siderable decussation between the continuations of the fibres of the posterior roots in the spinal cord. It may be that some of the fibres which cross each other in front of the central canal of the cord are not, as now admitted, fibres of the anterior roots, but fibres of the posterior ones, which, after having passed obliquely from the posterior parts of the cord into the anterior, become trans- versal there, and pass horizontally into the other lateral half of the cord. But, whatever may be true in this respect, there are con- ductors connected by means of cells with the fibres of the posterior roots, and they pass from one lateral half of the cord into the other one. They have been seen and described, and represented more or less clearly, by most of the micrographers who have recently pub- lished papers and plates on the organization of the spinal cord. "We will name only E. Wagner, Lenhossek, Schrceder Van der Kolk, Bidder and his pupils (Kupfer, Owsjannikow, Metzler) Still- ing, and Gratiolet. According to the actual teachings of micro- scopical examinations of the spinal cord, many of the fibres of the posterior roots reach the cells of the gray matter on their own side, and these cells send fibrils to cells which are in the other half of the spinal cord, and these last cells send fibrils upwards towards the encephalon. This organization is assuredly sufficient to explain the crossed transmission of sensitive impressions. Omitting the representation of the cells, we give a diagramatic view of a transversal section of the spinal cord. (See Fig. 14.) The fibres of the posterior roots are seen to pass through the gray mat- ter into the posterior and the lateral columns. It is necessary to understand that most of them do so only after having been in com- munication with cells, or, rather, that we consider the fibrils ema- nating from cells as the continuations of the fibres of the posterior roots in connection with them. Pathological cases, as I will now begin to show, bear out almost | all the conclusions I have just related, and they are not in oppo- sition to those few conclusions which they do not prove. Experi- ments on animals could not lead to certain conclusions which I shall be able to draw from some of the pathological cases I intend relating. I shall first examine what are the effects of alterations or injuries to the posterior columns of the spinal cord. It is necessary, in the first place, when discussing the principal circumstances of these | cases, to take notice of the extent of the injury. In the experiments I have mentioned, after a transversal section of the posterior columns ILLUSTKATIVB PATHOLOGICAL CASES. 55 there is hyperesthesia in the parts of the body which are behind the section ; the same thing exists in man, after either a section of the posterior columns, or pressure by a tumor, a piece of bone, &c. But there is much less hyperesthesia when the posterior columns are altered in a great part of their length, even when the posterior roots and the gray matter remain normal, and this is explained by the fact that many conductors of sensitive impressions, which pass for a short distance in these columns, are injured, and, although the same causes of hyperesthesia exist then, as after a simple sec- tion, this excess of sensibility does not show itself, on account of the diminution of sensibility due to the alteration of the posterior columns. There is, then, a kind of compensation between the causes of hyperesthesia and those of anesthesia, so that the degree of sensibility remains nearly normal. In cases of alteration occupying a great length of the posterior columns, there is a notable diminution in the power of standing and of walking, and when the affection has lasted long, there may be a complete loss of these powers. The causes of this weakness are : 1st. That the posterior columns, as we shall show hereafter, are the principal channels for the excitations which produce reflex movements, so that when they are altered there is a great diminu- tion of these movements, and as they are absolutely necessary for the actions of standing up or walking, it seems very plain that these actions become lessened when the posterior columns are altered. 2d. That after a time, when an alteration exists in these columns, the amount of power of action in the other parts of the spinal cord diminishes. Besides these two causes of weakness of the lower limbs, there are others, when, with the posterior columns, the posterior roots of nerves and some parts of the gray matter and of the lateral columns are altered. This was the case in the pathological facts which Longet has collected to establish his view, that the posterior columns are the only channels of sensitive impressions in the spinal cord. AVe will show that the case he relates cannot give such a proof; and, still more, that in some respects there is a disagree- ment between the views he held and the facts he mentions. Case 1. — L was admitted in December, 1823, at Bicetre, for an extreme weakness of the lower limbs, which could hardly bear the weight of the body. In 1825, his limbs, which were atrophied, when not prevented doing so, had automatic and irregular move- 56 THE CENTRAL XERVOFS SYSTEM. ments, which the patient could not control. Sensibility was abso- lutely lost everywhere except in the face. He did not feel the coldest objects. Autopsy. — The whole encephalon without alteration. From the origin of the spinal cord to its termination, its posterior half, in- clusive of the gray matter, as far as the central commissure, was con- verted into a yellow, transparent substance, shining like a solution of gum, and resembling gelatin or softened horn, without any appearance of organization. The rest of the cord was perhaps harder than the pons Varolii is normally, but it had no other alteration. The anterior roots were normal. The posterior roots were of a yellow- grayish color ; they shared the alteration of the corre- sponding part of the cord. (Hutin, cited by Longet, Traite tVAnat. et de Physiol, du Syst. Xerv., 1843, vol. i. p. 346.) This fact is certainly in opposition to the views of Longet and of those who contend that the antero-lateral columns of the spinal cord are the only channels for the orders of the will. Before the appearance of choreic movements in this case, there was an extreme weakness in the lower limbs, and the antero-lateral columns were not altered, except that they were a little harder than in a perfectly normal condition. The loss of sensibility cannot account for this weakness. In cases of complete anaesthesia without paralysis of movements, as we shall show hereafter, there is no weakness, but a difficulty or a complete impossibility of guiding the voluntary move- ments, unless the patient looks at the limbs, in which case he can execute any movement. In the above case the lower limbs could hardly bear the weight of the body ; it is not so with patients who have lost only sensibility. As regards the value of the case for the question at issue in relation to the transmission of sensitive impressions, the posterior roots being altered, the case cannot prove anything concerning the posterior columns. Dr. E. B. Todd 1 has already, with great pro- priety, stated' that in cases capable of proving anything in this re- spect the posterior columns must be altered, while the posterior roots and the antero-lateral columns are not. To this we will add that the gray matter also must not be altered. Case 2. — A woman, partially paralyzed of sensibility and mo- tion, dies from a disease having no relation to the paralysis. 1 Cyclopaedia of Anatomy and Physiology, vol. iii. p. 721, P. ILLUSTRATIVE PATHOLOGICAL CASES. 57 Several times I had endeavored to make her walk ; but her in- ferior limbs gave way, and were entirely unable to support her. Autopsy. — The two posterior columns are converted into a soft gray-pinkish pulp, rich in bloodvessels. The alteration diminished gradually from the lower to the upper regions of the spinal cord, and it stopped at about an inch from the nib of the calamus. In the lower part of the cord the alteration had begun to invade the lateral columns in the neighborhood of the posterior ones. The posterior roots of nerves were very thin, particularly in the lower part. The rest of the spinal cord was perfectly healthy. The whole en- cephalon was in the most perfect condition. (Cruveilhier, cited by Longet, loco cit., vol. i. p. 347.) In this case, also, we find the posterior roots altered, and, there- fore, the diminution of sensibility cannot be attributed to the state of the posterior columns. As regards movements, we see here that the lower limbs were not able to bear the weight of the body, although the alteration had attacked only a very small part of the lateral columns besides the posterior. Case 3. — M , for two years paralyzed. In the beginning, numbness in the lower limbs. Afterwards, a numbness and half- paralysis appeared in the upper limbs. To keep a needle between her fingers she must look at them. Motion is diminished; all the movements are executed, but they are weak, and cannot accomplish the functions for which they are designed. The lower limbs, which she can move when in bed, are not at all able to serve for the verti- cal position. Autopsy. — Spinal cord small ; a pseudo-membrane on the hind part of the cord ; gray degeneration of the posterior columns of the cord; atrophy of the posterior roots of nerves. (Cruveilhier, cited by Longet, loco cit., vol. i. p. 349.) Here, again, the posterior roots were altered. There was also such a weakness that the patient could not stand, although it is stated that the antero-lateral columns were no otherwise altered than is implied in the statement that the spinal cord was small. There were here all the circumstances which, in such cases, usually cause the impossibility of standing on the lower limbs. Case 4. — Miss G , admitted at the Salpetriere, in 1825, died in 1835, having never been out of bed during these ten years. After several years, during which there was numbness and difficulty 58 THE CENTRAL NERVOUS SYSTEM. of walking, the patient was confined to bed. When observed last, she had disordered involuntary movements, which she could not control. When not prevented by the bed sheets, the lower limbs were agitated by the most violent and irregular movements. These convulsions were produced when the patient attempted to move voluntarily. The upper limbs were less attacked than the lower. The muscles of the face, of the larynx, and those employed in de- glutition and respiration, shared also in the disorder. Sensibility was very obtuse; pinching and pricking were perceived, but very slightly. To hold a pin between her fingers she must look at them. She did not feel an eschar on the sacrum. Autopsy. — Eed softening of the occipital circonvolutions of the left side of the brain. Brain otherwise healthy, as also the cerebel- lum and medulla oblongata. The spinal cord was atrophied, and reduced to two-thirds of its ordinary volume. The posterior median columns were transformed into a gray -yellowish, indurated strap all along the spinal cord, and extending into the middle of the cere- bellum. In the spinal cord, the alteration is confined only to the median posterior columns, while the antero-lateral columns were perfectly healthy. The posterior roots of the spinal nerves were com- p)letely atrophied; they were transparent, filiform, and quite different from the anterior roots, which had their normal appearance and volume. (Cruveilhier, cited by Longet, loco cit., vol. i. p. 355.) In this case, the posterior roots were altered with only a part of the posterior columns — the median columns. It is strange, to say the least, that such a case has been presented, as proving that the posterior columns are the only channels for sensitive impressions ! We will point out the atrophy of the spinal cord as being a suffi- cient cause, with the choreic movements and the alteration of the posterior roots, to prevent walking and standing. Case 5. — A woman had, at first, a numbness which rendered her walking similar to that of a drunken man. She had frequent falls, and in one of them she broke her leg. Three months afterwards she was paraplegic. The fracture had not been painful. On admission, she had a complete loss of sensibility in all the parts of the body below the epigastric region ; but she felt pain in the bones and in the joints of the lower limbs. Frequently she had cramps, which were painful and made her shriek. Pinching and pricking were not at all perceived. In bed she executed all the movements of exten- ILLUSTRATIVE PATHOLOGICAL CASES. 59 sion and flexion of the lower limbs; but when put on her feet and held up by two persons, she was hardly able to make use of her limbs to support herself. Hardly could she move these limbs to go for- ward ; they gave way, crossing each other. In the upper limbs sensibility was diminished, not lost ; voluntary movements were nearly perfect. Autopsy. — Brain perfectly healthy. The alteration of the spinal cord was exactly limited to the posterior columns, and consisted in the transformation of the posterior columns into a gray-yellowish transparent substance. It occupied the whole extent of these columns in the lumbar and dorsal regions; but it became narrower and occupied only the median columns in the cervical region. The antero-lateral columns and the gray matter were perfectly healthy. (Cruveilhier, cited by Longet, loco cit., vol. i. p. 351.) In this case there is no mention at all of the state of the posterior roots. The case, therefore, cannot be of use. It would be if it had been stated that the posterior roots were healthy. Perhaps it will be urged that, had they been found in an abnormal condition, Cruveilhier would have stated the fact, and that his not having spoken of these roots is a proof that they were in a normal condi- tion. This is no proof at all, as Cruveilhier usually speaks of the healthy parts as well as of the altered ones, and in the case we are examining, he states that the brain and certain parts of the spinal marrow were healthy. At any rate we shall bring forward so many facts showing that the posterior columns are not the channels for sensitive impressions, that it will become evident that, in this case, the posterior roots of nerves must have been altered. The five cases above related are all those which Longet has pub- lished in proof of his views. It is pretty evident, from the exami- nation of the circumstances of these cases, that they do not give the least support to these views ; and we may safely state, that the pathological facts mentioned by Longet are not more able than his experiments to prove his views. Still more, as regards voluntary movements, these facts are certainly in positive opposition to the view that the antero-lateral columns are the only channels through which the will acts upon muscles. We pass now to the exposition of other facts, which positively establish that the transmission of painful and purely tactile impres- sions may take place through other parts of the spinal cord than the posterior columns. 60 THE CENTRAL NERVOUS SYSTEM. Case 6. — A young man was admitted into the Charite on the 10th of June, 1839, under the care of M. Bouillaud. He complained of pain in the left shoulder and in the neck. The next day he could not turn his head. There was no paralysis anywhere, either of motion or sensibility ; but the left upper limb was weak. Heat normal. On the 19th, headache; pulse 52-56. No paralysis, but the legs were weak. On the 22d, intelligence diminished; senses affected. No trace of paralysis. On the 25th, symptoms of menin- gitis; death. Autopsy. — The lower part of the cervical region of the spinal cord was much enlarged, and contained a cancerous tumor of the size of a large olive, around which the nervous substance was notably softer than elsewhere. The seat of the tumor was in the posterior part of the cord. The development of the tumor had taken place from the surface of the sheath of the cord. The tumor being taken away, the white substance of the spinal cord was found to be com- posed of two large bands, of a soft consistence, without notable injection. The rest of the spinal cord was healthy. The roots of nerves were normal. Slight inflammatory alterations in the ence- phalon. (Henroz and Bouillaud, in the Journal des Gonnaissances Medicates, 1844, vol. xi. p. 40.) This is a decisive case, although the description of the condition of the spinal cord is not clear. It is quite certain that very little if any part of the posterior columns remained, and, nevertheless, sensibility was not diminished. Had the patient been observed sooner, and at a time when he had, for three weeks, what he called rheumatismal pains, it would very likely have been ascertained that he had hyperesthesia. When he was admitted the tumor had grown, and had produced more or less alteration in the gray matter, so that hyperesthesia had ceased. This case is excellent, as it shows that a destruction of the posterior columns in a small part of their length does not cause a paralysis of voluntary movements. Case 7. — P. N , a soldier, received a bayonet wound between the twelfth dorsal and the first lumbar vertebra), injuring the spinal cord. After several bleedings the first pains diminished; but, on the second day, and till his death, he had the most excruciating pains and violent cramps in all the parts below the wound. The skin of the lower parts of the trunk and the surface of the abdominal limbs was so sensitive that one did not dare touch him, and he had ILLUSTKATIVE PATHOLOGICAL CASES. 61 to keep himself on his knees and hands. He died on the seventh day, without having had any paralysis. Autopsy. — The existence of a wound of the spinal cord was ascer- tained. There was an inflammation of the spinal cord and its mem- branes, and also of the brain. (Gama, Traite des Plates de Tete et de VEacephalite, 1830, p. 318.) There is no doubt that, in this case, the hyperesthesia was, in a certain measure, the result of the meningitis ; but as this inflamma- tion existed all along the cranio-spinal cavity, while the excessive hyperesthesia was limited to the lower limbs and lower part of the trunk, we must admit that there was another cause to it. Probably the inflammation of some of the nerves originating from the cord, in the neighborhood of the wound, contributed to the hyperes- thesia; but the principal cause, most likely, was the injury to the spinal cord itself. I have ascertained, upon animals, that a wound, on the posterior surface of this organ, is followed by a greater hyperesthesia, in the lower limbs, when it is made in the middle of the enlargement which gives nerves to those limbs than when it is made higher. It is to be regretted that Gama did not state what was the extent of the injury to the spinal cord, but it is evident that the posterior columns were the principal, if not the only parts wounded. Case 8. — A man fractured his spine in the cervical region ; he was at first paralyzed in the lower and upper limbs, and he lost sensibility, almost entirely, in the left limbs, and had only a dimi- nution of this property in the right limbs. Gradually he recovered sensibility and voluntary movements, and, after three months, being completely cured, though weak when walking, he left the hospital. The same day he went on foot to a distance of nine miles from Paris, and, on his return, he fell, and became again paralyzed both in motion and sensibility. Nearly two weeks after he died. Autopsy. — The fracture which had first caused a paralysis had produced a displacement of a part of the posterior arch of the fourth cervical vertebra, in consequence of which the posterior columns had been divided. (See Fig. 15.) There was in the centre of the cord, where the pressure had taken place, a fibro-cellular nucleus, chiefly formed by the pia mater. The anterior columns of the cord evidently existed, but the posterior seemed to be interrupted at the place of the flbro-cellular nucleus. The gray matter, from above and from below the injured part, extended to this nucleus. (Ollivier 02 THE CENTRAL NERVOUS SYSTEM. d'Angers, Tralte ties Maladies de la Moelle Epiniere, 3d edit., 1837, vol. i. p. 294.) We give here (see Fig. 15) a reproduction of a figure, published by Ollivier, representing the extent of injury in this case. It seems evident, from the description and from the figure, although both are obscure, that the continuity of, at least, a part of the gray matter and that of the anterior columns was preserved; but the posterior columns entirely, and, probably, a part of the lateral columns and the gray horns, had been severed. However, sensibility and volun- tary movements had returned, after a period of great diminution. This case is, undoubtedly, an excellent one to show that the poste- rior columns are not the channels for voluntary movements nor for sensitive impressions. We must remark, that this condition of the spinal cord had not been produced when the man fell down and be- came paralyzed a second time. He had then a fracture of the callus, which had united the broken parts of the first fracture, and paralysis was probably due to a pressure near the divided portion of the cord. Case 9. — G , aged fourteen, admitted into the Charlie, under the care of M. Kayer. From his childhood, after having been very ill, the four limbs of this patient have been drawn convulsively, and kept in the position of those of a foetus in the uterus. He seems to be completely paralyzed. Some muscles of the shoulders, however, appear to have voluntary movements, and the head, eyes, larynx, and tongue obey the orders of the will, as also most of the respiratory muscles. Energetic spontaneous or reflex convulsions take place in the four limbs. There is hyperesthesia everywhere in the limbs and in the trunk. He shrieks every time he is touched. Lately convulsions have increased, delirium has appeared, and death has taken place eight hours after the state of exquisite sensibility has shown itself. Autopsy. — There were various alterations belonging to a very old spinal meningitis, and an acute cerebral meningitis. Tuber- cles upon the left cerebral lobes. There is softening of the pos- terior columns of the spinal cord principally at the level of the sixth and seventh cervical vertebra?; the softening diminishes gradually from this point, and ceases at the level of the third or fourth dorsal vertebra, and at the medulla oblongata. This case, which I witnessed at the Charite, in 1849, is a valuable one, as regards the question we examine, in this respect, ILLUSTRATIVE PATHOLOGICAL CASES. 63 that sensibility was not lost nor diminished, although the posterior columns were softened. As to the loss of movements and the morbid increase of sensibility, there were too many alterations sufficient to produce them for us to try to show what relation they had with the softening of the posterior columns. The following case is very much like the preceding, but it is, in sorrye respects, more important. Case 10. — Mr. F. F had been in good health until 1837, when he had an attack resembling congestive fever. The next year he had a similar attack, with a more lasting delirium. His strength did not return, although his appetite became very good. His walk was peculiarly unsteady and tottering. Pulse slow; tem- perature of skin low. Gradually paralysis came on in both the upper and the lower extremities. Violent counter-irritation was employed, and he got better, but soon became worse again. In May, 1839, he began to complain of pain in the joints, and soon after the pains came on with paroxysms attended with spasmodic contractions of the limbs. Any forcible attempt to extend the limbs caused immediate spasmodic contraction, with excruciating pain. The upper and lower extremities became permanently con- tracted, the lower more than the upper, in which the spasms were attended with less pain. He could use his fingers to a certain ex- tent, but had little power over the larger joints. The knees were drawn up towards the abdomen, the legs bent upon the thighs, so that the heel rested firmly upon the soft parts covering the tuber ischii. The surface of the body during the early stages of the con- tractions of the limbs was morbidly sensitive, so that the approach of a person caused him to cry out, lest he should be hurt. He re- mained in this state for several months, with little amendment, except a gradual diminution of pain. Hectic fever set in, and he died. Autopsy. — Various alterations of the cranium, the dura mater, the arachnoid, &c. Hardly any morbid appearance in either the pia mater, the brain, or the cerebellum. Tuber annulare and me- dulla oblongata firmer than usual. From the foramen magnum to the first or second dorsal vertebras all the membranes of the spinal marrow were firmly united. The spinal cord in the cervical region very soft; on its hack part semi-fluid. The lower end of the spinal marrow firmer than usual. (McNaughton in American Journal of the Medical Sciences, July, 1812, pp. 57-63.) 61 THE CENTRAL NERVOUS SYSTEM. We are very willing to admit that at least a good part of the morbid excess of sensibility in this case was due to the meningitis, but whatever be the exact truth in this respect, it remains certain that sensitive impressions were freely transmitted, and the autopsy showed that the back part of the spinal cord — i. e., its posterior columns— was serai-fluid. Case 11. — A woman, for mairv months, complained of headache. Four or five months before admission into a hospital she felt weak, and had numbness in the four limbs, with vertigo, and diminution of sight. All the senses were somewhat impaired. No facial palsy. Yery violent headache ; paralysis not very marked ; diminution of the general sensibility; the muscles of the neck in a tetanic spasm; respiration embarrassed, interrupted. She died five or six hours after admission. Autopsy. — Encephaloid tumor, of the size of a small walnut, in the triangular space formed by the left processus cerebelli ad pon- tem, the pons Varolii, and the restiform body. The medulla oblon- gata was at least four or five lines larger than usual ; between the medulla oblongata and the processus cerebelli ad pontem there was a notable quantity of softened and yellowish nervous matter, chiefly from the left restiform body, which was entirely destroyed. The fourth ventricle was considerably dilated by a yellowish serosity. (Cartier, in Bulletins cle la Societe Anatom., 1810, pp. 85-87.) This case is extremely important ; here is a complete destruction of the assumed sole channel for the sensitive impressions on one side, and yet sensibility persists ! It is true sensibility was diminished, but the diminution existed on both sides, and, therefore, could not depend upon the destruction of one of the posterior columns of the medulla oblongata, and there were alterations enough to produce this diminution (notable enlargement of the medulla oblongata, dilatation of the fourth ventricle, &c). • Case 12. — A woman, aged fifty-five, began in 1831 to feel great weakness, with extreme pain in her lower limbs, and, from time to time, spasms. The weakness increased gradually, and, after a few months, the patient was unable to stand on her feet, the lower limbs losing all voluntary movement, while their sensibility remained entire. In January, 1832, she recovered some power of motion, but after two months the paraplegia returned, and with it acute pain in the lower limbs and abdomen. In October, 1833, she was ILLUSTRATIVE PATHOLOGICAL CASES. 65 admitted into St. Louis ; her lower limbs had lost all movement : they were atrophied; a slight " contracture" existed. These limbs retained all their sensibility; feelings of pricking and painful sensa- tions seemed to originate in them. The bladder and rectum were paralyzed. Pain became so violent, that it prevented sleep. The "contracture" increased, and the heels came almost in contact with the thighs. It was impossible to extend the legs. No new symp- tom appeared, and death occurred on the 26th of October, 1833. During the last days, however, sensibility seemed to be slightly diminished (emoussee) in the paralyzed limbs. Autojjsy. — Brain and cerebellum healthy. At the level of the second dorsal vertebra, against the left and posterior part of the spinal cord, there was a tumor, two inches long, six lines wide, nearly oval, lying longitudinally between the two sheaths of the arachnoid. The part of the spinal cord upon which the tumor had pressed was reduced nearly to two-thirds of its normal volume. It seemed, with the part below it, to be softer than usual. (Hardy, in Archives de Medecine, &c, 1834, vol. v. pp. 229-233.) The author of this important case observes, that sensibility was~ slightly diminished, only during the last hours of life, and that the conservation of this property is "the more remarkable as the tumor, situated behind the cord, compressed principally its pos- terior part, which, according to modern physiologists, is especially used for sensation." It is to be regretted that the author has not described with more precision the alteration of the spinal cord; but as it is, however, this case shows that, although the posterior columns, and one of them particularly, were much altered, if not destroyed, the trans- mission of sensitive impressions continued to take place. Other parts of the spinal cord must also have been altered, and to this fact we attribute the loss of voluntary movements. We will try, by and by, to explain why any alteration of the spinal cord, and particularly that which is due to pressure, so often produces a paralysis of voluntary movement, and allows the transmission of sensitive impressions to continue. We will merely state now that this difference between voluntary movements and sensibility is very well known. In an important work of one of my most eminent hearers, I read, that "occasionally the loss of voluntary power over the muscles is a total loss of sensibility (in cases of caries of the spine); but more frequently, while the former function of the nerves is destroyed, the latter remains but little or not at all impaired." E 6ft THE CENTRAL NERVOUS SYSTEM. (Sir B. C. Brodie, Patholog. and Surg. Observ. on Diseases of the Joints, p. 332.) A very able observer, Dr. W. W. Gull, has col- lected many facts establishing the truth of this statement. (Gulsto- nian Lectures on the Nervous System. — Medical Times, 1849.) The following case is very important, and it has more value than most of those we have related, on account of the microscopical exa- mination of the altered parts of the spinal cord. Case 13. — A woman, aged forty-seven, on admission at the Sal- petriere, on the 11th of July, 1855, gave the following account: Three years ago, after a violent emotion, she had a feeling of numb- ness and formication in the upper limbs, more in the left, and after- wards in the lower limbs. Gradually weakness came in all the left side, and, after eight months, the left arm could not hold anything unless she looked at it, while the right was only weakened; she also had violent pains in the spine and chest with a feeling of burning. The sensibility of the skin was then so great that she dreaded the presence of any one by her. Galvanism produced an amelioration in her condition, but a vicarious menstruation by the anus weakened her, and then she came under my observation. There was violent spontaneous pain and an extreme sensibility in all the left arm, and between it and the spine; touching these parts made her cry out. The degree of morbid sensibility was not so great in the right arm. Although so sensitive for painful impressions, these parts, and particularly the left arm, or at least the fingers, had lost the tactile sensibility. Hyperesthesia was as great in the lower as in the upper limbs, and particularly on the left side; the feet, however, felt numb. The skin of the face was the seat of formication. Movements of the left arm were easy, but, if she did not look at it, she would drop what might be between her fingers. The move- ments of the right arm were perfectly free. It was so with the lower limbs ; they were moved easily in bed, but walking was pos- sible only with the help of an assistant, as there were weakness and vacillation in the lower limbs. The pain went on increasing, and ■diarrhoea caused death. Autopsy. — Brain and cerebellum, carefully examined, were found healthy. No alteration of the membranes of the cord. The pos- terior columns were altered in all their length, from about one inch, above the cervico-brachial enlargement to the lower extremity of the organ. They were yellow, and infiltrated with serosity. On transversal sections it was ascertained that the whole thickness of ILLUSTEATIVE PATHOLOGICAL CASES. 67 the posterior columns was altered. A microscopical examination of these columns made by me (Dr. Luys) and by Dr. Charles Robin showed : 1st, a considerable amount of yellow, spherical, granular bodies, mixed with broken nerve-fibres, and a small number of longer nerve-fibres; 2d, an amorphous matter containing many granulations, amongst which several were fatty; 3d, the blood- vessels were in a state of fatty degeneration. The gray matter was normal, except that there was more fat than usual both in the cells and in the amorphous substance. The anterior and lateral columns, and also the anterior and posterior roots of the spinal nerves, were healthy. (Luys in Oomptes rendus de la Societe de Biologie, pour 1856, pp. 94-97.) " This case is important in many respects. In the first place, it shows that the posterior columns are not directly employed in voluntary movements, as we see that the movements existed when guided by sight (tactile sensations and reflex actions missing). In the second place, this case shows hyperassthesia (for painful impres- sions), and therefore the transmission of painful excitations, con- tinuing to exist, although the posterior columns were hardly able to have a share in this function. And lastly, this case would seem to show that the tactile impressions are transmitted to the senso- rium by the posterior columns. In this respect the case is in oppo- sition to several others that I have mentioned, and still more to a few that I have yet to relate. In the long and detailed account given by M. Luys there are some facts of which I have not spoken, which prove that there were some cerebral alterations which have not been detected at the autopsy. It may be that these alterations have caused the tactile anaesthesia. The facts I allude to were, a paralysis of the motor branch of the trigeminal and of the facial nerve on the two sides (more on the left), and a notable diminution of sight, with an acoustic hypersesthesia. I do not think, however, that an alteration of the posterior columns occupying such a length as in this case could exist without impair- ing the transmission of sensitive impressions ; as my experiments, as well as anatomy, establish that a number of fibres of the posterior roots pass into the posterior columns. There may be a certain number of these fibres transmitting tactile impressions, and others transmitting painful impressions; and, therefore, an alteration of the whole of the posterior columns in the length of the dorso lumbar enlargement, for instance, ought to diminish tactile and painful sensibility in the lower limbs. If we see that there is no appear- 68 THE CENTKAL NEKVOUS SYSTEM. ance of diminution, this depends upon the fact that there is a cause of increased sensibility which gives more than what is lost. In the justly celebrated cases of Mr. Stanley, of Dr. Webster, and of Dr. Bucld, of which I will now give a short summary, it is very probable that tactile sensibility persisted as well as painful sensi- bility. Case 14. — J. C , aged forty-four, admitted into St. Bartholo- mew's Hospital for paraplegia. The patient was lifted into a chair, and when thus sitting, he did succeed, by a great effort, in raising his legs from the ground; but afterwards the inability of motion became complete through each lower limb in its entire extent. There was no discoverable impairment of sensation in any part of the limbs ; on scratching, pricking and pinching the shin, nowhere was any defect of feeling acknowledged by the patient. In the upper limbs there existed no defect either of motion or sensation. Autopsy. — The spinal cord was the only seat of disease ; mem- branes healthy. The posterior half, or columns of the cord, through- out the entire length, from the pons to the other end, was of a dark- brown color, extremely soft and tenacious. The anterior half exhibited its natural whiteness and firm consistence. The roots of the spinal nerves were unaltered; the brain was healthy. (Mr. Edward Stanley, in Medico- Ghirurgical Transactions, 1840, vol. xxiii. pp. 80-83.) This case is undoubtedly one of the principal that I have to mention against the view that the posterior columns are the only channels for the sensitive impressions. Many things are united here to give value to the case. In the first place, the name of the ob- server is a perfect guarantee of exactitude in the observation of symptoms, and the description of the condition of the nervous centres. In the second place, the color of the softening shows that it was not a recent one. In the third place, the patient seems to have had sensations of touch (scratching) as well as sensations of pain (pricking and pinching.) /'Throughout the progress of the case," says Mr. Stanley, " the opinion had been freely expressed, that it was one of disease of the anterior half, or columns of the spinal cord." So that, were this not entirely unnecessary, we should have in this expectation another guarantee of correctness. But we must say that there are details which we should have liked to see mentioned, and that there are circumstances in this case which render it probable that certain alterations have escaped notice. ILLUSTRATIVE PATHOLOGICAL CASES. 