L22tl ^ ^ %j,.y ;-- . '^^'- -15 1932 727 " /, CORNEL L UNIV ERSITY ^ Ji^lompr Hftmtiary ICtbrary FOUNDED BY ROSWELL p. FLOWER for the use of the N. Y. State Veterinary College 1897 .My This Volume is the Gift of P.r.,....Y,....A.,...M.QD.r.e.. 356 Compliments of CORNELL UNIVERSITY LIBRARY 3 1924 104 224 781 A. G. YOUNG, M, D., Sec'y of the State Board of Health, ^ Augusta, Maine, Disinfectants and Disinfection BY A. Q. YOUNG, n. D., Secretary of the State Board of flealth of Maine. Reprinted from the Tenth Report. AUGUSTA KENNEBEC JOURNAL PRINT 1898. ,1.^/ ', f 7U . «T t y Lf. YC8 CONTENTS. PAGE Prefatory i Acids 3 AloShol 4 Alkalis — ^Potash and Soda 7 Ammonia 9 Anilin Dyes (Pyoctanin) 11 Anytin and Anytols 12 Bedding 14 Mattresses 14 Straw Beds, Feather Beds, Etc 14 Benzine 15 Boiling 15 Books 16 Boric Acid 18 Bromin 18 Calcium Cresylate 19 Carbolic Acid 19 Auxiliaries 20 Heat as an Auxiliary 23 Disinfection of Excreta 24 ( Disinfection of Tuberculous Sputum 24 Comparison with Other Coal-Tar Derivatives 25 Crude Carbolic Acid 25 Cresol 25 Lysol 25 Creolin 26 Solveol 26 Solutol 26 Toxicity 26 Solutions and Uses 27 Cattle Cars. (See Veterinary Practice.) 27 Chinosol 27 IV CONTENTS. PAGE Chlorid of Lime (Hypochlorite of Calcium) 29 Applications 32 Comparisons 33 Preparations 33 Chlorin Gas 33 Uses of Chlorin 35 Chloroform 36 Clothing 36 Copper Salts 37 Copper Sulphate 38 Comparisons 39 Corpses 39 Corrosive Sublimate (See Mercuric Chlorid.) 4° Creolin 40 Excreta 41 Surgical 41 Toxicity 42 Cresol 43 Excreta 45 Surgical 45 Toxicity 46 Cresol Saponate 47 Dead Bodies. (See Corpses.) 47 Disinf ectol 47 Electrolysis 48 Webster Process 48 Hermite Process 49 Woolf Process Si Electrical Purification of Water S3 Chlorin Manufactured by Electrolysis S4 Essential Oils 58 Eucalin S9 Excreta 59 Disinfection in the Sick- Room 59 Excreta in Bulk 61 Ferric Sulphate 61 Ferrous Sulphate (Sulphate of Iron) 62 Floors 64 Formaldehyde 65 Germicidal and Antiseptic Value 66 Available Sources 68 Formaldehyde Generators 69 Temperature 72 Dampness or Dryness 72 Action on Colors, Fabrics, Metals, Etc ■^;^ Fixfition of Stain? ,.,,., 74 CONTENTS. V PAGE Formaldehyde — Concluded : Toxicity 75 Disadvantages after Disinfection 76 The Disinfection of Rooms 76 Percentage or Amount for Room Disinfection 82 Power of Penetration 84 Clothing 86 Furniture 88 Books 89 Surgical Instruments 89 Disinfection of the Mails 91 Tuberculous Sputum 91 ;jji Embalming 92 } Brushes, Combs, Etc 92 1 As a Spray 92 Local Antiseptic and Therapeutic Action 93 ' , As a Food Preservative 95 Freezing 96 Furniture 97 Guaiacol 98 Hands 98 Heat 107 Heat as an Auxiliary 108 Hydrogen Peroxid 109 Hypochlorites. (See Chlorid of Lime, Sodium Hypochlorite, and Electrolysis. ) 112 latrol 112 Influenza 113 Instruments 113 lodin Trichlorid 116 Iodoform 117 Light 119 Typhoid Bacilli 121 Cholera 122 Tuberculosis 122 Diphtheria Bacillus 123 Bacteria of Suppuration 123 How Light Acts 124 Sewage, and the Self-Purification of Rivers 126 The Influence of Light upon the Animal Organism 128 The Real Value of Light as a Disinfectant 128 Lime 130 Special Uses 134 Comparison with Other Agents 135 Preparation 136 VI CONTENTS. PAGE Little's Soluble Phenyle 136 Lysol 136 Influence of Media I37 Excreta I37 Tuberculous Sputum I37 Surgical Uses 138 Toxicity 138 Solutions and Uses 138 Mercuric Chlorid (Corrosive Sublimate) I39 Influence of Media 14° Some Recent Precautions 141 Auxiliaries 143 Other Solvents, Etc I45 Disinfection of Excreta 145 Antiseptic Value 146 Poisonous Qualities 148 Solutions and Uses 149 Other Mercurial Salts 150 Milk 151 Mouth 151 Mud, Ooze, Sludge 154 Nitrate of Silver 154 Ozone 154 Purification of Water 156 Paraform 159 Peat 159 Permanganates 161 Potassium Permanganate 161 Calcium Permanganate 161 Phenol-Alcohols 162 Phenosalyl 163 Plague 164 Potash 166 Privies 166 Pyoctanin 166 Resorcin 166 Rooms 166 Salicylic Acid 168 Salubrol » 169 Saprol i6g Silver and Silver Salts 174 Actol and Itrol 174 Protargol 177 Nitrate of Silver 177 PAGE Soap 178 Summary 180 Solutions 181 Soaps, Antiseptic 181 Soda 184 Sodium Hypochlorite 184 Solutol 186 Solutions 187 Solveol 187 Solutions 190 Sozoiodol Preparations 190 Spraying 191 Steam Disinfection 193 Sulphate of Iron 193 Sulphur Fumigation 193 Other Objections 196 Comparison with Other Gaseous Disinfectants 197 Surgical Antiseptics 197 Thymol 199 Tuberculosis 200 Fresh Tuberculous Sputum 200 Dried Tuberculous Sputum 203 Tuberculous Milk 203 Veterinary Practice 205 Walls 207 Water 210 Bromin 21a Chlorid of Lime 211 Permanganates 212 Hydrogen Peroxid 212 Various Methods 212 Filters 214 Heat 215 Water-Closets 215 Water Mains 215 Wells 216 Xeroform .' 217 Zinc Chlorid 218 Zinc Sulphate 218 Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924104224781 NOTES ON DISINFECTANTS AND DISINFECTION. By A. G. Young, M. D., Secretary of the Board. PREFATORY. In the following "Notes" the aim has been to present a review of the experimental work which has been done, more particu- larly in recent years, for the purpose of determining the germ- icidal value of the various agents which have been in use, or have been suggested as disinfectants. Incidentally their anti- septic and deodorant qualities receive some attention. In addition to the bare results obtained by each worker, or the conclusions which he draws, a few words in regard to his methods, or the conditions under which his experiments were done, are given for some of the more important pieces of work. In the references to the literature consulted, the year of publi- cation as well as the volume and page is given, because it is worth something to him who would look up the original paper to know whether the work is, or is not, recent. As a general rule the more recent the work, the more trustworthy the results. A logical arrangement of a work of this kind would be into disinfectants and the practical application of disinfecting agents to special purposes. As a convenience in reference, however, everything is brought under one alphabetical arrangement. The amount of valuable work which has been done since the publication of Koch's remarkable paper in 1881, and the report of the Committee of the American Public Health Association a few years later, has truly been enormous, nevertheless, these notes show very conclusively that an immense amount of work is still required to determine unsettled points relating to the value of even the best known disinfecting agents, or their applicability to various purposes. The casual reader of the results which have already been obtained is, perhaps, confused by discrepancies. The careful student of literature of this kind PREFATORY. may, however, learn to estimate the approximate value of the work of various investigators, and of each succeeding series of years. Some of the reasons why the results obtained by dif- ferent persons have not been more nearly uniform are these : /„. I. The -tpsti-bacteria used by different investigators have not been the same. The vital resistance of the various species is very diverse. yThe results obtained in testing disinfectants on the spirillum oTxholera or the bacillus of plague give but little information relative to the value of the same disinfectants when used for the destruction of the infection of diphtheria^-er-of- tuberculosis. A fault of many of the older experiments is that test-organisms were used which are of put l -ittle mterest to the practical health officer. The practical value of the later experi- ments is greater because they have more generally dealt with the infection of typhoid fever, diphtheria, tuberculosis, and ^Staphyiococcus pyogenes aureus, — species of bacteria with -which most of the work of disinfection has to do. 2. The power of resistance of the same species of bacterium varies greatly under different conditions, or when -their source is different. For instance, Baer found that a freshly inoculated, culture of the bacillus of diphtheria was destroyed with i -.5000 of nitrate of silver, but that a 24-hour culture required i :iooo of the same agent to sterilize it in the same space of time. In some work done by Esmarch he made use of anthrax spores from seventeen different sources. They were destroyed by steam at 212° F. in from one to twelve minutes, and by a 5 per cent, solution of carbolic acid in from two to forty-two days,. 3. The media^n which the test-bacteria exist influences strongly the action of disinfectants'. The bacillus of tuber- culosis dried upon threads or in aqueous suspension may be destroyed by mercuric chloride, but in fresh tuberculous sputum, it cannot be trusted to sterilize it. As illustrative of the influ- £i3e€-e-f-media, Behring says that sporeless anthrax bacilli in water are killed by corrosive sublimate, i :5oq,ooo ; in bouillon, by I :40,000 ; but in blood serum not with certainty by i :20oo. Some disinfectants, are influenced very much by the character of the material which contains the infectious germs, while other dis- infectants are influenced in a comparatively slight degree. The experimental work which does not take the influence oi media into account is not of much value, and frequent failures are to ACIDS. 2 be expected in the work of the disinfector who does not bear^the- •saffie-thi-n-g^n-m-ind . 4. The temperature under which a disinfecting agent acts influences very much the rapidity and the certainty of its action. Thus,Jn Heider's experience, anthrax spores that survived the action of a 5 per cent, solution of carbohc acid thirty-six days at ordinary room temperature, were killed in from one to two hours at 131° F., and in three minutes at 167° F. Some inves- tigators have failed to state the temperature under which their disinfectants acted. >^ 5. In many of the experiments, the inhibitory action of the agent in question has been mistaken for its germicide action. After the bacteria have been subjected to the influence of a dis- infectant for a given time, though not killed, their vegetating and__ pathogenic capabilities may be weakened. When, in this Con- dition, they are transferred to fresh culture media a minute trace of the disinfecting agent suffices to retard growth for some time or indefinitely. The precautions against the trans- ference of a trace of the disinfectant which were observed only a few years ago, do not correspond wit;h the requirements of the present day. To Geppert^ belongs the credit of bringing this fact prominently into view. In most of the later work the necessity of a comparatively long period of observation for the cultures is recognized, a precaution which was not sufficiently observed in much of the earlier work. 6. In other respects than those which have been mentioned, the methods pursued by investigators have differed. In many works the description of the methods followed are not suffi- ciently explicit to enable one to judge of the trustworthiness of the results or conclusions. ACIDS. Among the acids that, when sufficiently concentrated, are capable of destroying spores, Behring^ classes hydrochloric, nitric, and sulphuric. Diluted with water the minimum propor- tion of these acids which prevents the growth of the anthrax bacillus is 1 1555, 1 :384, and i 400 respectively. Hydrochloric acid is, according to Behting, more antiseptic than either of 1. See ^fercuTic Cblorid. 2. Bekampfung der Inlectionskrankheiten, II., 86. 1894. 4 ACIDS ALCOHOL. these other acids. Koch^ found that 2 per cent, of hydrochloric proved deadly to anthrax spores in ten days, and that a i per cent, dilution of sulphuric acid did not kill, but only retarded their growth. In the experiments of Uffelmann^ sulphuric acid and water in equal parts destroyed with certainty all germs in fecal matter in two hours, and a mixture of acid, one part, and water, two parts, destroyed them in six hours. Hydrochloric acid and water, equal parts of each, sterilized in twelve hours; but one part of acid with two parts of water, did not destroy all germs with certainty in twelve hours, but did in twenty-four hours. In Baer's' experiments, the tests were made by adding the acids to bouillon cultures. With hydrochloric acid, sporeless anthrax cultures were sterilized in two hours with from i :i6oo to I :iioo of the acid; diphtheria with from i :i6oo to i 700 ; glanders in from i :300 to i :200 ; typhoid in from 1 1900 to 1 1300 ; cholera in from i :i8so to i :i3SO. The first proportions were with fresh cultures, the second with 24-hour cultures. With sulphuric acid sporeless anthrax cultures were sterilized in two hours with from i :i700 to i :i300; diphtheria with from I :i200 to 1 :500; glanders with i 1250 to i :20o; typhoid with 1 :5oo; cholera with from i :i8oo to i :i300. The irritating and corroding action of the acids reduces the antiseptic and disinfectant adaptability to a very narrow sphere. Their addition to solutions of carbolic acid and of corrosive sublimate are mentioned under the appropriate headings. ALCOHOL. The experiments to determine the disinfectant and antiseptic value of alcohol, and the conditions under which its use is, or is not, successful, have given rise to diverse conclusions. In the experiments of Sternberg* 95 per cent, alcohol did not destroy the bacteria (spores) in broken down beef tea in forty-eight hours. Micrococcus Pasteuri was destroyed by two hours' exposure in a 24 per cent, solution ; pus cocci required a 40 per 1. Mitthell. a. d. Kala. Ges., I., 268. 18SL 2. Berliner Klin. Wooh.— Centr. fur Bak., SIX., 233. 1892. 3. Zeit. tUr Hygiene, IX., 182. 1890. 4. Manual of Bacteriology, p. 189. 1892. ALCOHOL. 