69 We are not told when the last examination was made as regards the state of sensibility. The loss of movement was so absolutely complete that there was certainly some other alteration, besides that of the posterior columns, producing it, and to which was due the difference between the upper and the lower limbs. However, one clear and positive fact remains; there was a notable alteration (and one of long standing) of the posterior columns, and sensibility was not lost. We shall find the same fact in the following case: — Case 15. — R. H , a sailor ; on admission at the Seamen's Hospital, his lower extremities were extended, and very rigid, with sensation unimpaired, except slight numbness of the thighs. Voluntary movements completely impossible in the lower limbs; reflex convulsive movements very powerful; slight convulsions (much more feeble than before) could be excited to the last ; his intellect remained unimpaired, and sensation in the lower limbs, and elsewhere, unaffected. Autopsy. — There was a curvature of the spine formed by promi- nence of the dorsal vertebrae, from the fourth to the ninth inclusive. The posterior columns of the cord, for the extent of about two inches in the portion corresponding to the curvature, were softened. The tissue was not diffluent, but became flaky and partially dis- solved when a small and gentle current of water was poured on it. The anterior columns were scarcely, if at all, softened, and resisted considerable traction. The cord above and below the affected part was perfectly healthy, and so were the nerves, even those arising from the softened part. (Dr. W. Budd, Medico- Chirurgical Transac- tions, 1839, vol. xxii. pp. 162-165.) The condition of the gray matter is not mentioned. However, this is an important case, showing that although the posterior columns were deeply altered, the transmission of sensitive impres- sions continued to take place. There was in this case complete loss of voluntary movements, for the explanation of which we refer to our remarks on the succeeding case ; but we must say that there was here, for a long period, a cause of difficulty and even of impos- sibility of voluntary movement — I mean, the spasmodic state of the muscles. In two ways the spasms act to prevent the will from pro- ducing movements: whilst they exist, they oppose a direct resist- ance to the will ; and after they have ceased to exist, the muscular irritability is for a time too much exhausted to allow voluntary contractions to occur. 70 THE CENTRAL NERVOUS SYSTEM. "We regret that we have not time to speak of various important circumstances of this and other cases observed by Dr. Budd or by Prof. Busk, which cases are recorded in the very interesting paper of Dr. Budd which we have quoted. Case 16. — W. IT. Gr , aged thirty-six. After various accidents and epileptic fits, he became unable to walk steadily without sup- port. He became better, but soon had a relapse, and then was entirely deprived of the use of both legs and arms. Ultimately the muscles of the abdomen and chest were also affected. Notwith- standing the total loss of power over all the muscles situated below the neck, the sense of touch still continued as acute as ever throughout the entire frame; indeed, the cutaneous surface appeared occasionally to be even more sensitive to external impressions than in the patient's previous good health, since he could, for instance, feel most acutely the slightest change in the temperature of the surrounding atmosphere. His sense of feeling was so accurate that he could distinctly tell the particular part of his body to which the attendant's finger was applied. He had spasmodic twitchings of the legs attended with great suffering. Autopsy — about eighteen hours after death. Slight and unim- portant alterations of the brain and its membranes. The part of the spinal cord corresponding to the three or four lower cervical vertebras appeared larger than usual, felt soft and pulpy, and, on being divided, its substance seemed to be in an almost diffluent state, infiltrated with serum, but of a normal color; in the anterior and posterior columns not much difference was observed at the first superficial examination of the cord; both divisions seemed con- siderably softened, infiltrated, and disorganized, particularly the posterior columns. Above and below the affected part, the me- dulla spinalis was healthy and quite natural in appearance. Dr. Todd made a microscopical examination : he found great destruc- tion of the posterior columns, and did not find any loss of substance in the antero-lateral columns. He says that he was unable to detect any trace of gray matter. (Dr. J. Webster, in Med.-Chir. Trans., 1843, vol. xxiv. pp. 1-18.) This case differs from the preceding by the extent of the injury to the posterior columns, and here we find hyperesthesia, as in cases of tumors upon these columns, or after their transversal sec- tion in animals. There was, however, a cause of diminution of ILLUSTKATIVE PATHOLOGICAL CASES. 71 sensibility here, otherwise the hyperesthesia would have been much greater. If we were to take for granted, as it might be con- cluded from a few words of Dr. Todd, that the gray matter was destroyed, we should have to admit that the antero-lateral columns, even somewhat altered, are sufficient for such a notable degree of transmission of sensitive impressions as that which existed in this case. But I will remark that when this eminent biologist made his examination the gray matter had been divided, and then ex- posed for some time to the action of the atmosphere on a July day, and then the specimen had been put in spirits and kept some time longer, before it came into the hands of Dr. Todd. Although it is probable that the gray matter was more or less altered in this case, it seems certain, from what is shown by other pathological cases and by experiments, that it had not entirely lost its share in the transmission of sensitive impressions. A striking fact, well made out by Dr. Todd, is that the antero-lateral columns, although soft- ened, had not lost their structure. The loss of movement in this case, in the lower limbs, did not depend in any way, upon the same cause, as in Cases 1, 2, 3, 4, 5, 14, &c, and the alterations in the posterior columns in the cervical region cannot have produced the loss of voluntary movement in the lower limbs, as will be shown in a moment by a case I will relate. The real cause of loss of move- ment probably, therefore, resided in alterations in the antero-lateral columns and in the gray matter. The question, How could these alterations have destroyed the power of action of the will on muscles without rendering impossible the transmission of sensitive impres- sions? we cannot answer, otherwise than by stating, as we have already done, that any cause acting on the whole circumference of the spinal cord or of a nerve produces very much more easily a diminution or a loss of motor transmission than of sensitive trans- mission, and that in a great measure this difference is due to the difference in the reagents at the extremities of the conductors : for one kind, the sensorium, so easily acted upon ; for the other kind, muscles and bones, so difficult to move. Case 17. — A soldier was paralyzed of voluntary movement in the upper limbs only. He had not lost sensibility anywhere. Autopsy. — The posterior columns of the spinal cord were altered in structure between the fifth cervical and the third dorsal vertebras. They were softened, and this alteration gradually diminished from 72 THE CENTRAL NERVOUS SYSTEM. the surface to the centre of the cord. The posterior roots also were altered. (Malle, in Clinique Chirurgicale de VHopital de Strasbourg. 1838.) This case is unfortunately without details, and, for instance, it is not stated when sensibility was ascertained to exist. But, at any rate, we find here an alteration of the posterior half of the spinal cord, with a loss of voluntary movements in the limbs alone that correspond with the part altered. The action of the will on the muscles of the lower limbs had continued to take place through a spinal cord altered enough to prevent voluntary movements in the upper limbs. As regards the posterior roots of the cervico-brachial nerves, which are said to have been in a state of putrilaye, it is certain that they must have lost at least a part of their power of transmitting sensitive impressions; and this proves that the last examination of the patient, when sensibility was found existing in the upper limbs, must have been made a somewhat long time before death. But in this case, as well as in others, the loss of certain functions has more value than the conservation of others; and we find voluntary movements lost in the upper limbs, and nothing to explain this loss except the alteration of the posterior parts of the cord — an alteration which, for some time at least, had not destroyed sensibility. Case 18. — A woman, aged forty, received a blow on her back. Six weeks after, she felt pain starting from the right foot. Gradually the pains extended to the various parts of the limb, and after a month they were accompanied with spasmodic contractions and a diminution of voluntary movements. She walked with great diffi- culty, even with the help of a stick. There was no alteration in sensibility nor in temperature in this limb. The convulsions ex- tended to the other limbs and to the head, and the patient died. Autopsy. — Brain normal; cerebellum a little softened; no menin- gitis ; spinal cord healthy, except in the swelling for the lower limbs, which, for an extent of eighteen lines and a depth of one line in its posterior part, was softened, looking like cream some- what rose-colored. (Genest, Clinique de Chomel, in Gazette Jfedicale de Paris, 1831, p. 84.) We have no remark to present about this case, except that there was a considerable alteration of the posterior columns, and con- servation of sensibility. ILLUSTKATIVE PATHOLOGICAL CASES. 73 Case 19. — A young girl died after having been paraplegic, and without having lost sensibility. The encephalon was in a normal condition, except that the corpora geniculata were of a gray color. The spinal cord in all its length had a gray-rose color column formed by the median posterior columns ; the rest of this organ was healthy. (Cruveilhier, in Anat. Pathol., 32d livraison, p. 21.) It is quite certain that the loss of voluntary movement in this case cannot be attributed (at least only) to the alteration found in a small part of the cord ; but we relate this fact (which Cruveilhier has published without any detail) because it shows that there may be an alteration of the little median posterior columns with pre- servation of sensibility. We might relate a great many other cases showing that altera- tions of the posterior columns do not produce anaesthesia, and are often, on the contrary, attended with hyperesthesia. For the sake of brevity, we will merely point out a few circumstances connected with some of these cases, and give the references of the others. In a paper by Dr. Ludwig Tiirck (Beobachtungen iiber das Leitungsver- rnogen des Menschlichen Ruckenmarkes, 1855), there is a case of old alteration of a part of the right side of the spinal cord extending between the origins of the fourth and sixth cervical nerves. In' certain sections the alteration occupied a part of the lateral column and a part of the posterior column (see Fig. 16, al)- and, in another section (between the fifth and sixth cervical nerves), it occupied the whole of the right posterior column. The altered parts were indu- rated, of a reddish-gray color, and did not contain a trace of nerve- fibre. This alteration, therefore, had produced there just the same result as a transversal section of the posterior column and of a part of the lateral column on the right side. Numerous and careful examinations have shown that the hands and fingers had no anaes- thesia. In this case the anterior parts of the spinal cord were also altered in the cervical region, so that the transmission of sensitive impressions must have taken place through the central gray mat- ter. The last examination of the state of sensibility unfortunately was made long before death ; but the alteration found is one that occurs very slowly. The same remarks might apply to another case observed by the same pathologist. The two internal segments of the posterior columns (see Fig. 17, al) were altered (and without any trace of nerve-fibre) between the fifth and sixth cervical nerves, and sensibility to touch in the parts animated by these nerves per- sisted. 74 THE CENTRAL NERVOUS SYSTEM. Dr. E. B. Todd says, that in two cases which occurred in King's College Hospital, under his own care, the prominent symptom was impairment of the motor power, without injury to the sensitive; yet the seat of organic lesion in both was in the posterior columns of the cord. (Cyclopaedia of Anatomy and Physiol., vol. iii. p. 721, P.) Serres speaks of a woman who had been paraplegic for two months, and had sensibility preserved in her lower limbs, although the posterior columns were alone altered, and in three places. (Anat. Comparee du Cerveau, vol. ii. p. 221.) H. Nasse mentions a case, observed by Wittfeld, in which a tumor pressing upon the posterior columns in the lumbar region had produced a paralysis of movement, and not of sensibility. (Unter suchung en zur Physiol, und Pathol., vol. i. p. 226.) Sandras says, without any more detail, that he has seen two cases of alteration of the posterior columns, in one of which sensibility was lost, and, in the other, voluntary movements. {Journal General de Med., dx., 1829, p. 360.) M. Nichet relates a very important case, of which we shall have to speak elsewhere, in which sensibility had persisted, although the spinal cord had been reduced to a thickness of two lines near the medulla oblongata, the gray matter, almost alone, seeming to exist. (Gaz. Med. de Paris, 1835, p. 534.) We might cite many other cases by Hutin, Prus, Velpeau, Bel- lingeri, Liberali, Colin, Bourdon, Ollivier, Caron, Hersent, Fricault, Cruveilhier, Guyon, Goupil, J. "W". Ogle, &c, in which sensibility has persisted, and, sometimes, has been much increased, although the posterior columns were the only, or principal seats of alteration. I think that it is impossible, after such a mass of evidence, not to admit that if the posterior columns of the spinal cord convey sensitive impressions to the encephalon, their share in this function must be extremely slight. In the next lecture, before speaking of the pathological facts which prove that the conductors of sensitive impressions decussate in the spinal cord, I will relate some facts concerning the transmis- sion of these impressions through the gray matter, and discuss some important questions on the diagnostic value of anaesthesia and hyperesthesia. inal cord, except the posterior columns. — Loss of voluntary movements and of all kinds of sensibility. Keflex actions increased or diminished in certain parts of the body, according to the place of the alteration in the length of the spinal cord. I know many cases in which one of the two last kinds of altera- tion has existed. In another lecture, I will relate three of them, which have been recorded by Mr. Caesar Hawkins, by Dr. John W. Ogle, and by Dr. T. Inman. 139 LECTURE IX. ON THE PHYSIOLOGICAL AND MORBID ACTIONS DUE TO THE GREAT SYMPATHETIC NERVE. Effects of a section of the sympathetic nerve in the cervical region. — Effects of the excitation of the same nerve, in the same region, by a galvanic or an electro- magnetic current. — Almost all the effects due to the section or galvanization of this nerve are owing to the condition of bloodvessels after these operations. — The sympathetic nerve originates chiefly from the cerebro-spinal axis. — Simili- tude between the effects of a section of the sympathetic nerve, and those of a section of a lateral half of the spinal cord. — Persistence of a contraction of bloodvessels due to irritation of the cerebro-spinal axis in certain diseases. — Two kinds of normal or morbid influences of the nervous system upon nutri- tion, secretion, &c. ; one upon bloodvessels, the other upon tissues. T pass now to quite a different subject. In the preceding lec- tures, I have chiefly examined what relates to voluntary movements and sensibility; I come now to the influence of the nervous sys- tem upon nutrition, animal heat, secretions, &c, and I begin by the peculiar influences of the sympathetic nerve on these functions in health and disease. Before entering into the subject of the influence of the nervous system upon the functions of organic life, it is necessary to state what are the effects of the section and of the galvanization of the cervical sympathetic nerve. I hope I may be allowed to fix some dates of publication of the principal discoveries in this respect. Prof. CI. Bernard published the results of his first researches on the effects of the section of the cervical sympathetic nerve in 1851, and in the beginning of 1852. 1 The only great fact announced in these publications was, that this section was constantly followed by a considerable afflux of blood in the parts of the head to which the sympathetic goes. Led by experiments that I had made several years before, with my friend Dr. Tholozan, on the influence of 1 Comptes rendus de la Soc. de Biol., Dec. 1851, in Gaz. Med., 1852, p. 74.— Comptes rendus de l'Acad. des Sciences ; seance du 29 Mars, 1852. 140 THE CENTKAL NEEVOUS SYSTEM. nerves on bloodvessels, I understood at once that the fact disco- vered by Prof. Bernard was due to the paralysis of the bloodves- sels after the section of the sympathetic; and I thought that, if this view were right, I should find galvanization of this nerve produc- ing the reverse of the effects of the section. The experiment being made, I found, as I had foreseen, that the bloodvessels contracted, and that the quantity of blood and the temperature diminished. The date of my first publication is Aug. 1st, 1852. 1 Three or four months afterwards, Prof. Bernard not knowing what I had done, announced to the Socie'te' de Biologie (in October and November, 1852), that he had seen galvanization of the sympathetic nerve diminish the quantity of the blood and the temperature, &c. 2 In February, 1853, a very able English physiologist, Dr. Augustus Waller, being unaware of what I had published, and of the more recent paper of Prof. Bernard, announced to the Academy of Sciences of Paris, 3 that he had found the galvanization of the sympathetic nerve producing effects opposite to those of its sec- tion ; and he gave the same theory that I had already proposed — a theory which has since been admitted by almost all the physiolo- gists who have written on this subject. As I consider that the knowledge of the effects of the paralysis, and the irritation of the sympathetic nerve, opens a new and most important field in physiology, in pathology, and in therapeutics, I will give at length two lists of the phenomena which have been observed after the section and after the galvanization of the cervi- cal sympathetic nerve. I. Effects of the Section of the Cervical Sympathetic Nerve. Phenomena observed in the head, on the side of the Authors who have made operation. the first observation. 1. Constriction of the pupil .... Pourfour du Petit. 2. The eye seems to he smaller, or even truly shrinks . Idem. 3. The eye is drawn hack-wards and a little inwards . Idem. 4. The eyelids are partially closed . . . Idem. 1 Philadelphia Medical Examiner, August, 1852, p. 4S9. This paper has "been reprinted in my -work, " Exper. Researches applied to Physiol, and Pathol." p. 9. New York, 1853. 2 Comptes rendus de la Soc. de Biol., in Gaz. Med., 1852, p. 775 ; and 1853, p. 71. 3 Comptes rendus de l'Acad. des Sciences, seance du 28 Fevrier, 1853. — I will, by and by, point out what had already been done as regards the influence of nerves on bloodvessels, by Stilling, Henle, Mr. James Paget, and Mr. Wharton Jones, before the researches of Prof. Bernard. SECTION OF CERVICAL SYMPATHETIC NERVE. 141 Phenomena observed in the head, on the side of the operation. 5. The third eyelid, or nictjtant membrane, advances upon the globe of the eye, and sometimes extends over a part of the cornea. .... 6. The production of the palpebral mucus is increased . 7. The cornea becomes natter and dimmer 8. Almost all the muscles of the eye are contracted 9. The muscles of the angle of the mouth and of the nostril are contracted .... 10. The ear is kept erect, partly on account of the con- traction of some of its muscles 11. There is an evident increase in the quantity of blood 12. The temperature is notably increased 13. Sensibility is increased .... 14. When the animal is killed, the reflex faculty lasts longer there than in the other side 15. Voluntary movements seem also to last loDger. 16. Sensibility also lasts longer .... 17. The reflex movements of the iris last longer . 18. The sense of hearing seems to be more acute . 19. The sensibility of the retina seems to be increased 20. Perspiration (particularly from the ears in horses), is increased ...... 21. The secretion of cerumen is increased 22. The secretion of tears is increased 23. Absorption is more rapid .... 24. Chloroform destroys sensibility there later than else- where ...... 25. The color of venous blood is changed 26. The quantity of fat diminishes (?) 27. The first convulsions, after poisoning by strychnia, take place there ..... 28. A galvanic current, too weak to act on the other side, may produce contractions there 29. The so-called recurrent sensibility of the facial nerve is increased ...... 30. The pressure of blood on the walls of the arteries is increased ...... 31. After death the motor nerves of the face seem to re- main excitable longer than on the other side 32. The muscles, also, and the iris remain contractile longer ...... 33. The irritability of the arteries, and particularly of the principal auricular, is increased, at least for several weeks after the operation, and it lasts longer after death ...... 34. Cadaveric rigidity comes later, and lasts longer 35. Putrefaction comes later .... 36. The galvanic current of the muscles, detected with the galvanoscopic frog, is stronger than in those of the other side ..... Authors who have made the first observation. Pourfour du Petit. Idem. Idem. Bernard. Idem. Brown-Sequard. Dupuy and Bernard. Idem. Bernard. Idem. Brown-Sequard. Idem. Idem. Idem. Idem. Dupuy. Schiff. (?) Bernard. Idem. Martini and Bernard. Martini. Brown-Sequard. Idem. Idem. Bernard. Brown-Sequard. Idem. Idem. Idem. Idem. Idem. 142 THE CENTRAL NERVOUS SYSTEM. Phenomena observed in the head on the side of the operation. 37. Injections of red blood by the carotid and vertebral arteries, after death., are able to regenerate the vital properties of the nervous and of the contractile tis- sues, later there than on the other side 38. Various pathological alterations may take place, \ chiefly in the eye j Authors who have made the first observation. Brown-Sequard. Petit, Molinelli, Mayer, J. Reid, &c. I pass now to the list of phenomena observed after the gal van ization of the cervical sympathetic. Phenomena observed. 1. Dilatation of the pupil .... 2. The eyelids are wide opened, and the globe of the eye protrudes ...... 3. The bloodvessels contract, and the quantity of blood diminishes ...... 4. The temperature diminishes .... 5. Sensibility diminishes .... 6. The conjunctiva and the cornea become dry . 7. Strychnia produces less convulsions there than on the other side ...... 8. After death, the vital properties of the motor and sen- sitive nerves disappear there sooner than on the other side ...... 9. The irritability of the iris and of the muscles disap- pears also sooner after death 10. The contractility of the arteries lasts less time after death ...... 11. The galvanic current given by the muscle3 is very weak . . . 12. Cadaveric rigidity comes sooner, and lasts less time . 13. Putrefaction comes sooner .... 14. The faculty of regeneration of the vital properties in the muscles of the face after cadaveric rigidity has appeared, is lost sooner than on the other side Discoverers. Aug. Waller & Budge. Bernard. Brown-Sequard. Idem. Idem. Idem. Idem. Idem. Idem. Idem. Idem. Idem. Idem. Idem. It is evident that all these phenomena are just the reverse of those which follow the section of the cervical sympathetic. The phenomena observed after the section or the galvanization of this nerve, with the exception of a few, may be summed up under the three following heads: — Section of the Nerve. 1. Dilatation of Bloodvessels. 2. Afflux of Blood. 3. Increase of Vital Properties. Galvanization of the Nerve. 1. Contraction of Bloodvessels. 2. Diminution of Blood. 3. Decrease of Vital Properties. The view, that the section of the cervical sympathetic is followed by a paralysis of the bloodvessels, in consequence of which more SECTION OF CERVICAL SYMPATHETIC NERVE. 143 blood passes through these vessels in a given time, producing the increase of the vital properties of the contractile and nervous tis- sues — this view- is now admitted by almost all physiologists. It is based on a great many various experiments made by Dr. Aug. Waller, Donders, and several of his pupils, Kussmaul, and Tenner, Moritz, Schiff, and myself, showing that all the circumstances, whatever they may be, which cause an increase in the quantity of blood passing in the bloodvessels of the head in a given time, pro- duce there almost all, if not all, the phenomena following the sec- tion of the cervical sympathetic. The hanging down of an animal, by holding it by its hind-legs, in producing a congestion in the head, produces very nearly all the effects of this section. 1 We regret very much not having time to relate the most decisive proofs of the view that we hold. Many of these facts not only prove the correctness of our view, but they show the untenability of a vitalistic theory, according to which the normal actions of the sympathetic nerve would be increased after it has been divided, and diminished when it is excited by galvanism, and according to which, also, nutrition and animal heat would be dependent upon the sympathetic nerve, which would produce an increase of these two functions after it has been divided (although it then ought to cease to act), and a diminution of these functions when it is galva- nized (although it then ought to act more than normally). However, we are ready to acknowledge that there are other causes of active circulation in the head, after the section of the cer- vical sympathetic, besides the paralysis of the bloodvessels. The very fact that there is more blood producing an increase in nutri- tion and secretion — a fact which depends chiefly, as we- have said, upon the paralysis of bloodvessels, produces an increase in the normal suction-power of the capillaries. In other words, the greater afflux of arterial blood is itself, through the increased chemical changes of nutrition and secretion, a cause of attraction of arterial blood. 2 To this cause another one of the same kind ought to be 1 See my paper, " Sur les Effets de la Section et de la Galvanization du Grand Sympathique. Paris, 1854. 2 For the demonstration of the normal attraction of arterial blood by the living tissues, and of the participation of capillaries in the causes of the circulation of blood, I will refer to the learned treatises on Human and Comparative Physiology of Prof. Carpenter ; to the original works of Professor Draper, of New York ; and, especially to a most able and complete treatise on the subject — although modestly published as a review — by Mr. W. S. Savory. {Brit, and For. Med.-Chir. Rev., April and July, 1855.) 144 THE CENTRAL NERVOUS SYSTEM. added: it is, that as there is more blood, the temperature is in- creased, and as the temperature is augmented, the chemical changes, which are a cause of attraction of blood, are also augmented. From this statement it may be concluded that the primitive, and, I may say, by far the principal, cause of augmentation in the afflux of blood, is the absence of contraction of the bloodvessels, which allows this liquid to pass easier there than elsewhere. We now come to the question, What is the origin of the cervical sympathetic nerve? That most ingenious physiologist, Dr. Augus- tus Waller, has made experiments, with Prof. J. Budge, which seem to prove that the nerve-fibres of the cervical sympathetic that go to the iris originate from the spinal cord, between the sixth cervical and the fourth dorsal vertebrae. We have ascertained that the origins of the fibres of the sympathetic going to the iris are more extended than they thought. A section of a lateral half of the spinal cord at the level of the fifth, the sixth, and even sometimes as low clown as the ninth or tenth, dorsal vertebra, affect the iris like the section of the sympathetic, though in a less degree. On the other hand, we have seen, as Schiff also has, that some of the fibres animating the iris ascend the cervical part of the spinal cord, and most probably go up to the medulla oblongata. As regards the other fibres of the sympathetic, those going to the bloodvessels of the various parts of the head, I found, as early as 1852, ' that they come out chiefly from the spinal cord, by the roots of the last cervical, and first and second dorsal nerves. Their place of real origin I think to be, partly the spinal cord, partly the higher portions of the encephalon, but chiefly the me- dulla oblongata and the neighboring parts of the encephalon. In the other parts of the body the nerves of bloodvessels seem to come chiefly from the cerebro-spinal centre, as well as the cer- vical sympathetic. If we divide transversely a lateral half of the spinal marrow in the dorsal region, we find in the lower limb on the same side most of the effects of a section of the sympathetic in the neck. Amongst these effects we may point out the following: 1st, dilatation of bloodvessels ; 2d, greater afflux of blood; 3d, ele- vation of temperature; 4th, hyperalgesia; 5th, increase of the vital properties of muscles, and of the motor nerves. 2 The following list contains the most interesting features of this comparison: — 1 Medical Examiner, Philadelphia, Aug. 1852, p. 489. 2 See Proceedings of the Royal Society, vol. viii. No. 27, 1857, p. 594. ORIGIN OF NERVES OF BLOODVESSELS. 145 Section of the cervical sympathetic nerve ; its effects on the corresponding side of the face. 1. Bloodvessels dilated (paralyzed). 2. As a consequence, more blood. 3. Elevation of temperature. 4. Sensibility slightly increased. 5. Sensibility lasting longer there than on the other side, when the animal is chloroformized. 6. Sensibility lasting longer there than on the other side, during agony. 7. Many muscles contracted. 8. Absorption more rapid. 9. Increase of sweat and other secretions. 10. Reflex movements last longer there than elsewhere, after death. . • 11. After poisoning by strychnia, the first convulsions take place. 12. A galvanic current too weak to ex- cite contraction elsewhere, may act there. 13. The motor nerves after death, re- main longer excitable there than on the other side. 14. The muscles, after death, remain longer contractile there than on the other side. 15. The contractility of bloodvessels is greater, and lasts longer there. 16. The galvanic muscular current (as ascertained with the rheoscopic frog), is stronger, and lasts longer there than on the other side. 17. Cadaveric rigidity appears later there than on the other side, and it lasts longer. 18. It is easier to regenerate there than on the other side, the vital properties of nerves and muscles by injections of red blood, a short time after they have disappeared. 19. Putrefaction comes on later, and seems to progress more slowly there than on the other side. Section of a lateral half of the spinal cord in the dorsal region ; its effects on the posterior limb on the corresponding side. 1. The same effect. 2. The same effect. 3. The same effect. 4. Very much increased. 5. Lasting longer than anywhere else, during chloroformization. 6. Lasting longer than anywhere else during agony. 7. A state of slight contraction in many muscles. 8. The same effect. 9. Increase of sweat. 10. The same effect. 11. The same effect. 12. The same effect. 13. The motor nerves, after death, re- main notably longer excitable there. 14. The muscles after death remain much longer contractile there. 15. The same effect. 16. The same effect (more marked). 17. Cadaveric rigidity appears notably later there than elsewhere, and lasts longer. 18. The same effect (more marked). 19. The same effect (more marked). The question concerning the real origin of the nerves of blood- vessels in the cerebro-spinal centres is not yet entirely solved, but K 146 THE CENTRAL NERVOUS SYSTEM. many points are already established. I will postpone, however, all that I have still to say on this subject till I treat of the share these nerves take in certain pathological conditions. We have already said what are the effects of the galvanization of the cervical sympathetic nerve. We will add only a few re- marks to our previous statements. The motor nerve-fibres of the sympathetic which go to bloodvessels (the vasomotor nerve-fibres), are able to act when directly excited; but there does not lie the principal feature of their physiological history; they are also able to produce the contraction of the bloodvessels by a reflex action. The first fact in science which established positively that such a phenomenon is possible, was observed by my friend Dr. Tholozan, and myself. We found that the bloodvessels of one hand contract very much when the other hand is dipped into water at a very low temperature (from 32° to 34° Fahr.). The more pain we felt from the influence of the cold water, the more and the sooner did the bloodvessels of the hand left out of the water contract. 1 Since the time we published these facts, several physiologists have found that the bloodvessels of the ear, which receive their motor nerve-' fibres from the cervical sympathetic, contract when the cutaneous branches of some of the spinal nerves are excited. Various deci- sive experiments have proved that this contraction takes place by a reflex action. When we treat of epilepsy, we will show that one of the principal features of a fit depends upon a reflex contraction (through the sympathetic), of the bloodvessels of the brain proper. The bloodvessels, like muscles of animal life, may have spasms, as well as they may be paralyzed. In certain injuries to the nervous centres there are spasms produced in the bloodvessels of many parts of one-half of the body, at the same time that there are paralysis and dilatation of those of the other half of the body. A section of a lateral half of the spinal cord near the medulla oblongata produces this curious effect; on the side injured, the bloodvessels of the extremities are paralyzed; while on the oppo- site side they are spasmodically contracted. Very often the spasm persists for days, and after temporary relaxations it alternately re- appears and disappears again. The spasm of bloodvessels may be so great that circulation is almost entirely suspended; the temperature of the limbs (especially 1 See my Experimental Researches on Physiology and Pathology, 1853, p. 32, and Journal de la Physiologie de l'Homme, etc., Paris, Juillet, 185S. p. 497. SPASM OF BLOODVESSELS. 147 that of the toes) falls quicker than after death, and it is soon at nearly the same degree as that of the atmosphere. In one case, in a dog, we have seen the temperature of the toes on the left side, after the section of the right half of the cord in the cervical region, falling from 26° Centigrade (78.8° Fahr.) to 15J° (59.9° Fahr.), the atmosphere being at 15° (59° Fahr.). In the toes, on the right side, the temperature had increased extremely, and reached 36° Cent. (96.8° Fahr.). If we have time, we will try to show, in another lecture, that this spasm of bloodvessels is the cause of the coldness of the feet and hands in epileptics and certain paralytics: it is a result of an irritation of the cerebro-spinal axis, and chiefly of the upper parts of the spinal cord and of the medulla oblongata. We will also try to show the share of this spasm in the cold stage in intermittent fever, in cholera, or after the introduction of a catheter in the urethra, &c. In the posterior limb of a dog, in which the bloodvessels are in a state of spasm, the circulation is so much impeded, that the cut- ting of the skin hardly gives a drop of blood. As this state exists in cases of a section of a lateral' half of the spinal cord, near the encephalon, and as the other posterior limb has then its blood- vessels paralyzed, and, therefore, dilated, it might be supposed that the diminution in the amount of blood in one limb depends on the increase of its amount in the other. Let us imagine, for instance, that the right lateral half of the spinal cord has been divided; the bloodvessels of the posterior limb, as, also, those of other parts on the same side, are paralyzed, and, therefore, they do not oppose any resistance to the causes of the circulation of the blood, while the left posterior limb continues to have its bloodvessels resisting to these causes. I suppose that the amount of blood passing in the aorta, where it divides into the two common iliac arteries, is, in a given time, twenty ounces, ten for each of the posterior limbs, and that, after the operation (the aorta continuing to give the same amount of blood), sixteen ounces, instead of ten, pass in the right common iliac, on account of the paralyzed state of its branches, and of their ramifications. The result of such a change ought to be, that only four ounces will pass in the left common iliac. Sup- posing this to be the case, the diminution of circulation in the left limb might be explained, without our admitting the existence of a spasm of bloodvessels. But it is not on the simple fact that circu- lation is diminished, that I ground the opinion that there is a .US THE CENTRAL NERVOUS SYSTEM. spasm : it is on the result of direct experiments, the detail of which I have not time to describe, but of which some show — 1st, that if a ligature be put round the right iliac artery in a dog operated upon as we have already stated, the temperature rises but little, and slowly, in the extremity of the left limb, although almost the whole of the blood coming from the aorta passes into the left iliac, and it is quite evident that the small arteries, at least near the toes, do not allow the blood to pass freely; 2d, that an injection of blood by the femoral artery is difficult to be made in the left limb, compared to limbs of healthy dogs. In those cases of gangrene in which no obstruction has been found after death in the vessels of the dead parts, it is extremely probable that a long-persistent spasm of the bloodvessels has existed, rather than simply a cessation of the attraction of blood, according to the explanation of Dr. Houston. 1 Now, to sum up all that we have stated about the sympathetic nerve, we will say — first, that it is essentially (though not exclu- sively) a motor nerve of bloodvessels ; secondly, that it originates chiefly from the cerebro-spinal axis ; thirdly, that its paralysis is characterized by a dilatation of bloodvessels and an afflux of blood, with the results of this afflux; fourthly, that its excitation, direct or reflex, is characterized by a contraction of bloodvessels, and the results of this contraction. The question now comes : Can we explain all the phenomena, normal and pathologic, showing the direct or the reflex influence of the nervous system on nutrition and secretion, by the above notions concerning the effects of paralysis or excitation of the sympathetic nerve on bloodvessels ? For several years I have felt inclined to admit the possibility of an explanation of these pheno- mena founded only upon these notions, but I must say, that facts discovered by Ludwig, by Czermak, and, especially, by Professor Bernard, seem to have solved the question in the most positive manner, and that it seems absolutely certain that there is some agency of the nervous system which is not simply an influence on the constricting muscular fibres of the bloodvessels, in the normal or pathological phenomena of nutrition and secretion. I must add, also, that the views held, in this respect, by the most eminent British physiologists (Mr. J. Paget, Dr. Carpenter, Dr. Todd, and 1 See his interesting remarks on a case of Mortification after Fever, in the Dub- lin Medical Journal, 1836, pp. 217-219. INFLUENCE ON NUTKITION AND SECEETION. 149 others) have, by the discovery of the facts I allude to, received a sanction which, I confess, they needed. The principal amongst these facts is the following: Instead of contracting, the blood- vessels of the salivary glands become enlarged, when certain nerves are excited. 1 I think that this enlargement in the blood- vessels must be due to a greater attraction of the arterial blood by the tissue of the gland; and we explain this increased attraction by the production of the chemical interchanges between the secre- tory tissue and the blood, which are rendered manifest by the secretion of saliva, then taking place. The researches of Czermak and of Professor Bernard tend to show that the increase in the salivary secretion does not depend on the sympathetic nerve, but on the lingual ; and we have now, in this discovery, the explanation of the following apparent con- tradiction : how can it be that the glands of the eye, of the ear, &c., secrete more when their bloodvessels are paralyzed and en- larged after the section of the sympathetic nerve, and that an increase in the secretion of the salivary and other glands is due to a nervous excitation ? How can it be that, in one case, secretion is increased when the bloodvessels are dilated, and that, in other cases, it would be increased while their vessels ought (according to what we thought) to be contracted ? This contradiction dis- appears now that Bernard shows that, instead of being contracted, the bloodvessels are dilated in these last cases. Besides, the experi- ments of Czermak and Bernard show that the salivary secretion is arrested when the sympathetic nerve is excited ; and we know that this nerve, when excited, has the same stopping influence on the lachrymal and on the mucous glands of the eye and ear, &o. From this discussion we conclude that there are two kinds, at least, of immediate influences of the nervous system, either by a direct or by a reflex action, on nutrition and secretion, normal or pathologic. By one, which we see plainly when the cervical sym- pathetic nerve is excited, the bloodvessels contract, and there is a diminution of secretion and nutrition ; by the other, the discovery of which is chiefly due to Prof. Bernard, the bloodvessels dilate in consequence of a greater attraction for arterial blood developed in the tissues- 2 Which of these two modes of action is the most fre- 1 This had been found by Professor Bernard. See the Journal de la Physiol, de l'Homme, &c, April, 1858, p. 240, and especially October, 1858, pp. 646-665. 2 Recently, Professor Bernard has considered this dilatation as an active phe- nomenon ; and he has imagined that the capillaries have two properties, one of 150 THE CENTRAL NERVOUS SYSTEM. quent? and which is the most powerful in producing the normal and the morbid phenomena of nutrition and secretion ? These are questions very difficult to be solved. If we have time, however, we will, in our next lecture, mention facts throwing some light upon them. contraction and the other of dilatation ; and that the first of these properties is put in play by one set of nerves, and the other by another set. We have no doubt that he will soon abandon these hypothetic and untenable views. (See Journal de Physiol, pp. 646-665.) 151 LECTURE X. ON THE INFLUENCE OF THE NERVOUS SYSTEM UPON NUTRITION AND SECRETION; WITH REMARKS ON THE IMPORTANCE OF THE KNOW- LEDGE OF THIS INFLUENCE FOR THE TREATMENT AND THE EXPLA- NATION OF THE PRODUCTION OF MANY DISEASES. Distinction between the effects of the excitation of the nervous system and those of the absence of action of this system. — Three kinds of reflex actions : contrac- tion, secretion, and modification of nutrition. — Normal and morbid reflex secre- tions. — Normal and morbid reflex changes in nutrition. — Reflex influence of injuries of the trigeminal nerve upon the eye. — Reflex influence of one eye upon the nutrition of the other. — Sudden arrest of the heart's movements by a reflex action. — Cause of the rapid death after injuries of the abdominal sympathetic nerve. — Stoppage of the heart's movements by the application of cold to the skin, by the influence of cold drinks, and in some cases of death by chloroform. — Reflex influence of burns on the principal viscera. — Inflammation of the eyes, of the testicles, of the nervous centres, &c, by a reflex action. — Muscular atrophy due to an irritation of sensitive nerves. — Paralysis and ansesthesia due to a reflex action. — Disturbance of the functions of the brain and of the senses produced by irritation of centripetal nerves. — Other instances of reflex changes of nutrition. — Mode of production of the secretory and nutritive reflex actions. — Importance of the knowledge of the reflex secretory and nutritive phenomena for the treatment of disease. — Influence of the irritation of the nervous centres and of the centri- fugal nerves on nutrition and secretion. — Influence of the absence of nervous action on nutrition, repair and secretion. Mr. President and Gentlemen: To understand fully the mode of influence of the nervous system, in health and disease, upon nutrition, secretion, and animal heat, it is necessary to distinguish clearly the effects due to this influence from those due to its absence. Although these two kinds of effects are very different one from the other, they have very often been confounded. For instance, it might be easily shown that many of the best writers on physiology and pathology, when trying to prove that an influence of the nerv- ous system is necessary to nutrition and secretion, bring forward facts showing the effects of excitation of the nervous system, together with facts depending upon the absence of action of this system. 152 THE CENTRAL NERVOUS SYSTEM. The influence of the nervous system on organic functions cannot be proved to be necessary by facts showing only that this system can act upon these functions. There is no question at all that the nervous centres and most of the nerves, directly, or by a reflex action, can produce the greatest and the most varied effects on nutrition and secretions; but this power of acting of the nervous system does not and cannot show that these organic functions re- quire for their normal existence a peculiar influence of the nervous organs. The only facts that can prove positively that a nervous influence is necessary to the organic functions, are to be found in the effects of the absence of any influence of the nervous system. We will, by and by, examine this kind of effects; at present, we propose to study the effects of excitation of the nervous system upon those functions. The influence of the nervous system on the organic functions as well as upon contractile tissues, may take place in consequence of irritations on centrifugal nerve-fibres, on nervous centres, or on centripetal or sensitive nerve-fibres. We will first study the effects of the irritation of the centripetal nerve-fibres. It is well known that three kinds of reflex phenomena may be due to such an irrita- tion : 1st, a contraction of muscles or of any kind of contractile element; 2d, a secretion; 3d, a change in the nutrition of some part of the body. 1 These three kinds of reflex actions are represented in Fig. 23. 1 A short time before his death, Dr. Marshall Hall {The Lancet, 1857, vol. i. pp. 4 and 108) announced, as a new discovery, the supposed existence of a system of excito-secretory and secretory nerves. Dr. H. F. Campbell, of Georgia (U. S.), has claimed the priority of this discovery, which Dr. Hall has, in a great measure, candidly conceded to him {ibid., pp. 462-464). We will merely remark here, that Dr. Campbell seems really to have been the first to introduce in science the hypo- thesis that there exists a secretory and excito-secretory system of nerves, but that neither he nor Dr. Hall has adduced a single fact to prove the existence of this pretended independent or distinct system of nerves. Both these physiologists seem not to have been aware that reflex secretions and reflex changes in nutrition were perfectly known, and that the question was, not to prove that there are such reflex phenomena, but whether they are to be explained by a reflex influence on blood- vessels or otherwise. Any one desirous to know the state of science, in this re- spect, before the first publication of Dr. Campbell, will find, easily, that it was more advanced than in the last paper of this able physiologist, in Mueller's Manual of Physiology (2d German edition, 1837), in Stilling's Treatise on Spinal Irritation (1840), and in several works of Henle published in 1840 and 1841. Since that time there has been no treatise on Physiology or General Pathology, and no paper nor other work on Inflammation, that does not speak of reflex phenomena of nutri- tion or secretion as of something well known. However, we are pleased to be able INFLUENCE ON NUTRITION AND SECRETION. 153 The first decisive experimental proofs that secretions may take place by a reflex action have been given by Ludwig, 1 Colin, 2 Czer- mak, and Prof. Bernard for the salivary secretion, and by this last physiologist for the secretion of sugar in the liver. The laws of reflex secretions seem to be the same as those of reflex movements : 1st, the peripheric ramification of centripetal nerves has much more power than their trunks for the production of a reflex secretion; 2d, there are certain centripetal nerves which normally can produce certain secretions by a reflex action, while others cannot; but a morbid condition of a nerve or of the nervous centres is able to render almost any nerve capable of producing any secretion ; 3d, certain kinds of irritation produce reflex secretions which other kinds cannot produce, except in morbid states. These laws are proved by many facts, some of which I will relate as illustrations of reflex secretious. The consensus between the various digestive organs affords the most positive demonstrations of reflex secretions. For instance, we find saliva secreted when the mucous membrane of the stomach is irritated by food. Dr. Gairdner 3 speaks of a man, whose oesophagus being divided, had a secretion of from six to eight ounces of saliva during a meal of broth injected into the stomach. The reverse takes place also; the excitation of the nerves of taste produces an abundant reflex secre- tion of gastric juice, and also a flow of bile and pancreatic juice in the bowels. Several times I have seen injections of warm water in the rectum of a dog, having a gastric fistula, producing a secretion of gastric juice. There is some importance in the knowledge of these facts ; for instance, guided by this knowledge, we can, if necessary, increase or decrease the quantity of gastric juice, in re- commending the use of very sapid or of nearly insipid food, &c. The morbid influences acting upon the digestive organs to pro- duce secretions are very well known. I shall only point out that the curious effects of the ligature of the oesophagus (congestions and secretions in the stomach and bowels, efforts of vomiting, &c), to declare that, as if it were impossible for Dr. Marshall Hall to write, even on a well-known subject, without putting upon it the stamp of his inventive genius, he has suggested a very important explanation of the alterations in the mucous secre- tions of the lungs after a section of the par vagum, in his first paper on reflex secretions (loco cit., p. 4). 1 Zeitschrift fuer Rationelle Medicin, 1851, N. P., vol. i. 1851, p. 260. 2 Comptes Rendus de l'Acad. des Sciences, 1852, vol. xxxv. p. 130. 3 Edinburgh Med. and Surg. Journal, vol. xvi. p. 355. 154: THE CENTRAL NERVOUS SYSTEM. which have been observed by Messrs. Bouley and Keynal, 1 are very simple phenomena, if we look upon them as reflex actions resulting from the irritation of the centripetal nerve-fibres of the oesophagus. It is important to know that the gastric juice may be so altered by a reflex action due to an irritation on the nerves of the anus or of the rectum, that digestion becomes almost impossible. The late Dr. Chapman, 2 of Philadelphia, relates two cases of dyspepsia (in one of which the gastric juice is said to have been extremely corro- sive) which were cured almost immediately after the extirpation of painful piles. I know a case in which vomiting of a great quantity of unduly-acid gastric juice took place under the irritating influence of worms in the rectum. K. Whytt says, that "the pain of hemor- rhoids is, sometimes, accompanied by a sickness of the stomach and faintness." (Observations, etc., p. 26.) The ptyalism due to neuralgia is a good example of morbid reflex secretion. Dr. Notta (Archives de Medecine, Sept., 1854, p. 298) states that ptyalism has been observed 14 times out of 128 cases of trifacial neuralgia. Dr. Cain, of Charleston, 3 in a very interesting paper, in which he gives many instances of reflex disturbances of secretion and nutri- tion, relates cases which seem to show that croup may be produced by a reflex irritation starting from the stomach. Facts of this kind were already known ; but here the theory of the modus agendi of the gastric irritation on the larynx is clearly exposed and based upon many facts and very sound reasonings. The production of tears affords decided instances of reflex secre- tions. We find that any irritation of the eye, or of the mucous membrane of the nose, causes an increase in the production of tears. Two cases mentioned by Henle 4 as having been observed, one by Sir Charles Bell, the other by Vogt, prove that it is through a nervous excitation that the shedding of tears takes place when we touch the eye. In two patients, the eye having lost its sensi- bility, tears were no more shed when this organ was irritated. Mr. Castorani has recently confirmed, by decisive facts, the view that it 1 See the Report of Prof. Trousseau to the Academy of Medicine of Paris, and my remarks on this Report in the Journal de Physiol., October, 1858. 2 Lectures on the more important Diseases of the Thoracic and Abdominal Vis- cera, 1844, pp. 216-7. 3 The Southern Journal of Medicine, &c, 1847, p. 377. 4 Anatomie Generate, French translation, 1843, vol. ii. p. 255. KEFLEX SECKETIONS. 155 is not through the optic nerve that the secretion of tears is increased in cases of photophobia, when the eye is exposed to the irritation of light: it is through the exalted excitability of the trigeminal nerve. A curious fact observed by Deslandes 1 is in harmony with this view: a man totally blind, had an abundant secretion of tears at every time that he passed from a dark place to a lighted one. The shedding of tears under the influence of irritation of other parts than the eye and nose is less and less the farther the irritation is from the eye. I have experimented upon myself, and found that the pinching of the neck or of the back parts of the head hardly produce lachrymation, while that of the face produces it more and more the nearer to the eye the irritation is made. This increased secretion exists only on the side irritated, except when the pinch- ing is made very near the median line. Mr. Notta 2 mentions that lachrymation has been noted as an effect of neuralgia of the fifth pair of nerves 61 times out of 128 cases. It is chiefly in cases of neuralgia of the supra-orbitary branch that lachrymation is pro- duced. The fact that the irritation of the cornea by a foreign body causes lachrymation, and that the removal of this irritative agent is at once followed by a cessation of this abundant and abnormal secretion, is a good illustration of its mode of production. If I had time, I would show that we must admit that it is by a reflex action that the following secretions take place in the circum- stances that I will point out: 1. Secretion of milk by an irritation of the uterus, of the skin of the mammae, or of the mucous mem- brane of the vagina (particularly by the steam of a decoction of the jatropha curcas, as done at the Cape de Verde Islands). 2. Mens- truation in consequence of an irritation of the ovaries of the vagina or of the mammas by warm poultices, &c. 3. Secretion of nasal mucus increased by application of cold water to the feet, and some- times stopped at once by dipping of the feet in iced water, 3 and increased by a draught of cold air on the neck. 4. Secretion of semen increased by the irritation of the genital organs. 5. Perspi- ration due to neuralgia, as in a case by Dr. Galliet, or due to the excitation of the nerves of taste, by salt or sugar, etc., as in a case I have mentioned to the Society of Biology, in a communication on reflex secretions in 1849. (See Cornptes Rendus de la Soc. de Biol., vol. i. p. 104.) 1 Dictionn. de Med. et de Chir. Pratiques, vol. ii. p. 179. 2 Archives Gener. de Medecine, etc., Juillet, 1854. 3 Hyp. Cloquet, These sur les Odeurs, p. 162. 156 THE CENTRAL NERVOUS SYSTEM. Before treating of the reflex changes in nutrition, which are by far more frequent, and more important to be well investigated, than the reflex secretions, I must remark that the reflex character of facts more or less similar to those I have to mention has been known for a long while, and that the modern theory is not far in advance of that given, in this respect, by Kobert Whytt 1 in the last century. In one of his important works he has shown that the normal and morbid sympathies, either for movements, nutrition, or secretion, are reflex phenomena. Still more, he has shown that the share of bloodvessels is very great in many of these phenomena. Although Kobert Whytt and several other writers, amongst whom I will name Tissot, Prochaska, Barthez, J. Mueller, Henle, and Prof. Martyn Paine, have published so many interesting facts concerning the sympathy between various parts of the body, phy- siologists and practitioners have not paid a sufficient attention to this most important subject. I regret that I cannot enter into great developments on the capital points concerning this subject; but I will, at least, endeavor to show their importance. Keflex changes in nutrition ought to be known as being amongst the most frequent causes of many diseases. An irritation starts from an excitable part of a nerve, it reaches the nervous centres, and thence, being reflected to a more or less distant part of the body, it produces either a contraction of a bloodvessel, and, through this, effects a diminution of nutrition, or it acts directly upon the tissues, and produces an alteration of the interchanges between them and the blood. The eye, amongst all the other organs in the body, is the one that gives the most evident and the most frequent in- stances of this kind of affection. The most positive of these facts, as regards the production by a reflex action, are the following: 1st. When the supra-orbitalis nerve has been crushed or injured, in such a way that it remains irritated, an inflammation or some other affection of the corresponding eye supervenes, which is cured either by the means that diminish the irritation of the injured nerve, or by its section between the nervous centre and the injured part, so as to prevent reflex actions starting from this irritated part. 2d. When an eye is the seat of a violent inflammation, and particu- larly if it be of traumatic origin, it is not rare for the other eye to become affected, and the successful treatment for the affection of this last eye consists in preventing, by various means, the irritation 1 Observations on the Nature, Causes, and Cure of Nervous Disorders, pp. 1-65. EFFECTS OF KEFLEX CHANGES IN NUTRITION. 157 from the first one reaching the nervous centre, by which a reflex action is operated upon the secondarily attacked eye. These two facts are now proved by so many cases, that there can be no doubt as to the mode of production of the consecutive affec- tion of the eye, in both kinds of facts. However, there have been men of great reputation who have doubted the correctness of the etiology of these affections of the eye. For instance, Walther 1 denies that there is a single fact proving that amaurosis may be due to an injury of the frontal nerve. J. Mueller 2 says that it is much more natural to attribute amaurosis, following a blow upon the forehead, to the commotion of the eye and of the optic nerve ; and Mr. Sichel 3 expresses the same opinions. But most of the recent works on the diseases of the eyes contain many, and the most posi- tive facts, showing that several kinds of affection of the eye may be the result of an injury to the frontal or of other branches of the trigeminal nerves. Besides some facts that I shall relate, I will mention the publications of Mr. Deval, as containing many facts of this kind. 4 A paper of Mr. Notta, on Neuralgia, 5 shows that this kind of irritation very often causes congestion of the eye and photophobia. Out of 128 cases of neuralgia of the trigeminal nerve, the eye was congested thirty-four times; and in most of those cases the nerve attacked was the supra-orbitalis. Photophobia existed in eighteen cases; and a real ophthalmia has sometimes been observed. Mr. James, 6 a pupil of Magendie, has seen amaurosis caused by a neu- ralgia, Mr. Notta (loc. cit., Juillet, pp. 12-21) mentions ten cases of amaurosis due to neuralgia. The short duration of this amau- rosis, its relapsing character, and, moreover, its appearance during, or immediately after, an attack of neuralgia, and the fact that it was cured when the neuralgia was cured, prove that it resulted from the irritation of the trigeminal nerve. Alterations in the cornea have been observed in a very curious case of neuralgia of the face, by Mr. Mazade. 7 In a case of hyperaemia of the eye, which had resisted for a year many kinds of treatment, Dr. Emmerich, 1 Journal filer Chirurgie und Augenheilkunde, 1840, vol. xxix. p. 505. 2 Manuel de Physiologie, Trad. Francaise, 1851, p. 707. 3 Traite de l'Ophthalmie, 1837, p. 697. 4 See particularly his Traite de l'Amaurose, Paris, 1850, 8vo. 5 Archives de Medecine, Juillet, Septembre, et Novembre, 1854. 6 Gazette Medicale de Paris, 1840, p. 678. 7 Annales d'Oculistique, 1848, p. 128. 158 THE CENTRAL NERVOUS SYSTEM. quoted by Schiff, 1 states that an immediate cure was obtained after the extraction of a tooth. Prof. Paul F. Eve, of Tennessee, U.S., suggested the idea of the extirpation of a carious tooth to Dr. II. F. Campbell, 2 in a case of ophthalmia, and, the operation having been performed, the patient was at once cured. In a case recorded by Vallez, quoted by Schiff (foe. cit., p. 116), there was strong hype- remia of one eye, with abundant mucous secretion, followed by an ulceration of the cornea, in a man who had received a deep wound in the face, dividing the supra-maxillary nerve. Dr. Alcock, in his important article on the Fifth Pair of Nerves, 3 relates experiments on animals, in which an injury to the infra-orbitalis nerve had pro- duced inflammation and suppuration of the eye. It is worthy of remark that, in these experiments, when the wound healed the eye returned to its normal condition. Morgagni, 4 says that Valsalva has seen amaurosis instantly produced in a woman whose eyebrow had been struck by the beak of a cock. The cases which prove the reflex influence of one eye upon the other are more numerous than those showing the influence of vari- ous branches of the trigeminal nerve of one side upon the corres- ponding eye. Schenk, Eichter, Bidloo, and many other writers of the two preceding centuries, have mentioned facts proving that one eye may be affected by a disease or an injury of the other. In this century, particularly in England, facts of this kind have been very well studied, and the treatment, consisting in the extirpation of a wounded eye to save the other, has been applied many times. 5 The happy influence of such a treatment shows, if this were necessary, that it is on account of an irritation starting from the first injured eye, that the other is affected. Even a cataract may be produced in a healthy eye by a nervous reflex influence, either from some part of the trigeminal nerve on the same side, or from the other eye. Mr. Notta mentions two cases, one of a wound of the frontal nerve, and another of neuralgia, both followed by cataract. (Loc. ciL, Juillet, 1854, p. 28.) Albers 1 Untersucliungen zur Physiol, des Nervensystems, 1855, p. 115. 2 The Secretory and Excito-Secretory System of Nerves, 1857, p. 98. 3 The Cyclopaedia of Anat. and Physiol., vol. ii. p. 312. 4 De Sedibus et Cansis Morhorum, Epist. xiii., s. 5, vol. ii. p. 14. 5 I will refer to an inaugural dissertation (These pour le Doctorat, Paris, 24 Juillet, 1858, par M. de Brondeau), in which there is a relation of no less than twenty-four cases observed by the author, showing the influence of one eye upon the other, for the production of disease. EXAMPLES OF EEFLEX CHANGES IN NUTRITION. 159 relates a case of a wound of the cornea and the iris on the right side, followed, in three days, by an opacity of the cornea of the left eye, and in eight days by a cataract in this last eye. (De Brondeau, he. eit, p. 16.) Aug. Berard has insisted extremely 1 on the necessity of operating on one eye attacked with cataract to prevent the other from beins: attacked. As a second series of examples of reflex changes in nutrition, I will mention what takes place in cases of sudden stopping of the movements of the heart, in consequence of an irritation of some peripheric parts of the nervous system. Whether the heart's move- ments depend, as I have tried to show long ago, 2 upon an excita- tion from some substance contained in the blood circulating through the tissue of this organ upon its muscular fibres, or whether they depend upon some peculiar rhythmical change in nutrition, as ingeniously suggested by Mr. James Paget, 3 their stoppage in the cases I shall mention is produced by a reflex action. The sudden death which sometimes occurs when very cold water is drunk in a warm day, or in cases of a blow on the abdomen, of a sudden perforation of the stomach or intestine, of a wound of some abdominal viscus (without a notable hemorrhage), &c, seems to be due to a reflex stopping of the heart's action. I have made a great many experiments, which show positively that a sudden excitation of the abdominal sympathetic nerve sometimes kills, and often diminishes the movements of the heart, by a reflex action. 4 The excitation goes up to the spinal cord, chiefly along the great splanchnic nerve, and ascends the spinal cord until the place of origin of the par vagum, and through this pair of nerves it comes to the heart. This is proved by the fact that a section of either the par vagum, or the spinal cord, or the splanchnic nerves, allows any kind of irritation to be made on the abdominal sympathetic without a stopping taking place in the heart. In some animals, the influence of the irritation of the sympathetic in the abdomen is much more marked than in others; it is so, probably, in man. I have seen a gentleman suddenly drop down pulseless, in the most complete syncope, from a pain in the abdomen. The same gentleman is easily attacked by syncope from any kind of pain. One day, while 1 Annales d'Oculistique, vol. xi. p. 183. 2 Experimental Researches applied to Physiology and Pathology, 1853, pp. 77 and 114. 3 Proceedings of the Royal Society, May 28, 1857. 4 Recherches sur les Capsules surrenales. Paris, 1856. 160 THE CENTRAL NERVOUS SYSTEM. I was trying to bleed him with the assistance of my learned friend Professor Natalis Guillot, he had, as soon as pricked by the lancet, a complete stopping of the heart's movements, and we thought, for two minutes, that he would die. I took him by his feet, which I put on my shoulders, and then rising, I held him, the head hanging down, and he gradually recovered. It is by the reflex influence due to the sudden irritation of the branches of the par vagum in the lungs that chloroform has killed in the very rare cases in which the heart's action has been stopped before the respiration. In dogs, in which we can cause death in this way rather easier than in other animals, I have found that this mode of death never exists after the section of the par vagum. On the other hand, I have ascertained, in the same kind of animals, that the state of the heart is just the same as when death has been pro- duced by the irritation (by galvanism) of the medulla oblongata and par vagum, or by the extirpation of the so-called vital knot} Besides, another proof that it is in this way that chloroform kills in the cases which I try to elucidate is, that in some dogs, on which the heart's action has been suddenly stopped by the inhalation of a very large quantity of chloroform, I have been able to restore life by merely exciting the heart to contract by mechanical excitation (pressure on the chest). I must point out, apropos of the stopping of the heart's action by a reflex mechanism, that one of the means employed to restore life in asphyxiated children — which consists in the alternative dipping of the body in warm and cold water — is a most dangerous one. No doubt that it is a powerful means of producing reflex actions, as long as any reflex power remains in the cerebro-spinal axis, but in this very thing lies the danger. I have seen puppies asphyxi- ated, and having no more respiration, while the heart was still beating fifteen or twenty times in a minute, killed at once on being dipped into cold water, the heart stopping by a reflex action. I do not intend to say that such a means ought not to be employed; I wish only to point out the chance of a sudden arrest of the heart's action, so that practitioners may be on the watch respecting this accident. An extensive burn may also produce a stopping of the heart's movements, but it frequently produces other effects, which are much more interesting, and prove the great power of the nervous 1 See Journal de la Physiol, de PHomrne, etc., No. 2, Avril, 1S58, p. 217 et seq. REFLEX INFLUENCE OF BURNS. 161 system on nutrition. In an important paper of Mr. Long, of Liver- pool, 1 it is stated that death was caused, in many cases of extensive burns, by an inflammation of the various viscera. The three follow- ing conclusions have been arrived at by Mr. Long : 1st. That in almost every burn, indeed in every burn, lesions of one or more of the viscera contained in the three great cavities exist, being accord- ing to their frequency as follows: abdomen, chest, head. 2d. That the lesions of the different tissues contained in the abdomen are in the following order: mucous membranes, serous membranes, paren- chymatous tissues; in the chest it is quite the reverse — namely, parenchymatous tissues, serous tissues, and lastly mucous ; in the head — membranes, brain. 3d. That the seat of internal inflamma- tion corresponds sufficiently often with the external position of the burn, but that in a precisely equal number of instances no such correspondence can be traced. Mr. Curling, in a paper on the In- fluence of Burns on the Bowels, 2 relates ten cases of ulceration of the duodenum as a consequence of this powerful irritation of the skin. Lastly, in a very remarkable paper, Mr. J. E. Erichsen 3 gives the following as the result of observations of many cases of burns : — The cerebral organs were diseased in 33 out of 37 cases. The thoracic viscera " " in 30 out of 40 " The abdominal viscera " " in 31 out of 42 " I have given these numbers to show the frequency of this reflex influence of burns. When I come to the deductions to be drawn from the facts I have mentioned in this lecture, for the treatment of disease, I will show the importance of the knowledge of this in- fluence of burns, and I will show, also, what should be done against this frequently deathly influence, according to the view that it acts by a reflection from the nervous centres upon themselves, or upon the thoracic or the abdominal viscera. 4 When we come to the demonstration that the phenomena which we have mentioned in this lecture are really to be attributed to a reflex action, we will show what parts of the alterations in the various viscera, after extensive burns, belong to a reflex influence, and what parts are due to other causes. But we will, at once, 1 Philadelphia Medical Examiner, 1840, p. 492; from the London Medical Gazette, Feb. 1840. 2 Medico-Chirurgical Transactions, 2d Series, vol. vii. 3 London Medical Gazette, Jan. 1843, pp. 544 and 588. 4 That the nervous centres may act upon themselves, just as upon other organs, by a reflex action, will be shown hereafter. « L 162 THE CENTRAL NERVOUS SYSTEM. relate cases which show that several of the inflammations of internal organs after burns may be due to a reflex action, in showing that inflammations in various parts of the body may be caused by an irritation of the nerves of the skin or of other sensitive nerves. Inflammation by a reflex action. — In his admirable " Lectures on Inflammation," delivered in this College, Mr. James Paget said that whoever has worked much with microscopes may have observed, as he has upon himself, that the eye not employed becomes inflamed; and he adds that the fact cannot be explained except by the suppo- sition that the excited state of the optic nerve of the working eye is transferred or communicated to the nerves of the conjunctiva of the other eye. He thinks that the communication must take place through the encephalon, and therefore by a reflex action. 1 I know of a most curious case of inflammation of the cornea and conjunc- tiva, followed by ulceration and opacity of the cornea, due to that very cause : overwork with the microscope. It has occurred in a distinguished friend of mine, Dr. F , now Professor, at Lille. In this case, anesthesia and a degree of atrophy of the face were produced at the same time as the ophthalmia, on the left side, the micrographer making use of the right eye. If I had time I would endeavor to prove that it is not by a reflex action from the optic nerve, but from the filaments of the trigeminal, in one eye, that this inflammation of the other eye has proceeded. The recent works on diseases of the eye contain many cases of inflammation of this organ by a reflex action, and I will refer for some cases of ophthalmia due to this influence to the cases of irritation of the dental nerves, ob- served by Emmerich and by Dr. Eve, and to the experiments of Dr. Alcock, which I have already mentioned. It is not rare that an inflammation of the testicle takes place by a reflex action. Barras, quoted by Notta {he. cit, Nov., p. 547), and Marotte 2 relate cases of orchitis due to ileo-scrotal neuralgia. Sir B. Brodie 3 mentions a case of inflammation of one testicle due to the irritation of the ureter by a calculus, and a case of inflamma- tory swelling of the face due to a neuralgia. Mr. J. Paget (loco cit. } p. 54) says that it is through a nervous action that the urethra excites inflammation of the testicle ; that the irritation of teething excites this morbid nutrition in any distant part, and that inflam- 1 Lectures on Inflammation, 1850, p. 12. 2 L'Uiiion Medicale, 1851, p. 155. 3 Lectures Illustrative of certain Local Affections. London, 1S37, p. Il3. MUSCULAR ATEOPHY BY REFLEX ACTION. 163 mation of the brain has been caused by the application of a ligature to the brachial plexus, as in a case observed by Lallemand. Inflammation of the brain seems manifestly to have been gene- rated by a reflex influence in a case recorded by M. P. Meynier. 1 The same thing may be said of a great many cases of inflammation of the spinal cord or medulla oblongata, in tetanus or trismus nas- centium. 