5 cent, solution. Koch^ subjected anthrax spores to absolute alcohol, to 50 per cent, alcohol, and to 33 per cent, alcohol one hundred and ten days without the destruction of them. He found, however, that the growth of the anthrax bacilli without, spores was hindered by i per cent, of alcohol and ceased when the mixture of alcohol was i :i2.5 of water. Schill and Fischer^ found that tubercle bacilli in fresh tuber- cular sputum were destroyed in twenty hours with absolute alcohol. Their experiments indicated to them that more than five parts of alcohol to one of the material to be disinfected is required, and that the cost is prohibitive of disinfection with this agent. "Yersin found that in pure cultures the tubercle bacillus is killed by five minutes' exposure to the action of absolute alcohol."" As an auxiliary in the disinfection of the hands, Reinicke* claimed that beside its solvent action upon the oily matter in the skin, it has a true germicide action. In an extended series of investigations, Ahlfeld^ confirmed the opinion of Reinicke that alcohol under favorable conditions is an active disinfectant. A second series of experiments of Ahlfeld and Vahle^ shows quite conclusively that the most important condition favoring the action of alcohol is that the bacteria subjected to it shall con- tain water, — that is, that the material to be disinfected must previously be moistened. Thus used, they found alcohol to be a rapid and efficient disinfectant for the hands without the use of further disinfectants as in the Fiirbringer method. In Epstein's^ experiments in the disinfection of the hands with alcohol, he used infected threads carefully protected at all stages of the experiments not only from the action of direct light, but also from that of diffused light. The micro-organ- isms used as test-bacteria were pyocyaneus, prodigiosus, and Staphylococcus pyogenes aureus. His experiments show that as the strength of alcohol is diluted down to 50 per cent., its disinfecting power increases, but that there is a diminution of this power as the dilution is carried below fifty per cent. 1. Mlttheil. aus clem Kais. Gesunfl., I., 263 and 273. 1881. 2. Mlttheil. aus dem Kais. Gesund., II., 131. 1884. 3. Quoted from Sternberg. i. Centr. (Ur Gynakol.— Centr. fur Bak., XXII., 916. 1895. 5. Deutsche Med. Woch., XXI., 861. 1895. 6. Deutsche Med. Woch., XXII., 81. 1896. 7. Zeit. fur Hygiene, XXIV., 1. 1897. 6 ALCOHOL. His experiments include, also, the determination of the action of alcoholic solutions of various disinfectants. He tested sub- limate I :iooo; carbolic acid, 3 per cent.; lysol, i per cent.; and thymol, 0.5 per cent. An examination of all of his tables shows that solutions of these disinfectants in 50 per cent, spirit gave uniformly better results than when they were dissolved in water or in stronger or weaker alcohol. His tables also show that absolute alcohol and solutions of these disinfectants in absolute alcohol are almost entirely without disinfectant power. Their action is a little better, but is still very weak in 80 per cent, alcohol. As to the action of thymol, his tables show that in the low dilution of i part of thymol in 11 00 parts of 50 per cent, alcohol, it still has a disinfective power distinctly greater than that of 50 per cent, alcohol alone ; this action, however, is not so great as that of a 0.5 per cent, thymol solution. An advantage of alcoholic solutions of these disinfectants is that they penetrate more rapidly objects to be disinfected, thus removing oil. For the practical determination of the action of these alcoholic solutions, Epstein made the following solutions: Sublimate, I :iooo; carbolic acid, 3 per cent.; and lysol, i per cent. The hands to be disinfected were rubbed with a pledget of cotton batting saturated with a bouillon culture of the bacteria to be used. The bacteria were carefully rubbed into the spaces beneath and around the nails and into all the folds of the skin. Without preliminary washing of the hands, they were scrubbed with a brush and the disinfecting solution to be tested. Then, after the hands had been carefully washed with a large quan- tity of sterilized water, bouillon cultures were inoculated with the scrapings from beneath the nails, made with pieces of steril- ized wood. As Epstein's intention was to compare his results with those of previous workers, he did not treat the hands with ammonium sulphid after corrosive sublimate solution was used. An examination of the tables given by Epstein indicate that, in the practical disinfection of the hands, the solution in 50 per cent, alcohol gave the best results. ALKALIES POTASH AND SODA. 7 His conclusions are as follows : That absolute alcohol has no disinfecting power ; that 50 per cent, alcohol disinfects better than higher or lower concentrations; that antiseptics which have more or less efficiency as aqueous solutions lose their dis- infecting properties when dissolved in high grade alcohol, but that, on the other hand, solutions of sublimate, carbolic acid, lysol, and thymol have a higher power of disinfection in 50 per cent, alcohol than solutions of the same concentrations in water have. Lenti's^ experiments were for the purpose of learning the influence of alcohol upon solutions of disinfecting agents. The test-organisms used were anthrax spores. These spores were unaffected by a solution of 4 parts of corrosive sublimate in 1000 of absolute alcohol. A 10 per cent, solution of carbolic acid in absolute alcohol did not affect them. A i :iooo solution of corrosive sublimate in alcohol containing 2 per cent, of water destroyed the spores in twenty-four hours. A 10 per cent, solution of carbolic acid in 30 per cent, alcohol caused the destruction of the spores in forty-eight hours. ALKALIES POTASH AND SODA. Von Lingelsheim under the direction of Behring^ determined carefully the degree of acidity and of alkalinity required to inhibit the growth of anthrax bacilli and the quantity of each acid or alkali required to produce this effect. Of the alkalies only the hydrates are rated as destructive of spores at ordinary temperatures. A 30 per cent, solution of caustic soda destroyed anthrax spores in ten minutes, and a 4 per cent, solution in forty-five minutes. As to the action of alkaline carbonates, we are told that solu- tions of them are efficient disinfectants when used at higher temperatures than ordinary. With a 1.4 per cent, solution of washing soda at the temperature of 85° C. (185° F.) Behring destroyed anthrax spores in from four to ten minutes, and with the solution at 75° (167" F.) the spores were killed in twenty minutes. 1. Annali dell' Ist. d'lg. Sper. dell' Un. di Eoma, III. (Nuova Serie) ., 515. 1893. 2. Bekampfung der Infectinskrankbeiteii, II., 85. 1894. ° ALKALIES POTASH AND SODA. Heider/ in testing washing soda on anthrax spores, was not so successful as Behring. With him a 2 per cent, solution at 75° destroyed anthrax spores only after two hours. In Uffelmann's^ experiments, potash lye of 35 per cent, mixed half and half with water destroyed all germs with certainty in six hours. In the same series of experiments, a 5 per cent, solution of carbolic acid killed nearly all germs in twenty-four hours. Basing his judgment upon his own investigations, Gerloczy* pronounces the lye of wood ashes a very efficient disinfectant of fecal matter. While recommending sulphate of copper highly for this purpose, he says that, "a still more efficient method for the rapid disinfection of stools in the sick-room is pouring over them three times their bulk of hot lye (one part of ashes to two of water) ." Jaeger* destroyed readily anthrax bacilli, and the bacteria of chicken cholera and of erysipelas of swine with a i per cent, solution of potash or soda, but the bacteria of hog cholera and of glanders and Micrococcus tetragenus were not so easily destroyed. He could notice no difference between potash and soda. Comparative tests made by Vincent^ indicated that caustic soda is more efficient than caustic potash. All of his experi- ments show that the disinfecting value of soda is always a little superior to that of potash ; for certain microbes this difference is considerable. For instance, the bacillus of typhoid fever in cultures was killed in less than two minutes by i :200 of caustic soda, while i :ioo of caustic potash does not always destroy the bacillus in thirty minutes. The typhoid bacillus in stools requires 9 or 10 grams per 1000 to destroy them in twenty-four hours, and the cholera bacillus takes 6 per 1000 to effect its destruction in the same time. For the disinfection of the bacillus of plague, Giaxa and Gosio* found that a 5 per cent, solution of caustic potash at 60° C. (140° F.) suffices with twenty minutes' exposure. 1. AtcIi. fur Hygiene, XV., 341. 1892. 2. Berliner Klin. Woch.-Centr. f . Bak., XII., 233. 1892. 3. Deutsche Viert. f. off. Ges., XXI., 433. 1S89. 4. Arbeiten a. a. Kais. Ges., v., 247. 1889. 5. Annales fle I'lnst. Past., IX., 21. 1895. 6. Annali d'lgiene Sperim., VII., 261. 1896. AMMONIA. g The disinfecting power of lime and of potash or soda lye are equal when they are of the same degree of alkalinity, we are told by Behring.i He further states that neutral calcium chlorid and barium chlorid are much more powerful disinfectants than potassium chlorid or sodium chlorid. The disinfecting power of lithium chlorid is eight times, and that of barium chlorid four times that of calcium chlorid. AMMONIA. In Behring's table showing the minimum antiseptic strength of various acids and alkalies, it is shown that a i 417 solution of caustic ammonia inhibits the growth of anthrax bacilli, and that 1 :50 of ammonium carbonate has the same effect. In a paper "On the Antiseptic Property of Ammonia," Gottbrecht^ showed that both ammonia and carbonate of ammonia have well marked antiseptic powers. Specimens of animal tissue were shown in a very perfect state of preservation after they had been kept many months in from 5 to 8 per cent, solutions of Liquor ammonii caustici or in hermetically closed jars in which a piece of ammonium carbonate had been placed. In experiments with the object of determining the suitability of ammonia gas for the disinfection of rooms, Rigler^ poured aqua ammonia into large shallow vessels from which the gas evaporated. The room in which the experiments were made had a capacity of 99.8 cubic metres. The doors and windows were tightly closed. The test-bacteria were on linen threads free or packed. When packed, either in dry or damp cloths, the bacilli were enveloped in eight thicknesses of sterilized cloth. The temperature of the room was from 18° to 20° C. Cholera bacillus. — The threads enveloped in dry cloths were sterilized in three hours. In damp cloths, the time required for sterilization was four hours. Cholera threads, uncovered, were sterilized in two hours; but the controls in pure air were also sterile in three hours. Typhoid bacillus. — Free threads were sterilized in two hours ; in dry cloths, in two hours ; in damp cloths, in six hours. 1. Zelt. fur Hygiene, XXV., 413. 1897. 2. Deutsche Med. Woch., XIV., 601. 1888. 3. Centr. fur Bak., XIII., 651. 1893. ^O AMMONIA. Anthrax bacillus. — On threads lying free, and on those in dry cloths were destroyed in three hours; on those in damp cloths, in five hours. Anthrax spores. — On threads open and packed in dry cloths, were destroyed in three hours ( !) ; on threads in damp cloths, in eight hours. Diphtheria bacillus. — They were destroyed in four hours whether lying free, packed in dry cloths, or packed in wet cloths. Each of these separate experiments was repeated several times. With all these, control experiments were carried on, and in every case innumerable bacilli were present in twenty- four hours. After the shallow vessels were filled, the ammo- nia gas was given off at the following rates : 200 grams of the liquor ammonia in i hour ; 250 in 2 hours ; 300 in 3 hours ; 350 in 4 hours ; 390 in 6 hours ; and 450 in 8 hours. Rigler concludes that the vapor of ammonia has a very strong ■disinfecting action on the most important pathogenic bacteria. He advises the use of ammonia vapor in the disinfection of rooms, articles of clothing, and furniture in connection with cholera, typhoid fever, diphtheria, etc. One recommendation of this agent is its small cost and the absence of danger in the use of it. Further than this we are told that the furniture and fabrics in the room were in no wise injured or discolored. One kilogram is required for the disinfection of each 100 cubic metres of space to be disinfected. The aqua ammonia should be poured into large and shallow vessels, and the rooms should remain closed eight or ten hours. Under the direction of Bordoni-Uffreduzzi, Moreno^ carried out a series of experiments in the laboratory of the University of Torino for the purpose of confirming or disproving the cor- rectness of Rigler's conclusions. The results obtained in Torino, even with a much greater concentration of the vapor, are just the opposite of those in Budapest, and the conclusion is that "the vapor of ammonia is a very illusory and inefficient means of disinfection. It is distinctly less active than chlorin, bromin, iodin, or sulphurous acid gas, all of which disin- fectants have been given up, for one reason or another ; and ammonia merits no better fortune." I. La Eiforma Medioa, III.. 160. 1694. ANILIN DYES (PYOCTANIN). II ANILIN DYES ( PYOCTANIN ). Dr. Stilling's opinion of anilin as a local antiseptic, as trans- lated by Dr. Stevenson,^ is that the local application of a i :iooo .solution of methyl violet does not cause irritation. He says ihat in treating hundreds of patients with it, this has invariably been his experience. He has also found its use in surgical practice quite free from toxic symptoms. The irritating effects observed by some investigators and practitioners, he believes due to impurities such as chlorid of zinc, arsenic, and copper sulphate. The results of his experiments indicate that methyl violet is about three times as strong as sublimate in its action on the anthrax bacillus, and quite as effectual as sublimate in its action on Staphylococcus pyogenes aureus ; that it is a perfectly non- poisonous substance; that, in consequence of this, it is immate- rial how strong the solutions may be, even up to the use of the pure substance itself; that it does not coagulate albumen; and that it possesses an extraordinary power of diffusion, penetrat- ing into the eye like atropin. He has found it very efficient as a local application for various diseases of the eye. In conclu- sion, he calls the attention to the necessity that these anilin dyes be absolutely pure. As a topical remedy in diseases of the eye, he prefers, in many cases, auramin (yellow pyoctanin) as being more soothing and giving less noticeable stains. The favorable report of Stilling led many others to test for themselves the antiseptic value of the anilin colors. Petersen,^ of St. Petersburg, used it in many cases both in hospital and private practice, with excellent results. Fessler,' of Munich, found it to be a very efficient antiseptic in the surgical clinic of the University, used as a i :iooo solution and as a gauze. Bacteriological experiments confirmed his conclusions as to its bactericide value. Garre and Troje,* however, report less cer- tain clinical and antiseptic results. At the Tenth International Medical Congress, Valude,^ of Paris, stated that he had found that the anilin colors which 1. The Lancet, T., 1891. 