2 Other inflammations may be produced by a reflex action : I have seen purulent otorrhoea taking place at every attack of neuralgia of the auriculo-temporalis nerve in a young girl. I have seen a real inflammation of the stomach, in a dog, after the irritation of the filaments of the par vagum in the oesophagus, and Professor Trousseau has made a similar observation. My learned friend, Mr. P. Broca, has seen several cases of pleurisy due to an irritation of the nerves of the breast, by some operations. Muscular atrophy by a reflex action. — My friend and pupil, M. Clement Bonnefin, is now collecting facts of this kind, and already he has found a great many. He has observed a very evident one in which the atrophy is due to a neuralgia. M. Notta says {loco tit., Nov., p. 557) that in seven cases of neuralgia a more or less exten- sive atrophy has been observed. I have seen two cases : one of sciatica, having produced an atrophy of some of the muscles of the leg ; the other, in which pain starting from the cicatrix of a wound on the left forearm has caused atrophy of both arms. In the case of an injury to the supra-maxillary nerve which I have already men- tioned, 3 there was atrophy of the face. In the case of my friend, Dr. F , the ulceration of the eye, due to irritation of the other, is accompanied by an atrophy of some muscles of the face. In several of the cases of muscular atrophy collected by Dr. W. Roberts, 4 there is sufficient evidence that this condition of the mus- cles has been caused by a reflex action (particularly in some cases of Sir Charles Bell, of H. Mayo, of Aran, of Eomberg, of Frerichs, and of Dierner). That the paralysis of atrophied muscles is not the only cause of 1 Gazette Medicale de Paris. Decembre, 1856. 2 It is probable that it is in the same way that inflammation of the spinal cord was produced in those very interesting cases recorded by Dr. W. W. Gull, and in which a disease of the viscera of the pelvis or diphtheria has preceded the symp- toms of myelitis. (See the Medico- Chirurgical Transactions for 1856, and the Lancet, July, 1858, p. 4.) 3 Vallez, quoted by Schiff (loco cit., p. 115). 4 An Essay on Wasting Palsy. London, 1858. 164 THE CENTRAL NERVOUS SYSTEM. atrophy is shown by the fact that this state of the muscles has often existed without paralysis, or at least before paralysis, and some- times although there were convulsions in the muscles. jSTotta men- tions three cases in which constant or frequent convulsions occurred while atrophy was increasing. Paralysis and anaesthesia by a reflex action. — The number of facts of this kind is immense, as shown in the voluminous papers and works of E. Leroy d'Etiolles, 1 of Landry, 2 and of Macario. 3 It would be most important to review these cases to show that they cannot have been produced otherwise than by a reflex action, pro- ducing an alteration of either the spinal cord or of some of its nerves ; but we have not time enough for such a review, and we must therefore be content to mention a few amongst those facts which, more than the others, seem to prove that the cause of the paralysis or of the anaesthesia is truly in a reflex action. It is well known that we owe to Mr. Edward Stanley 4 the proof that diseases of the genito-urinary organs can be the cause of para- plegia. Eayer, 5 Leroy d'Etiolles (loco cit.\ Macario (loco cit.), and others, have related many facts which leave no doubt as to the possibility of existence of a more or less complete paraplegia with- out any visible alteration of the spinal cord or of its nerves, and due to a disease of either the bladder, the prostate, or the kidney. Other viscera of the abdominal and thoracic cavities may also be the starting point of a paralysis ; Dr. E. Graves 6 is the first who has well established this etiology of certain kinds of paralysis. In children, the pretended essential paralysis, so well studied by Heine, Kennedy, Dr. "West, Fliess, and Eilliet, 7 is evidently analogous in its mode of production with the reflex paralysis of adults. This paralysis of children is almost always due to the irritation of the dental nerves or of the bowels. Marchal de Calvi 8 relates four cases of neuralgia of the fifth pair 1 Des Paralysies des Menibres Inferieurs ou Paraplegies, lere partie, 1855 ; 2de p., 1857. 2 Recherches sur les Causes et les Indications Curatives des Maladies Nerveuses, 1855. 3 Gazette Medicale de Paris, 1857, pp. 564 and 606. 4 Medico-Chirurgical Transactions, vol. xviii. p. 260. s Traite des Maladies des Reins, vol. iii. 1851, p. 16S et seq. 6 Clinical Lectures on the Practice of Medicine. Ed. by Neligan. 7 Traite des Maladies des Enfants. par Rilliet et Barthez, 2d edition, 1853, vol. ii. p. 547. s Archives de Medecine, 1846, vol. xi. p. 261. PAKALYSIS AND ANESTHESIA BY KEFLEX ACTION. 165 of nerves which had produced a paralysis of the third pair. Notta (loco cit., Sept. 1854, p. 293) has seen two cases of paralysis of the elevator palpebrae, due to a neuralgia. Keucourt 1 and M. Grola 2 have each seen one case of facial paralysis cured at the same time that a neuralgia, which had caused it, was cured. Dr. Badin d'Hurte- bise 3 has seen a neuralgia of the supra-orbitalis nerve producing a paralysis of the third and sixth pairs of nerves, which paralysis ceased quickly after the cure of the neuralgia. Sciatica, also, may produce a paralysis : Notta (p. 556) mentions a case in which the paralysis of the extensor muscles lasted two months after the cure of the sciatica. Irritation of the bowels in adults has often pro- duced paralysis: besides cases recorded by Dr. Graves and by Leroy, there are two mentioned by Professor Trousseau, 4 several by Zabriskie 5 and by Camper. 6 Irritation of the lungs or the pleurae may also produce paralysis : I have seen a case of this kind, in 1850, at the Charite Hospital in Paris ; and Landry (loco cit., Obs. 118 and 119) relates two cases. The same thing has occurred in diseases of the liver, without our being able, in some cases, to ex- plain the paralysis by the presence of bile in the blood. I will point out especially a case of hepatic colic observed by Professor Fouquier (quoted by Landry, p. 99) and a case by Zabriskie. 7 A simple pressure on some sensitive nerve, or a wound, may cause an extensive paralysis : so it was in a case that I have observed with my friend M. Charcot, and in cases recorded or mentioned by Pabricius Hildanus (quoted by Whytt, loco cit., p. 18), and by Barthez (loco cit., vol. ii. pp. 41 and 42, notes, and p. 127). The production of anesthesia from irritation of centripetal nerves is as common as that of paralysis of movement. I have seen a case of anaesthesia of the two lower limbs due to sciatica. M. Notta (loco cit, Nov., pp. 552-54) mentions five cases like this one — three ob- served by himself, one by Grisolle, and one by Martinet. A case of anaesthesia of the arm in consequence of a cervico-brachial neu- ralgia, is also related by Mr. Kotta. Several cases of more or less extended anaesthesia, due to some kind of irritation of the skin, 1 Arch., 1849, vol. xx. p. 172. 2 Bulletin de Therapeutique, 1846, vol. xxxi. p. 389. 3 Annales d'Oculistique, 1849, vol. xxii. p. 12. 4 Gazette des Hopitaux, 1841, p. 192. 5 Med. Examiner, 1841, vol. iv. p. 750 ; and Gaz. Med. de Paris, 1842, p. 296. 6 Quoted by Barthez, " Science de l'Homme," 2d ed., 1806, p. 11, notes. 7 Gaz. Med. de Paris, 1842, p. 296. 166 THE CENTRAL NERVOUS SYSTEM. have been collected in an excellent thesis of Mr. O'Brien. 1 In one it followed a bite of the skin of the arm. I have seen a young woman who had a partial ana3sthesia of the face, with swelling and infiltration of the cheek, and complete paralysis of the facial nerve, in consequence of neuralgia of the infra-orbitalis nerve. I must say that, in this case, as also in all the cases of paralysis and ana3s- thesia I have mentioned, the patients were not hysteric. I will add that in those cases — 1st, the supposed cause has always preceded the paralysis of movement or sensibility ; 2d, the changes in the intensity of the cause have usually been accompanied by corresponding changes in the paralytic symptoms ; 3d, the remedies against paralysis and anesthesia have proved useless; 4th, these two affections, in many cases, have been speedily cured after the cessation of the irritating cause ; 5th, there was no visible alteration of the nervous system in several cases in which an autopsy was made. All these facts assuredly tend to show that the paralytic symptoms were not due to a disease of the central nervous system } but to an irritation of some centripetal nerve ; and we will show hereafter that it was in producing a peculiar reflex action that this irritation had acted. Morbid changes in the nutrition of the brain, of the sjnnal cord, and of the senses produced by an irritation of some centripetal nerve. — I shall not insist upon the demonstration of the influence that an irritation of almost every centripetal nerve may have on the production of nervous affections, which show that a change in the nutrition of the nervous centres has taken place. In one of the lectures I have still to deliver, I will show, by an immense number of recorded cases, that insanity in its various forms, epilepsy, chorea, catalepsy, extasis, hydrophobia, hysteria, and all the varieties of nervous com- plaints, may be the result of a simple, and often slightly felt, irrita- tion of some centripetal nerve. I will also then prove, or, at least, endeavor to prove, that it is by a reflex action of the cerebro spinal axis upon itself, through the nerves going to its bloodvessels, that this irritation acts to alter the nutrition of this nervous centre. As regards the influence of the irritation of centripetal nerves on the nutrition of the senses, I will refer to what I have already said of amaurosis, adding on]y that the influence by which worms acting on the bowels cause the paralysis of the retina is just the same as 1 Reclierches sur l'Anestliesie. Paris, 1834, pp. 14, 10, 21, and 24. NEURALGIA DUE TO REFLEX ACTION. 167 that by which a neuralgia acts in causing the same effect. 1 Deafness has also been caused by an irritation of the nerves of the bowels, as it has been in two cases of facial neuralgia. (Notta, loco cit., p. 297.) Neuralgia due to a reflex action. — Dr. Rowland mentions a girl, who had paroxysms of darting pain in the left temple and side of the head. Upon inquiry, it was found that several years previously she had received a severe cut over the right parietal bone, which cut was long in healing, and this spot had been tender ever since. A large uneven cicatrix was discovered, and a blister over this part relieved the pain for several weeks. (Parsons, Prize Essay on Neu- ralgia. 2 ) Sir Benjamin Brodie mentions a case of stricture of the urethra inducing lameness and pain in the foot, which were relieved by the introduction of a bougie in the urethra. The irritation caused by a carious tooth has produced neuralgia in the arm in two cases. (Parsons, loco cit., pp. 423 and 424.) Neuralgic hemi- crania is very frequently due to gastralgia. Romberg 3 mentions several cases observed by Wardrop, Abernethy, Denmark, and others, in which a neuralgia in many nerves has been caused by the injury of one. Various morbid influences due to an invitation of centripetal nerves. — I will only point out some of the most interesting facts. In the first place, I will mention the herpes zoster, which is now almost universally admitted as being often due to a neuralgia. Payer, G. Simon, Notta, Dr. Parsons, Delioux, Romberg and Parrot, 4 have related many cases, which leave no doubt on this point. Hasse 5 mentions, besides the zona, the following skin affections as having been caused by neuralgia: erythema, pemphigus, and urticaria. In the second place, I will say that hypertrophy of a bone, in cases of neuralgia, is frequent enough to explain how Sir Henry Halford has been led to imagine that tic douloureux depends upon this affection of bones. There is no doubt that a disease of bones can produce neuralgia — and such is the case for the reflex neuralgia of 1 As some persons deny that worms may have this influence, I will refer to a paper of Mondiere, in which several unquestionable cases are recorded. ( Gazette des Ilopitaux, 1840, p. 139 and p. 248.) In some cases an immediate cure has fol- lowed the expulsion of worms. (IS Experience, 1840, p. 47, and Gaz. Mid. de Paris, 1845, p. 655.) 2 American Journal of Medical Science, Oct. 1854, p. 421. 3 Lehrbuch der Nervenkrankheiten des Menschen, 3d ed., 1856, pp. 23-35. 4 Considerations sur le Zona, par J. Parrot. Paris, 1857. 5 Krankheiten des Nervenapparates, in Virchow's Handb. d. sp. Pathol., vol. iv., 1855, p. 48. 168 THE CENTRAL XERVOUS SYSTEM. most of the branches of the trigeminal nerve in cases of caries of a part of the cranium — but it seems certain also that hypertrophy of bone may be due to neuralgia, as is shown by cases of Komberg, Bouillaud, Neucourt, and Bellingeri. (Notta, loco cit., Sept. 185-1, pp. 311, 312.) I will only add to the list of effects of irritation of centripetal nerves, that oedema, a change in the color and thickness of the hair, and several other morbid alterations, have been observed, in cases in which they were evidently due to that cause. Many interesting facts might be added to those which I have mentioned as illustrations of the power of an excitation of centri- petal nerves to act on glands, so as to produce an increase of all the secretions, or to change their nature, or to stop them, and to act also, at a great or small distance, on the various tissues, so as to increase, diminish, or alter their nutrition. 1 I come now to the explanation of the mode of action of the excitation of a centripetal nerve in those various cases. The phenomena of sympathy between distant parts of the body have, at first, been explained by direct communications, which were supposed to exist between the nerves of the parts which have some sympathetic influence one upon the other. A second opinion was that the communications take place, partly through the nerv- ous centres, partly through anastomoses of nerves. At last, after Claude Perrault and others, Robert Whytt held the view that all nerves producing sympathetic actions communicate only in the brain or spinal cord. 3 Since the times of Whytt and Haller, who agreed as regards this opinion, it had been admitted by most phy- siologists until 1835, when Tiedemann 3 tried again to show that it is through anastomoses of nerves that sympathies take place. But after the microscope had proved definitively that nerve-fibres re- main usually quite distinct one from the other (a few only uniting together), and also, after the experiments of Kronenberg, of Van Deen, and others, had proved that the excitation of nerve fibres passing through anastomoses remains isolated in them, the old theory, renewed by Tiedemann, has been totally ruined, and now 1 For several facts worthy of interest, I will refer to the learned work of Henle, "Handbuch dor Rationelle Pathologie," vol. i. 3d ed., 1855, pp. 237-41. 2 See his two important works, " An Essay on the Vital and other Involuntary Motions of Animals," 2d ed., 1763, and " Observations on the Nature, Causes, and Cure of Nervous Disorders," &c, 2d ed., 1765, pp. 9-84. 3 Zeitschrift fuer Physiologie, vol. i., 1835. SYMPATHETIC PHENOMENA. 169 it is universally acknowledged that real sympathies require the intervention of the nervous centres. But, although admitted as the right one, this view seems not to be sufficiently understood, and the efforts made by Mueller, by Stilling, 1 by Henle, 2 by Dr. Marty n Paine, 3 and others, have not convinced every one that changes in secretion and in nutrition, due to a sympathetic influ- ence, are produced, in a great measure, by the same mechanism as that of the reflex movements. Let us take inflammation as an illustration. An operation is made on the cervix uteri, 4 and, one or two days after, a peritonitis supervenes, and the patient dies. How has this inflammation been produced ? Few persons will be ready to explain this affection by a reflex action from the uterus to the peritoneum, and many would laugh at the idea of such an explanation. It is evident, assuredly, that the inflammation may have begun in the uterus, and been propagated to the peritoneum by bloodvessels ; but let us suppose that no inflammation is found in the uterus or in the vagina, how then can an inflammation have been produced in the peritoneum, in consequence of an operation upon the cervix uteri ? If you do not admit that the excitation of the nerves of this part of the womb has been propagated to the spinal cord, and thence reflected by other nerves upon the . peritoneum, you will not be able to explain the phenomena observed. If we take separately almost any one of the facts I have mentioned as instances of reflex secre- tory or nutritive actions, many persons will decline admitting with 1 Physiol., Pathol., und Med. Pract. Untersuchungen ueber die Spinal Irritation. Leipzig, 1840, and Geschichte einer Exstirpation eines Krankkaft vergr. Ovarium's, u. s. ic. Hanover, 1841. 2 Handbuch der Rationellen Pathologie. Dritte anflage. Vol. i., 1855, and his Pathologische Untersuchungen, 1840, and Algemeine Anatomie, 1841. 3 The Institutes of Medicine. New York, 1847. The learned author of this work is a solidist and a vitalist, who has carried the theory of sympathies of Whytt and others far beyond the limits within which it ought to be restricted. 4 My learned friend, Mr. P. Broca, has recently communicated to the Societe de Chirurgie of Paris the case of a woman on whom an application of the actual cautery to the cervix uteri, after the extirpation of a polypus, was followed by an intense peritonitis and rapid death. The state of the uterus showed that this was not a case of propagation of inflammation from this organ to the peritoneum. See, for a summary of the case, the Lancet, Nov. 20, 1858, p. 530, and, for the details, the Gazette des Hopitaux and the Moniteur des Ropitaux, Nov. 1858. While I was writing this Lecture another case, similar to this one, has occurred. A woman, whose uterus has been cauterized by Mr. Jobert, has died of peritonitis, shortly afterward. 170 THE CENTRAL NERVOUS SYSTEM. us that it is perhaps really a reflex action. It is, therefore, neces- sary to say at least a few words, to show that the sympathetic phe- nomena we have mentioned, and many others of the same kind, daily observed by practitioners, are reflex phenomena. Suppose a foreign body in the cornea of one eye ; in a short time after the cornea has been submitted to this cause of irritation, we find that the conjunctiva is congested, photophobia begins, and tears are shed. There is no bloodvessel in the cornea; and, there- fore, we cannot admit that it is through this kind of tissue that the irritation has been propagated. Shall we admit that it is through the corneal tissue itself, and by its continuity or contiguity with the other parts of the eye, that the propagation has taken place ? If any one were tempted to imagine such an explanation, I would say that in cases of disease or section of the trigeminal nerve, in man and in animals, the irritation of the cornea is not followed by the least appearance of congestion of the conjunctiva. This con- gestion, therefore, in cases where the trigeminal nerve is uninjured, appears after an irritation of the cornea, in consequence of the transmission of the irritation to the encephalon by the corneal fila- ments of the trigeminal. Now, how can the congestion be pro- duced after the irritation has reached the encephalon, unless it be by nerve-fibres going from this nervous centre to the eye? We may have doubts as regards the question, by what nerves the encephalon reacts upon the eye in such a case ; but we cannot doubt that it does react, and that the congestion is due to this reaction, or, in other words, to a reflex action of the encephalon. Still more, in cases of irritation of one eye producing alterations in the other eye, it is clear that it is through the encephalon that the irritation is propagated. Let us take another example : suppose we have placed a tube in one of the ureters of a dog, so as to know what is the quantity of urine flowing out in a given time, after the dog has recovered from the shock of the operation. We then pinch the internal sur- face of the abdominal wall, in a part receiving its nerves from one of the first lumbar pairs, and, almost at once, we find that the secretion of urine is either stopped or very much diminished. It is not in consequence of a change in the circulation, due to the pain caused by the pinching, that the secretion is so much dimi- nished, as we find the same thing taking place whether the spinal cord in the dorsal region has been divided transversely, or left in communication with the encephalon. And if the part of the cord VISCEEAL ALTERATIONS RESULTING FROM BURNS. 171 which gives origin to the lumbar pairs of nerves has been de- stroyed — in which case the urinary secretion, after a short stop- page, becomes normal (as regards its quantity, at least), and is rather more than less abundant than before — we find that the irri- tation of the abdominal wall remains without effect upon the kidney. We must conclude, therefore, that when the spinal cord exists, the irritation passes through it, or, in other words, that the stoppage of the urinary secretion is due to a reflex action of the spinal cord. I have ascertained, also, that it is through the spinal cord, and by a reflex action, that the irritation of one kidney acts upon the other, sometimes to diminish, sometimes to increase, its secretion. Of course it is not by a reflex action only that some of the phe- nomena mentioned in this lecture are produced. In a case of ex- tensive burns, for instance, there are several circumstances which contribute to the production of the visceral alterations so well described by Dupuytren, Mr. Long, and Prof. Erichsen. In the first place, a certain amount of blood is submitted to such a tem- perature that several of its parts (the globules especially) must be altered; in the second place, there is a more or less considerable diminution of the cutaneous secretions and exhalations, and, as shown by the experiments of Fourcault, Gluge, Gerlach, Ducros, Magendie, Becquerel, Breschet, Bouley, and my friend, Mr. Bal- biani, 1 this is a cause of congestion of the various viscera. But as regards this last circumstance, there are many cases of burns in which visceral inflammations and rapid death have taken place when only a part of the skin, not larger than that of one limb, has been destroyed, so that it is impossible to admit that the cause of these inflammations and of death is only, or even chiefly, in the loss of the function of the skin, the greater part of which remains in a normal condition. As regards the other cause, the influence of heated blood on the viscera, I have made some experiments, the details of which I cannot relate now, which show that in animals in which the spinal cord has been divided at the level of the third or fourth lumbar vertebra, so that the posterior limbs cannot give any pain, and that, also, no irritation can be propagated from them to the viscera of the head, the chest, and most of those of the abdo- men, I have not seen — when I killed them two or three days after I had burnt one of the legs with boiling water — any marked alter- ations similar to those which are so often observed in man and 1 See his important thesis, " Essai sur les Fonctions de la Peau," &c. Paris, 1854, pp. 94-132. 172 THE CENTRAL NERVOUS SYSTEM. animals accidentally burnt, except in the bladder and rectum, and neighboring organs. On the contrary, when the section of the spinal cord was made as high as the third dorsal vertebra, I have seen all the abdominal viscera in a state of congestion, very much resembling inflammation in many parts, with serous infiltrations and ecchymoses, two days after one of the legs had been burnt by boiling water. It seems, therefore, that we are entitled to conclude that it is not only, and even not chiefly, to the cessation of function in a part of the skin, nor to the alterations of the blood, in cases of burns having destroyed all the skin, and most of the tissues of a limb, that we ought to attribute the inflammations, or the other altera- tions that the viscera present after burns. In two cases, on animals on which the trunks of the sciatic and crural nerves in one limb had been divided as high as possible, I have not found a state of marked congestion in any viscus, three days after I had carbonized this limb from the toes up to the middle of the thigh. From these experiments and the preceding, it results that it is, in a great mea- sure, by a reflex action of the spinal cord that burns produce their deadly influence on the viscera. In the cases of paralysis or of disease of the nervous centres, which appears after, and as a consequence of, an affection of a gland, as a kidney, or the liver, I do not need to say there may be a cause entirely different from that spoken of in this lecture, pro- ducing the paralysis or the disease of the nervous centres: I mean the presence of a poison in the blood on account of the diminution or alteration of an important secretion. There may be also other causes: for instance, Dr. K. B. Todd 1 relates a curious case, show- ing that a complete paralysis of motion and sensation of the lower limbs, apparently clue to a disease of the kidney (which he sup- posed depended upon suppressed gout), was cured, simultaneously with the renal disease, shortly after gout had been attracted to the feet. \Ve have now to examine how a reflex action may produce or stop a secretion, how it may produce an atrophy or an hypertrophy, an inflammation, or some other of the various changes in nutrition which we have mentioned. In the preceding lecture (see Lecture IX.) we have said that there are two modes of action of the nervous system upon the production of the phenomena of nutrition and 1 Cyclopaedia of Anat. and Physiol., vol. iv. p. 721. TWO MODES OF ACTION OF NERVOUS SYSTEM. 173 secretion. By one of these actions the nervous system determines an increase in the attraction of blood by the living tissues, and in this case the phenomena are accompanied by a dilatation of the bloodvessels; while the reverse exists when the nervous system, instead of acting upon the parenchyma of the tissues, acts upon the walls of the bloodvessels and produces a contraction. In the first case, the quantity of blood, passing through the part on which the nervous system has acted is increased; while in the second case it is diminished: in the first case the secretions are increased; in the second, diminished: in the first case nutrition is more active, and there is a tendency to hypertrophy and an augmentation of the vital properties of nerves and muscles; in the second case nutrition is not active, and there is a tendency to atrophy and a diminution of the vital properties of nerves and muscles: lastly, in the first case there is an augmentation of the temperature; while in the second, there is diminution. There is, therefore, the most complete difference between these two nervous influences. Let us now employ the knowledge of these two modes of action of the nervous system to explain what occurs in some cases of secretory or nutritive reflex phenomena. Suppose, for instance, a calculus in one of the ureters: it irritates the centripetal nerve- fibres of this canal, the irritation is transmitted to the spinal cord, which reflects it upon the muscular coat of the bloodvessels of the two kidneys, and produces a contraction, in consequence of which there is much less blood passing through these organs, so that the urinary secretion is stopped or much diminished. Suppose a worm in the bowels, irritating their centripetal nerve-fibres: the irritation is propagated to the spinal cord, which reflects it upon the roots of the cervical sympathetic nerve, by which it reaches the blood- vessels of the retina, produces their contraction, and, as a conse- quence of this cause of diminution in the amount of blood, an amaurosis. If instead of the reflex action on the bloodvessels there is an action on the tissues, as in the case of the experiments of Czermak and Prof. Bernard (see Lecture IX.), the bloodvessels dilate, and more blood passes through them. The cornea, for in- stance, is irritated ; its centripetal nerve-fibres transmit the irrita- tion to the pons Yarolii, which reflects it upon the retina, the 'lachrymal gland, the conjunctiva, &c; more blood is attracted by all these parts, their bloodvessels dilate, and the consequences of a greater amount of blood become manifest (increase of tears, pho- tophobia, &c). 174 THE CENTRAL NERVOUS SYSTEM. The two kinds of effects produced by the nervous system on nutrition and secretion, may coexist or follow each other ; and we have instances of such a combination or alternation in cases of neuralgia, of worms, &c. The simple fact of an increase or a diminution in the quantity of blood passing through a part, in a given time, is assuredly enough to explain the physiological and some of the morbid changes in secretion and nutrition which are usually observed; but some other morbid changes seem to require more than a simple change in the amount of blood for their production. For instance, an inflam- mation cannot be explained by such a change only, as we see that after the section of the cervical sympathetic nerve a very con- siderable increase in the quantity of blood exists in the eye, the ear, &c, and lasts for many weeks or months without an inflam- mation. It is true that this morbid process supervenes much easier by far in those parts than in others ; but, we repeat, that it does not appear spontaneously, and simply on account of the quan- tity of blood. We must, therefore, admit, that when a nervous influence acts upon certain tissues to produce inflammation, the principal cause of this morbid process is not in the augmentation of the quantity of blood, but in the change in the tissues which produces a greater attraction of arterial blood. 1 The history of the treatment of disease by means of the powerful influence of an excitation of centripetal nerves on remote organs, could afford us as many interesting facts as the history of the reflex production of inflammation and other morbid changes. But as I have not time enough to dwell on this subject, I will content my- self by indicating some rules of treatment founded upon the know- ledge of reflex actions. 1st. When we wish to produce a modification in the condition of any organ, we must apply the means of irritation that we prefer to the part of the skin or of the mucous membranes which have the 1 We regret very much not to be able to examine fully here this great question of the production of inflammation, either by a reflex action or by other causes. We regret also not to be able to show how much the recent advances of science agree with most of the observations made by Dr. Hughes Bennett, Dr. C. J. B. Williams, Mr. Wharton Jones, and Mr. James Paget. We do not agree entirely with Mr. Joseph Lister, whose very important researches we know only by a sum- ' mary of his paper (Proceedings of the Royal Society, vol. viii., No. 27, 1857, p. 581), but we can say that his view, that a change occurring in the tissues around the bloodvessels is the primary act in inflammation, might be supported by many facts entirely different from those so interesting which he has discovered. TREATMENT OF DISEASE FROM REFLEX ACTION". 175 most evident nervous relations with it. In most cases the parts acting with the greatest power upon another are those which receive their nerves from the same segment of the cerebro- spinal axis. If we wish, for instance, to act upon the kidney, the skin of the abdo- men in its upper part is the best for the application of any kind of irritation. Do we wish to act on the eye, in cases of amaurosis due to insufficiency in the amount of blood, the irritation ought to be applied chiefly to the supra or infra-orbitalis nerves. If the amau- rosis co-exists with hyperemia, the irritation of those nerves must be avoided, and the means of revulsion ought to be applied on the back of the neck, so as to act on the spinal cord, and, through it, by the sympathetic nerve, which has on the eye an influence en- tirely different from that of the trigeminal nerve. In cases of diar- rhoea, an influence upon the nerves of the bowels originating from nearly the middle of the dorsal region might be obtained by the irritation of the skin of the middle of the chest. The ovaries and the uterus being able to influence the nutrition of the mammas, and these glands being able to act upon the genital organs, irritation will be applied to one group of these organs when we wish to act upon the other. In amenorrhcea, for instance, various means of irritation to the breast have produced menstruation. 2d. The kinds of irritation which produce the most powerful effects are a great and sudden change of temperature, heat or cold, or th$ application of a very strong galvanic current. Frequent irritations, with periods of interruption between them, are better than permanent irritations. 3d. The suppression of the cause of irritation, when a disease is produced by a reflex action, is of course the principal mode of treatment. In cases of paralysis, of anaesthesia, or of a convulsive affection, &c, we must try to find out if there is an irritation on any centripetal nerve, and employ the most energetic means for its removal. But I must say that it is entirely useless to amputate a limb, or a part of it, as has been done sometimes in cases of con- vulsive affections produced by an external irritation. The section of a nerve will do as well, and this is already proved by many cases, and perhaps, as I will show in my last lecture, a simpler means might be employed. 4th. Time pressing me to go on, I will only add here that in cases of reflex congestions or inflammations due to burns or to congela- tion, or, in fact, in any case in which we have to avoid a reflex in- fluence, we must diminish the reflex faculty of the spinal cord and 176 THE CENTRAL NERVOUS SYSTEM. encephalon, and we know no medicine having so much power in this respect as belladonna. Direct influence of the nervous centres and of the centrifugal nerves upon nutrition and secretion. — I will only say here, that the same phenomena, which we have described as taking place by reflex actions, can be produced also in consequence of a direct irritation upon the nervous centres and the centrifugal nerves. The pheno- mena due to this direct irritation have very often been mistaken for consequences of absence of action of the nervous centres. I will merely point out here the rapid sloughs that are observed after a fracture or a luxation of the vertebral column, and the rapid change in the urinary secretion in similar cases. As regards the effects of direct irritation of centrifugal nerves, the following case, in which, however, there was probably some indirect influence of the nervous centres, has been observed by Mr. Hilton, and published by Mr. Paget : " A man was at Guy's Hospital, who, in consequence of a fracture at the lower end of the radius, repaired by an excessive quantity of new bone, suffered compression of the median nerve. He had ulceration of the thumb and fore and middle fingers, which resisted various treatment, and was cured only by so binding the wrist that, the parts on the palmar aspect being relaxed, the pres- sure on the nerve was removed. So long as this was done, the ulcers became and remained well; but as soon as the man was allowed to use his hand, the pressure on the nerves was renewed, and the ulceration of the parts supplied by them returned." 1 Mr. Paget also relates a case of Mr. Swan, which has great analogy with the preceding. These two patients might have been cured at once by the section of the irritated nerves. I will only add, as regards the influence of the pressure on the spinal cord producing sloughs on the nates and other morbid changes, that it is chiefly in exciting a persistent contraction in the bloodvessels of the parts where nutrition or secretion is morbidly altered, that the pressure on the cord acts. As it often happens that death, after a fracture or a luxation of the spine, is due to the slough formed on the nates, I think I must remark that a very good means of dilating bloodvessels consists in exhausting their irrita- bility by applications of powerful galvanic currents. Influence of the absence of the nervous system upon nutrition and secretion. — If I had time, I would show that most of the morbid 1 Lectures on Surgical Tathologj, vol. i. pp. 42-43. INFLUENCE OF NERVOUS SYSTEM ON ANIMAL HEAT. 177 changes which have been attributed to paralysis do not belong to it, but are the results of irritation upon either the nervous centres or the nerves ; and that the effects which are truly the consequences of a paralysis are due, only in an indirect way, to the absence of nervous action. For instance, atrophy of muscles is chiefly due to the state of rest; changes in secretion are chiefly due to the para- lytic dilatation of bloodvessels ; ulcerations of the toes, in animals in which the nerves of the limbs have been divided, only show an effect of the rubbing of the same parts on a hard floor; ulceration and inflammation of the eye after the section of the trigeminal nerve, are chiefly due to physical causes (the drying of the cornea and the conjunctiva, the prolonged action of light, &c). All these effects of paratysis may be, and have sometimes been, avoided. On the other hand, if we try to find out what is the power of cicatrization and repair, in cases of paralysis not complicated by irritation of nerves, we ascertain, as has long ago been done by Sir Benjamin Brodie, 1 and as we have done since, and in varying more the mode of experimenting, 2 that wounds, burns, and fractures may be cured as quickly in paralyzed parts as in others. Many facts might be advanced to prove (as in the preceding) that if the influ- ence of the nervous system is indirectly necessary to nutrition and secretion, it is nevertheless true that all the phenomena of nutrition and secretion may remain normal when the action of the nervous system on the various tissues is missing. Influence of the nervous system on animal heat. — We do not pro- pose, in these lectures, to treat exprofesso of this influence; we only wish to show what is the cause of the local diminution or augment- ation of temperature in paralyzed parts. As it is chiefly in cases of disease of the pons Varolii and medulla oblongata that these local changes of temperature are interesting in a practical point of view, we will postpone, till our lecture on these organs, the develop- ment of our views on this subject. We will say here, however, that the temperature of a superficial part of the body, or of a whole limb, depends greatly upon the state of the central nervous system; and that we may judge pretty well of this state by the degree of temperature of the feet, of the hands, &c. 1 See the "Treatise on Nervous Diseases," by J. Cooke, vol. i.,1820, pp. 130-133. 2 Experimental Researches applied to Physiology and Pathology, New York, 1853, pp. 6-17. M 178 LECTURE XI. ON THE ETIOLOGY, NATURE, AND TREATMENT OF EPILEPSY, WITH A FEW REMARKS ON SEVERAL OTHER AFFECTIONS OF THE NERVOUS CENTRES. Artificial production of an epileptiform affection in animals. — Influence of certain injuries to the spinal cord as a cause of real epilepsy. — Existence of an unfelt aura epileptica in many cases. — Means of detecting the existence of an unfelt aura and its point of starting. — Seat and nature of epilepsy. — Principles of treat- ment of this affection. — Analogy between epilepsy and many other nervous affec- tions, as regards their mode of production and their treatment. — Curious case of convulsions and insanity, in illustration of some views advanced in this letter. Mr. President and Gentlemen : It is impossible in the narrow compass of a lecture, to treat fully of the great variety of interest- ing points concerning several grave affections of the cerebro -spinal centre. I must, therefore, though I much regret it, limit myself to a short sketch of some new views, which, perhaps, deserve the attention of both practitioners and men of science. Although I will only mention here a few of the principal facts which have led me to these views, I hope it will be understood that, if I do not try to give a complete demonstration of them, it is because such a thing is impossible in a single lecture. I have found that a convulsive affection, very much resembling epilepsy, may be produced in animals. A few weeks after certain injuries to the spinal cord, in the dorsal or the lumbar region, espe- cially in guinea-pigs, fits appear spontaneously several times a day, or, at least, once every two or three days. But the most interest- ing point is, that it is possible to produce a fit when we choose, by simply pinching a certain part of the skin. These fits consist in clonic convulsions of almost all the muscles of the head, the trunk, and the limbs, except those muscles which are paralyzed. The animal seems to have lost its consciousness, or, at least, its sensi- bility. There is an evident laryngismus in the beginning of the fit, and, after it, when it has lasted long, a state of drowsiness or un- ARTIFICIAL EPILEPSY IN ANIMALS. 179 willingness to move. 1 I have ascertained that one part only of the skin has the power of producing the fit, and this part is that which covers the angle of the lower jaw, and extends from thence to the eye, the ear, and nearly to the shoulder. It is only the skin that has the power of generating the fit, as even the three nerves that send filaments to this part of the skin can be irritated without the occurrence of convulsions. When the spinal cord has been injured only on the right side, it is only on that side that the skin of a part of the face and neck has the power of inducing fits, et vice versd when the injury exists on the left side. If the two sides of the cord are injured, the two sides of the face can produce fits. It is not the pain due to the irritation of the skin which causes convulsions, as I have ascer- tained that the degree of sensibility of that part of the face and neck is not greater than that of the neighboring skin, and is less (by far) than that of some parts of the skin in one of the abdo- minal limbs. It is evidently a peculiar kind of irritation, starting from the cutaneous ramifications of some centripetal nerves, which alone possesses the power of producing the epileptiform convul- sions which are observed in animals in which the spinal cord has been submitted to certain injuries. It results from the facts which have led me to the above asser- tions: 2 — 1st. That the spinal cord in animals may be the cause (I do not say the seat) of an epileptic affection. 2d. That there is a mysterious relation between certain parts of the spinal cord and remote parts of the skin of the face and neck. 3d. That epileptiform convulsions may be the constant conse- quence of slight irritations upon certain nerves. 4th. That the trunk of a nerve may not have the power of pro- ducing convulsions, whilst its cutaneous ramifications possess this power. 5th. That even when an epileptiform affection has its primitive cause in the nervous centres, some cutaneous filaments of nerves, 1 For more details on this point, and on others concerning epilepsy in this lec- ture, see my " Researches on Epilepsy," &c, Boston, 1857, and the Journal de la Physiologie de V Homme et des Anunaux, 1858, pp. 241 and 472. 2 To those readers of these lectures who have not been amongst my hearers, I must say that I have shown the principal experiments relative to this subject, as well as to most of the principal subjects of my lectures, so that my assertions were, very often, accompanied by an actual and direct demonstration. 180 THE CENTRAL XERVOUS SYSTEM. not directly connected with the injured parts of these centres, have a power of producing convulsions, which other nerves, even directly connected with them, have not. In man, epilepsy very frequently presents most of these pecu- liarities. As regards the first of them, it cannot be doubted that a disease of the spinal cord or of its membranes, as well as an affec- tion of any centripetal nerve in the human body, may be the pri- mitive origin of a real epilepsy, quite similar to the erroneously- called idiopathic epilepsy. I will refer to cases recorded by Bonet, Lieutaucl, Morgagni, Musel, Portal, Esquirol, and a great many other excellent observers. The careful study of these cases shows clearly that in a number of them epilepsy has truly been generated by the disease of the spinal cord. I do not know yet of any case in which, in man, just the same thing has been observed as in my epileptic animals. But there are only very few cases on record in which the very injury which in them has caused epilepsy, has been observed in man ; and in those cases in which probably this injury has existed, we either do not know what have become of the patients, or they have died before the time after which epilepsy appears in animals after the injury to the spinal cord. But there are many cases on record in which an irritation of some point of the skin, or of some centripetal nerve, and sometimes even an unfelt irritation, has produced fits, just as, in my animals, the excitation of a part of the skin pro- duces them. I have collected such a number of facts in this respect, that the analogy between epilepsy in man and in my animals seems to be as great as possible ; and I may add that, in most cases of genuine and complete epilepsy, as well as in cases of simple vertigo, there is an irritation starting from some point of a centripetal nerve, especially from its peripheric parts in the skin, or in the various mucous membranes. There is no medical man who has been in practice for a few years, who has not seen some cases of this kind ; but almost all the recent writers on epilepsy having considered those cases as quite special, I must insist on saying, that even in the so-called idiopathic epilepsy there may be found an irritation start- ing from some centripetal nerve, and generating the convulsions; and I must add, also, that there is no radical difference between the symptoms of the sympathetic epilepsy, and those of the pre- tended idiopathic. I will leave aside here all the cases in which an evident irritation UXFELT AUEA EPILEPTICA. 181 on a centripetal nerve has caused epilepsy, such as cases of worms in the bowels, in the biliary ducts, or in the frontal sinus; of calculi in the ureter, in the biliary ducts, &c; of foreign bodies in the ear or beneath the skin; of tumors pressing on nerves; of decayed teeth; of necrosed bones, &c. But I must say that in several cases the peripheric origin of fits has been quite evident, as it was suffi- cient to press upon a certain part of the skin to produce the epi- leptic seizure. 1 In other cases, a draught of cold air, the applica- tion of a galvanic current to certain parts of the skin, a sound, a smell, or the sight of a certain color, were always followed by a fit. In cases of aura epileptica there is the greatest variety in the sensations felt, and the degree and the painfulness of the sensations are not such that we could explain by them the production of con- vulsions. It results from a thorough examination of a great many cases of aura, that we must admit that an unfelt irritation starts, at the same time as the aura, from some centripetal nerve, and is the real cause of the epileptic seizure. We will call this irritation an unfelt aura; and it would be well, indeed, if we could employ the name of "aura epileptica" for this unfelt irritation alone, so as to distinguish it completely from the vague and variable sensations which accompany it in many cases. There are facts proving that an unfelt aura may exist without any kind of sensation, either because the first effect of the irritation has been to destroy con- sciousness, or because the irritation does not start from sensitive nerve-fibres, but from centripetal nerve-fibres endowed only with the excito-motory power. 2 It is very important, on account of the treatment, to find out if there is an unfelt aura, and what is its starting point. In conse- quence of this view, the condition of all the organs of the body ought to be carefully inquired into. If the unfelt aura starts from some parts of the skin, or from some organ not deep-seated, as the testicle, or some part of mucous membranes, near the skin, either the first contractions in a fit, or the most violent or the most prolonged, are found in the neighbor- 1 See my " Researches on Epilepsy," pp. 31, 32, 38, and 48. I might add seve- ral other cases observed by myself or others. 2 See the curious cases of Pontier, of Joseph Frank, and of Henricus ab Heer, in my " Researches on Epilepsy," p. 32. In cases of worms producing epileptic fits, there is, sometimes, no sensation at all accompanying the unfelt irritation which causes the convulsions. 182 THE CENTRAL NERVOUS SYSTEM. hood of the point of starting of the aura. If no indication of this kind can be furnished by the persons who have seen the fits, it will be well to try the application of a very powerful galvanic current, with dry conductors, on the various parts of the skin, when the patient expects to have a fit. I have, in this way, twice ascer- tained the point of starting of an unfelt aura : a fit has been pro- duced by the galvanization of certain parts of the skin. Of course there are many cases where such a means of diagnosis ought not to be employed : every one will understand what are those cases. Another and the best means (so far as the limbs alone are con- cerned), to detect the existence of an unfelt aura, consists in appli- cations of ligatures on each limb alternately. Suppose a case of epilepsy in which the fits are frequent, and come at nearly fixed times, or after warnings of any kind, so that it may be known that it is to take place in a given time, or nearly so : a very tight liga- ture is put on one limb; and if the fit does not come, it is extremely probable that it depends on the irritation of an unfelt aura; if it comes, the ligature is applied on the other limbs at other times. I am sorry not to be able, to give more details in this respect; but I think it will be easy to understand how, by such a means, it may be ascertained if an aura comes from the upper part of a limb, or from a toe or a finger, and from which one. Even in cases of epilepsy due to a disease of the encephalon, the cause of the fits may originate from some points of the skin, and the prevention of the passage of the aura, in such cases, can pre- vent the fits. There are four cases of this kind that I know, in three of which the disease consisted in a tumor in the brain. In my animals the same thing exists; although the alteration of the spinal cord — which is the cause of epilepsy — persists, the aura being interrupted by the section of the nerves which go to the skin of the neck and face, epilepsy, so far as I have been able to ascer- tain, ceases. The aura may originate from any part of any centri- petal nerve, and there is no doubt that its place varies according to the location of disease in the nervous centres, when it is due to such a disease. A great many cases in which, by various means, the aura epilep- tica has been prevented from going up to the encephalon, show that the fit is very often due to a simple outside irritation. Applica- tions of ligatures, sections of nerves, amputations, &c, act in this way. We might say the same thing of the elongation of muscles (the first ones that are convulsed), and, in a certain measure, of SEAT AND NATURE OF EPILEPSY. 183 various means of revulsion (such as burning, blistering, &c), al- though the principal mode of action then consists in producing, by a reflex action, a change in the nutrition of the nervous centres, and of the nerves which are the channels of the aura. Epilepsy seems to consist essentially in an increased reflex ex- citability of certain parts of the cerebro-spinal axis, and in a loss of the control that, in normal conditions, the will possesses over the reflex faculty. The base of the encephalon, and especially the medulla oblongata, is the most frequent seat of the increase in the reflex excitability, so that this part of the nervous centre is the ordinary seat of epilepsy. The disturbance in the functions of the cerebral lobes, during and immediately after a fit, and in the inter- paroxysmal periods, is chiefly due to the alterations taking place in the brain during the fits. This hitherto mysterious coincidence of loss of consciousness, or, in other words, loss of the function of the cerebral lobes, with an increased action of the base of the encepha- lon, in a complete epileptic seizure, may now be easily explained. I have tried to show that the same cause that produces the first convulsions in some muscles of the neck, the eye, the larynx, and the face, produces also a contraction of the bloodvessels of the brain proper, which contraction is necessarily followed by the loss of consciousness. I am happy to state that two very able German experimenters — Messrs. Kussmaul and Tenner, 1 led by researches in several respects different from mine, have arrived at the same explanation. In reviewing the principal phenomena of a complete seizure of epilepsy, we find that they form a series of causes and effects, as shown in the following table: — Causes. 1. Excitation of certain parts of the excito-motory side of the nervous centre. 2. Contraction of the bloodvessels of the brain proper. 3. Extension of the first excitation, partly due to the accumulation of blood in the base of the encephalon. Effects. 1 . Contraction of bloodvessels of the brain proper and of the face, spasm of some muscles of the eye and face. 2. Loss of consciousness, and accumu- lation of blood in the base of the ence- phalon. 3. Tonic contraction of the laryngeal, the cervical, and the thoracic expiratory muscles. ( Laryngismus and trachelismus. ) 1 Untersuchungen zur Naturlehre, &c, von Moleschott, vol. iii., Part I., 1857. I must say that I had published the above explanation before these German phy- siologists ; but they have arrived at it quite independently, and almost at the same time as myself. 184 THE CENTRAL NERVOUS SYSTEM. Causes. Effects. 4. Contraction of laryngeal and of tho- 4. Crying, and stoppage of respira- racic expiratory muscles. tion. 5. Farther extension of the first exci- 5. Tonic contraction, extending to tation of the nervous centre. most of the muscles of the trunk and limbs. 6. Loss of consciousness, and tonic 6. Falling, contraction in the trunk and limbs. 7. Laryngismus, trachelismus, and 7. Asphyxia, with obstacles to the re- the fixed state of the chest. turn of venous blood from the head and the spinal cavity. 8. Asphyxia, and the accumulation of 8. Clonic convulsions everywhere ; con- black blood in the encephalon, and in tractions of the bowels, the bladder, the the spinal cord. j uterus ; erection ; increase of many se- cretions ; efforts at inspiration. 9. Exhaustion of nervous power gene- ! 9. Cessation of the convulsions ; coma rally, and of the reflex faculty especially, or heavy sleep, after which extreme fa- except for respiration, which gradually tigue and headache. becomes normal. Of course this table shows only the most frequent filiation of phenomena, and it is useless to say that there are great varieties as regards the first phenomena. The admirable researches of Dr. Marshall Hall have shown how important are the laryngismus and trachelismus, in the causation of the epileptiform convulsions. I will only add that the asphyxia, to which so great a share is due in the phenomena of epilepsy and in its most grave consequences, depends not only upon the state of the larynx, but on that of the chest; and that, not only the blood cannot return easily from the head, on account of the trachelismus, but also it cannot enter the chest from either the spinal canal or the head, on account of the fixed state of expiration. Besides, the bronchia? themselves are often contracted; and all these causes coexist with an increased production of carbonic acid, and with a change in the circulation of the encephalon, during which the blood accumulates in the base of this organ, and also in the spinal cord. As regards the treatment of epilepsy, we will only say that the principal rule is to find out if the disease has an external cause — i. e., if from any part of the centripetal nerves there is an irritation acting upon the nervous centres. To prevent this irritation reach- ing these centres, or to destroy the cause of this irritation, if it is known to exist, are the two things to be done. I must repeat that this will be found much more often than is generally supposed. Against the increased excitability of some part of the nervous cen- CASE OF CONVULSIONS AND INSANITY. 185 tres, the best means, assuredly, are the powerful modificators of nutrition, which, I am sorry to say, are so little employed by regu- lar practitioners — the cauterization of the back of the neck by moxas, or by the red-hot iron. Other affections very often have the same characteristic features as epilepsy, as regards their production. If I had time, I could relate a very large number of facts to prove that, much more fre- quently than might be imagined by most of my hearers, the various forms of insanity, of vertigo, of hallucinations, and of illusions, and also extasis, catalepsy, hysteria, chorea, hydrophobia, tetanus, local cramps, and even the general paralysis connected with insanit}^, may be due to irritations starting from a centripetal nerve, and frequently slightly felt, or even unfelt; and that the suppression of these irritations may promptly cure the patient, just as in cases of epilepsy. Instead of a description of this kind of affection, I will give here a case which is full of interest, and which I owe to the kindness of Mr. Campbell de Morgan, who had received it from the late Mr. Standert, of Taunton, who, according to Mr. de Morgan, was one of the most original thinkers and best surgeons of his day : — Case 44. — On rising in the morning, a lad, fourteen years old, was heard by his father making a great disturbance in his bed-room, who, rushing in to know the cause, found his son in his shirt, violently agitated, speaking incoherently, and breaking to pieces the furniture. Mr. caught the lad in his arms, and threw him back on the bed, when he at once became composed, but did not seem conscious of the mischief he had done. He said that on getting out of bed he had felt something odd, but that he was very well, and thought that he might have had a frightful dream, although he could not recollect it. I was immediately sent for, and the lad ordered to remain in bed until I had seen him. About five hours after, I found the lad lying in bed, reading some amusing book; his tongue clean, pulse regular, countenance calm and cheerful. He said he was quite well, and wished to get up, but that his father had ordered him to remain in bed until I had seen him. I was in- formed, before I went up to his bed-room, that the lad had never before been heard to complain of disturbed dreams, or walked in his sleep, or exhibited any epileptic symptoms, and that his general health had been good, and all his functions regular. Finding the patient free from any apparent disease, and that he had eaten with good appetite, and no disturbance, his usual breakfast, I desired 13o THE CENTRAL NERVOUS SYSTEM. him to get up. When, sitting up in his bed, he drew on his stock- ings; but on putting his feet on the floor and standing up, his counte- nance instantly changed, the jaw became violently convulsed, and he was about to rush forward, when I seized and pushed him back on the bed. He was at once calm, but looked surprised, and asked what was the matter with him. He assured me that he had felt no pain, had slept well, but that he u felt odd" when he stood up. I found that he had been fishing on the preceding day, and, having en- tangled his line, had taken off' his shoes and stockings, and waded into the river to disengage it; but he said he had not cut or scratched his feet or met with any other accident. To ascertain this point, I made him draw off his stockings, and examined his legs minutely. Not the slightest scratch or injury could be seen; but on holding up the right great toe with my finger and thumb to ex- amine the sole of that foot, the leg was drawn up, and the muscles of the jaws were suddenly convulsed, and on releasing the toe these effects in- stantly ceased. I then closely inspected the toe. The nail was per- fect; there was not the least swelling or redness in the surrounding parts, nor any tenderness or uneasiness felt when I compressed the toe laterally, or moved it, held thus, in any direction; but on the bulb of the toe, nearly at the point where the circumgyrations of the cuticle centre, there was a very small elevation, as if a bit of gravel, less than the head of a small pin, had been there pressed in beneath the cuticle. There was not the least redness on this spot, nor any sensation or effect produced by passing rny finger over its surface; but on compressing it with ?ny finger and thumb against the nail very cautiously, a slight convulsion instantly ensued. I asked the patient if anything pricked him? He said "No, but something made him feel very odd." On examining the part well with a pocket lens, no scratch or puncture of the cuticle could be discerned. I then with a pair of scissors included and snipped away the slightly elevated part, but not so deeply as to denude the cutis beneath. In the bit of cuticle thus removed I expected to find some point of a thorn or particle of sand, but could not detect anything of the kind. I then pressed the toe in every direction ; the strange sensation was gone, and never returned. I do not know that any member of the patient's family had ever been under treatment for insanity, but two of his uncles and I believe an aunt were suicides, and the patient himself, many years afterwards, was "found drowned" by the cautious verdict of an in- quest. " 187 LECTUEE XII. ON THE MEDULLA OBLONGATA, THE PONS VAROLII, AND SOME PARTS OF THE SPINAL CORD, IN THEIR RELATIONS WITH RESPIRATORY MOVE- MENTS ; WITH VERTIGINOUS OR ROTATORY CONVULSIONS ; WITH THE TRANSMISSION OF SENSITIVE IMPRESSIONS AND OF THE ORDERS OF THE WILL TO MUSCLES, AND WITH THE VASO-MOTOR NERVES AND ANIMAL HEAT.— GENERAL CONCLUSIONS OF THE COURSE. Medulla oblongata erroneously considered as the source or focus of life. — Causes of death in cases of sudden injury to this organ. — Respiration depending upon other parts of the cerebro-spinal axis, besides the medulla oblongata. — Causes of the cessation of respiration in cases of a complete section of the medulla oblongata. — How are the respiratory movements produced ? — Parts of the ence- phalon and spinal cord that may produce rotatory convulsions. — Causes of the vertiginous or rotatory convulsions. — The auditory nerve and its power of pro- ducing partial or general convulsions. — The olivary and restiform columns of the medulla oblongata and their relations with various nervous disturbances. — Reasons against the view that the fibres which decussate all along the median line of the base of the encephalon are voluntary motor fibres. — Reasons for admitting that the anterior pyramids contain nearly all the voluntary motor fibres of the body. — Three kinds of paralysis due to lesions in three different parts of the cerebro-spinal axis. — Anaesthesia and hyperesthesia in their rela- tions with the state of bloodvessels and the degree of animal heat. — Condition of voluntary movements, sensibility, and animal heat, in different cases of alteration of the central nervous system. — General conclusions. Mr. President and Gentlemen : Since the time of Galen 1 most of the physiologists, and particularly Lorry, Cruikshank, Lorenz, Bartels, and Legallois, have ascertained that a sudden and deep injury to the lower part of the medulla oblongata, in animals, causes immediate death, and many cases observed in man have shown the same thing. It has been almost universally admitted that death is then due to the fact that respiration ceases because the lower part of the medulla oblongata is the centre for respiratory move- ments. But if we study carefully what takes place in most of the 1 Galen clearly states that a section of the medullary axis, beneath the first or the second cervical vertebra in an animal, kills it at once. See De Anat. Administr., lib. 8, cap. 9, pp. 696, 697. Kuhn's ed., Leipzig, 1821. 188 THE CENTRAL XERVOUS SYSTEM. cases of immediate death caused by a sudden and deep injury to the lower part of the medulla oblongata, we find that it is impos- sible to explain this curious mode of death by admitting that it is only due to a sudden arrest of respiration. If we take two living animals of the same species, and decapitate them by a section passing, in one of them, on the nib of the cala- mus scriptorius, and in the other, on the fourth or fifth cervical vertebra, and cutting also, in both, the principal nerves of the neck, and avoiding the section of the carotids, we often find that the first one has no convulsions, or, in other words, no agony ; while the second almost always has very violent convulsions in the four limbs and in the trunk. In both cases the medulla oblongata is taken away and respiration is stopped ; we cannot, therefore, attri- bute to the cessation of respiration the absence of convulsions in only one of the cases. We will see in a moment what is the cause of this absence of convulsions. Before we come to this explanation, we must say that a physiologist who has attained a very high situation in France, M. Flourens, one of the perpetual secretaries of the Academy of Sciences, to explain the sudden death after the destruction of a small part of the medulla oblongata, has proposed a theory of which we ought to take notice, on account of the stand- ing of its author. M. Flourens imagines that life depends on a force springing from a very small part of the medulla oblongata, which small part he calls the vital point or the vital knot} If this hypothesis were true, certainly it would be very easy to understand why there are no convulsions, and hardly any sign of life in the heart and in other organs after the extirpation or de- struction of the pretended vital knot. Unfortunately for this theory, the part which is supposed to be the focus or the source of life may be taken away, and life persist, without any marked trouble. My experiments not only show that life may last long after the extirpation of a much larger part of the medulla oblongata 1 The paper of M. Flourens, containing his principal assertions in this respect is in the Comptes Rendus de VAcad. des Sciences, vol. xxxiii., 1851, p. 437. He declares that the vital knot is not larger than the head of a pin, and that its place is at the point of the small V of gray matter, at the nib of the calamus scriptorius. Forgetting all that he had said as regards the size of this small point, M. Flourens has just read a paper to the Academy of Sciences (Comptes Rendus, 1858, vol. xlvii. p. 803), in which he acknowledges that the extirpation of that small point does not destroy life, and he now places the vital knot in the midst of the medulla oblongata, between the V of gray matter and the crossing of the anterior pyramids. CAUSES OF THE CESSATION OF EESPIKATION. 189 than this small amount of gray matter erroneously considered as the source of life, but that neither any part nor the whole of the oblong medulla can be considered as the source of a pretended vital force. In the first place, a sudden irritation of the spinal cord, as well as that of the medulla oblongata, may cause a sudden death, without agony or convulsions, although in both cases, and especially in the first one, the pretended focus of life remains almost or entirely uninjured. In the second place, the extirpation of this pretended only source of life, when made carefully by slow and partial sec- tions, at a certain distance from it on the spinal cord and the pons Varolii, is followed by the most violent convulsions and by ener- getic movements of the heart, the bowels, the bladder, &c. In the third place, if the par vagum has been divided in a living animal, any kind of operation may be performed upon the medulla oblon- gata without destroying quickly or suddenly the movement of the heart ; and, in this case, the convulsions of agony take place with energy. From the above-mentioned facts and from several others, I have drawn the conclusions 1 that the irritation of the oblong medulla and of some parts of the spinal cord (a great portion of the cervical region) is able to produce a sudden stoppage or diminution of the movements of the heart, and that it is, in a great measure, to this influence on the heart that is due the absence of agony in most of the cases of sudden destruction of the oblong medulla. More than ten years ago, I found that certain animals may live for many weeks, and, in more recent researches, for eight months, after the extirpation of the whole medulla oblongata. 3 In these animals all the functions of organic life, except pulmonary respira- tion, continue without any apparent alteration, showing that these functions do not depend upon the medulla oblongata, as some physiologists have thought. The persistence of life in these animals was possible on account of the cutaneous respiration; but in animals in which the skin absorbs but a small amount of oxygen, such as birds and mammals, death is said to be always rapid after the extirpation of the medulla oblongata, even when care is taken to avoid the influence of the operation upon the heart. It seems, 1 See my paper, Recherches sur les Causes de Mort apres l'Ablation du Point Vital, in Journal de la Physiol, de VHomme, &c, Avril, 1858, pp. 217-233. 2 Comptes Rendus de l'Acad. des Sciences, 1847, vol. xxiv. p. 363, and my Exper. Researches applied to Physiol, and Pathol., 1853, p. 40. 190 THE CENTRAL NEBVOUS SYSTEM. therefore, that the medulla oblongata is an organ absolutely neces- sary to respiratory movements. Against this view I will remark, 1st, that Dr. Bennet Dowler, of New Orleans, has seen thoracic respiratory movements continuing in decapitated alligators; 2d, that Dr. B. "W. Richardson has observed the same fact in young mammals; 3d, that I have seen it also in birds, and in kittens and puppies. It seems, therefore, quite certain that the respiratory movements do not depend only upon the medulla oblongata. I have already tried to show, in 1851, that many parts of the encephalon are em- ployed in respiration, and, since then, I have collected a great many pathological facts, proving, I think, the correctness of this view. It is known that the only two appearances of proof that the medulla oblongata is the only centre of respiratory movements, or, in other words, the only source (direct or reflex) of these movements in the cerebro-spinal axis, are — 1st, that a transversal section of the lower part of the medulla oblongata causes a sudden cessation of respira- tion ; 2d, that when transversal sections are made on the encephalon, from its front to its back, taking away layer after layer, it is said that it is only after the greatest part of the medulla oblongata has been taken away, that respiration is destroyed. As regards the first of these two assertions, we have already shown the objections against it — objections which are also very good against the second assertion. But we must say a few words more of this second as- sertion. When, after a series of transversal sections of the ence- phalon, we have reached the medulla oblongata, just above the upper roots of the par vagum, we find that respiration continues almost normal. If now we cut away the part of the medulla giving origin to this pair of nerves, we find, in most cases, that respiration is suddenly stopped. This certainly seems to prove that the small part to which the par vagum is attached is the nervous centre for respiration. But is it truly so? I will try to prove that it is not. 1st. In weak animals, after many parts of the encephalon have been taken away, the whole of the medulla oblongata and of the pons Varolii remaining, respiration sometimes continues normal, but it suddenly stops after a small part of the pons is removed. It would be wrong to draw from this experiment the conclusion, that this small part is the central organ of respiration. To draw such a conclusion, however, would be to employ the same reasoning which has been adopted concerning the part of the medulla oblon- gata giving origin to the par vagum. The stronger an animal is, the more parts of its encephalon can be taken away before we destroy respiration. It is in animals in which the spinal cord is rich in gray matter, and possesses a powerful reflex faculty, that we find respiration persisting after the whole of the encephalon, including the oblong medulla, has been extirpated ; such is the case in alligators, in birds, in young dogs and cats. 2d. In the strongest animals, death occurs in a few hours, and from insufficiency of respiration, after the ablation of the encephalon except the whole of the medulla oblongata ; and so it often is with anencephalic monsters. These facts show clearly that, although respiration may be carried on, for a time, almost as well as in the normal condition of the central nervous system, when only the medulla oblongata and the spinal cord exist, these organs are in- sufficient for a long persistence of this function. A series of ex- periments on pigeons has given me the following results : with the spinal cord alone, respiration continues a few minutes ; with the spinal cord and the part of the oblong medulla giving origin to the principal excitors of respiration — the vagi — this function continues many hours (the longest duration we have seen is thirteen hours); if there is also a great part of the base of the encephalon left, re- spiration continues longer, but I have never seen it last more than a day and a half; if the cerebrum alone is taken away, respiration remains undisturbed ; and if death occurs, it is not on account of an insufficiency of the parts left of the cerebro-spinal axis to carry on respiration. 3d. In man, hemorrhage in the various parts of the base of the encephalon, near the median line or upon it, produces a trouble in respiration, which is more and more marked the greater the amount of effused blood, and the nearer it is to the medulla oblongata. Certainly, in many cases, the trouble of respiration may be partly attributed to pressure on the medulla oblongata, but it is not always so ; and, at any rate, in several cases of softening of the pons Varolii, in which it cannot be said that there was a pressure on the oblong medulla, there has been a trouble in respiration. From the examination of a great many cases, 1 1 have been led to the conclusion that the whole base of the encephalon is employed in respiration. 1 Most of these cases have heen published in the thesis of my pupil, Dr. J. B. Coste, Recherches sur le Role de VEnctphale dans la Respiration, Paris, 1851. 192 THE CENTRAL NERVOUS SYSTEM. 4th. Many cases have been observed in which the medulla oblongata has been so much altered that almost all its actions as a nervous centre ought to have been destroyed, and, nevertheless, respiration has continued to take place ; in those cases there was still, however, a more or less free communication between the pons Varolii and the spinal cord, and probably several of the filaments of the par vagum continued to act as excitors of respiratory move- ments. All the facts just mentioned, and many others of which I have no time to speak, have led me, first, to abandon the view so gene- rally admitted, that the medulla oblongata is the essential source of the respiratory movements in the nervous centres ; and secondly, to propose the view that these movements depend upon all the incito-motory parts of the cerebro-spinal axis, and on the gray matter which connects those parts with the motor nerves going to the respiratory muscles. I must add that, according to the theory I have arrived at, the principal cause of respiration is in the lungs, as Dr. Marshall Hall has tried to prove ; but that excitations coming from all parts of the body, as shown by Yolkmann and Yierordt, and also direct irritations of the base of the encephalon and of the spinal cord, almost constantly taking place, contribute to the pro- duction of respiratory movements. I pass now to another and a quite different subject, although it is connected with the physiology and pathology of the parts of the nervous centres which have the principal share in respiration. I wish to say at least a few words about rotatory or vertiginous move- ments. It seems, indeed, wonderful to see animals, sometimes after a slight puncture of some part of the encephalon with the point of a needle, turn round, just like a horse in a circus, or roll over and over for hours, and sometimes for days, with but short interruptions. The same phenomena having often been observed in man, I think it may prove interesting, if not useful, to point out the parts of the encephalon which may produce vertiginous or rotatory convulsions. The convulsions differ a great deal, accord- ing to the place injured and the depth and size of the injury. If we suppose that the right side of the encephalon, in the places I will name, has been injured, we find that the animal turns or rolls, and that in the first case the side on which it turns is either the left or the right; while, if it rolls, the rolling begins either by the left or the right side. PARTS THAT MAY PRODUCE CONVULSIONS. 