872. 2. St. P. Med. Wooli.— Centr. fUr Bak., IX., 134. 1891. 3. Munoliener Med. Woch.— Centr. tur Bak., IX., 135. 1891. 4. Ibid. B. Centr. fur Bak., IX., 711. 1891. ^^ ANYTIN AND ANYTOLS. are called "Pyoctanin," are only feebly antiseptic, yet their power of penetration recommends them as superior to mercuric chlorid in some cases. Of the anilin dyes, malachite green is, according to Behring, the most effective, anthrax and cholera bacilli being destroyed with 1 :25,ooo ; diphtheria bacilli with i :8ooo ; and glanders and typhoid bacillus with i :30o. In bouillon, Baer^ found that methyl violet restrained the growth of sporeless anthrax bacilli in the proportion of i :70,- ooo; diphtheria, i : 10,000; glanders and typhoid fever, 1 12500; cholera, i :30,ooo. The quantity required to destroy in two hours, bacteria in 24-hour cultures in bouillon was : anthrax bacilli, 1 15000 ; diphtheria, i :2000 ; glanders and typhoid fever, I :i5o; cholera, i :iooo. With malachite green, the same experimenter learned that in bouillon the growth of sporeless anthrax bacilli was restrained with 1 : 1 20,000; diphtheria with 1 140,000; glanders and typhoid fever, 1:5000; cholera, 1:100,000. The quantity required to destroy in two hours bacteria in 24-hour cultures in bouillon was : anthrax bacilli, i :40,ooo ; diphtheria, i :8ooo ; glanders and typhoid fever, i :30o ; cholera, i :5ooo. Baer's results, therefore, confirm those of Behring in showing that malachite green is more actively germicidal than methyl violet. ANYTIN AND ANYTOLS. Anytin when dry is in the form of a brownish-black, exceed- ingly hygroscopic powder which is soluble in water, giving clear solutions in all proportions. It is a coal-tar derivative. Its solutions in water have the remarkable property of rendering easily soluble, phenols, cresols, essential oils, the camphors, iodine, etc., which are but slightly soluble in water. These agents when brought into solution by the aid of any- tin are called anytols. Loeffler^ gives the results of a series of investigations which have been carried on in the Hygienic Institute of the University of Greifswald to determine the germicidal properties of anytin 1. Zeit. fur Hyg., IX., 424. 1S90. 2. Zelt. fur Hygiene, IX., 482. 1890. 3. Deutsche Med. Woch., XXIV., 149. 1898. ANYTIN AND ANYTOLS. 13 and anytols. He used as test-organisms B. diplitherise, B. anthracis, Streptococcus pyogenes, B. mucosus ozaenae, B. typhi, Staphylococcus pyogenes aureus, B. pyocyaneus, and B. cholera Asiaticae. The tables which are presented indicate that the anytols are distinctly more efficient as germicides than simple aqueous solu- tions of the respective disinfecting agents. Thus a Yz per cent, solution of cresol-anytol acts as vigorously as a i per cent, cresol solution, and is as efficient as a 2 per cent, solution of carbolic acid. Solutions of anytin alone have a distinct germ- icide action. The tables further show a marked difference in the action of anytin and the anytols upon different organisms. While the bacillus of diphtheria and of anthrax and Strepto- coccus pyogenes were readily destroyed, the anytols were less efficient when applied to the other bacteria. Albuminous mat- ters did not interfere with the antiseptic action of the anytols. Loeffier shows that a i per cent, meta-cresol-anytol solution is about equal to a 3 per cent, carbolic acid solution, and he finds that the 3 per cent, cresol-anytol solution has a strong disin- fecting power, a momentary exposure sufficing to destroy all of the bacteria. Experiments were also made with stronger solutions of the anytols. A 5 per cent, cresol-anytol solution was tested upon anthrax spores which had an extraordinary resistance. These anthrax spores were destroyed in forty hours by the cresol- anytol solution, while, after they had been exposed to a 5 per cent, carbolic acid solution sixty hours, vigorous growths were obtained. A 10 per cent, cresol-anytol solution was not more effective than the 5 per cent. The 3 per cent, cresol-anytol solution is recommended for the disinfection of the hands. It affects the skin but very little. Hands were thoroughly rubbed with the culture of staphy- lococcus in bouillon, then, after Fiirbringer's method, brushed with soap and warm water one minute; washed one minute with alcohol; immersed in a i or a 3 per cent, cresol-anytol solution for one minute, and finally rinsed with sterilized water. Even when the i per cent, solution was used, the hands were rendered sterile so far as streptococci are concerned, though a few colonies of sporing bacilli were present even after the use of the 3 per cent, solution. ^4 BEDDING. Another series of experiments indicate that cresol-anytol solu- tions are very effective for the local treatment of diphtheria. These solutions, not only are very efficient in the destruction of diphtheria bacilli, but his experiments indicate that they alsO' have the power of neutralizing diphtheria toxin. BEDDING. Where facilities for steam disinfection are absent, the effi- cient disinfection of bedding is somewhat difficult. When a steam disinfector is available, mattresses, quilts, comforters, blankets, and pillows should be treated in it. In the absence of a steam disinfecting apparatus of ample size to receive mat- tresses, the work may be done as follows : Mattresses. — If the room is disinfected with formaldehyde gas, leave them in their places entirely uncovered. If formal- dehyde is not used, spray or wash thoroughly the entire sur- face of the mattress with a solution of corrosive sublimate I :iooo; or lysol, 4 per cent.; or carbolic acid, 5 per cent.; or formalin, 5 per cent. In cases of scarlet fever, diphtheria, or pulmonary tuber- culosis, it may be assumed as probable that the infection is only upon the surface. In many cases of typhoid fever, however, when the mattress has been soiled with the discharges of the patient, the only safe assumption is that the infection has pene- trated the interior, and in these cases the methods of treatment which insure the efficient disinfection of the interior of the mat- tresses are absolutely required. The experiments of Prof. Robinson with a gas-tight bag sug- gest the probability that the interior of mattresses may be sterilized by enclosing them in impermeable coverings and injecting formaldehyde into their interiors directly, or indirectly by ripping the mattresses. Mattresses of but little value should be burned when the facilities for their sure disinfection are not available. Straic Beds, Feather Beds, etc. — The contents of straw beds, should be burned, their ticks may then be treated as for clothing. Feather beds, pillows, quilts, comforters, and blankets should be disinfected with steam. If nothing better is available extemporized apparatus may be used for this purpose. BENZINE BOILING. 1 5, Treatment with concentrated doses of formaldehyde may suffice,. but exposure in ordinary room disinfection will not. BENZINE. As the action of benzine upon disease germs, — when used in the cleansing of infected clothing, for instance, — ^had been under discussion, Chassevant and Got^ tested commercial benzine upon anthrax bacilli and Bacterium coli commune. They found that, prolonging the action of benzine from one half to twenty-four hours and then subjecting the goods to a tempera- ture of 70° for another twenty-four hours, bacteria were never destroyed. BOILING. All disease germs with which the health officer has to do may be killed by boiling, and most of them are killed in a few minutes by the action of hot water at a temperature consider- ably lower than the boiling point. Thus Sternberg^ found that the cholera spirillum was destroyed at the temperature of 125.6° F. in four minutes; typhoid bacillus at 138.8° in ten minutes; bacillus of pneumonia at 132.8° in ten minutes; Staphylococcus pyogenes aureus at 136.4° in ten minutes. The first committee on disinfection of the American Public Health Association prescribed boiling in water for half an hour for the destruction of spore-containing infectious material, and boiling in water for ten minutes for the disinfection of infectious material which owes its infecting power to the presence of sporeless micro-organisms only.^ Comparing boiling water and steam, Krieger* states the advantages of the former as follows : In boiling water bacteria absorb water, are softened and thus their vitality is almost instantly destroyed. In the disinfection with steam it is otherwise; the opportunity is not so favorable for the preliminary maceration and softening. Further, the same volume of steam contains 1700 times fewer molecules of I. ComptesKend. tleDd. Soc. de Biol. (Dlxleme Serie), III., t73. 1S9C. ■2. Manual of Bacteriology, p. U7. 1892. 3. Disinfection and Disinfectants, p. 233. 18S8. Concord. i. Archivfuroff. Gesund. InElsass-Lothrlngen, XV, 9. 1893. BOILING BOOKS. water. Therefore, a longer time is required for the bacteria to absorb a sufficient quantity of water to cause them to swell and soften. Another obstacle which steam encounters in penetrating bac- teria is due undoubtedly to a coating or layer of minute air- bubbles adherent to the germs. Plunged in water, air-bubbles have a tendency to rise to the surface. This is due to the great difference in the specific gravity of air and water. A difference at the tempera- ture of 100° C. of about i to i,ooo. In steam disinfection this great help in getting rid of the air is not present. The specific gravity of steam and of air at ioo° C. is about as 3 to 5. BOOKS. The disinfection of books without injuring them has been difficult. Unbound books may be disinfected with steam with but little harm to them. Bindings are, however, spoiled by steam. The only feasible way of disinfecting bound books appears to be with formaldehyde. If the books are placed on edge, suspended with their leaves opened, or otherwise arranged in a gas-tight casket or disinfecting box so that their leaves will be separated as much as possible, they may be sterilized with formaldehyde in rather concentrated doses. The fact that the bacteria of some of the most prevalent and dangerous infectious diseases are capable of retaining their vitality for a considerable period of time after they are dried, evinces the danger in books that have been used by infectious persons. According to Fliigge,^ the bacillus of diphtheria in false membrane remains alive three or four months after dry- ing. AbeP found that diphtheria infection on toys remained virulent six months. Eyff^ had typhoid bacilli viable three months after drying on books, and tubercle bacilli from six to nine months. Bordoni-Uffreduzzi* found that the diplococcus of pneumonia, in dried sputum, remained alive a long time. Du Cazal and Catrin^ examined an old book that had been used in the hospital for a long time. Bacteria cultivated from 1. Zeit. fur Hygiene, XVII., 405. 1894. 2. Centr. tUr Bak., XIV., 756. 1893. 3. Zelt. £ur Hygiene, XXI., 181. 1896. 4. Centr. tur Bak., X., 305. 1891. 6. Annalea de I'lngt Past., IX., 865. 1896. BOOKS. 17 pieces of the leaves were fatal to guinea-pigs. Staphylococci were present. The corners of the leaves furnished more col- onies than other parts of the pages. The leaves of new books were soiled with streptococcus pus, pneumonia sputum, diph- theria membrane, typhoid feces, and tuberculous sputum. The leaves were then dried and cultures in bouillon were made from portions of them. Guinea-pigs were inoculated with a drop or two. Positive results were obtained with streptococcus, pneu- mococcus, and diphtheria. On the other hand, the animals inoculated with typhoid and tuberculosis survived. The books used in the former experiments were subjected to disinfection forty-eight hours with formaldehyde. All of the leaves were sterilized except those which had been soiled with typhoid feces. After old hospital books had been submitted to the action of steam they were found to be thoroughly disin- fected. The leaves were not injured, but the bindings were badly spoiled. One of the English sanitary journals^ announced, some time ago, that a new disinfecting apparatus for books had been estab- lished at the Central Free Library, Sheffield. The principal upon which the disinfection is based is the vaporization of car- bolic acid by heat which, as it is claimed, makes carbolic acid more potent and active. It is stated that the carbolic acid can be vaporized at 80° F., and that at 100° the carbolic acid will be active and will purify the books. The degree of heat used, however, is from 150° to 200° F. dry heat, and the books are subjected to this process for a quarter of an hour. Letters of protection were taken out. As of interest in this connection, it may be mentioned, upon the authority of a German journal,^ that all the letters which are written in the Asylums Board Hospital at Kent, England, are subjected to disinfection with steam before they are sent out. In 1884, there were about 1000 cases of small-pox, and postal officials complained that their employes often contracted small- pox. Since the disinfection of letters began, no complaints of this kind have been received. As the letters remain uninjured, the suggestion is made that this process would be suitable for 1. Sanitary Eeoord, IX., 369. 1888. 2. Zeit. lurSchulgesunci., VII., 105. 