193 Parts producing turning or rolling after an injury on the right side. Turning or rolling by the right side. Turning or rolling by the left side. 1. Anterior part of the optic thalamus. 1. Posterior part of the optic thalamus. (Schiff.) (Schiff.) 2. The hind parts of the crus cerebri. t 2. Some parts of the crus cerebri, near (Schiff.) the optic thalamus. (Brown-Sequard.) 3. The tubercula quadrigemina. (Flou- 3. Anterior and superior parts of the rens.) pons Varolii. 4. Posterior part of the processus cere- ; 4. Anterior part of the processus cere- belli ad pontem. (Magendie.) . belli ad pontem. (Lafargue.) 5. Place of insertion of the auditory and 5. Place of insertion of the glosso- of the facial nerves. (Brown-Sequard pharyngeal nerve. (Brown-Sequard.) and Martin-Magron.) 6. Neighborhood of the insertion of the 6. Spinal cord, near the oblong medulla, lower roots of the par vagum. (Brown- (Brown-Sequard.) Sequard.) While rotation takes place, it is easy to ascertain, 1st, that it is not its production by contractions resembling those of voluntary movements which causes the rolling or the turning; 2d, that some muscles are in a state of tonic contraction ; 3d, that the trunk and neck of the animal are bent by a spasmodic action on the side of turning if it has a circus movement, and that it is bent like a cork- screw, as much as the bones allow, in cases of rolling ; 4th, that sensibility and volition may remain, and that there are frequent efforts to resist the tendency to turn or roll. It seems clear from these observations and several others, that these rotatory move- ments depend chiefly upon the fact that certain muscles are in a state of spasm. I shall not try to show that the theories of Magendie, of Flourens, and of Longet, are in opposition with many of the particularities of the experiments. 1 Any one knowing these theories may find out from the above statement of facts, that these hypotheses are not acceptable. The theory of Henle, who admits that convulsions are produced in the eyes, and that as a consequence a kind of vertigo is generated, which causes the rotatory movements, is not more acceptable, as there are some cases in man, and many in animals, in which the eyes had no convulsions at all, although rotation existed. My friend, Dr. Lebret, has seen a case of this kind in man. That a state of vertigo may sometimes be the prin- 1 See my Experimental Researches on Physiology and Pathology, 1853, p. 18. N 194 THE CENTRAL NERVOUS SYSTEM. cipal cause of turning or rolling, is, I think, beyond question ; ! and that this state may be induced either by the irritation of some vaso-motor nerve in the encephalon, or by the too great attraction of blood by some parts of this organ, is, I think, also very pro- bable; but I believe that in most cases the principal cause is in the irritation of a peculiar set of nerve-fibres not usually employed by the will — nerve-fibres, the division of which is not followed by paralysis, although they are able to act on muscles to produce contractions, and even more powerful than those caused by nerve- fibres employed by the will in voluntary movements. It is a fact worthy of attention, that a puncture with a needle through the anterior pyramids which contain, as I will soon prove, very nearly all, if not all, the nerve-fibres employed in voluntary movements, will hardly produce a momentary contraction in some muscles ; while certain punctures through the olivary column of the medulla oblongata at once produce a spasm of many muscles, although this column does not contain more than very few (if any at all) voluntary motor-fibres ! And, now, to add to the strangeness of the fact, in this last case, the muscles remain contracted sometimes for hours, sometimes for days and weeks ! We have all been taught, and several probably in this room, where there are so many professors and lecturers, have taught that, after the removal of a cause of ex- citation in the nervous centres, as well as in the nerves, the effects of the excitation disappear until inflammation supervenes and pro- duces a permanent excitation ; while here, however, we see a punc- ture with a needle or a section with a knife, before any inflammation can have begun, followed by a persistent effect. There is, therefore, in some parts of the nervous centres, a property of acting in a persistent manner to produce muscular spasms, during and after a mechanical excitation. The persistent spasmodic contractions, due to a mechanical in- jury to certain parts of the nervous centres, are always curious, but never so much so as when they result from some irritation of a part like the auditory nerve, which we were accustomed to con- sider simply as a nerve of sense. M. Flourens 2 has found that the section of the semicircular canals, in certain animals, is followed by a strange disorder of movements, and sometimes by a rotation 1 See the very able and learned paper of Dr. Russell Reynolds, entitled Vertigo. London, 1854. 2 Rech. sur les Propr. et les Fonctions du Syst. Nerveux. 2de ed., 1842, p. 454 et seq. CAUSES OF ROTATORY CONVULSIONS. 195 (circus movement). I have ascertained that the phenomena ob- served in these experiments do not depend on the section of these canals, as this operation may not cause these phenomena, but that they are the results of an irritation of the auditory nerve, from the drawing upon it by the membranous semicircular canals at the time we divide them. In frogs and in mammals, the direct irrita- tion of the auditory nerve is followed by the most interesting phenomena. It is well known that in frogs the peripheric ex- tremity of this nerve is inclosed in a bag containing carbonate of lime ; as soon as this bag is laid bare and slightly touched, and still more if it be punctured with a needle or a bistoury, the ante- rior limb, on the opposite side, is thrown into a state of slight con- vulsion, and kept almost constantly in a spasmodic pronation ; and almost at every attempt to move forwards the animal turns round on the side injured. As long as it lives (many days, or even many months), these phenomena may be observed, although not quite so marked as immediately after the injury, or after the first twenty- four hours. In mammals, the least puncture of the auditory nerve causes rolling, just as after the irritation of the processus cerebelli ad pontem ; violent convulsions then occur in the eyes, the face, and many muscles of the neck and chest. The doctrine that the nerves of the higher senses are not endowed with general sensi- bility (i. e., are not able to cause pain) seems not to be true with regard to the acoustic nerve ; at least, the signs of pain given after an irritation of this pretended nerve are often as great as those observed after an irritation of the trunk of the trigeminal nerve. In man, also, the auditory nerve seems to be able to act as it does after an injury in animals. 1st. Any one who has received an injection of cold water in the ear may know that it produces a kind of vertigo, and that it is diffi- cult to walk straight for some time after this irritation. 2d. A sudden noise makes the whole body jump, particularly in old people, or in persons attacked with anaemia, chlorosis, epilepsy, chorea, hysteria, hydrophobia, and in certain cases of poisoning; in a word, in all circumstances in which the control of the will over reflex actions is lost or diminished. 3d. Yertigo and various convulsive movements, in cases of irri- tation of the acoustic nerve, 1 have been observed in adults and 1 Walter and Lincke, quoted by Harless in art. " Horen," in Wagner's Hand- worterbucli der Physiol., vol. iv., 1853, pp. 420, 423. 196 THE CENTRAL NERVOUS SYSTEM. children. Rotatory movements have taken place in cases of sup- purative inflammation of the ear, and twice immediately after an injection of a solution of nitrate of silver. 1 Quite recently Mr. Hinton has read a paper to one of the London medical societies, in which he relates several cases of convulsions in children, without any other visible alteration after death, except in the ear. I could point out several other facts to prove that irritation of the auditory nerve may cause vertigo, rotatory movements, and various other kinds of convulsions; but I think I have said enough to call the attention of practitioners to this subject, and this was my principal object. I will only add a few words more to say that the causes of rotatory movements are numerous, and that, besides the one which is the principal in most cases (and that is the spasm produced in some muscles, as I have already said), there is a cause similar to that of simple vertigo, depending upon anaemia, or gene- rated by an irritation upon some centripetal nerve (as, for instance, in cases of gastralgia), and producing a contraction of some blood- vessels of the brain, by a reflex action, and this cause is the insuffi- ciency of blood, and the consequent alteration in the nutrition of certain parts of the brain. The parts of the base of the encephalon, which are capable of producing persistent spasms, seem to be quite different from those employed in the transmission of sensitive impressions or of the orders of the will to muscles, at least in the medulla oblongata and the pons Yarolii. They constitute a very large portion of these two organs, and perhaps the three-fourths of the first one ; they are placed chiefly in the lateral and posterior columns of these organs; many of their fibres do not decussate, and produce spasms on the corresponding side of the body; they seem to contain most of the vaso-motor nerves, by which, directly or through a reflex action, they may act on other parts of the nervous system, as I will show hereafter; they have much to do with the phenomena of several, if not most, of the convulsive diseases ; and, lastly, I will say that the history of their properties and actions throws a great deal of light on the effects of extirpation or diseases of the cerebellum. The above assertions, which I advance with the greatest reluc- tance, as I have not time enough to show that they are based on 1 See the case of Prof. Burggroeve, recorded by himself (Gaz. Mid. de Paris, 1842, p. 25). A most eminent military man, I am told, has twice been seized with rotatory convulsions after injections in the ear. RELATIONS OF COLUMNS OF MEDULLA OBLONGATA. 197 positive and numerous facts, are not the only ones to which I wish to call attention. Connected with them there is a theory of which I have already spoken (see Lecture VII.), and which I must now try to demonstrate. This theory is, that almost all, if not all, the voluntary motor fibres of the trunk and limbs that come from the brain pass by the anterior pyramids, or in the layer of gray matter in contact with them. This view, which is pretty nearly the one held already by Mistichelli, Pourfour du Petit, and others, has been universally abandoned, in this century, after the publication of the important researches of Foville 1 and of Valentin, 2 showing that there seems to be a complementary decussation of nerve-fibres, all along the median line of the base of the encephalon. The small number of fibres in the anterior pyramids, on the one hand, has appeared to be insufficient for the conveyance of the orders of the will to all the muscles of the trunk and limbs ; and the existence of paralysis on the side injured in the encephalon, on the other hand, has contributed to lead to the actually admitted opinion that the voluntary motor fibres make a part of their decus- sation in the medulla oblongata, and the other part in the pons Varolii, and also higher up between the two sets of tubercula quadrigemina and the two cerebral peduncles. Long ago Cruveil- hier 3 had said that " the small fascicles, called anterior pyramids, cannot be sufficient for the extensive phenomena indicating a cross- ing of action in the brain." A man of great authority in physi- ology as well as in pathology, Dr. R. B. Todd, 4 says that " anatomy suggests that a lesion limited to either anterior pyramid would affect the opposite side of the trunk, for it is known that such an effect follows disease of the continuation of it in the meso-cephale or crus cerebri ; and that lesion limited to the posterior half of the medulla oblongata, on either side, would affect the same side of the body, no decussation existing between the fibres of opposite restiform or posterior pyramidal bodies." Longet, 5 with Foville and Valentin, expresses the idea that there are two sets of voluntary motor columns in the medulla oblongata : one, the anterior pyra- mids, and the other the olivary or innominated columns; and that 1 Traite Complet de l'Anatomie du Syst. Cerebro-Spinal, 1844, pp. 298-326. 2 Traite de Nevrologie, Trad. Franc., pp. 236, 237, 246. 3 Article "Apoplexie," in "Diet, de Med. et de Chir. Prat.," vol. iii. p. 226. 4 Art. "Nervous System," in the Cyclop, of Anat. and Physiol.," vol. iii. p. 722. T. 5 Anat. et Physiol, du Syst. Nerveux, 1843, vol. i. p. 383. 198 THE CENTRAL NEEVOUS SYSTEM. this last set has a decussation of fibres all along the pons Varolii and before it. (See Fig. 24, B, B.) Against this theory, the follow- ing decisive arguments may be advanced : — 1st. Suppose an alteration in one of the crura cerebri. (Fig. 25, p, o.) According to the theory, as a part of the decussation of the voluntary motor nerve-fibres takes place there, we should find that voluntary movements are diminished on both sides of the body — more, of course, in the side opposite to the alteration, but partly also in the same side of the body. This is not what exists. One side only of the body is paralyzed ; and it is the opposite side. A number of cases prove that this is the rule. The hemiplegia may be complete or incomplete, according to many circumstances, and particularly the extent and the nature of the alteration, and the rapidity of its formation ; but there is something constant coexist- ing with any one of these numerous varieties: it is that the seat of the paralysis is in the side of the body opposite to that of the dis- ease. It is evident, in consequence, that the decussation of the voluntary motor nerve-fibres has entirely taken place before they reach the crura cerebri. 2d. The same thing may safely be said of the corpora quadrige- mina. (Fig. 18, ?i, t, and Fig. 24, mn.) Although the cases relative to these organs are much less numerous than the cases relative to the crura cerebri, there are enough of them on record to prove that the crossing of the voluntary motor nerve-fibres must have taken place entirely before they reach the base of the corpora quadrigemina. Besides some other cases, there are two very in- teresting ones which have been published, one by Mohr, and the other by Burnet — both of which I have already quoted. 3d. As to the pons Varolii (Fig. 18, p, and Fig. 25, v), the ques- tion is much more interesting, because this is the place where the decussation of voluntary motor fibres, according to Foville, Valentin, and Longet, more particularly takes place. Here, according to the theory of these distinguished anatomists, we ought to find different symptoms in these three different cases : 1st, alteration limited to the superior part of the organ ; 2d, alteration limited to the infe- rior parts (the nearest to the medulla oblongata); 3d, alteration occupying the whole of a lateral half of the organ. In the first case we should see an incomplete paralysis in both sides, but greater on the side of the body opposite to the side of the disease; and, in the second case, we should see also an incomplete paralysis in both sides, and almost to the same degree in both. Many cases THEOEY OF VALENTIN" AND OTHERS DISAPPROVED. 199 are on record proving that it is not so, and that whatever is the part of the pons altered (the superior, the inferior, or the middle), the same effect is produced on voluntary movements. When para- lysis is produced by the lesion, it exists, exclusively, in the opposite side of the body ; and when the alteration is not limited to one side of the pons, and extends to the other, then the side most para- lyzed in the body is the one opposite to the most altered side of the pons. If the theory of Valentin, Longet, and others were true, we should find in cases where the whole of one-half of the pons is diseased, the two sides of the body partly paralyzed, and the side opposite to the alteration less than the other. On the contrary, we find that paralysis exists only in one side, and that is the one which, according to the theory, should be less paralyzed. I might prove that I am right by relating here many pathological facts; but as I have already mentioned some (see Lecture VII.), and as I shall have in a moment to mention several others, I will merely now affirm again that there are many. 4th. Still more, if the theory we disapprove were true, we should see in cases of alteration of a lateral half of the medulla oblongata, above the decussation of the anterior pyramids (Fig. 25, jo, a), a paralysis nearly as marked in the same half of the body as in the opposite half. But this is not what is observed, and we find para- lysis only in the opposite side. (See particularly Cases 38 and 89, Lecture VII.) It seems absolutely certain, from the above facts and reasonings, that there is no decussation of the voluntary motor fibres of the trunk and limbs above the crossing of the pyramids. On the other hand, we have already shown, in a previous lecture, that there seems to be no decussation of these fibres in the spinal cord — i. e. } below the crossing of the pyramids; so that we are led to admit that most of, if not all, the conductors of the orders of the will to muscles decussate at the lower part of the medulla oblongata, and that these conductors chiefly form the anterior pyramids, after their decussation. An interesting fact, in addition to those already men- tioned, concerning these pyramids, is, that when a lesion exists at the place of decussation, it produces a paralysis in the two sides of the body, because it destroys fibres belonging to them both. This is a feature quite peculiar to this part of the cerebro-spinal axis. (See Fig. 21—1, 2 and 3.) From the preceding remarks, and from the facts and reasonings 200 THE CENTRAL NERVOUS SYSTEM. contained in our lectures (the third and seventh) on the decussation of the conductors of sensitive impressions, it results that, as regards anaesthesia and paralysis, three different groups of symptoms may be observed, according to the place of the alteration in a lateral half of the cerebro-spinal axis : 1st, above the decussation of the pyra- mids, a lesion on either the medulla oblongata, the pons Varolii, the crura cerebri, the optic thalami, the corpora striata, or the brain proper, if it produces anaesthesia and paralysis, produces them both in the opposite side of the body; 2d, below the decussation in the pyramids, a lesion in the spinal cord produces paralysis in the same side, and anaesthesia in the opposite side ; 3d, at the level of the decussation of the pyramids, and upon the decussating fibres, and also behind them, a lesion produces paralysis in both sides of the body, and anaesthesia only in the opposite side. So that wherever the lesion, in a lateral half of the cerebro-spinal axis, may be — below, above, or at the level of the crossing of the pyramids — if it produces ancesthesia, it is in the opposite side; 1 while paralysis, in these three cases, is either in the same or the opposite side, or in both sides. (See Figs. 18 and 21.) A striking proof of the exactitude of the view that the anterior pyramids are almost the only channels for the orders of the will to muscles in the medulla oblongata, and that the olivary or interme- diate columns have no share in this function, is given by those very interesting cases of atrophy of one-half of the brain and of the corresponding anterior pyramid, with paralysis and atrophy of the two limbs of the opposite side, and also atrophy of the opposite half of the spinal cord, while the olivary and restiform columns are unaltered. There are now several cases of this kind on record; I have seen two, and Mr. Turner has given a complete description of three or four. 2 Many persons have thought that the cases of paralysis depend- ing upon an alteration in a lateral half of the encephalon, and ex- isting in the same side of the body, could not be accounted for except by admitting that there are voluntary motor nerve-fibres that do not decussate in the medulla oblongata. I have not time 1 Of course, a lesion in one-half of the cerebro-spinal axis, anywhere at the level of the entrance of a sensitive nerve, besides producing anaesthesia everywhere below the seat of the injury on the opposite side, causes it also in the same side, but only in parts receiving the nerve or nerves the roots of which pass through the altered part of the nervous centre. 2 De l'Atrophie unilateral du Cerveau, du Cervelet, &c. These. Paris, 1855. INCOMPLETE PARALYSIS. 201 enough to examine fully the various explanations that may be pro- posed about paralysis in the same side as the encephalic lesion, but I will try to show — 1st, that there is a part of the encephalon which almost always produces this kind of paralysis ; 2d, that this para- lysis ought to be regarded as similar to the reflex paralysis due to an irritation of centripetal nerve-fibres, in any viscus, any mem- brane, or the trunk of a nerve. (See my Journal de Physiol, Juillet, 1857, p. 534.) When a tumor exists, pressing upon the anterior surface of one of the crura cerebelli and upon the insertion of the trigeminal nerve (see Fig. 25, c c), if it causes paralysis, it is in the same side of the body. I have collected fourteen cases of this kind, all having the same features, which are incomplete paralysis in the side of the lesion, no anaesthesia (except in one case), and frequent fits of vertigo. Now, as to the explanation of this kind of paralysis, we will say, that it is either the result of the destruction of some conductors employed in voluntary movements (to regulate them or to act other- wise), or of the irritation of certain nervous fibres in the peduncle itself, or near it. Were the first hypothesis the true one, we should find that a destruction of the whole peduncle causes paralysis in the corresponding side only, or in it and in the other one, and not in this other alone; but there are several cases in which there has been, with such an alteration, a paralysis in the opposite side only. 1 We should find, also, that alterations of the parts by which the crus cerebelli communicates with the muscles produce a paralysis in the same side of the body, together with a paralysis in the opposite side. But this is not what is observed. I have collected more than thirty cases of alteration in a lateral half of the pons Yarolii and medulla oblongata, in many of which the lesion extended to the crus cerebelli, and in all the paralysis was in the opposite side only. 2 For instance, in a case of Dr. Annan, which I have related (see Case 38, Lecture VII.), the whole connection of the right crus cerebelli with the right half of the medulla and of the pons was destroyed, and the paralysis existed only in the left limbs. (See Fig. 25, c c.) As to the other hypothesis, we will say that it is the only one 1 See especially a case carefully recorded by Serres (Traite d'Anatomie comparee du Cerveau, vol. ii. pp. 623-6). 2 There are a few cases, however, in which a tumor has pushed backwards and upwards the crus cerebelli and the corresponding half of the pons, producing only a slight degree of paralysis in the same side of the body. 202 THE CENTRAL NERVOUS) SYSTEM. we can find able to explain the production of the paralysis in the side injured, in cases of irritation of the crus cerebelli ; and we will add that, perhaps, the same explanation would be the right one for all the cases of the so-called direct paralysis. But whether it is the irritation of the fibres of the crus, or of those of the trigeminal nerve, which causes the paralysis, we cannot tell, and we have no time to discuss the question. The same reason prevents our exa- mining why the anterior surface of the crus cerebelli, or the trige- minal nerve at its point of insertion, have more power than in their other parts, or than the rest of the encephalon, to cause a paralysis, in consequence of an irritation. I will only say that we find that the peripheric parts of the same nerve in the gums and the bulbs of the teeth, as also certain parts of the sympathetic nerve, have more power to produce a paralysis than other nervous ramifications in many parts of the body ; and that, therefore, there is no ground for an objection to our hypothesis from the fact that such a para- lysis is not caused by the irritation of other parts of the encephalon than the crus cerebelli. I may add, that when an irritation on a nerve causes a paralysis, it is usually in the corresponding side of the body that it appears, just as is the case when a tumor exists between the petrous bone and the crus cerebelli. To complete, as much as time will allow, the exposition of my views on the physiology and pathology of the central nervous sys- tem, I have now to speak of the condition of animal heat in cases of alteration of the spinal cord and the encephalon. The follow- ing conclusions may be drawn from a great many facts bearing on this subject : — 1st. That usually anaesthesia is accompanied by a diminution of temperature. 2d. That hyperesthesia almost always co-exists with an increased temperature. 3d. That in paralysis, without either a notable hyperaesthesia or anaesthesia, the temperature is nearly normal. I must remark that the state of heat of a part is due to the amount of blood, the degree of heat of this fluid, the exposure of the part to the influence of the temperature of the surrounding medium, and the temperature of this medium. Now, in anaesthetic parts the bloodvessels are usually contracted, and, therefore, there is less blood in them, and also a lower temperature. In hyper- aesthetic parts the reverse exists. Pathological cases show that when there is an alteration in one- ANESTHESIA AND HYPERESTHESIA. 203 half of the spinal cord, the bloodvessels in that side are paralyzed, as are also the muscles. There is more blood in these paralyzed, parts, and the temperature is higher than it is normally. In the opposite side the reverse obtains. It seems from these facts, and from many experiments, that it is from paralysis of the vaso-motor nerves, and from their irritation in the cerebro-spinal axis, that arises the difference of temperature between the two sides of the body, in cases of alteration of a part of one-half of this axis. In combining what is taught by pathological cases, as regards tempe- rature, with the symptoms concerning sensibility and voluntary movements, we are led to give the following indications of the usual phenomena to be observed in cases of disease in one part of a lateral half of the cerebro-spinal axis. Table of symptoms in the trunk and limbs, according to the seat of a lesion in one lateral half of the cerebro-spinal axis. 1. Lesion in the brain proper, the optic thalamus, or the corpus striatum. On the opposite side. On the same side. Sensibility Diminished or lost Normal Voluntary movements Ditto, ditto Ditto Temperature (even) Increased Ditto without fever) . ) 2. Lesion of the pons Varolii or the medulla oblongata above the decussation of the anterior pyramids. On the opposite side. On the same side. Sensibility Diminished or lost Increased Voluntary movements Ditto, ditto Normal Temperature Diminished Increased 3. Lesion of the medulla oblongata at the level of the decussation of the ante- rior pyramids. On the opposite side. On the same side. Sensibility Diminished or lost Increased Voluntary movements Ditto, ditto Diminished or lost Temperature Diminished Increased 4. Lesion of the spinal cord. On the opposite side. On the same side. Sensibility .Diminished or lost Notably increased Voluntary movements .... vUfh^ Ditto^ ditfro Ji oni'ly noime > l fy/j^ Temperature Diminished Increased It is unnecessary to say that nothing is more variable than the degree of temperature of paralyzed or anaesthetic parts, and that, therefore, what is stated in the above table ought to be considered as the most frequent condition, and not as a constant one. Paralyzed bloodvessels may contract under the influence of cold, and the tern- 204 THE CENTRAL NERVOUS SYSTEM. perature and the hyperesthesia of a part may, in this way, diminish for a time. On the other hand, contracted bloodvessels will neces- sarily relax after a long period of contraction, because they lose their power of contraction by a persistent and somewhat spasmodic action, and, in this way, anaesthetic and cold parts may temporarily become warm. 1 GENERAL CONCLUSIONS OF THE COURSE. Our principal object in these lectures has been, to prove, chiefly by experiments upon animals and by pathological cases observed in man, many new views concerning the physiology and pathology of the central nervous system. A number of these views have been proposed by myself; whilst the others, although advanced by several physiologists, have not yet been sufficiently proved. At the same time that we have tried to build new doctrines, we have shown the insufficiency and, sometimes, the complete untena- bleness of certain theories which had been more or less generally admitted. In the following conclusions, which are only a very small part of those that might be drawn from the facts and reason- ings which have been mentioned in our lectures, we will point out the most important views that we have tried to establish: — 1st. Excitations of the anterior roots of the spinal nerves may be a cause of pain, because these roots, being motor, produce a cramp. The pain due to this cramp is what has been erroneously called recurring sensibility. Cramps, and several other kinds of painful spasms (of the uterus during parturition, of the sphincter ani in certain cases, &c), are painful on account of a galvanic irri- tation of sensitive nerves accompanying muscular contractions. (Lecture I.) 2d. Our movements seem to be guided by the peculiar sensations we derive from the galvanic irritation of certain sensitive nerves of muscles, while they contract. (Lecture I.) 3d. The power of transmitting sensitive impressions exists in many parts which are not able to give pain or any other sensation when they are excited by our usual means of irritation ; so it is with the gray matter of the spinal cord, and with many parts of 1 See for other parts concerning this subject my Experim. Researches applied to Physiol, and Pathol., 1853, pp. 73-78. GENERAL CONCLUSIONS. 205 nerves, which, however, are conductors of sensitive impressions. (Lecture II.) 4th. Hyperesthesia is a constant result of certain injuries upon, or alterations of, the posterior parts of the cerebro-spinal axis, from the tubercula quadrigemina down to the lower end of the spinal cord. (Lectures II., IV,, and V.) 5th. The transmission of sensitive impressions, in the spinal cord, takes place chiefly through the gray matter, and partly through the anterior columns; but, before reaching the gray matter, the impres- sions, in. a certain measure, pass through the posterior columns. (Lectures II., IV., and V.) 6th. The conductors of sensitive impressions from the trunk and limbs decussate in the spinal cord, and not in the encephalon, as was universally admitted. (Lectures III. and VII.) 7th. Although the spinal cord is greatly altered or injured, sen- sibility, more or less diminished, may persist everywhere, on account of a peculiar arrangement of the conductors of sensitive impressions. (Lectures IV. and VI.) 8th. The various kinds of sensitive impressions seem to be trans- mitted by quite distinct conductors, in the nerves and in the nervous centres, and the place of passage of some of these conductors, in the spinal cord, seems not to be the same as that of the others, but none of them go up to the sensorium along the posterior columns. (Lecture VII.) 9th. In the upper part of the cervical region of the spinal cord, near the medulla oblongata, most of the conductors of the orders of the will to muscles are in the lateral columns, and in the gray matter between these and the anterior columns. (Lectures IV. and VIII.) 10th. The voluntary motor conductors decussate at the lower part of the oblong medulla, and not all along the median line of the base of the encephalon. (Lectures VII. and XII.) 11th. The posterior columns of the spinal cord have a great share in reflex movements, and this is the principal cause of the peculiar kind of paralysis so often observed in cases of alteration of these columns. (Lecture VIII.) 12th. The effects of excitation of the vaso-motor nerves consist essentially in a contraction of bloodvessels, which is followed by a diminution of the quantity of blood, in the temperature, and in the activity of nutrition. The effects of interruption of continuity of the vaso-motor nerves (■?'. e., their paralysis) consist essentially in a 206 THE CENTRAL NERVOUS SYSTEM. paralytic dilatation of bloodvessels, which is followed by a greater afflux of blood, an increase of temperature, and a greater activity of nutrition. (Lecture IX.) 13th. As a great many vaso-motor nerve-fibres go up to the brain and to the cerebellum along the spinal cord, the medulla oblongata and the pons Varolii, the diseases or injuries of the various parts of the cerebro-spinal axis, besides symptoms concerning sensibility and movement, present symptoms depending upon irritation or paralysis of vaso-motor nerves : contraction or relaxation of blood- vessels, diminution or augmentation in the quantity of blood, increase or diminution of temperature, alterations of nutrition, of secretions, &c. (Lectures IX. and XII.) 14th. Besides the kind of influence of the nervous system upon nutrition, absorption, and secretion, through the vaso-motor nerves, there is another kind, which seems to consist in changes in the ele- ments of the tissues — changes producing various modifications in the quantity of blood attracted, and in the interchange of materials between the blood and the tissues. (Lectures IX. and X.) 15th. The absence of the influence of the nervous system on any part of the body is hardly a cause of other alterations of nutrition than atrophy, while the irritation of the nervous system is a most powerful direct or reflex cause of a great many morbid changes in nutrition, secretion, &c. (Lecture X.) 16th. The sympathetic, normal, and morbid changes of nutrition, secretion, &c, are reflex phenomena, the study of which shows how many diseases are produced by a reflex action, and how a rational mode of treatment might be arrived at. (Lectures X. and XL) 17th. The loss of consciousness in simple vertigo or in complete attacks of epilepsy does not depend upon a disease of the brain, but upon a contraction of the bloodvessels of the cerebral lobes — contraction due to some irritation of the vaso-motor nerves of these vessels, either by some direct cause irritating them in the base of the encephalon or the spinal cord, or by a reflex influence. 18th. Much more frequently than has been imagined, all the fol- lowing affections may be produced by a peculiar kind of irritation starting from almost any centripetal part of the nervous system ; epilepsy, the various forms of insanity, chorea, catalepsy, hysteria, tetanus, hydrophobia, &c. (Lectures X. and XL) 19th. The medulla oblongata is neither the only nor an essential nervous centre for the respiratory movements. (Lecture XII.) 20th. There are a great many nerve-fibres and nerve-cells in the GENERAL CONCLUSIONS. 207 medulla oblongata, the pons Yarolii, and the other parts of the base of the encephalon, which are not employed in the transmission of sensitive impressions or of the orders of the will to muscles, and are endowed with the singular property of producing, after even a slight irritation, a persistent spasm in certain muscles, and especially in the neck. Eotatory convulsions very often depend chiefly upon the production of such spasms, and of changes in the bloodvessels of certain parts of the encephalon. (Lecture XII.) 21st. The irritation of the auditory nerve may cause rotatory or simple clonic convulsions. (Lecture XII.) 22d. The conductors of the orders of the will to muscles, of the sensitive impressions and of the nervous influences to bloodvessels, decussating at different places in the cerebro-spinal axis, various symptoms are to be observed, depending upon either the irritation or the paralysis of these three kinds of conductors, according to the part of a lateral half of the cerebro-spinal axis where an alteration exists. (Lecture XII.) APPENDIX. APPENDIX. "We propose to make here many additions, which, we hope, will increase the value our lectures may have, both in a scientific and in a practical point of view. There are objections to the opinions we have advanced, which we have not been willing to discuss in our lectures, for, had we stopped for such a discussion, this inter- ruption might have proved injurious to the clearness of the demon- strations. It is one of the objects of this appendix to examine these objections. On the other hand, there are deductions for the treat- ment of many diseases, which are to be drawn from the principles that we have, tried to establish in our lectures; it is also one of the objects of this appendix to give the most important of these deduc- tions. PART I. EXAMINATION OF OBJECTIONS THAT MIGHT BE MADE AGAINST MANY OF THE VIEWS WHICH ARE HELD IN THE PRECEDINC LECTURES. "We think that it is quite wrong to say — as many physiologists and practitioners do — that a fact is not true, simply because it is in opposition with generally admitted views. Many discoveries might be made by scientific inquirers, who, without prejudice, would collect facts, which, though they seem to have been well observed, appear to be contrary to admitted doctrines, and would try to find out an explanation of these facts. We will only say that there is no great discovery in science which has not been in opposition with previously admitted doctrines. The preceding assertion will serve as an apology for the discussion of certain facts, the exist- ence or the exactitude of which has been generally doubted, al- though it seems to have been positive. 212 APPENDIX. 1. Alleged existence of voluntary movements and of sensibility in children apparently deprived of the cerebrospinal axis. I think that it is now impossible to deny that there have been cases in which such monsters (Amyelejicephalous, Be"clard), have had movements, either inside or outside of the uterus, and, without doubt, purely reflex, and which have been mistaken for voluntary movements, and admitted as a proof that sensibility existed. Among numerous cases collected by Isidore Geofifroy St. Hilaire 1 and by Ollivier d' Angers, 2 there are some which cannot be considered as entirely erroneous statements, and, to laugh at the believers in these facts, as Longet 3 does, cannot be an argument against their existence. What is to be done is, no more to deny, but to try to explain, and this I will do, after having related some extremely curious cases, recently published, and, perhaps, better authenticated than those of which Longet has spoken. The first case I will relate is recorded in the very rich and in- teresting catalogue of the Boston Anatomical Museum, for which science is indebted to the zeal and activity of my learned friend Prof. J. B. S. Jackson. Case 1. — A pregnant woman did not feel the movements of her child, until about the end of the fifth month, and they were always feeble and peculiar. In the last month, slight motions of the child were still occasionally felt, even after a profuse discharge of liquor amnii. Labor came on, and was accomplished with very little pain; the child was born alive, the mother having felt its motions for fif- teen or twenty minutes after it was expelled. On the arrival of Dr. Hildreth, half an hour afterwards, the lower extremities of the child were still in the vagina. Autopsy. — The spinal marrow was wanting, and the spinal column being open throughout, the nerves terminated in the membrane upon its posterior face. A very small bundle of nervous fibres was seen passing down over five or six of the processes upon the left side, and a few of the cranial nerves were found, among which, it was thought, was the par vagum. Nerves of the trunk and extremities well developed. 1 Hist, des Anomalies de l'Organisation, vol. ii. 1836, pp. 344-351, and 371-4. 2 Loco cit., vol. i. p. 146. 3 Anat. et Physiol, du Syst. Nerv., 1842, vol. i. p. 323. EXAMINATION OF OBJECTIONS. 213 The brain existed, weighing three ounces (the weight of the monster being three pounds and one ounce). It rested' upon the expanded dorsal and lumbar vertebras, and upon the integument which covered the depressed cranial bones. It was divided into two equal hemispheres, and, imperfectly, into convolutions, the arachnoid membrane being continuous about the base with the common integument. The whole mass was very soft, and of a dusky color, from congestion, and effused blood ; there being in each hemisphere a cavity which was rilled with coagula. No other parts of the brain were recognized, and no connection was traced be- tween this mass and any of the nerves, either cerebral or spinal. 1 It is to be regretted that some circumstances have not been pointed out in this case, and, for instance, the size of the ganglions of the sympathetic and of the spinal nerves. The movements of the child, after birth, not having been ascer- tained by the physician himself, we cannot know whether they were respiratory, convulsive, or reflex. As to what took place before birth, if we can rely upon the assertion of the mother, there have been movements, but they began late, although much sooner than these uterine contractions, which are sometimes mistaken for movements of the child. The mother had had already two chil- dren, and therefore was able to distinguish the movements of a child. I must say also that, in a physiological point of view, although the brain was existing in this monster, it is exactly as if it had been missing, because it was not connected with the nerves. In the following case we will find that movements have existed, during pregnancy, in a case, the circumstances of which may lead us to explain how movements can exist. Case 2. — A woman, pregnant for the sixth time, was not aware of the fact, although her abdomen had become large, and her men- struation had stopped, and she was much surprised when she felt the movements of her child, which were so strong, that even the hand of another person could perceive them. The 8th of May, she felt the movements for the last time ; and after the expulsion of a very considerable quantity of water, she was delivered of a child, 1 A Descriptive Catalogue of the Anatomical Museum of the Boston Society for Medical Improvement. By J. B. S. Jackson, 1847, p. 263. (Case by Dr. Charles T. Hildreth.) 214 APPENDIX. who, out of the uterus, remained motionless. Its weight was from 3 to 3J lbs. It had no neck, and the head — very small — appeared to be lodged in a cavity in the trunk. From the upper part of the orbitary arcade, the skin was missing all over the head. The spinal canal, open all along, from the cranium to the lumbar region, con- tained a spinal cord, being in shape like a band, flattened from be- hind forwards, and of about one line and a half in thickness; its beginning at the base of the cranium was somewhat bifurcated, and evenly cut. It was lying on a fatty and fibrous mass, which filled a deep excavation, found in the place where the neck should have been, had it existed. This medullary band was very loosely at- tached to the spinal canal, by some fibrous filaments. This band had no connection with the nerves, which terminated in the verte- bral foramina by a swollen and ganglionary extremity. In the trunk and limbs, the nerves were well developed. There was no brain. The chest was large; no respiration had taken place, as the lungs showed. The upper part of the cranium was missing, and the basis was convex. It is very much to be regretted that Dr. Olier, 1 to whom w r e owe the relation of this interesting case, has not given more details about the nervous system. He does not speak either of the cranial nerves or of the sympathetic. I have now to examine the value of the two cases I have related, and of many other analogous to them, which are more or less authenticated. The first question is, whether there has been any decided volun- tary movement, and any perception of a sensitive impression in these monsters. Nothing proves that sensibility exists, and the movements con- secutive to an excitation, however regular or co-ordinate they may be, cannot give such a proof. Nothing in these circumstances proves that these movements are not reflex. It is now generally admitted, as Bischoff, 2 Prof. Simpson, 3 and others have established, that the movements of healthy children in the uterus, and even for some time after birth, are merely reflex. If it is so for them, a fortiori, is it so for the pseudencephalic monsters. These reasons against the existence of sensibility may be employed against that 1 Observ. d'un foetus Anencephale, in Comptes Rendus de la Soc. de Biologie, 1S50, vol. ii. p. 106. 2 Traite du developpement de l'liomme. — Trad" 10 , franchise, 1843, p. 459. 3 Edinb. Monthly Journal of Med. Science, July, 1849. EXAMINATION OF OBJECTIONS. 215 of a Will, in these monsters. Their movements are almost always consecutive to an external excitation. Nevertheless we admit that they have, sometimes, an apparently spontaneous movement ; but, we well know that reflex movements may be excited by any irrita- tion of the viscera, and that the respiratory movements of the chest may excite reflex movements in the limbs. Besides, the same ex- citation which produces respiratory movements, is able to produce movements in the limbs. I have tried to prove, in a work 1 which I published five years ago, that the nerves, muscles, and some other parts of the body, may be excited to act, by blood, containing a great quantity of carbonic acid. Very likely, respiratory move- ments, in monsters, as well as in healthy children and adults, take place in consequence of an excitation produced by carbonic acid, and an excitation, by this agent, may also be the cause of some of the falsely called voluntary movements in the pseudencephalic mon- sters. 2 To conclude, we will say that, if there appears to be no doubt that movements may exist in these monsters, nothing proves that they are voluntary and that they result from true sensations. On the contrary they appear to be purely reflex or mere excited move- ments. A second question now arises, much more difficult to be solved than the preceding. How to explain reflex movements, if there is no spinal cord, or if this organ, though existing, is not united with the nerves? Let us examine alternately the different possible explanations. 1st. A man of genius, Etienne GeofYroy St. Hilaire, 3 has given credit to the idea that the liquid which is sometimes found in the pseudencephalic monsters, in the cranio-spinal cavity, and filling there a tube, formed by the meninges — may be considered as con- taining the elements of the brain and spinal cord, in their primitive state of development. In many cases this liquid is not found in the membranous tube formed by the meninges, but then it appears 1 Experimental Researches applied to Physiol, and Pathol. New York, 1853, pp. 101-113. * The pseudencephalic monsters compose the genus Pseudenctfphale of the family of the Pseudencons Varolii or of the neighboring parts, has produced paralysis in the same side of the hod//. I regret not to have room enough to treat at length this subject, about which much has been said already in Lecture XII. I will merely give here, one only of the cases that are on record; then I will relate, shortly, the different modes of explanation of these facts, and, at last, I will show that these cases cannot be opposed to what I have said, as regards the place of decussation of the motor and sensitive nerve-fibres. 1 Monthly Jour, of Med. Science. April, 1S51, p. 365. EXAMINATION OF OBJECTIONS. 239 Case. — Hemiplegia of the left side, without loss of sensation in the arm and leg, but in the left side of the face both sensation and motion were entirely lost. Loss of hearing in the left ear. Autopsy. — A tumor was found in the left side of the pons Varolii, which compressed the origin of the 5th and 7th nerves against the base of the skull. The tumor was of the size of a walnut, of a firm consistence, and extended into the left crus cerebelli. 1 This case is positive, and the co-existence of the paralysis in the face and the body, in the same side, points out, at once, a striking difference between the ordinary cases and this extraordinary one. In the ordinary cases, paralysis exists in the side of the alteration in the face, and in the opposite side of the trunk and limbs. I will remark that in this case there was no paralysis of sensi- bility in the limbs, and I will add that it has been so, in all the cases, but one, that I know, in which paralysis has existed in the same side as the alteration. Now, how to explain these facts ? 1st. There is an explanation to which we are naturally led : it is, that in the men spoken of in these cases, there was no decussation at all of the sensitive and voluntary motor nerve-fibres. This would explain, not only the cases relative to the pons, but also the cases in which alterations have existed in one side of the cerebrum, of the cerebellum, of the corpora striata, or of the thalami optici, and in which hemiplegia has existed in the same side. Longet 2 says that, sometimes, he has not found any appearance of decussation of the pyramids, in man, and I have also made the same observation on animals. 2d. It may be imagined that the decussation of voluntary motor and sensitive nerve-fibres, instead of taking place as usually, takes place, in some men, only in front of the pons, between the corpora quadrigemina and the crura cerebri. 3d. It may be, as it results from what we have related above, and what has been found by Prof. H. Bennett, that the true altera- tion which really produces the paralysis, and which can be detected only with the microscope, is in the side of the encephalon, opposite to the side where an alteration is seen, with the naked eye. Now, I ought to say that, a few years ago (in 1855), by examining the circumstances of the cases in which there has been only a par- 1 Stanley in Lond. Med. Gazette. Vol. i. 2 Anat. et Physiol, du Syst. Nerv. Vol. i. p. 383. 240 APPENDIX. alysis of movement, I was led to think that there was no decussa- tion of the pyramids, and that the decussation of the voluntary motor fibres either did not exist at all, in these cases, or existed above the pons. As to the case in which there was together a paralysis of movement and of sensibility, I thought it might be ex- plained by what results from Prof. Bennett's researches. But now, as it may be seen in Lecture XII., and with more details in the Journal de la Physiologie, Nos. 3 and 4, July and Oct., 1858, I have some other views concerning those cases. I shall not expose those views again here, as my object is now only to be able to state that those extraordinary cases may be explained. Both the theories actually proposed about the place where exists the decussation of the voluntary motor and of the sensitive nerve- fibres, one which is the theory of Longet, Foville, Valentin and others, and the second which is mine — are, as much, in apparent opposition with these cases (of paralysis in the same side where is the alteration), one than the other. If it were true, as admitted by Foville, Valentin, Longet, etc., that the decussation of the voluntary motor and sensitive nerve-fibres, takes place partly in the pons and partly behind and before this organ, a considerable alteration of its sides, producing paralysis, should produce it, in both sides of the body ; so that, if paralysis exists, only in one side, be it the side of the alteration or the other, the fact, in both cases, appears as much in opposition with the theory. But we repeat that there is now an apparently well-grounded explanation of the cases of paralysis in the side altered in the ence- phalon, and we refer to the above quoted lecture and journal for the details on this subject. 8. Cases and experiments which appear to prove that there are, in vari- ous parts of the encephalon and in the sp>inal cord, motor nerve-fibres, which are not voluntary motor. As to the spinal cord, the existence, in it, of fibres, which are motor but not voluntary motor, has alread}^ been pointed out by some physiologists. As it is not necessary for my object here to demonstrate the fact, I will merely state that I believe it is certainly true that there are such fibres. As to the encephalon, not only the doctrine of the existence of such fibres is a new one, but the proofs themselves, upon which it is grounded, are mostly new or presented here in a new light. EXAMINATION OF OBJECTIONS. 241 For a long while since Hippocrates, it was admitted that in wounds in the brain, the convulsions were always in the injured side, while paralysis was in the opposite side. Haller, though inclined to admit this doctrine, had remained in doubt about it. Flourens 1 thought he had decided the question, and he gave the following conclusions : — 1st. The cerebral lobes and the cerebellum never give convul- sions. 2d. The quadrigeminal tubercles give convulsions in the opposite side. 3d. The medulla oblongata and spinal cord give convulsions in the injured side. Flourens has been led to erroneous conclusions, partly because he has not taken notice of what has been observed in man, partly because he has particularly experimented on birds. Burdach, according to J. Mueller, 2 has given the following statis- tics : Out of 268 cases of alteration on one side of the encephalon, there have been 10 cases of paralysis in both sides of the bod}', anc l 258 of hemiplegia, of which 15 were in the side of the alteration. Convulsions took place in 25 cases in the side of the alteration, and in only 3 cases in the opposite side. From many facts recorded by Andral, Eochoux, Eostan, Aber- crombie, Serres, Bright, Bouillaud, Lallemand, and Eomberg, it results that convulsions in the side of the alteration appear to be less frequent than convulsions in the opposite side. So that the results arrived at by Burdach are opposed to the results of these more recent writers. But whatever may be about this, it is suffi- cient, for my object now, that it is certain that convulsions may take place, either in the side where is the alteration or injury of the encephalon, or in the opposite side. Now, there are other and very curious facts which also prove that contractions of certain muscles of the body may take place either in the side of the body corresponding to the injured side of the encephalon, or in the opposite side, exactly as in the cases of ordinary convulsions, as I have just said. And, in fact, this might have been foreseen, had it been known that a convulsive state of certain muscles is the cause of the phenomena of which I will now say a few words. 1 Loco cit., p. 120. 2 Manuel de Physiol. Ed. Littre, 1851, vol. i. p. 783. Q 242 APPENDIX. If a puncture or rather a slight section is made, on mammals, in different parts of the encephalon, we see quite different effects, according to the part which has been injured. The animal turns round or rolls over itself (see my paper on Taming and Rolling in Exp. Researches, p. 18, and Lecture XL), and this, as I will prove elsewhere, in consequence mostly of local convulsions. Turning or rolling takes place after an injury of the right side, sometimes on the right, sometimes on the left side of the body, as I have already shown. In almost all these experiments, turning or rolling exists on the side where there are convulsions in certain muscles. The spasms exist in all cases, in the muscles of the neck, frequently in those of the trunk, and sometimes in those of the limbs. The convul- sions of the muscles of the neck and trunk are sufficient, without the assistance of the limbs to produce rolling, as I have frequently seen, after the amputation of the four limbs. It seems quite certain from these two series of facts (i. e., pure convulsions in one side of the body and the local spasms coexist- ing with turning and rolling), that convulsions may be produced in muscles of one side of the body, by the same alteration which produces paralysis in the opposite side. From this it results that there are two different sets of motor nerve-fibres, which appear to originate from the same place, in many parts of the encephalon, one set being composed of voluntary motor-fibres, which then become paralyzed, and the other set composed of motor fibres, which are not voluntary motor, because, were they so, their altera- tion would produce paralysis, and we should, therefore, have then a paralysis in both sides of the body, although the alteration should exist only in one side of the brain. But what are these fibres, as they cannot be voluntary motor? 1 They certainly are able to pro- duce muscular contractions, and, therefore, we are entitled to call them motor, but we do not know whether the irritation acts directly 1 It is well known that no movement is produced in the limhs and trunk, when an excitation of any kind is hrought upon the cerebral lobes or even the corpora striata. As the voluntary motor fibres extend into the encephalon, if not into the cerebral lobes, at least into the corpora striata, it is certain that there these fibres cannot be irritated by our means of excitation. It may be that these fibres remain so, unirr italic all along, from these parts of the encephalon to their termi- nation in muscles, and that the nerve-fibres which produce contractions when we irritate them, either in the encephalon, in the spinal cord, or in the nerves, belong to the other class of motor nerves, the existence of which I am now trying to establish. EXAMINATION OF OBJECTIONS. 243 upon them, or whether it is by a secondary, that is a reflex action that they become excited. It may be, and this seems very proba- ble, that they are merely reflecto-motor. But, whatever is the truth about their nature, they are motor, and they exist in great number, in all the isthmus of the ence- phalon, and particularly in the medulla oblongata. We can by this fact understand why there are so many motor fibres belonging to the anterior columns of the spinal cord which are not voluntary motor. 9. Anatomico-pathological dissections which appear to prove that there are nerve- fibres, coming from the spinal cord, which decussate in parts above the medulla oblongata. The interesting facts discovered by Dr. Luclwig Tiirck, of Vienna, 1 showing that when there is an alteration of a part of the ence- phalon, the nerve-fibres which go from that part into and along the spinal cord, become very much altered in their structure, have proved that there is a decussation for these fibres in the Pons Varolii or in parts before it. 2 I do not think necessary to dis- cuss at length the value of these researches, in relation to the subject of this paper. I believe it is sufficient to say that, as long- as there are other fibres, besides the sensitive and the voluntary motor, which originate from the different parts of the encephalon, nothing in the curious facts described by Dr. Tiirck would prove against our admitting, that the decussation of the sensitive and voluntary motor fibres takes place where I have tried to show that it does. This means of study of Dr. Tiirck will have the greatest value when (and only when) it shall be combined with all the other means that science already possesses to determine what are the kinds of 1 See Braithwaite's Retrospect, Amer. edit., part xxvii. p. 344. 2 Dr. Tiirck is disposed to consider the alteration produced, in these cases, in nerve-tubes, as a result of absence of action. I believe this view is partly right, but there is another cause of alteration, which is — according to what I have tried to show in a paper presented more than five years ago, to the Society de Biologie — that the nerve-tubes are endowed with capillarity, and that liquids, in which is placed a divided end of them, are absorbed, and conveyed very far in their canal, and there altering their contents. The spinal cord may become secondarily affected, in that way, by diseases of the different viscera, and this may prove to be a good means of finding the course of the roots of the nerves in the spinal cord. I had already made some researches about the disposition of these roots five years ago, and I intend to resume them as soon as possible. 244: APPENDIX. nerve-fibres existing in the nervous centres, and what is their re- spective course. General Conclusions. — In the first part of this appendix I have tried to prove successively : — a. That reflex movements alone, and not sensations and volitions, exist in monsters, deprived of a great part of their cerebro-spinal axis. b. That when the spinal cord, the medulla oblongata, or the Pons Varolii are altered, even considerably, sensibility and voli- tion may continue to exist, because there are still communications by nerve-fibres through the altered part, between the nerves of the trunk and limbs, and the parts of the encephalon, in front of the Pons. c. That if the reasons given by many physiologists to prove that the Pons Varolii is the seat of the centre for volition and for per- ception of sensitive impressions were true, we should have to admit that the medulla oblongata is the centre (or, at least, a part of the centre) for these faculties, because the same reasons appear to prove the same for this organ as for the Pons. d. That very likely these faculties have not their centre (at least their principal centre) in the Pons Varolii, and, still less, in the medulla oblongata. e. That there appears to be, in many places of the encephalon, nerve-fibres, which are not voluntary motor, and which, neverthe- less, go to muscles, either in the same side of the body as the side of the encephalon, from which they originate, or in the opposite side, and that these muscular nerve-fibres are able to produce con- vulsions when they are irritated by an injury or an alteration in the encephalon, so that convulsions may take place either in the paralyzed side or in the other. /. The results of the researches of Dr. Ludwig Tiirck cannot, in the actual state of science, prove against or in favor of any doctrine relative to the place of decussation of sensitive and voluntary motor nerve-fibres. PART II. APPLICATION OF SOME OF THE FACTS AND VIEWS, EXPOSED IN THE PRECEDING LECTURES, TO THE TREATMENT OF DISEASE. I will give here a short' summary of several of the principal de- ductions for the practice of the various branches of medical science, that may be drawn from many of the facts and views presented in APPLICATION OF FOREGOING- VIEWS TO SURGERY. 2-45 my lectures. I shall divide this second part of this appendix into several chapters, which will contain : 1st, application to surgery ; 2d, application to medicine; 3d, application to obstetrics. Chap. I. Application to /Surgery.— The first object to which I shall call the attention of my readers, concerns the treatment of frac- tured spine, and the first question I shall examine on this subject, is whether it may or not be useful to employ the trephine, with the view of removing a broken part of the bony ring of the ver- tebrae. I am convinced that the life of some patients might be saved by this means, and I hope the following discussion will give the same faith to others. I shall try to prove : 1st, that the laying bare of the spinal cord is not a dangerous operation ; 2d, that death, after a fracture of the spine, is usually due to the effects of a pres- sure, or an excitation upon the spinal cord, and not the result of a partial or a complete section of this organ ; 3d, that reunion may take place after a wound of the spinal cord, so that its lost func- tions may return ; 4th, that the removal of some parts of the ver- tebras may be followed by a production of new bone ; 5th, that the cases of fracture of the spine in which the trephine has been applied show the usefulness of this operation. 1st. The exposition of the spinal cord to the action of the atmosphere is not a dangerous operation. — One of the principal objections raised against the use of the trephine, in cases of fractured spine, is that the laying bare of the spinal cord is a dangerous thing. This quite erroneous opinion has no other foundation, that I am aware of, than the well known fact that the laying bare of the brain or of its meninges is dangerous, and that in cases of tapping, for spina bifida, a meningitis is sometimes produced by the supposed irrita- tion of atmospheric air upon the spinal meninges. But, as regards the first one of these grounds for an opinion that I consider entirely erroneous, it is sufficient to say, that it is only an inferential reason and not a direct proof, and as regards the second, I will say that certainly it is not the laying bare of the spinal cord, or its mem- branes, which causes a meningitis after tapping, in cases of spina bifida, as this inflammation occurs as frequently after the perform- ance of the operation by the subcutaneous method, as after the use of the old method. We may add that the meninges of the spinal cord, in ordinary circumstances, do not become inflamed so easily as in cases of spina bifida, and that the meninges of the brain are much more liable to become inflamed than those of the spinal 246 APPENDIX. cord, as is proved by the relatively small number of cases of inflammation of the spinal meninges after they have been injured by a piece of bone, a sword, etc. The opening of the spinal canal and the laying bare of the spinal meninges, or of the cord itself, are not dangerous operations in animals. I may safely say, that one dog, cat, or guinea-pig, out of ten, hardly dies from having the spinal cord laid bare, in the extent of an inch or even more. Of course, these facts cannot prove that in man the same innocuity would exist, as we know that certain membranes and organs are much more easily inflamed in man than in animals. But there are facts, of which I will speak hereafter (especially the similarity of results of fractures of the spine in men and in the animals already mentioned), which seem to show that there is no great difference between these animals and men, as regards the power of inflammation of the spinal cord, or its mem- branes ; so that it is at least very probable, that what is found in the above experiments on dogs, cats, etc., would also be observed in man. One of the most decisive reasons, however, for our admitting the truth of the proposition, that there is no danger in the laying bare the spinal cord in man, consists in the existence of several cases like the following in which there has been no ill effect at all, caused by the exposition of this organ to the contact of the atmo- sphere. In a curious case of syphilitic caries of the spine, A. Mercogliana, an Italian surgeon, removed (through a deep ulcer of the throat) the body of the third cervical vertebra, leaving the spinal cord bare. The patient had no trouble whatever in the functions of this nervous centre, and recovered. [Gazette Medicate de Paris, 1832, pp. 589-90.) In another case, analogous to the preceding, a part of a cervical vertebra was removed by another Italian surgeon, Marcacci. The patient was quickly cured. (Gazette Medicate de Paris, 1850, p. 268.) In a case of acephalocystic cyst, in the spinal canal, the bones became altered, and the cyst having been opened, the spinal cord was laid bare. No ill effect is mentioned as the result of this operation. (Traite des Maladies de la Moelte qnn., par Ollivier d ? Angers, 1837, vol. ii. p. 547.) Three cases of exfoliation of the atlas, one observed by Mr. Robert Wade, the two others by Mr. Prescott Hewett, were com- municated to the Royal Medico-Chirurgical Society of London in APPLICATION OF FOREGOING VIEWS TO SURGERY. 247 February, 1849. The three patients got well. {London Journal of Medicine, April, 1849, p. 395.) From these facts, and from several similar ones which have been published in various medical journals, it seems that we are entitled to draw the conclusion that the action of the air upon the spinal cord is not a dangerous one. But it is still more important to state that there are no cases on record, so far as we know, of removal of broken parts of the spine, in which the operation has been followed by a meningitis. This assertion will be proved hereafter, when we give the principal details of all the cases we know of application of the trephine to the spine. In animals I never saw meningitis produced by injuries to the three membranes that surround the spinal cord. It seems certain, from the facts above mentioned, that the laying bare of the spinal meninges, or even of the spinal cord after the section of the meninges, cannot be considered as dangerous opera- tions either in man or in animals. 2d. Death after a fracture of the spine is usually due to the effects of a pressure or some excitation upon the spinal cord, and not to the results of a partial or a complete section of this organ. — It would be out of place here to enter fully into the demonstration of this pro- position. TVe will only give a short account of the various causes of death after a fracture of the spine, which will sufficiently show what share a pressure or a mechanical excitation of the spinal cord has among these causes. When the spine is fractured high up in the cervical region, if the spinal cord is crushed, death occurs instantaneously or after a very short time, on account, partly, of the cessation of respiration, and also, partly, of a peculiar influence on the heart similar to that influence exerted by the par vagum when it is galvanized by a powerful and interrupted galvanic current. 1 But when the fracture is in the lower part of the cervical region, or in the upper part of the dorsal region, the effects it produces are usually quite different. If the cord is partially crushed or incised, and if there is no pres- sure upon it, the patient's life may be saved. It is only when this nervous centre is completely or almost completely severed, that death seems to be unavoidable. But if there is pressure only, as 1 For the influence of the medulla oblongata and spinal cord on the heart, see my paper in Journal de la Physiologie, vol. iii. 1860, p. 152. 248 APPENDIX. is usually the case, life may be saved ; and it is in such cases that the application of the trephine might be very useful. When the fracture is in the middle of the dorsal region, there is a chance for the patient to have his life saved, even if the cord is completely severed ; and, of course, the chance is still greater if only a part of the thickness of this organ is divided or crushed. If there be only pressure, we think there is a great probability of cure by the removal of this mechanical excitation. The influence of a mechanical excitation of the spinal cord by a broken piece of bone deserves the full attention of both the phy- siologist and the practitioner. Among the alterations in the nutri- tion of the paralyzed parts in cases of that kind we will particularly notice the sloughs on the sacrum, and the various morbid changes that take place in the bladder and in the urinary secretion. These alterations in nutrition and secretion are certainly frequent causes of death after fractures of the spine. Therefore, it is of the greatest importance to find out the mode of production of these morbid changes, and to try to prevent or to cure them. The production of sloughs on the sacrum cannot be considered as an effect of prolonged pressure of the trunk upon the parts of the skin where they appear, as they sometimes are produced in a few days and even in a few hours after the fracture. They result from a morbid excitation of the spinal cord, and not from the loss of action of that nervous centre owing to its partial or complete section, as proved by experiments showing that they never occur after sec- tion of the cord. The proof that pressure upon the sacrum has but a slight influence on their production is clearly given in the case of animals on which, after a fracture of the spine, I have seen sloughs occurring in parts that were not submitted to pressure. Besides, it is known that men who are confined to bed by other causes than a nervous complaint, may bear pressure upon some part of the body for a long while without the production of sloughs. Pressure on the sacrum is, therefore, only an additional cause of sloughs. For the mode of action of the nervous system in pro- ducing alterations of nutrition, I will refer to my lecture on the influence of the nervous system upon nutrition, 1 and I will only 1 Lecture X. pp. 151-177. For more details on the capital point that it is chiefly owing to a morbid action of the nervous system that alterations of nutrition take place in diseases of that system, and not, as generally supposed, to a para- lysis, i. e., to the cessation of action of that system, see Journal de Physiologie, 1859, p. 112. APPLICATION" OF FOREGOING VIEWS TO SURGERY. 249 say here that an irritation and not a paralysis is the cause of these morbid changes. It is an important fact that, after fractures of the spine in the dorsal or lumbar regions, it is very frequent that sloughs cause death by the propagation of the inflammation of the fibrous tissue lining the sacrum, to the membranes of the spinal cord, producing a very acute and quickly fatal meningitis. As a pressure upon the spinal cord by a fractured bone may produce sloughs and a fatal meningitis, it is important to try to remove such a mechani- cal excitation of the cord. We must say, however, that after the removal of the broken pieces of bone, the danger of the production of sloughs, though much diminished, would not be altogether re- moved, as a cause of them may remain, i. e., a myelitis. Another morbid change due to a mechanical excitation of the spinal cord may also cause death after a fracture of the spine ; it is the alteration which takes place in the kidneys, an alteration some- times amounting to a real inflammation. We hardly need to say that the changes in the urinary secretion, owing or not to an in- flammation of the kidneys, and also the hematuria or the alterations in the mucous membrane of the bladder in cases of fracture of the spine, are morbid phenomena depending upon an irritation of the spinal cord, and not upon a paralysis due to a division of this organ. On the one hand, a section of the cord is never followed by these alterations in the kidney or the bladder; on the other hand, we often observe these alterations too quickly after the spine has been fractured, to admit that they are due to a paralysis. Other causes of death besides the preceding exist in cases of fracture of the spine, depending also upon a mechanical excitation of the spinal cord. I will simply name the principal of these causes ; they are, a myelitis, an increase in the amount of the cerebro-spinal fluid, and the influence upon the heart when the excitation exists in the cervical region. It is not a section of the spinal cord that usually produces these causes of death ; it is the excitation of this nervous centre by broken pieces of bone. If we divide or crush the spinal cord in animals, we rarely find an in- flammation occurring in this organ, and the beatings of the heart, instead of being diminished in frequency and force as when the spinal cord is irritated, increase in a more or less marked degree. It is, therefore, extremely important to remove, if possible, the pieces of bone that irritate the spinal cord, to avoid a myelitis, and the other causes of death above mentioned. 