1894. BORIC ACID BROMIN. the disinfection of school books that have been in the hands of infectious pupils. Dr. Schab/ in the Institute of Infectious Disease, of Berlin, investigated the value of the so-called pictet gas mixture for the disinfection of books. This consists of a mixture in equal parts of sulphurous acid and of carbonic acid gases. As test objects he used pyocyaneus, staphylococcus aureus, and anthrax spores. In addition tubercle bacilli from tuber- culous sputum were used. The experiments did not give satis- factory results, and he found that this process for the disinfec- tion of books is untrustworthy. (See Formaldehyde-5oo^.j.) BORIC ACID. Koch's^ experiments indicated that boric acid has some anti- septic action. A i : 1250 solution retarded the growth of anthrax bacilli. In Sternberg's experiments a saturated solution failed to kill pus cocci in two hours. ** As applied to Staphylococcus pyogenes aureus on threads, Pane^ found that a 5 per cent, solution has no effect at 15° C. ; and at the temperature of 37° C. (98.6° F.) it has no effect except to retard slightly the devel- opment of the bacteria. RideaP says that boric acid is in no sense a disinfectant, and its antiseptic powers are low. BROMIN. A few experiments, of Koch's indicate that bromin gas is somewhat more active than chlorin. The conditions of the experiments, however, were not like those in practical disinfec- tion. Fischer and Proskauer^ preferred chlorin because the same disinfecting effect can be had at a lower cost than with bromin, and for the further reason that bromin is still more destructive than chlorin of the goods subjected to their action. The disagreeable and dangerous character of liquid bromin renders it unsuitable for placing in the hands of the public. 1. Ceutralb. fiir Bak., XXI., Ul. 1897. 2. Mitthfcil. ausflem Kais. Gea. I.,271. 1881. 3. Manual of Bacteriology, p. 174. 1892. 4. Annali dell' IstitutoDTg. Sp. dell' Univ. di Roma, II., 78. 1890. 5. Disinfection and Diainfectanta, p. 99. 1895. London. 6. Mittheil. a. d. Kais. Gea., II., 307. 1884. CALCIUM CRESYLATE CARBOLIC ACID. I9 CALCIUM CRESYLATE. This is recommended by Professor Foder as a disinfectant. It is prepared by slaking i part 'of caustic lime with 4 parts of water and adding 5 parts of crude cresylic acid (cresol). The result is a syrupy fluid, said to be miscible with water in every proportion. "It is cheaper than crystallized carbolic acid, and superior in every way as a disinfectant."^ CARBOLIC ACID. As a disinfectant for material containing spores, Koch^ deter- mined that carbolic acid is hardly suitable; for the destruction of anthrax spores, a 3 per cent, solution must act seven days, and a 5 per cent, solution requires two days. For sporeless anthrax bacilli, however, he found that a i or 2 per cent, solu- tion sufficed to destroy them in a few minutes. In liquids free from albuminoids, carbolic acid is about one hundred times weaker in disinfecting power than corrosive sublimate, yet in many respects carbolic acid has advantages over the other disinfectant. Its action is uninfluenced by the presence of acids, alkalies, salts or albumen. Behring^ is also authority for the statement that a 0.5 per cent, solution of car- bolic acid destroys, in a few hours, the anthrax bacillus without spores, the bacillus of typhoid fever, of diphtheria, and of glan- ders, the spirillum of cholera, and streptococci. All of these are killed in one minute with a i to 1.5 per cent, solution. Staphy- lococci require a strength of from 2 to 3 per cent. The experiments of Sternberg and Bolton* fixed a i per cent, solution of carbolic acid as near the germicide potency of car- bolic acid for pathogenic bacteria generally which are sporeless. Even when the bouillon subjected to the action of carbolic acid contained 10 per cent, of dried egg albumen the results were the same. Elsewhere Dr. Sternberg sums up the value of carbolic acid as follows : "Carbolic acid, in the absence of spores, is a most effective disinfecting agent, and we have put it seventh in the list below 1. American Analyst, IX., 98. 1893. 2. Mittheil. a. d. Kais. Gesunil. I., 241, 243. 1881. 3. Zeit. £Ur Hygiene, IX., 416. 1890. 4. Disinfection and Disinfectants, p. 163. 1888. Concord. 20 CARBOLIC ACID. mercuric chloride, although for many purposes it is preferable to this salt. It is now generally used in Germany for the dis- infection of the excreta of typhoid and cholera patients. It is not itself destroyed, and may be left indefinitely in contact with the material to be disinfected. Experiments show that a i per cent, solution destroys the cholera spirillum and the typhoid bacillus, as well as the various pus micrococci. So when we direct the use of a 5 per cent, solution we think we are on the safe side, and it has the advantage of being quite as effective in the presence of albumen as in its absence. It destroys spores after a very long exposure."^ Uffelmann^ learned from his own experiments that a 5 per cent, solution of carbolic acid failed to destroy typhoid bacilli in one hour, but effected a complete sterilization in twenty-four hours. Auxiliaries. — Experiments made by Laplace^ of New Orleans, in Koch's laboratory show that the disinfecting power of solu- tions of carbolic acid is greatly increased by the addition of the mineral acids. Thus he found that "2 per cent, of crude car- bolic acid with i per cent, of pure hydrochloric acid destroyed anthrax spores in seven days, while 2 per cent, of carbolic acid, or I per cent, of hydrochloric acid alone, did not destroy these spores in thirty days. A 4 per cent, solution of crude carbolic acid, with 2 per cent, of hydrochloric acid, destroyed spores in less than one hour ; 4 per cent, of carbolic acid solution alone did not destroy them in twelve days." The mixture of crude carbolic acid and sulphuric acid sug- gested by Laplace, — the mixture of the two liquids in equal quantities by weight, — was tested by Frankel.* The mixture should be carefully prepared, else a high degree of heat is evolved, by adding the sulphuric acid gradually to the crude carbolic acid. Frankel learned that the disinfecting strength of this mixture depends very much on whether it is or is not kept carefully cooled during its preparation. Prepared cold it is much more efficient than when it heats. Anthrax spores were killed within one day by the action of a 5 per cent, solu- 1. Brooklyn Medical Journal, III., 348. 1839. 2. Deutsche Med. Wocli., XVI., 37. 1890. 3. Deutsche Med. Woch., XIII., 867. 1887. 4. Zeit. fur Hygiene, VI., 521. 1889. CARBOLIC ACID. 21 tion of the crude carbolic acid and sulphuric acid prepared cold, while the 5 per cent, solution of the mixture prepared hot required nine days to destroy them. An objection to the use of the mixture of crude carbolic acid and sulphuric acid is the corrosive action of the latter. In his paper on rendering crude carbolic acid soluble by means of soap solutions, Nocht^ says that the stronger the solution of soap, the more carbolic acid is it capable of dissolving. At 60° C. a 3 per cent, solution of soap will dissolve 6 per cent, of car- bolic acid, and a 6 per cent, soap solution will take up 12 per cent, of carbolic acid. While hot, the solutions are clear, but in cooling they become more or less turbid. In his tests it was shown that the percentage of soap had nothing to do with determining the germicidal action of the solution. That was dependent alone upon the quantity of car- bolic acid which was held in solution. Sporeless bacteria, cholera and typhoid bacilli, and staphylococcus aureus, were killed in half an hour in a cold solution containing 1.5 per cent, of carbolic acid. In practice it is best to use a 3 per cent, solu- tion of soap at 40° or 50° C. (104° or 122° F.), into which up to 5 per cent, of the carbolic acid can be poured and a clear solu- tion obtained. At the temperatures indicated, this solution can be used to disinfect clothing, leathern articles, etc. As show- ing the superior action of the hot solution, Nocht states that, using a 5 per cent, solution, anthrax spores survived an expos- ure of six days, but they were killed in six hours when the solu- tion had a temperature of 50". In making the soap-carbolic acid mixture we are directed by Freund^ to mix and stir i part of 100 per cent, carbolic acid (a crude carbolic acid) with 20 parts of hot solution of black soap (green or potash soap).^ There is some difficulty in understanding some of the foreign references to the trade designations of different grades of car- bolic acid. Nocht refers to three kinds of carbolic acid, — crude, the so-called 100 per cent., and the pure liquefied. Crude car- bolic acid is almost wholly insoluble in water, dissolving to the extent of only 2 to 4 per cent., but it is wholly soluble in a solu- 1. Zeit. tUr Hygiene, VII., 521. 2. Gesundhelt, XX., 53. 1895. 22 CARBOLIC ACID. tion of caustic soda. The effective agent in the crude carbolic acid is cresol. Buchner^ explains that lOO per cent, carbolic acid means only that it is wholly soluble in a solution of caustic soda. The quantity of carbolic acid and cresol represented by each trade designation is as follows : 25-30% C. A. has 2-2)°/o of carbolic acid and cresol. 40-60% " " " 3-5% " " " " 80% " " " 50% " " " " 100% " " " 80% " " " " Crude carbolic acid has 10-25 P^r cent, of phenol. Koch^ was the first to call attention to the fact that, when dis- solved in oil or alcohol, carbolic acid has not the least disinfect- ing action, whether applied to spore-bearing or sporeless anthrax bacilli. Lenti^ confirms Koch's statement that carbolic acid in olive oil has no disinfectant power. Tested on anthrax spores a 10 per cent, solution of carbolic acid in absolute alcohol had no effect, but when the solution contained 70 per cent, of water, the anthrax spores were killed in forty-eight hours. As to the action of glycerine, Lenti found that a 10 per cent, solution of carbolic acid in pure glycerine had no effect, but when the carbolic acid solution contained 80 per cent, of water, the spores were killed with certainty in forty-eight hours. Epstein's* work indicated that solutions of carbolic acid, lysol, or thymol act more efficiently when made in 50 per cent, alcohol than when in absolute alcohol, in water, or in dilutions of alcohol above or below 50 per cent. In a paper on the molecular conditions of aqueous solutions of disinfectants as regards their eiificiency. Dr. Scheurlen^ states that I per cent, solutions of carbolic acid or of the cresols in water failed to destroy Staphylococcus pyogenes aureus in five minutes, but i per cent, solutions of carbolic acid with 24 per cent, of common salt or i per cent, cresol with 12 or 13 per cent, of common salt, destroyed the same organisms in one minute. 1. Jr. £iir Gasbel. u. Wasserversorgung, XXXVI., 128. 1S93. 2. MittUeil. a,, d. Kais. Gesundh., T., 251. 1888. 3. Annall dell' Ist. d'Ig. Sper. della Univ. di Eoma, III., (N. S.), 515. 1893. 4. Zeit. fur Hygiene, XXIV., 1. 1897. 5. Archiv fur Exper. Pathol, u. Phar., XXXVII., 74. 1896. CARBOLIC ACID. 23 He found also that i per cent, carbolic acid with 12 and with 20 per cent, of common salt, and J/2 per cent, as well as i per cent, o-cresol with 13 and again with 19 per cent, of common salt destroyed anthrax spores in three days at the latest, while these solutions without the addition of the salt had hardly the slightest effect upon the spores. Upon his recommendation, certain surgeons have used the J4 per cent, solution of ortho-cresol with 12 per cent, of common salt as a very satisfactory antiseptic. The rusting of instru- ments in it can be prevented by the addition of i :iooo of sodium thiosulphate (hyposulphite of sodium). Repeating the experiments of Scheurlen, Beckmann^ con- firmed his results. With a culture of staphylococcus aureus, the addition of even 3 per cent, of common salt to a i per cent, solution of carbolic acid increased its disinfectant power very decidedly. On the other hand, when applied to anthrax spores a I per cent, solution of carbolic acid showed no increase in its germicidal power until 24 per cent, of common salt had been added. The addition of this proportion of common salt increased the efficiency of a i per cent, solution of carbolic acid so that it gave better results than a simple 6 per cent, solution in water. Romer's^ results were also confirmatory of those of Scheur- len,. In his experiments a 3 per cent, solution of carbolic acid had but little effect upon anthrax spores in fifteen days, but in the same space of time they were completely killed with a 3 per cent, solution of carbolic acid to which i per cent, of common salt had been added. The addition of 4 per cent, destroyed them in nine days, and 8 per cent, in six days. The addition of 16 per cent, increased the efficiency of the 3 per cent, carbolic acid solution no more than 8 per cent. Romer found that sodium Sulphate, sodium nitrate, and ammonium sulphate also augmented the action of carbolic acid solutions. Heat as an Auxiliary. — We have already seen that, in the hands of Nocht, the time required for his soap-carbolic acid solution to kill anthrax spores was reduced from six days at the ordinary room temperature to six hours at the temperature of 50° C. (122° F.). Extending his investigation in the same 1. Centr. fur Bak., XX., 16, 17. 1896. 2. MUnoliener Med. Wooli., XLV., 298. 1898. 24 CARBOLIC ACID. direction, so far as concerns the influence of a moderate increase in temperature, Heider^ learned that while the anthrax spores used by him resisted the action of a 5 per cent, solution of car- bolic acid thirty-six days at ordinary room temperature, at 55° C, they were killed in from one to two hours, and at 75° C. in three minutes. At 75° C, even a 3 per cent, solution destroyed them in fifteen minutes. Disinfection of Excreta. — In testing the comparative value of carbolic acid, creolin, and lysol, Remouchamps and Sugg- found that in the presence of albuminous matter carbolic acid and lysol were superior to creolin. With typhoid stools and artifi- cial cholera stools, when a 2.5 per cent, solution of these three disinfectant agents was applied in a volume equal to that of the matter to be disinfected, there was no difference in the efficiency of the three. In the experiments of Vincent^ a i per cent, solution of car- bolic acid destroyed most of the saphrophytic bacteria, but a 3 per cent, solution was required to kill B. coli commune. Laplace's mixture of crude carbolic acid and sulphuric acid is undoubtedly an efficient disinfectant and deodorant for fecal matter, but its preparation is somewhat troublesome. Disinfection of Tuberculous Sputum. — The investigations of Schill and Fischer* indicate that carbolic acid is a trustworthy disinfectant for fresh tuberculous sputum, provided the solu- tion used is as strong as 5 per cent, and has a chance to act not less than twenty-four hours. Jaeger" recommends for the destruction of the bacillus of tuberculosis Laplace's 4 per cent, solution of crude carbolic acid with 2 per cent, of hydrochloric acid (8 cc. of 50 per cent, crude carbolic acid, 2 cc. of hydrochloric acid, and 90 cc. of water), or the mixture of crude carbolic acid and sul- phuric acid also suggested by Laplace. The experiments of Jaeger were not, however, made with fresh sputum in quantity, but with the bacillus on silken threads. 1. Centr. fur Bak., IX., 221. 1891. 2. Mouvement Hyg.— Hygienische Eunclsobau, I., 436. 1890. 3. Annales de I'inst. Past., IX., 23. 1895. 4. Mittbell. a. d. Kais. Ges., II., 146. 1884. 5. Arbelten a. d. Kais. Ges., V., i76, 292. 1889. CARBOLIC ACID. 25 Comparison with Other Coal-Tar Derivatives. — Various other coal-tar products have been recommended as substitutes for carboHc acid. Crude Carbolic Acid. — Cresol is its effective constituent. The work of Laplace, Nocht, Frankel, and others indicates that solutions of crude carbolic acid with mineral acids or with soap are as efficient as solutions of the pure acid, or more so. Cresol. — Obtained from crude carbolic acid. Tested on anthrax spores and the staphylococcus of suppuration, Vahle^ concludes that Raschig's cresol and carbolic acid are very nearly equal in their action. Gruber^ considers the cresols far supe- rior to carbolic acid. Behring^ says that cresol exceeds carbolic acid only in liquids containing no albumen. Buttersack's* experiments seem to indicate that the disinfecting power of cresol is somewhat higher than that of carbolic acid. Ham- merP says that, in solutions of equal per cent., cresol has twice as strong a disinfecting action as carbolic acid. Cresol, so says Heider,"' has greater disinfecting power than carbolic acid. Hammer' rates cresol higher than carbolic acid as a disinfectant. As to toxicity, the results of Grigor Jeff's^ experiments confirm the assertion of Delplanque that tricresol is four times less toxic than carbolic acid. Some experiments made by Dr. C. O. Avery^ indicate that tricresol is a very safe antiseptic. Lysol. — Consists of neutral potash soap, water, and cresols. Remouchamps and Sugg^° think there is little difference between lysol and carbolic acid as regards their germicidal action. Laser^ quotes Schottelius as recommending lysol for the disin- fection of excreta as more efficient than carbolic acid. Vincent^^ ranks lysol a little more active than cresol. Pohl^^ concludes that lysol is more efficient than carbolic acid. Lingelsheim^* 1. Hyg. Rundschau, III., 901. 1893. 2. Arohiv fur Hygiene, XVII., 618. 1893. 3. Zeit. fur Hygiene, IX., 420. 1890. 4. Arbeiten a. d. Eais. Ges., VIII., 359. 1892. 5. ArcMv lur Hygiene, XXI., 198. 1894. 6. Archlv fur Hygiene, XV., 341. 1892. 7. Arohiv fur Hygiene, XII., 369. 1891. 8. Beitr. zur Path. Anat. u. z. all. Pathol.— Centr. fur Bak., XVII., 853. 1895. 9. The Medical News, LXVII., 68. 1895. 10. RevueD'Hygiene, XIII., 640. 1891. 11. Centr. fur Bak., XII., 232. 1S92. 12. Auuales de I'Inst. Past., IX., 26. 1895. 13. Eln Beintrag zur Kentnis der disinfect. Eigenschaft des. Lysol. 1893. 14. Quoted by Pohl. 26 CARBOLIC ACID. found that, applied to streptococci, lysol is more effective than creoHn. Freund^ thinks lysol more efficient than carbolic acid. Heider^ finds that when containing the same percentage of cre- sol, lysol does not destroy anthrax spores so rapidly as solveol or solutol. Hiller^ rates lysol lower than solveol as an antiseptic. Creolin. — An emulsion of the cresols of crude carbolic acid in a solution of hard soap. As a surgical antiseptic Behring* says it is inferior to carbolic acid. Its action is hindered by albumen. Ermengem' ranks it above carbolic acid as a germ- icide. Hunermann" concludes that creolin is not so efficient as carbolic acid for anthrax bacilli or the bacteria of suppuration. Solveol. — Said to be a neutral, aqueous solution of cresol rendered soluble by means of cresolinate of soda. Used for surgical purposes principally. Hiller^ deems it the most desir- able antiseptic, and superior to carbolic acid. He quotes the results obtained by Hammer as showing that a solution of sol- veol containing 0.5 per cent, of cresol, outranks lysol, creolin, and even carbolic acid in 2.5 per cent, solutions. Solutol. — A watery solution of cresol in which sodium cresolate is used to render the cresol soluble. Adapted to gross disinfection. For the disinfection of slaughter-houses and stables, H. Koch* found solutol to be the best disinfectant. It penetrates the interior of masses of coagula of blood and other material more rapidly than lysol. In Buttersack's^ experiments crude solutol destroyed anthrax spores much more promptly than other forms of cresol, and very much more quickly than carbolic acid. A solution of solutol containing 5 per cent, of cresol, in Heider's^" hands killed anthrax spores in one hour at 55° C. temperature. Hammer, as quoted by Laser,^^ says that solutol is superior to lysol. Toxicity. — There seems to be a consensus of opinion that car- bolic acid is more poisonous than the cresols. Comparing the 1. ttesunahelt, XX., 51. lS9o. 2. ArcMv tUi- Hygiene, XV., 370. 1S92. 3. Deutsolie Med. Woch., XVIII., S41. 1893. i. Bekampfungder Infectloiibkrankhelten, 11., 110. 1S94. 5. Centr. fUr Bak., VII., 75. 1S90. 6. Cent!-, fiii- Bak., V., 650. 1889. 7. Opus oit. 8. Hyglenlsohe Runaschau, III., 233. 1893. 9. Arbelten a. fl. Kais. Ges. VIII., 369. 1892. 10. AroMv fill- Hygiene, XV., 1892. 11. Centr. f. Bak., XII., 231. 1892. CARBOLIC ACID CHINOSOL. 2/ three agents in this respect Remouchamps and Sugg^ state that carboHc acid is more poisonous than lysol or creolin. As determined by them the fatal dose per kilogram of rabbit is 0.30 for carbolic acid, i.io for creolin, and 2.00 for lysol. As quoted by Pohl,^ Pee decided that carbolic acid is eight times, and ■creolin more than twice as poisonous as lysol. Solutions and Uses. — Solutions of carbolic acid in oil, alcohol, or glycerin have very little disinfecting power. Laplace's mixture of crude carbolic acid and sulphuric acid is efficient, but the range of its applicability is limited. The solution of crude (100 per cent.) carbolic acid suggested by Nocht, might well find a somewhat extended use. Solutions of carbolic acid with "hydrochloric acid are more efficient than without it, but the irritating and corrosive action of acid solutions renders them undesirable for many purposes. It appears that the addition of common salt to solutions of carbolic acid increases their effi- ciency, and this addition might, therefore, be made to solutions for various uses.^ For the disinfection of clothing and for some other purposes, a 2 per cent, solution of carbolic acid was recommended by the first Committee of the American Public Health Association, to act four hours. Particularly when clothing can subsequently be boiled, this would be ample. For excreta, tuberculous sputum, or for the dead, a 5 per cent, is none too strong, and when the application is to be but momentary, as in washing walls or furniture, carbolic acid is of doubtful trustworthiness. CATTLE CARS. (see VETERINARY PRACTICE.) CHINOSOL. Dr. H. Ostermann,* of Hamburg, has used chinosol and finds it a very convenient as well as efficient antiseptic in gynocologic and obstetric practice. It can be obtained in the form of tablets, it is readily soluble, is but slightly toxic, is odorless, and the solutions used by him (0.5 : 1000 to 2 : 1000) are not irritating. For the disinfection of the hands his experiments show that it 1. Mouvement Hyg.— Hyglenlscbe Runds., I., 436. 1S90. 2. Op. clt. 3. See page 22. 4. Tberapeutlsotie Monataliefte, X., Ibi. 1896. 28 CHINOSOL. is efficient, particularly after the preliminary preparation of the hands with soap and water and with alcohol. Ahlfeld and Vahle^ tested crinosol clinically and bacteriologi- cally. Solutions of a strength even up to 3 per cent, were found wholly untrustworthy for the disinfection of the hands. It was, however, found to have marked antiseptic power, but in contrast with the results of Emmerich, the antiseptic action was not dis- tinct with a smaller proportion than i : 20,000. Their results indicate that, when tested on bouillon cultures of Staphylococcus pyogenes aureus, chinosol has no great disinfecting power. Kossmann,^ of Berlin, criticises unfavorably the methods pursued by Ahlfeld and Vahle and refers to the favorable results obtained in the bacteriological tests made in the Analytical Laboratory of Apothecaries' Hall, London. Witte,^ of Berlin, finds that chinosol is painfully irritating when applied in powder to raw surfaces, and that it stains cloth- ing and the hands badly. He refers to the statement of Pro- fessor Emmerich that the growth of Staphylococcus pyogenes aureus is distinctly inhibited by i : 40,000 of chinosol. The experiments of Bonnema,* of Holland, indicate that chin- osol is not an efficient germicide. Among pathogenic bacteria he tested it upon Staphylococcus pyogenes aureus only. As it has been affirmed that the antiseptic power of chinosol is forty times greater than that of carbolic acid and even superior to that of corrosive sublimate. Professor Giovannini^ tested its ability to prevent the development of the bacillus of syphilis (Ducrey's bacillus) upon inoculated surfaces, — auto-inoculation. He found that, for this purpose, it is far inferior to corrosive sublimate ; and much less efficient than carbolic acid, though his data for the latter comparison were meagre. As stated by an English journal," Mr. C. G. Moor tested the action of chinosol on the bacteria of typhoid fever, diphtheria, anthrax, cholera, and on the chief organism of pus. His results show the germicidal power to be so great that even the tenth of an ounce in three gallons of water makes a reliable disinfecting 1. Centralblatt tiir Gynokologie, XX., 235 1896. 2. Centr. lur Gynokologie, XX., 369. 1396. 3. Centr. lur Gynokologie, XX., 233. 1896. 4. Therapeutisohe Monatshefte, X., 663. 1896. 6. DeutscbeMea. Wooh., XXIH., 585. 1897. 6. The Sanitary Eeoord, XXI., 117. 1898. CHLORID OF LIME. solution. It is further stated that Dr. Klein has investigafttt- the action of chinosol on bacillus subtilis, on anthrax spores, and on the Staphylococcus pyogenes aureus, and that he states that a I per cent, solution of chinosol is fatal to them in five minutes, whereas they live for forty-eight hours in carbolic acid of five or six times the strength. CHLORID OF LIME (HYPOCHLORITE OF CALCIUM. "Especial care," says Dr. Sternberg,^ "will be required in the practical use of the oxidizing disinfectants, such as potassium permanganate and the hypochlorites of calcium and sodium. These agents owe their power to the fact that they are promptly decomposed by contact with organic matter but this decomposi- tion is entirely a chemical reaction, and only a given amount of organic material can be oxidized by a given quantity of the oxidizing agent; on the other hand, the disinfecting power of such agents is neutralized by a given quantity of organic mate- rial, whether this is in the form of living micro-organisms, or of dead animal or vegetable matter. If, then, the organic material is in excess, germs embedded in it will escape destruc- tion, and the only safe rule in the practical use of oxidizing dis- infectants is to use such a quantity of the disinfecting agent that it shall he in excess after the reaction has taken place." He had already demonstrated that the very resistant organ- isms in putrid beef tea are destroyed with chlorid of lime, and further experiments showed its capability of sterilizing fecal matter. One pint of solution of chlorid of lime, with 0.65 per cent, of available chlorin, failed to sterilize 4 ounces of semi-solid feces in twenty-four hours. No chlorin remained. Two quarts of solution with 0.85 per cent, of available chlorin added to 7 ounces of semi-solid feces, sterilized completely. A trace of chlorin remained. In later experiments cultures of the bacillus of typhoid fever, cholera spirillum, anthrax bacillus with spores, Staphylococcus pyogenes aureus, and other organisms were almost invariably destroyed with a i per cent, solution of chlorid of lime. It is recommended by the committee of 1885 as one of the most effi- cient of chemical disinfectants. 1. Disinfection and Disinfectants, pp. 84, 153. 1888. Concord. 30 CHLORID OF LIME. In the experiments made for the Imperial Board of Health of Germany, Koch^ tested a 5 per cent, solution of chlorid of lime on anthrax spores with unfavorable results. This is appar- ently the reason why this agent has been so little used in many European countries. There is, however, in Koch's report noth- ing to indicate whether the tests were few or many, or what percentage of chlorin was available in the chlorid of lime used by him. Behring^ too affirms that, though chlorid of lime has some bactericidal action, its power in this direction is about twenty times less than that of caustic lime. He adduces no experi- ments. In a later work,' however, after the results of Nissen's work had been reported, he found no great disparity in the dis- infectant power of the two agents, but still shows a personal preference for caustic lime. The careful work of Nissen* tended to confirm the value which. Dr. Sternberg and the Committee of the American Public Health Association had ascribed to chlorid of lime. Nissen's experiments were made with pure cultures of the bacillus of typhoid, of cholera, of anthrax, and Staphylococcus pyogenes aureus, and Streptococcus erysipelatis. The micro-organisms, were in bouillon with i per cent, of peptone and 0.5 per cent- of common salt. Typhoid bacilli were destroyed with certainty in five minutes, when the bouillon contained not less than 0.12 per cent, of chlo- rid of lime whether the mixture was filtered or not. Cholera- bacilli were always killed in five minutes and in most cases in one minute. Nissen refers to the results obtained by Liborius and Kitasato with caustic lime, and states that the action of chlorid of lime is much more rapid. Anthrax bacilli without spores were destroyed in one minute with a 0.1 per cent, solution; and streptococcus just as quickly when the bouillon contained 0.2 per cent, of chlorid of lime. Solutions of chlorid of lime were found to lose their disin- fectant power rapidly when used on anthrax spores. This was. 1. Mlttbell. a. d. Kals. Ges., I., 264. 