250 APPENDIX. To complete the demonstration of the proposition that death after a fracture of the spine is usually due to the effects of the ex- citation of the spinal cord by broken pieces of bone, and not to the results of a partial or complete section of this nervous centre, we will only say that there are many cases on record showing that a section or even a crushing of the spinal cord has not proved fatal, and that in animals death is rarely caused by a partial or complete section of the cord in the dorsal region, while they die as quickly and as often as men after a fracture of the spine, if the broken pieces are not removed. 3d. Reunion may take place after a wound of the spinal cord, so that its last functions may return. — My experiments upon animals, 1 and also several pathological cases observed in man, prove the truth of this proposition. I must say, in addition, that I have sometimes seen a notable return of lost functions in animals the spine of which had been fractured and the spinal cord crushed. 4th. The removal of some parts of the vertebrce may be followed by a production of new bone. — This is a fact that I have observed a great many times in animals, even in cases when I had taken away the 'posterior half of the bony ring of five or six vertebras. Generally the reproduction of bone is very slow except in young animals. The new bones are larger and thicker than those taken away. I never saw, but once, the reproduction of a spinous process. In man, after fractures of the spine, new pieces of bone have often been found round the callus, in cases when life has lasted more than one or two months. 5th. The cases of fracture of the spine in which the trephine has been applied show the usefulness of this operation. — Before mentioning these cases I must say a few words on the results of my experi- ments upon animals. I have found that if, after a fracture of the posterior arch of some vertebras in the dorsal or lumbar region in dogs, cats, and guinea-pigs, I removed the broken pieces of bone, most of them were quickly restored to health. Some of them, in which the spinal cord had been either crushed or partially divided, remained more or less paralyzed either for a long while or per- manently. A few died either of myelitis or some other cause. These experiments clearly prove the importance of the removal of fragments of bone in certain kinds of fracture of the spine in animal* No positive conclusion, however, could be drawn from 1 Experimental Researches applied to Physiol, and Pathol., New York, 1853, p. 17. APPLICATION OF FOKEGOING VIEWS TO SUKGEEY. 251 these experiments alone as regards trephining in cases of fracture of the spine in man, as animals may be quite different from man. But, as I have ascertained that dogs, cats, and guinea-pigs almost always die after having presented the same symptoms that are observed in man, after a fracture of the spine, when the broken pieces of bone are not removed, it is fair to conclude, from the above experiments, that trephining might be a useful operation in man as it is in animals. The first case of trephining of the spine in man, in which the operation was successful, is related by Louis, the most celebrated French surgeon of the eighteenth century. A man received a gun- shot in the dorsal region of the spine, in consequence of which he became completely paralyzed in the lower limbs ; the wound was enlarged at once, and the ball taken out. Louis saw the patient on the fourth day after the injury; he found that there were several fragments of bone pressing upon the spinal cord. He removed these fragments, and, although there was a considerable suppuration after this operation, the paraplegia slowly but gradually disappeared, and the patient was completely cured, excepting, however, a slight weakness which remained in his lower limbs. 1 In the above case we have a proof that the removal of broken pieces of bone may be quite successful, at least when the fracture of the spine is due to gunshot, and limited to the posterior arch of a vertebra. Another important case of cure of fracture of the spine, obtained by surgical interference, is mentioned in the following terms in the British and Foreign Medical Review, for 1838, p. 162: "We know only four cases, and of these one was performed successfully, as we are informed, only a few months ago, by a surgeon of the name of Edwards, living at Caerphilly, in South Wales. There were present the usual symptoms of compression, paralysis of the organs of locomotion, the rectum, and the bladder. The situation (of the fracture), as far as the operation was concerned, was unfavorable — the lumbar region. The posterior arch of the bone was raised, the symptoms of compression relieved, and the patient did well." It is a pity that the details of this fact have not been published. However, we have there a clear proof that the most happy result may be obtained by the elevation of a depressed bone in a case of fracture of the spine. 1 Memoire posthume, in Archives Gen. de Medecine, etc., Aout, 1836, p. 397. 252 APPENDIX. A third successful case of surgical operation on the spine after a fracture, has been published by Dr. Alban W. Smith, of Kentucky. {North Amer. Med. and Surg. Journal, July, 1829, p. 9-i.) Two years after a fall that was followed by complete paralysis of the four limbs, except the muscles above the elbow on each side, it was supposed that there was a fracture of the base of the spinous process, and that there was compression of the spinal cord by the broken piece of bone. "The diagnosis," says Dr. Smith, "was confirmed by the operation." The fragments were found displaced laterally, but so completely fused and offering so smooth a surface that the line of separation was not well marked. With a Hey's saw the operator divided first each side of the second dorsal vertebra, as near as possible to the bases of the transverse processes ; and re- sected and raised up a portion of the spinous processes of two vertebras, half that of the third and all that of the fourth, which seemed most deeply driven in. No lad symptoms ensued ; sensibility was regained in the thighs and in the hands, auguring well for the re-establishment of motion. It is much to be regretted that the further history of this case has not been published ; but, so far as it goes, it proves, like the two preceding cases, that in man as in animals, the exposition of the spinal meninges to the atmospheric air is not a dangerous operation ; it shows also that good results may be quickly obtained by the removal of a bone compressing the spinal cord. The account published by Dr. Alban "W. Smith has been severely criticized by several writers. We agree with Malgaigne 1 when he says that the diagnosis was made out carelessly, and the operation rashly undertaken; but he certainly is unjust when he says that "all the dates are omitted, and the seat of the lesion not stated." True, the dates are omitted, but it is said that it was two years after the frac- ture that the operation was made ; and, as regards the seat of the lesion, the second, third, and fourth dorsal are clearly designated. If we now study those cases of trephining applied to the spine, in which the operation has not saved the life of the patients, we find, in the first place, that the operation has not proved injurious, and, in the second place, that it has been often followed by an ame- lioration in the condition of the patient. We also find that those cases were all very bad ones, and that death was to be expected in 1 See the excellent translation published by Dr. J. H. Packard, of Philadelphia, of Malgaigne's Treatise on Fractures, Philad., 1859, p. 336. APPLICATION OF FOREGOING VIEWS TO SURGERY. 253 all. Still more, in some cases besides the fracture of the spine, there were other injuries sufficient to cause death. We will men- tion some of the most interesting of those cases, and also those the authenticity of which is most certain. In 1822, a patient with a fracture of the ninth and tenth dorsal vertebras was admitted at St. Thomas's Hospital. There was a complete paraplegia of the lower limbs, the bladder, and the rectum. The posterior arch of the two broken vertebrae was removed, so that three inches of the spinal meninges were laid bare. A few hours after the operation, the patient felt when he was pinched, which had not been the case previously ; he recovered at least partly the voluntary power over the lower limbs, the bladder, and the rectum. However, the patient died a fortnight after the opera- tion, but from a peritonitis and an enteritis, which seem to have been produced by the cause of the fracture. 1 Mr. J. F. South, in one of the important notes he has added to his excellent translation of Chelius, 2 says of the above case : " The result of Tyrrell's case, which was certainly most favorable for operation, the cord not having been subjected to other injury than pressure, was most highly encouraging, and I cannot but think that if the after-treatment had been different he would probably have recovered." Dr. J. Ehea Barton performed the operation with as good results as those obtained by Tyrrell, as shown by the following account : "J. P. was received in the Pennsylvania Hospital, August 18, 1824, with a fracture of the spine, caused by a fall from the mast-head of a brig. The lower part of the trunk and the inferior extremities were totally paralyzed. He continued in this state, discharging his feces and urine involuntarily, until the 30th of August, when Dr. Barton performed the following operation : An incision was made, about eight inches in length, immediately over the injured vertebras. He found the spinous process and arched portion of the seventh dorsal vertebra broken off and depressed on the spinal marrow. When this was done, it was ascertained that the bodies of the seventh and eighth dorsal vertebras were dislocated from each other, without any fracture but that above mentioned. Lint 1 See the account given of this case hy Georgii, who witnessed the operation, in the work of Ollivier d'Angers, Traite des Maladies de la Moelle epin., 3d ed., 1837, vol. i. p. 381. 2 A System of Surgery, hy J. M. Chelius, translated hy J. F. South, London, 1845, vol. i. p. 540. 254 APPENDIX. was laid over the wound. The paralysis not being immediately relieved, it was inferred that compression was kept up by blood effused within the spinal canal, which would possibly escape with the suppuration from the wound. About forty-eight hours from the time of the operation, sensibility began to return below the injured vertebra?, and gradually extended toward the toes until the third day, when he was attacked with a violent chill, which con- tinued, notwithstanding all the stimulant medicines given, until his death, which occurred in twelve hours from its commencement. On opening the thorax, the posterior mediastinum was found filled by about half a gallon of coagulated blood, which accounts for the difficulty of respiration, especially when he lay on his back. This being cleared away, the condition of the vertebral column was seen. The seventh and eighth dorsal were injured as before stated, the body of the ninth was fractured, and blood was effused throughout the spinal canal." 1 In this case death was most likely due to the loss of blood com- bined with the difficult}' of breathing. In the following case we will find also that the operation was followed by good results as regards the functions of the spinal cord. In the next case the result of surgical interference was extremely marked. A strongly-built young man, having been struck on the neck, was brought to a hospital. Symptoms of fracture of the spine were observed. Three months and a half after the accident. Dr. A. Potter, of New York, saw the patient and found him paralyzed both as to sensibility and motion in all the parts below the seat of the fracture. Dr. Potter thought that there was compression of the spinal cord by the broken pieces of bone, and proposed to raise or extract these pieces. The next day he performed the operation, and took away several pieces belonging to the last four cervical and the first two dorsal vertebra?. The patient recovered sensibility almost immediately, and a few hours after he could easily say ichat foot and what toe were touched. The wound was in the way of healing, when a thoracic inflammation, which existed before the operation, increased rapidly, and caused the death of the patient, eighteen days after the operation. 2 This case is a most important one, as it clearly shows, 1st. That 1 J. D. Godman's edition of Sir A. Cooper's Treatise on Dislocations and Frac- tures, p. 421 ; see also Packard's translation of Malgaigne, p. 343. 2 See Gaz. Med. de Paris. 1S45. p. 74S. or Xew York Journal of Medicine. March, 1845. APPLICATION OF FOREGOING VIEWS TO SURGERY. 255 the extraction of broken pieces of vertebrae has been followed by a complete return of sensibility ; 2d. That cicatrization of the wound due to this operation may proceed rapidly ; 3d. That the operation had proved in a great measure successful, and that the cause of death was altogether independent from it. The following case, though less important than the preceding, is a very interest- ing one. A man fractured his spine in the cervical region. His breathing was performed by the diaphragm alone; sensibility and motion were lost everywhere in the trunk and lower limbs ; the bladder was paralyzed ; pulse very low. He became gradually worse, and, five days after the accident, Mr. G. M. Jones, of Guernsey, 1 took away the posterior arches of the fifth and sixth cervical vertebrae. " The pulse after the operation rose to 80, and no longer inter- mitted. At 8 P. M. the patient had entirely recovered from the effects of chloroform ; merely complained of smarting pain in the neck and back; was perfectly cheerful, and had entirely recovered sensation as low down as the umbilicus. 11 He recovered also the power of raising his arms, and he could, without inconvenience, throw them across the chest. During the first succeeding clays the improvement continued, and Mr. Jones had some reason to hope that recovery might take place, when suddenly, after the nurses had changed the linen of the patient, he was attacked with "coma," and died shortly after. The autopsy showed that there was con- siderable effusion at the base of the skull. "Whatever may have been the real cause of death in the above case, it is certain that it is not to be found in the operation or any of its effects. We find, in this last case as in all the preceding, that the laying bare of the spinal cord, instead of being followed by any grave symptom, was followed by a return of some of the functions of this nervous centre, especially as a conductor of sensi- tive impressions. Two cases of operation upon the spine after a fracture have been published in Germany; they both show the importance of this operation. In one of them, the patient was operated upon by Dr. A. Mayer, of Wurzburg. 2 There was a notable amelioration in the symptoms, but the patient, after a fortnight, died from disease of the lungs. In the other case the patient, after a fracture of the 1 See Medical Times and Gazette, July, 1856, p. 86. 2 Journal der Chirurgie, von Walther und Ammon, vol. xxxviii. 1848, p. 178. 256 APPENDIX. eleventh and twelfth dorsal vertebras, had a complete paraplegia, with retention of urine, vomiting and vertigo. He was seen first on the thirteenth day by Dr. Holscher. He found a slough begin- ning on the sacrum, and a notable depression at the level of the fracture. After having made a crucial incision, and exposed the bones to view, he took away the posterior arch of the eleventh and twelfth vertebrae, and removed a little coagulated blood. The sloughing healed after considerable exfoliation. In six weeks the wound of the operation had healed well. Eight weeks after the injury, sensibility reappeared in the dorsum of the foot, and after- wards higher up. A few weeks later, the patient moved the legs a little. After twelve weeks, he was capable of raising himself up in his bed, and of moving slightly the lower limbs ; but after that time his strength diminished. He had oedema in his feet, ascites, and hydrothorax. He died fifteen weeks after the fracture, and besides the anasarca, there was found pericardial dropsy. The spinal membranes were denser and more vascular at the place of the operation, and there were ligaments uniting the bony parts ; the spinal cord seemed healthy. 1 We will mention but one more case, that of a man w r ho had a fracture of the ninth dorsal vertebra, and on whom Professor Lau- gier 2 practised trepanation. In this case the spinal cord had been ruptured, and therefore there was no chance of a return of sensation and motion in the lower limbs, but respiration became easier, lie felt desire of voiding the bladder, and had abundant stools. Four days after the operation the patient died, chiefly from a pleuro-pneu- monia caused by a fractured rib. We cannot but agree with Jaeger, 3 who, concluding from some of the above facts, and also from some others recorded by Attenbur- row, Holscher, Wickham, and Sogers, declares that after the opera- tion of trephining or removing broken pieces of bone, there is not any aggravation, but rather, in most cases, a notable improvement, with restoration of motion or sensibility. To the above cases I might add an interesting one, not of frac- ture, but of dislocation of the fourth cervical vertebra. An incision was made, and it was found that there was no fracture. The re- duction of the luxation was performed, and the patient improved 1 Hannoverschen Annalen, vol. iv. p. 330, 1839. 2 Bulletin Chirurgical. 1839, vol. i. p. 401. 3 Cited by Chelius (A System of Surgery, translated by J. F. South, 1845, vol. i. p. 538). APPLICATION OF FOREGOING VIEWS TO SURGERY. 257 after it. ITe died, however, on the sixth day, from a hemorrhage in the spinal cord. 1 The objections brought forward against trephining in cases of fractured spine by Sir Charles Bell, Sir Benjamin Brodie, and others, have probably prevented many surgeons performing this operation. Already Mr. J. S. South 2 has convincingly refuted some of these objections; consequently, we will say but little of them, inasmuch, also, that any reader who will weigh carefully the argu- ments we have advanced in favor of the operation, will find in them a sufficient reply to most of the objections of Bell, Brodie, and others. The following objections are those which alone deserve to be noticed : — 1st. It has been said that it is dangerous to expose the spinal cord or its membranes to the action of the air. We have at length shown how erroneous is this opinion. 2d. It has been objected that the parts divided to lay bare the spinal cord will necessarily become inflamed, and that the inflam- mation may be propagated to the membranes of the cord. Experi- ments on animals and the cases of trephining in man, do not show any case of meningitis due to such a cause. Besides, there is much more danger of inflammation from the laceration existing in a fracture than from a clean cut. 3d. It has been objected that we often do not know whether there is a fracture of the posterior arch of the vertebras or only of their body. Surely a mistake may be made in f that respect, but the laying bare of the spinal cord may be useful in allowing the escape of the bloody fluid effused in the vertebral canal. At any rate, the worst would only be that an operation, which is not dangerous, has been performed without profit. 4th. It has been said that the pressure upon the spinal cord, after a fracture of the spine, being due, in a great many cases, to the body of the vertebras, sometimes even when some other part of these bones are fractured, the removal of a portion of the pos- terior arch or its raising up would not change the situation of the body of the vertebras. It is true that there would be no change, but certainly we need not insist upon the fact that if there is no resistance on the back part of the cord, there will be no compres- sion by a displaced bone forward, as the cord, being movable, will simply be pushed backward. 1 Catalogue of Boston Museum, 1847 ; case of Dr. William J. Walker, p. 25. 2 Ibid. R 253 APPENDIX. 5th. It has been objected that, in many cases of fractured spine, we do not know whether the spinal cord is considerably injured or not. It is true that if the paralysis of movement and sensibility is complete, it will be very difficult and sometimes impossible to say what is the extent of the injury to the spinal cord. But there is no reason not to perform the operation on account of our ignorance of the condition of the spinal cord, as the object of the operation is to give a chance of saving a life which otherwise would be lost. 6tb. It has been said that, after having taken away the posterior arch of one or two vertebrae, the spine would not be sufficiently strong to support the body. The three cases of cure we have re- ported show that this objection should not be minded. 7th. Mr. Malgaigne calls this operation " a desperate and blind one," 1 and he adds that he would not advise any one to perform it. He does not give the reasons of his opinion against it, and contents himself with simply asserting that "it has always been undertaken at great risk, and has never been justified by the results." As clearly shown by the facts we have related, the truth is that this operation has always been undertaken without any great risk, and that it has fre- quently been quite justified by the results. Mr. Malgaigne says, in answer to Sir Astley Cooper, who has written in favor of trepana- tion of the spine, that " it is not accurate to call it our only scien- tific resource. In every fracture w r ith displacement, the most scientific and rational plan is first to attempt reduction by the ordinary methods ; and to this rule fractures of the vertebras do not constitute an exception." We know full well that several surgeons (Ehrlich, Schub, Wittfeld, Tuson, Stafford, and others 2 ) have related cases of fracture and luxation of the spine successfully treated by extension and reduction ; but we know also that there is on record at least one case of sudden death caused by the efforts at reduction, 3 and we feel very much inclined to repeat with Mr. South, 4 "that the attempt to set a fracture through the body of a vertebra, accompanied, as it almost invariably is, with displacement, and most commonly with fracture of the vertebral arch, or articular processes, is, as Chelius says, most highly dangerous and ought never to be attempted." No doubt that the reduction may some- 1 Packard's above quoted translation, p. 345. 2 See the good dissertation of Ricliet : Des Luxations Traumatiques du Rachis, 1851, p. 85. 3 See Traite des Maladies Chirurgicales, par Boyer, 5th ed., vol. iii. p. 650. Loc. cit., p. 538. APPLICATION OF FOREGOING VIEWS TO SURGERY. 259 times succeed admirably, but in some cases this operation might be the cause of a more or less extensive crushing or laceration of the spinal cord. Conclusions from the above Clinical Facts and Experiments. — It is quite evident that the laying bare of the spinal cord is not a dan- gerous operation. Experiments upon animals, and clinical facts observed in man, agree completely in giving a demonstration of the exactitude of this assertion. It is evident, also, from the results of experiments and from clinical facts, that the operation of trephining gives a chance of saving the life of patients in whom one or several vertebra are broken, so that if we take notice of the fact that most patients are sure to die after a fracture of the spine, especially in the neck or in the upper part of the dorsal region, we cannot understand why this operation has been so rarely performed. In- deed, it is surprising that a man is allowed to die without any attempt to save his life, by an operation which is neither dangerous nor very difficult. It is evident, also, that operations which are not dangerous, and which may save the life of three or four 1 patients out of a number of sixteen or seventeen, i. e., nearly 20 per 100, should not be neglected. The percentage of cure after these operations, compared to the percentage of cure (perhaps less than 1 per 100) when neither of them is performed, shows clearly the importance of such kinds of surgical interference after fracture of the spine. Three distinct operations may be performed on the spine in cases of fracture : 1st. The extirpation of broken pieces of bone ; 2d. The raising up or lifting out of the posterior arch of one or several vertebra, when they press upon the spinal cord ; 3d. The 1 To the cases of cure above recorded, I would have added the interesting case published by Dr. J. B. Walker, of Boston, had the seat of the fracture been indi- cated with more precision. A man was struck upon the back of the neck, and immediately lost all power of motion and sensation below the middle of the chest. The next day an incision was made over the back of the neck, and, the muscles having been dissected away, it was found that the spinous process of the sixth cervical vertebra was fractured and quite loose, though not driven in ; the bone was seized and twisted away. The wound was closed by four sutures, and healed without any trouble. On the third day from the operation, there was some return of sensibility, and twelve days later it was reported as quite natural. The power of the bladder partly returned, and, although symptoms of myelitis appeared, he recovered some power upon the lower limbs. Two years afterwards, his condition was stationary. His general health was very good. ( Catalogue of the Museum of the Boston Society for Medical Improvement, by J. B. S. Jackson, 1847, p. 31.) 260 APPENDIX. application of the trephine. Examples of each of these three operations have been reported above. These various operations, or one or two of them, ought to be employed in almost all cases of fracture of the spine, especially in the cervical region, and in the upper parts of the dorsal region, where pressure upon the spinal cord is attended with so much danger. The operation should be performed as quickly as possible after the fracture, and before inflammation has set in. If, after having laid bare the spinal cord, it is found necessary to reduce a fracture of the body of one or several vertebrae, the reduction will then be much easier, and attended with much less danger than if the vertebral canal had not been opened in its back part. In concluding these remarks upon trephining in cases of fractured spine, we cannot do better than to repeat these sentences of Sir Astley Cooper: "The proposal is laudable, and the operation is not severe, nor does it increase the danger of the patient ; time and ex- periment can only determine its value. If we could save one life in a hundred by it, we should deserve well of mankind ; and if any good does ultimately result from it, Henry Cline has the merit of proposing it." 1 To this we will only add that three or four lives have been saved already by that or by kindred means, and it is high time that surgeons should put aside their fear of compromis- ing themselves, and rather expose their reputation than allow a man to die whom they have a chance to cure. II. Prevention and Treatment of Sloughs on the Sacrum, Nates, etc., in Cases of Fracture of the Sjnne, Myelitis, Meningitis, etc. — I will not insist upon this point: I only wish to say that, led by the knowledge of facts showing the influence of nerves upon nu- trition through their action upon bloodvessels, I have tried to prevent or to cure those sloughs which are an evident result of disturbance of nutrition due to an irritation of nerves of blood- vessels, by acting upon the bloodvessels of the part where sloughs exist. I have made many experiments upon animals, showing that by applying alternately two poultices, one of pounded ice, the other a very warm bread or linseed poultice, there is a rapid cure of sloughs due to a nervous irritation. Several medical men have already obtained the same result in man that I have obtained in 1 Lectures on Surgery, p. 16. Sir Astley is mistaken in saying that Cline lias the merit of having proposed this operation. Many surgeons had made the pro- position long before Cline. RATIONAL TREATMENT OF HYDROPHOBIA. 261 animals, in following the plan of treatment that I have proposed. The pounded ice, kept in a bladder, is applied for eight or ten minutes, and the warm poultice for an hour or two, or even a longer period. It is especially in cases of fracture of the spine, or of myelitis, that this mode of treatment would be employed with great success. As it is certain that when they are not quickly the cause of death, fractures of the lower part of the spine destroy life chiefly through the production of sloughs, and the propagation of the inflammation to the fibrous structures of the sacrum, and thence to the spinal meninges, it will easily be understood how im- portant it would be to make use of the means I have just spoken of, against sloughs. I think I can safely say that, in cases when a slough is beginning, its progress will always be stopped by the means I propose. III. Rational Treatment of Burns. — I have shown, in one of the preceding lectures, that burns are very often fatal, on account of the reflex disturbance of nutrition that they produce, by a reflex action in one or several of the thoracic, abdominal, or cranial vis- cera. (See Lecture X., pp. 161, 171, and 175.) I will only say now, that of the various modes of treatment of burns there is one which has given admirable results at the great military hospital of Paris, the Vol de Grdce, and theoretically there is no better means. As the principal object of the treatment is to prevent reflex influ- ences and pain, the best therapeutical means consists in applica- tions of ice upon the burnt part. But, as it has been found long ago, applications of cold, if once made, must be continued without interruption. 1 Cold, by diminishing considerably the vital proper- ties of the nerves, will prevent pain, and, what is more important, those reflex influences which are so often the causes of death after burns. I need not repeat here what I said (pp. 175, 176), that bella- donna is the best narcotic to be employed in cases of burns, as it is the most powerful agent to diminish the reflex power of the spinal cord. Opium must be avoided, not only because it produces congestion of the brain, but also because it increases the reflex power of the spinal cord. IV. Rational Treatment of Hydrophobia. — We only wish to say a few words on this most important subject. The facts and views exposed, in several of our lectures, on the production of nervous 1 See the Notes of Mr. South, in his translation of Chelius' Surgery, vol. i. pp. 112, 113. 262 APPENDIX. diseases by an irritation starting from the periphery of the body, tend to show that tetanus, epilepsy, hysteria, catalepsy, chorea, etc., may have their origin in an irritation on some peripheric part of a nerve. "We think it is so, also, as regards hydrophobia, and if really such is the origin of symptoms, it seems rational to employ in this affection, as well as in certain cases of tetanus and other convulsive diseases, the section of the nerve through which the excitation is transmitted to the nervous centres. This view will certainly seem very strange to those persons who look upon hydrophobia as the result of the absorption of a poison, which acts upon the nervous centres, through which it circulates with the blood. But if we observe: 1st, that an alteration takes place in the part of the body that has been bitten by a rabid dog, before the convulsive and other phenomena of hydrophobia appear; 2d, that the convulsions of hydrophobia occur by fits following a kind of aura (pain or other sensations) starting from the wound of the bite or its cicatrix (which very often then gives way and is re- placed by a bleeding or suppurating wound) — we are forcibly led to think that the cause of hydrophobia is in the irritation of the wounded nerves, and cannot be an action of a poison on the nerv- ous centres. Many other facts lead to the same conclusion. The following is the most important. An eminent physician, Dr. W. Stokes, of Dublin, after having heard a lecture I delivered last year on this subject, told me that his father was led by the following fact to admit the view I hold. A tourniquet having been applied on a limb of a patient attacked with hydrophobia, the symptoms were quickly improved, and even seemed to cease altogether. The sur- geon then proposed to his colleagues to amputate the limb, but they declined giving their assent to this operation. It was ascer- tained several times that so long as the tourniquet was applied there were no convulsions, and that they occurred at every time it was taken away. As the danger of producing gangrene prevented a constant application of the tourniquet, the patient ultimately died. We admit as everybody that there is a poisonous principle in the saliva of rabid animals, but we think that it is in consequence of changes produced locally in the nerves wounded by the bite, that the phenomena of hydrophobia occur. We arc told that this hypothesis has been already put forward by a London surgeon in an article published many years ago in the Lancet, and that the ADDITIONAL FACTS. 263 author of this article has proposed the division of the wounded nerve as a means of treatment. I think that the first thing to be done in a case of hydrophobia, owing to a bite in a limb, would be to apply the tourniquet upon the principal artery of the limb, above the wounded part, and if there is no tourniquet at hand, to apply a very tight ligature round the upper part of the limb. If the symptoms cease in consequence of either of these means, then I would advise the resection of two inches of the trunk of the nerve that gives fibres to the wounded part. But if the patient is seen a short time after the bite, I would advise, besides the application of the heated-iron to the wound, the resection of a part of the nerve at a small distance above the wound. If the bite has been made on some part of the head or trunk, I would advise also the resection of the nerve that gives fibres to the wounded skin or flesh. It may be that patients will only be temporarily cured by this mode of treatment, and that the parts of the poison that are ab- sorbed and circulate in the blood, will, after a time, act upon other nerves than the one that has been wounded and resected ; but as there is no certainty, and, I might say, no probability of such a recurrence of hydrophobia, and I do not hesitate in urging the trial of this mode of treatment. In a fatal affection like hydro- phobia, anything that gives even the slightest chance of a cure should be eagerly tried. PART III.— ADDITIONAL FACTS IN PROOF OF SOME OF THE VIEWS OF THE AUTHOR. We have stated in Lecture XII. (see p. 201), that there is a pecu- liar kind of paralysis quite distinct from the ordinary cases of paratysis, produced by lesions of the encephalon, and characterized essentially by its being on the side of the seat of the lesion, instead of being on the opposite side, and we have tried to prove that this special kind of paralysis is due not to any immediate alteration of voluntary motor conductors, but to an irritation of some parts of a crus cerebelli (Fig. 25, h, p) ) producing a paralysis by a reflex action upon some other part of the nervous centres. It is probable that the mechanism of production of this paralysis is just the same as that which we have described in our " Lectures on Paralysis of the Lower Extremities, Philadelphia, 1860, Lectures I. and II." We will not enter into any discussion on this subject here. We only in- 264 APPENDIX. tend to refer the reader to several articles in which we have related facts in favor of our view (see Journal de la Physiol., 1858, vol. i. p. 531 et seq., and 1859, vol. ii. p. 121), and to give a short account of a case recently published by Dr. J. W. Ogle. Case. — Mrs. S., oet. 46, had enjoyed good health until 1848, when she occasionally lost her sight for a few seconds at a time, and had pain at the front and vertex of the head ; afterwards she had epileptic seizures and became totally blind. Dr. Ogle saw her in December, 1851. She was pale ; had her mouth drawn to the right side ; pupils dilated; no ptosis; left ear deaf ; very intelligent ; incomplete loss of power on the whole of the left side of the body, with hyperes- thesia of the face on that side. At times twitching of the left arm (in March, 1852) ; the paralysis was then less than it had been. In April, pain, with a feeling of numbness and stiffness in all the limbs, but no anaasthesia anywhere ; sense of smell lost in the left nostril. In September, loss of taste in the left side of the tongue. She re- mained in pretty much the same condition until September, 1856, when she died, after a violent fit of convulsions, which were almost entirely limited to the left side of the body. Autopsy. — Connected with the anterior cerebellar artery on the left side of the brain, there was an aneurism (see Fig. 26, <7,) of about the size of a small nutmeg, resting immediately upon the in- ferior surface of the left middle crus certhelli, and indenting, although very slightly indeed, the contiguous structures of the pons Varolii and left lobe of the cerebellum, which parts, at the point of con- tact, were very superficially softened. The root of the fifth nerve was pressed upon by the aneurism, and the facial nerve was stretched by it. 1 We give this summary of this case, both because it has been recorded by a most accurate observer, and because it may serve as a type of analogous cases. This case offers all the principal fea- tures that may exist in consequence of irritations of the cerebellum, of the trigeminal nerve, and of the middle crus cerebelli ; i. ,/. -// ^OLUMBIA UNIVERSITY LIBRARIES This book is due on the date indicated below, or at the expiration of a definite period after the date of borrowing, as provided by the library rules or by special arrangement with the Librarian in charge. DATE BORROWED DATE DUE DATE BORROWED DATE DUE Dfr.8 1 965 ') C28( lO- 53) lOOM Htetorfeaf Colie< QP361 B81 Copy! Brown- Sequard Course of lectures on the physiol- ogy and pathology of the central nervous system. > £[& MB 1 5. iocc DIMT\rnt. Historical Collection (// ?/ /: : X -^