1881. 2. Zeit. Jul- Hygiene, IX., 408. 1890. 3. Bekamptung der Infectionskrankheiten, II., 92. 1894. 4. Zelt. fur Hygiene, VIII., 62. 1890. CHLORID OF LIME. 31 observed even in ten, fifteen, and thirty minutes after they were prepared. The anthrax spores first used were not of a very resistant kind. On threads they were occasionally killed in five minutes with a 5 per cent, solution ; they were often killed in fifteen minutes, and almost always in thirty minutes. The author received from Nocht some very resistant spores. Dried on silken threads they retained their vitality four hours in a i per cent, solution of sublimate, the precautions of Geppert being observed. They were killed in twelve minutes in flowing steam, but not in ten minutes. In a 5 per cent, filtered solution of chloride of lime, they were destroyed in four hours and a half. Pure cultures of typhoid fever in sterilized feces were disin- fected completely in two minutes with i per cent, or 0.5 per cent, of chlorid of lime. On cultures of typhoid fever in equal parts of sterilized blood serum and sterilized feces o.t; per cent, of chlorid of lime had no effect in fifteen minutes ; but i per cent, of the disinfectant sterilized in five minutes. The various experiments showed that chlorid of lime, whether as powder or in solution, added to diarrheal feces in the proportion of 0.5 per cent, always destroyed typhoid bacilli in ten minutes. For the disinfection of fresh typhoid or cholera stools with caustic lime, Pfuhl states that one hour is required. Disinfec- tion of the same may be accomplished in a few minutes with chlorid of lime. Chlorid of lime thus has the advantage over caustic lime of disinfecting in a much shorter time. Nissen says that chlorid of lime may be added in the form of powder to dejections at the rate of 0.5 per cent, of the volume of the matter to be disinfected, or, taking into consideration the difference in the quality of the chlorid of lime, i per cent, may be added ( i gram to 100 cc.) The stool may be emptied in ten minutes after the addition of the chlorid of lime. In the tests of various agents for the rapid disinfection of stalls and cattle cars, Jaeger^ found that the bacteria of chicken cholera, erysipelas of swine, hog cholera, and anthrax were destroyed with a i per cent, solution of chlorid of lime. But anthrax spores required a mixture, or milk of chlorid of lime. 1. Arbelten a. d. Kais. Ges. v., 272. 1889. 32 CHLORID OF LIME. of 1:3, and this in one experiment failed to kill the bacillus of glanders. Its action even in this strength was uncertain with the tubercle bacillus. Jaeger's judgment is that chlorid of lime is a very efficient disinfectant. Vincent^ ranks chlorid of lime as one of the best of chemical agents for the disinfection of excreta, though he does not place it first in point of efficiency. The chlorid of lime used in his experiments showed by titration no litres of chlorin in each kilogram. A saturated solution was used. To completely sterilize diarrheal stools, 10 per cent, of their volume of this saturated solution was required; and the same proportion was required to destroy Bacterium coli commune in a mixture of normal feces and urine. Sometimes the destruction of the bacillus of typhoid fever in typhoid stools may be accomplished in seven hours with from 6 to 8 grams of chlorid per 1000 cc. of fecal matter; but to destroy this bacillus with certainty in twenty- four hours, 12 grams per 1000 must be used. The cholera bacillus is easily destroyed with chlorid of lime. To do it with certainty a quantity of the saturated solution equal to 10 per cent, of the matter to be disinfeced is required, or 8.3 grams of the chlorid per 1000 cc. of material to be disinfected. In the disinfection of vaults Vincent recommends acidifying their contents with commercial hydrochloric acid, before adding the chlorid of lime. Applications. — The most frequent use of chlorid of lime is in the disinfection of excreta. With an excess of this agent, as Sternberg advises, the pathogenic organisms in excreta may be rapidly destroyed. To accomplish this result, there must be an intimate mixture, by stirring or otherwise, of disinfectant with material to be disinfected. Chlorid of lime is an efficient deodorant, but its own smell is substituted, which is very dis- agreeable to many persons. A solution may be used for the disinfection of the dead, by saturating with it the sheet in which the corpse is to be envel- oped. For the disinfection of tuberculous sputa, there is room for doubt as to its trustworthiness. Its odor is also objection- able. Whether the "milk of chlorid of lime" may be trusted 1. Annales fle I'Inst. Past., IX., 12. 1895. CHLORID OF LIME CHLORIN GAS. 33 in veterinary practice to disinfect stalls infected with tuber- culosis or glanders, further experiments seem to be needed to decide the question. For the purpose of destroying typhoid fever germs in the mains of the water-works in Maidstone, Eng., Dr. Sims Wood- head dissolved about ten tons of chlorid of lime in 240,000 gal- lons of water in the reservoir and allowed the solution to flow into the mains. At a certain hour it was turned into all the house connections in the district. Comparisons. — As may be seen by an examination of the results of the experimental tests of caustic lime and chlorid of lime, most of the later work and that of Dr. Sternberg indicate that chlorid of lime is the more rapidly active of the two. In point of efficiency in the disinfection of excreta, Vincent places the cresols and sulphate of copper first, and chlorid of lime next, with caustic lime considerably lower. In point of cost, he places chlorid of lime first as being the cheapest. Nissen's estimate is that from 0.5 to i per cent, of chlorid of lime is required to disinfect sterilized feces with typhoid bacilli. Pfuhl found that 1.5 per cent, of caustic lime is required to produce the same effect. We may entirely disregard Behring's former opinion that the germicidal power of chlorid of lime is not more than one twentieth of that of caustic lime. Preparations. — The solution recommended by the Committee of the American Public Health Association is made by adding six ounces of chlorid of lime to one gallon of water. This is approximately a 4 per cent, solution. Solutions of chlorid of lime lose their strength rapidly; they should, therefore, be freshly prepared, but if well corked may be kept several days. Exposed to the air chlorid of lime soon loses a large part of its disinfecting power. It should, therefore, be preserved in air- tight receptacles. CHLORIN GAS. Chlorin has, according to Rideal,^ three possible modes of action, i. It may replace hydrogen in the organic substances, forming innocuous compounds and poisoning the bacteria. Such action is slow. 2. The offensive gases of putrefaction are decomposed by chlorin,— sulphuretted hydrogen, phosphoretted ]. Disinfection and Disinfectants, p. 58. 1895. London. 3 34 CHLORIN GAS. hydrogen, ammonia, and compound ammonias. 3. The com- mon and most important action of chlorin is as an oxidizing" agent. In the presence of water, more especially in light, it combines with hydrogen to form hydrochloric acid, and liber- ates oxygen. The oxygen so formed is far more active than atmospheric oxygen, and is in a condition to burn up the putres- cent matters and kill the organisms which accompany the putrefaction. But there are several conditions indispensable to thorough disinfection, and amongst these the presence of moisture is absolutely essential when chlorin fumigation is resorted to. In Koch's^ comparative tests of bromin and chlorin he found that bromin is more rapidly active than chlorin. Chlorin gas did not kill anthrax spores in less than two days, while bromin, under the same conditions (a damp atmosphere), destroyed them in one day. Immersed in chlorin water, or 2 per cent, solution of bromin, anthrax spores were destroyed in one day. As a gaseous disinfectant, Koch found chlorin gas more effi- cient than sulphur dioxid. Fischer and Proskauer^ took up the work with chlorin, for the Imperial Board of Health, where Koch had left it and sought to determine more definitely the efficiency and the limitations of chlorin in the disinfection of rooms. The gas was used at various concentrations from i : 25,000 to 1 12.5 of air, the air in the experimental chamber being sometimes dry and some- times damp. It required twenty-four hours for 44.7 parts of chlorin in 100 parts of air to destroy anthrax spores, the spores and the chlorin atmosphere being dry. But when the air and the spores were moistened, complete sterilization was effected in one hour with 4 per cent, of chlorin. Anthrax bacilli were destroyed in twenty-four hours with i : 2500 of chlorin, moisture being pres- ent. In practical experiments in rooms they found it was impossible to secure the same certitude of action as was prac- ticable in flasks where definite preportions of the chlorin could be used. These investigators also determined the action of the gas upon various fabrics. The following are some of the points in their concluding remarks : 1. Mlttlieil. a. a. Kals. Ges., I., 273. 1881. 2. Mittbeil. a. d. Kals. Ges., II, 228. 1884. CHLORIN GAS. 35 Chlorin gas has a narrow range of applicability in disinfec- tion. It has but little power of penetration. Compared with sulphur fumigation, chlorin is more efficient. Most things are injured by the action of chlorin. Moisture increases the efficiency of chlorin, but, at the same time, adds very much to its destructive action on clothing, metals, etc. Clothing, par- ticularly, must not be subjected to the action of chlorin. Sternberg says that, "chlorin gas is the most effective gas- eous disinfectant without doubt, but there are certain disadvan- tages in its application; it is irritating, corrosive, and bleaches and destroys fabrics. It would not do, for instance, to turn chlorin gas loose in one of our nicely finished ships, as it would do a great deal of damage to paint and brass work, and also to the hangings and furniture; but where it is applicable it is the best gaseous disinfectant."^ Dr. Rohe summed up very judiciously the case of chlorin for the Committee on Disinfectants : "Chlorin is an efficient disinfectant when present in the pro- portion of I part in loo, provided the air and the objects to be; disinfected are in a moist state, and the exposure continues for! upwards of one hour. ; "Chlorin, when used in sufficient concentration to act as a trustworthy disinfectant, injures colored fabrics and wearing apparel. "The use of chlorin, and in a greater degree of bromin, requires considerable experience in management. When care- lessly handled they may cause inconvenient, or even dangerous symptoms in persons using them. For these reasons they are not suitable as disinfectants for popular use."^ Uses of Chlorin. — ^"For each cubic metre of space use 0.35 kilograms of hydrochloric acid and 0.25 kilograms of freshly pre- pared chlorid of lime. Let the gas act eight hours at least. Its action is hardly more efficient than that of sulphurous acid" (Von Esmarch"). Chlorin gas was not included in the disin- fecting agents recommended by the Committee on Disinfectants of the American Public Health Association. 1. Brooklyn Med. Jr., III., 344. 1889. 2. Report of Committee on Disinfectants, A. P. H. A., p. 26. 3. Hyglenischea Tasclienbuch, p. 208. 1896. 36 CHLOROFORM CLOTHING. CHLOROFORM. In Koch's^ experiments immersion in chloroform one hundred days did not suffice to destroy the vitality of anthrax spores. Behring^ states that the bacillus of anthrax, and of typhoid fever, the spirillum of cholera, and Staphylococcus pyogenes aureus are all very quickly killed with chloroform; that i per cent, of chloroform will kill the spirillum of cholera in less than one minute ; that J4 per cent, will kill the same micro-organism in one hour ; and that J^ per cent, will destroy typhoid bacilli in one hour. He recommends chloroform water as a mouth wash. CLOTHING. The most trustworthy agency for the disinfection of clothing is moist heat, — steam or boiling. Those woolen or other goods that would be injured by boiling, or by maceration in liquid solutions, may be disinfected in steam disinfectors of quite simple construction, provided an abundance of steam streams through the disinfecting chamber. Subjection to boiling for half an hour insures the disinfection of all clothing that can be so treated. When infected bed or body linen is removed, it may be treated differently according to circumstances. If stained, it should be soaked some hours in a disinfecting solution at a temperature not exceeding 120° F. A 2 per cent, solution of lysol is very suitable for this purpose. Subsequent boiling, as in the ordi- nary laundry processes, will complete the sterilization. Unstained clothing may be immersed in a disinfecting solution and treated as already advised, or it may be transferred immediately to the wash-boiler or steam disinfector or to hot disinfecting solutions. Clothing which has been immersed in a disinfecting solution or is otherwise wet, is not readily penetrated by the heat in steam disinfection. In transferring infected clothing from the sick room, it should be wrapped in a sheet wet in a disinfecting solu- tion or in simple water, if the disinfecting solution is not at hand. Colored goods and the garments for outside wear generally, may be disinfected with steam, or by maceration in a 3 per cent. 1. Mlttheil. au3 dem Kal3. Ges., I., 263. 1S81. 2. Bekampfung der Inleotionskranklaelten, II., 107. 1894. CLOTHING COPPER SALTS. 37 solution of carbolic acid, or a 2 per cent, solution of lysol, or a 1 : 1000 solution of corrosive sublimate. Maceration in simple sublimate solution is no more likely to change the colors of goods than soaking in water alone. The solution of lysol changes the colors of some fabrics. It has about the same effect as soaking in soap and water would. It is quite likely that solutions of formaldehyde will be found efficient in the disinfection of clothing. A 5 per cent, solution of formalin changes colors but very little, not more than a 5 per cent, solution of carbolic acid, or the i : 1000 solution of corro- sive sublimate. COPPER SALTS. Dr. Green,^ of Hanover, Germany, investigated the disinfec- tive power of crude and pure sulphate of copper, bichlorid of copper, nitrate, acetate, and aluminate of copper, sulpho-car- bolate of copper, and ammonio-copper sulphate. He finds that all of these salts, with the exception of the bichlorid, precipitate albumen as corrosive sublimate does. There should, therefore, be the same limitations in the use of all the copper salts, except the bichlorid, as there is in the use of sublimate when albumen is present. He found that the bichlorid is more efficient than the sulphate and the other copper salts, particularly in albumin- ous liquids. On account of the action of copper salts upon metals and their staining of fabrics, the use of them must be limited almost exclusively to the disinfection of excreta. For the disinfection of cholera and typhoid dejections in the sick-room, the vessel should contain before use about four times the bulk of the dejections of a 5 per cent, solution of copper bichlorid, and it should stand at least an hour before it is emptied. Summarizing his results he says : The soluble copper salts, and particularly copper bichlorid has considerable disinfecting value. Anthrax spores were not destroyed in less than thirty days, or, at least, none of the salts except copper bichlorid would destroy them in less time ; spore- less infectious matter, on the contrary, was destroyed in a much shorter time. 1. Zeit. fur Hyg., XIII., 495. 38 COPPER SALTS— COPPER SULPHATE. In albuminous solutions, copper bichlorid alone is suitable. With the other salts an insoluble albuminous precipitate ensues. In surgical work, the treatment of wounds, copper bichlorid is far preferable to copper sulphate which is sometimes used. Cholera and typhoid bacilli were destroyed with certainty with copper bichlorid in not less than two hours, staphylococcus aureus in not less than five hours, in bouillon. COPPER SULPHATE. In the experiments of Dr. Sternberg^ for the Commit- tee of the Arnerican Public Health Association, sulphate of copper failed to disinfect material containing spores, but it readily destroyed sporeless bacteria. In later work a large number of sporeless organisms in bouillon, including the bacillus of typhoid fever and of cholera, and staphylococci, and streptococci, were invariably killed with i per cent, of sulphate of copper. The addition of 10 per cent, of albumen lessened the disinfecting action of the copper salt in a marked degree. In an extensive series of experiments made by Gerloczy^ in the Hygienic Institute of Buda-Pesth, sulphate of copper, sul- phate of zinc, crude carbolic acid, creolin, crude sulphuric acid, milk of lime, potash lye, and other agents were tested. He found sulphate of copper to be a very efficient disinfectant. Added to sewage in the proportion of i : 1000, it rendered it odorless, and it remained permanently sterile. When used in sufficient quantity fresh excreta and even the contents of privy vaults were disinfected. For privy vaults he recommends a strong solution, at the rate, at least of 40 kilograms of sulphate of copper to each cubic meter of material to be disinfected (2^^ pounds, to each cubic foot). For discharges from the bowels in the sick room, one part of the copper salt to one hun- dred parts of excreta is sufficient. Vincent^ warmly recommends sulphate of copper as the most efficient for excreta tested by him. In privy vaults it destroyed with certainty pathogenic bacteria. Bacterium coli commune, and the bacillus of putrefaction. For the complete disinfection of 1. Jr. Am. Pub. Healtli Assoc, XI., 235. 1885. 2. Deutsche Vlert. f . off. Ges. XXI., 433. 1889. 8. Annales de I'Inst. Past., IX., 31. 1895. COPPER SULPHATE CORPSES. 39 fecal matter in twenty-four hours, from 7 to 8.5 grams to 1000 cc. of fecal matter were required, but for the same quantity of typhoid stools, 5 grams, or of cholera stools, 4.5 grams, were found to suffice. The activity of cupric sulphate was increased by the addition of sulphuric acid. Comparisons. — The range of applicability of sulphate of cop- per is rather limited. It may be used for the destruction of the germ of typhoid fever or of cholera in fresh excreta or in privy ■vaults. Chlorid of lime, however, is cheaper and probably will be found to act with greater rapidity. Milk of lime is also cheaper, and when it can be given sufficient time to act, may be deemed efficient, though Vincent ranks its degree of efficiency far below that of sulphate of copper. One consideration, in some places, in favor of lime is that it is not injurious to vegeta- tion, while sulphate of copper is. For the disinfection of fecal matter, in the sick-room or in vaults, some of the cheaper cresol solutions, solutol, creolin, soap or acid solutions of crude car- bolic acid, or, when time may be given, saprol, will probably be determined to be preferable to sulphate of copper, on account of lower cost, greater or equal efficiency, and more pronounced deodorizing qualities. CORPSES. The disinfection of corpses may be accomplished by wrap- ping them in sheets wet in a 3 or 4 per cent, solution of chlorid of lime, or of a solution of sodium hypochlorite ( i part of Labar- raque's solution to 9 of water). Carbolic acid is not so trustworthy. The cresols are more active germicides, and their efficiency as well as that of carbolic acid, can be augmented by the addition of common salt to their solutions. (See pages 191-192.) A 5 or 10 per cent, solution of formalin would probably be efficient. Solutions of mercuric chlorid have been much used, but their action extends no farther than the solution penetrates. The antiseptic and germicide action of solutions of the hypochlorites ' (including chlorid of lime) and of formaldehyde are increased by their vapors which are diffusible and far-reaching. When it is deemed best to fill the space between the casket and the outside box with sawdust or other absorbent material, a 4° CREOLIN. solution of formalin or of the hypochlorites would be a suitable and efficient one with which to dampen it. The ordinary processes of the embalmer's art cannot be classed among the methods of disinfecting corpses. All unnecessary operations preceding the wrapping of the corpse in the disin- fecting sheet and the packing with disinfecting material, facili- tate the scattering of infection. CORROSIVE SUBLIMATE. (See MERCURIC CHLORID) . CREOLIN. The constituents of creolin, to which its disinfectant power is chiefly due, are the cresols dissolved, or rather emulsified in a solution of hard soap. Two kinds of creolin were put upon the market: an English preparation, Pearson's, and one of German manufacture, Artihann's. The latter has repeatedly been shown to have but slight value as a disinfectant and will, therefore, receive no further notice. Pearson's creolin contains about lo per cent, of cresols with a small quantity of carbolic acid. Mixed with water a dirty-colored, milky mixture results. As to the bactericidal powers of creolin, Ermengem^ found a 5 per cent, solution to be a trustworthy disinfectant for cholera and typhoid germs, and for the streptococcus of erysipelas and Staphylococcus pyogenes aureus. He regards creolin as a dis- infectant of the first rank, and one which is decidedly superior to carbolic acid. It is also commended as a deodorant. Laser^ confirms the statement of Ermengem that a 5 per cent, solution may be trusted to disinfect stools, and further com- mends it for its deodorant qualities and for its safety and cheap- ness. Remouchamps and Sugg^ conclude that a 2.5 per cent, solu- tion of creolin is an efficient disinfectant agent for typhoid stools and artificial cholera stools. In the presence of albumen, how- ever, creolin suffers the loss of some of its germicide power. 1. Bui. de I'Acacl. Boy. ae Med. de Belglgue.— Centr. fur Bak., VII., 75. 1890. ■i. Centr. fiir Bak., XII., 233. 1892. 3. Op. cit. CREOLIN. 41 In the experiments of Santovecchi/ a i per cent, solution of creolin destroyed the bacillus of typhoid fever in one minute. He found that light and heat have no effect upon the keeping qualities of creolin. On the other hand, Behring states that creolin freshly prepared is more efficient than old. Watery solutions of creolin up to 60 per cent., in the experi- ments of Sirena and Alessi,- failed to kill anthrax spores. On the other hand, a 2 per cent, solution destroys the bacillus of hog-erysipelas in twrenty-four hours, and a 10 per cent, solu- tion destroys sporeless anthrax bacilli in fresh blood in ten minutes. As a numerical statement of the comparative germicide power of carbolic acid, cresol, and creolin in bouillon, Behring^ classes them as i, 4, and 10, respectively. Thus in the absence of albuminous matter, the disinfectant power of creolin greatly exceeds that of carbolic acid, but under different conditions, when albumen is present, carbolic acid is 3 or 4 times more efficient than creolin. The conclusions of Hiinermann* are that creolin is not so effective as carbolic acid on either sporeless anthrax bacilli or the staphylococcus of suppuration. Excreta. — As a disinfectant for fecal matter the results of the experimental work already cited, indicate that creolin is a trust- worthy agent, and it is moreover an excellent deodorant. There are, however, reasons for apprehending that the inhibitory action of creolin has to some extent been mistaken for a germi- cide action. Surgical. — Creolin has been recommended and used as a surgical antiseptic, but others of the cresol preparations are far preferable to it. For Pearson's creolin Esmarch and Eisenberg found its antiseptic value to be 1:5000 to i : 15,000, while Behring^ found it to be not more than i : 175 to i :225. Behring, therefore, attributes an antiseptic value to creolin about 50 times lower than that of these other investigators. The expla- nation of this discrepancy is that Behring's tests were made with bacteria in blood serum, an albuminous medium, while the other 1. Centr. fur Bak., SIII., 413. 1893. 2. La Eiforma Med.— Centr. tUr Bak., XII., 178. 1892. 3. Bekampfung der Infeotionskrankheiten, II., 110-113. 1894. i. Centr. lur Bak., V., 650. 1889. 5. Deutsche Med. Wooli., SV., 869. 1889. 42 CREOLIN. experimenters used non-albuminous media. The difference in the character of the media, on the other hand, affects the value of carbolic acid but little. Its antiseptic value is generally esti- mated at from i :6oo to i igoo. As to which method is the correct one for estimating the anti- septic value of disinfectants, Behring^ reminds us that, when used in surgical work, they are brought into contact with blood, pus, and the serous exudations from wounds, all of which are albuminous. The antiseptic value of an agent determined in blood serum should, therefore, be the more correct one. Else- where he affirms that, "in surgical practice, where the antiseptic is to come in contact with the secretions from wounds, or in any case in the presence of albumen, carbolic acid is preferable to creolin." As an antiseptic for anthrax spores Hunermann found that, in bouillon, i : 10,000, and in nutritive gelatin 1 15000 prevented their development, while for Staphylococcus pyogenes aureus, 1 : 1000 in bouillon, and 3 : 10,000 in gelatin were required. Thus, according to this experimenter, this staphylococcus required for the prevention of its growth in bouillon ten times as much as was required for anthrax spores, while in gelatin scarcely twice as much of the creolin is needed for staphylococ- cus as for anthrax spores. In veterinary practice Dr. Frick^ has had some cases in which severe smarting and itching have been caused by creolin. For this reason and on account of the inconvenience in transporting it on account of its bulk, he has discarded it. Toxicity. — Behring^ says that, while creolin in inferior to car- bolic acid as an antiseptic, it may act as a dangerous poison. His law of toxicity, which extended experimental research has developed, is: to each kilo of the weight of the animal, six times the dose required to inhibit the growth of anthrax bacilli is a fatal dose to the experimental animal. This applies to car- bolic acid, corrosive sublimate, and to creolin. According to Remouchamps and Sugg,* the fatal dose of creolin is nearly four times that of carbolic acid. Various other observers testify to 1. Op. cit. p. :5i. 2. Deutsche Zelt. tUr Thlermed., XVII., 71. 1890. 3. Deutsche Milltar. Zelt.— Centr. fiir Bak., V., 139. 4. Loc. cit. CRESOL. HO the toxicity of creolin. It was at first heralded, as non-poison- ous, or but sHghtly toxic. CRESOL. This is a coal-tar product obtained from crude carbolic acid by fractional distillation at a temperature between 185" and 205" C. Frankel^ states that there is a great difference in the disin- fecting power of the distillate obtained from crude carbolic acid at different temperatures. He investigated the germicide action of the three forms, — ortho-cresol, meta-cresol, and para-cresol, — and found that meta-cresol is more efficient than either of the others. Hammer, on the other hand, found a mixture of the three cresols more efficient than either alone. Tricresol is said to be a mixture of the three forms of cresol. Of the various solutions of cresol which are on the market, Hammer^ divides them into two classes : A. Those which become opaque when water is added to them, for example, creolin, cresolin. Little's soluble phenyl. B. Those which remain clear when water is added : lysol, solutol, and solveol. As given by Heider,^ the quantity of cresol in each of the following preparations is : lysol, 50 per cent. ; solveol, 27 per cent. ; solutol, 60.4 per cent. ; creolin (Pearson's), 10 per cent. In Hammer's* work a 5 per cent, solution of the three cresols destroyed in five minutes the micro-organisms of green pus, cholera, and typhoid fever, and staphylococci. Anthrax spores were killed in five minutes with 10-20 per cent, solutions of crude cresol in sodium cresolate when the solution was used at a tem- perature of 55° C. (131° F.). The anthrax spores used were capable of resisting the influence of sublimate, i : 1000, thirty minutes, and carbolic acid, 5 per cent. 62 days. As neutral solutions of cresol, when compared with carbolic acid, are practically unirritating and non-corrosive, and as a 0.5 per cent, solution of cresol acts as energetically as a 2 or 3, and sometimes as a 5 per cent, solution of carbolic acid, it has a great advantage over carbolic acid. Hammer thinks that cresol 1. Zeit. fur Hygiene, VI., 521. 1889. 2. Archiv tur Hygiene, XIV., 116. 1892. 3. Ibid., XV., 366. 1892. 4. Ibid., XII., 375-381. 1891. 44 CRESOL. IS well adapted to come into general use as a disinfectant in medical and surgical practice, and to supersede carbolic acid, which is not always trustworthy. Repeating the experiments of Hammer with anthrax spores, Heider^ obtained results which he regards as satisfactory, but the spores were not killed in less than from 30 to 45 minutes. Comparing the cresols with carbolic acid, Gruber- considers them far superior, — as 3 to i, — when measured by the rapidity with which these preparations destroy Staphylococcus pyogenes aureus mixed with water. One advantage of cresol is that it is influenced but little by the presence of albumen. But on this point Behring'' places some emphasis on his statement that albuminous matter affects unfavorably the action of the cresols. Only in fluids containing no albumen, he says, is cresol more efficient than carbolic acid. For the testing of the disinfecting power of the cresols. Butter- sack* used anthrax spores possessing a high degree of resist- ance. Experiments with carbolic acid were carried on, at the same time, for the purposes of comparison. To prevent the transmission of a trace of the disinfecting agent to the culture media, the spores were dried, not on the ordinary silken threads, but on little knots of glass silk, from which the disinfecting agent could be removed more readily by simple rinsings. Vari- ous preparations of cresol were tried. Besides anthrax spores. Staphylococcus pyogenes aureus and tuberculous sputum were used. In the experiments with the staphylococcus, a i per cent, solu- tion of six of the brands of cresol destroyed the infection in one minute. A i per cent, solution of three other preparations of cresol, and also of lysol, sterilized in three minutes. It required five minutes for one of the brands of cresol to produce the same results. One of the cresols, and also a i per cent, solution of carbolic acid, failed to kill the staphylococcus in ten minutes. In the experiments with anthrax spores, a 5 per cent, solution of carbolic acid failed to kill in 50 days. A 10 per cent, solu- tion of two of the cresols destroyed them within four days ; the other nine kinds of cresol failed to disinfect in one week. 1. Arcliiv fur Hygiene, XV., 369. 1S92. 2. Ibid., XVII., 618. 1893. 3. Zeit. fiir Hygiene, IX., 420. 1890. 4. Arbeiten a. d. Kais. Ges., VIII., 359. 1892. CRESOL. 45 With fresh sputum containing an abundance of tubercle bacilH, a lo per cent, solution of two of the cresols destroyed the bacilli within six hours. The experimental work of Vahle^ leads him to the conclusion that, on anthrax spores and the staphylococcus of suppuration, Raschig's cresol and carbolic acid are of equal disinfecting value. The experiments of HammerP indicate that solutions of tri- cresol of the same percentage are superior to those of carbolic acid. A 0.5 per cent, solution of tricresol is considered equal to a I per cent, solution of carbolic acid, when tested on Staphy- lococcus pyogenes aureus. Streptococcus pyogenes longus, and brevis, and B. pyocyaneus. On anthrax spores, a 2 per cent, solution of tricresol was about equal to a 5 per cent, solution of carbolic acid, and a 2.5 per cent, solution of tricresol was dis- tinctly superior to the 5 per cent, carbolic acid. Excreta. — Vincent^ states that with him cresol has shown itself to be an excellent disinfectant of fecal matter. It is also an excellent deodorant. The dose required for the sterilization of fresh diarrheal discharges is 5 to 8 parts per 1000 ; but the colon bacillus does not disappear before sixteen hours. In prac- tice the requisite quantity of cresol for the disinfection of normal fecal matter is stated as 9 to 10 : 1000. The typhoid bacillus in stools is destroyed in 24 hours with 6 or 7:1000. In a few cases in which the bacillus was very abundant 10 : 1000 was necessary. Vincent states that, in spite of its quite active power, cresol is not one of the best agents for the disinfection of typhoid stools. (See Excreta.) On the other hand, the spirillum of cholera is very easily killed with cresol: a 3:1000 solution destroys it in less than seven hours. It is, therefore, one of the best of disinfectants, if not the best, for choleraic dejections. Surgical. — Gruber* discovered that the watery solution of cresol which may be made from crude carbolic acid has an extraordinary disinfectant and antiseptic value. The solubility of the cresols varies from 0.5 per cent, to more than 2 per cent. 1. Hyg. Eundscliau, III., 901. 1893. 2. Archiv tur Hygiene, XXI., 198. 1891. 3. Annales de I'Inst. Past., IX., 25. 1895. 4. Arclilv fur Hygiene, XVII., 618. 1893. 46 CRESOL. A solution of i per cent, of cresol by volume made from crude carbolic acid in water destroys Staphylococcus pyogenes aureus within half a minute with certainty, and a 0.5 per cent, solution sterilized the same micro-organism in from ten to twelve minutes, and the cholera germ in from one to two minutes. , Gruber thinks that a i per cent, watery solution of cresol pos- sesses great advantages in surgical antisepsis. This solution is free from the disadvantages of most of the other preparations. It is colorless, and, diluted with hard well water, it remains per- fectly clear and renders neither the hands nor the instruments slippery. It is only slightly toxic. It has no benumbing or other unpleasant effect upon the skin, as occurs in using a 3 per cent, solution of carbolic acid. It causes but little smarting when applied to mucous membranes. Its cost is low. Any one can easily make the solution. HammerP also recommends a 0.5 to i per cent, solution of tricresol, especially in surgical work. Hiller^ joins also in nam- ing the various advantages of a solution of solutol containing 0.5 per cent, of cresol which he ranks as the equivalent of a 2.5 or 3 per cent, solution of carbolic acid in surgical practice. On the other side, Vincent^ says that solutions of cresol are less efficacious when applied to Staphylococcus pyogenes aureus and its allied micro-organisms. Toxicity. — Grigorjeff* tested the comparative toxicity of tri- cresol and carbolic acid. The result of his experiments was the confirmation of the assertion of Delplanque that tricresol is four times less poisonous than carbolic acid. Dr. Avery^ made a few experiments for the purpose of testing the toxicity of tricresol on guinea-pigs. He says : "These experiments would tend to show that tricresol is a very safe antiseptic, as no such quantities as were employed here would ever be introduced into the body in the proportions that are used in antiseptic mixtures." Professor Charteris, of Edinburgh, investigated the antiseptic value of tricresol, and he concludes that while it is a three times stronger germicide than carboHc acid it is three times less toxic.*- 1. Arohiv tiir Hygiene, XXL, 198. 1884. 2. Deutsobe Mea. Woch., XVIIl., 841. 1892. 3. Annales de I'Inst. Past., IX., 8. 1895. 4. Beltr. zur patholog. Anat. u. z. Allg. Path.-Centr. fur Bak., XVII., 853. 1893.. 5. Medical News, LXVII., 68. 1896. 6. N. B. Med. Monthly, XIII., 604. 1894. CRESOL SAPONATE DISINFECTOL. 47 To secure the better solution of meta-cresols in water, Schuetz recommends the addition of five parts of alcohol to two parts of the cresols. In this way he is able to make a 2 per cent, solu- tion of cresol in water which is clear and which remains unchanged for a long time.^ CRESOL SAPONATE. This is prepared by melting a pure, soft soap in a dish on a steam-bath with an equal quantity of clear, crude carbolic acid. The resulting solution is heated until it remains clear upon cool- ing and dissolves in distilled water. It is a clear, Madeira- colored fluid of neutral reaction, and soluble in all proportions of water, alcohol, or glycerin. It is said to have a less disagree- able odor than that of lysol, besides being as satisfactory as the best pure lysol.^ DEAD BODIES. (See CORPSES.) DISINFECTOL. Dr. Laser,^ referring to disinfectol, says that this is a prepara- tion somewhat resembling creolin, which Dr. Bruno Lowenstein, of Rostock, has introduced. Beselin* claims that this has many advantages over other disinfecting agents in the disinfection of excreta. It contains hard soap. In his experiments, Beselin used diarrheal feces from typhoid cases, and found that a 5 per cent, emulsion of disinfectol sufHced within eighteen hours com- pletely to disinfect an equal volume of fecal matter. A 10 per cent, emulsion was capable of disinfecting twice its volume of fecal matter. According to Beselin, disinfectol, 5 per cent.; creolin, 12.5 per cent. ; muriatic acid, 33 per cent. ; carbolic acid, 5 per cent. ; sublimate 2:1,000, with or without muriatic acid; are equal as regards their power of disinfecting fecal matter. He says that 1. Jahresberlcht ueber die Fortschritte u. Leist. auf clem Geblete der Hygiene.. XIV., 280. 1897. 2. Centr. fur Gyn.-Amer. Meclico-Surg. Bulletin, VI., 423. 1893 3. Centr. fur Bak., XII., 232. 1892. i. Centr. lur Bak., VII., 364. 1890. 48 ELECTROLYSIS. disinfectol, lo per cent., exceeds all of the other agents which he enumerates for semi-fluid feces. ELECTROLYSIS. The two principal ways in which electricity has been applied to the disinfection of sewage are represented by the method of Mr. Webster, of England, and by that of M. Hermite, of France. In the Webster process, the electric current acts directly upon the sewage; in the Hermite process, natural or artificial sea- water is submitted to electrolysis and thereby acquires disinfect- ing properties. This electrolyzed sea-water is then mixed with the sewage or other matter to be disinfected. Webster Process. — In this process, the electrodes consist of iron plates which are submerged in the sewage to be purified or disinfected. Chlorin evolved at the positive electrode combines immediately with the iron of the electrolytic plate, and a sec- ondary transformation converts the chlorid into an oxid of iron which, as precipitant, carries down a part of the bacteria and some of the other organic matter. Experimental plants were put in for the purpose of testing this process in Salford, Cross- ness, and Bradford, England ; but, so far as I know, no perma- nent works have been established for treating sewage in this way. Dr. McLintock, Medical Ofiicer of Health of Bradford, at a meeting of the British Medical Association in 1890, made a report on the results of the Webster process in his town, in which he stated that about 70 per cent, of the noxious and putrescible portion of the sewage is removed. He expressed the opinion that, "there is every reason for believing that, in electricity as used in Mr. Webster's patent, we have an agent capable of purifying even the worst sewage to such a degree as to render it fit to enter an ordinary stream."^ Several of the leading authorities on public sanitation, who took part in the dis- cussion, could not see much promise in this method. In the Hygieneic Institute of Munich, Fermi^ conducted a series of laboratory experiments to determine the value of the Webster process. His conclusions are that the electric current is capable of reducing the percentage of dissolved organic matter 1. Brltiah Med. Jr., II., 1890, 49S. 2. ArcliiT fiir Hygiene, XIII., 207. 189L ELECTROLYSIS. ^g in sewage one half, and that precipitation with lime is cheaper and more efficient than electrolysis. So far as I know, the most thorough investigation of this process yet made is the recent work of Konig and Remele.^ They conclude that the Webster process is nothing more than a method of chemical precipitation by means of the resulting hydroxid of iron; that there is no direct oxidation; and that processes of electrical purification are advisable only where other superior methods, land irrigation for instance, are out of the question, or where a natural power is available for the genera- tion of electricity. Hermit e Process. — In this there is no treatment of sewage by electricity, as in the Webster process. Electricity is used only to decompose the sea-water, and this altered sea-water is then used as a disinfective agent for sewage or for other purposes. M. Hermite's complete method includes a separate system of pipes through which this electrolyzed solution is to be pumped to the places where it is needed, thus rendering it available for general domestic and municipal flushing. In the Hermite system the positive electrode is of platinum, instead of iron as in the Webster process. In the report of the Lancet^ Commission the following statement of the chemical reaction was made : "By electrolysis of the magnesium chlorid in the sea water, magnesia and chlorin are liberated, which subsequently combine to form magnesium hypochlorite Mg (OCl)^ and magnesium chlorid. This liquid may be regarded as the magnesian equiv- alent of bleaching powder solution. The magnesium hypo- chlorite dissociates into magnesia, which deposits on the walls and floor of the electrolyser, and free hypochlorous acid, which remains in solution. "The Hermite solution then practically resolves itself into a dilute solution of hypochlorous acid, and may be cheaply imi- tated by passing carbonic acid through a solution of ordinary bleaching powder. It is admitted, however, that this -artificial Hermite' gave in bacteriological examination 'varying results, and could not be depended on to exert constantly an equivalent 1. Archiv fur Hygiene, XXVIII., 185. 1S97. 2. Lancet, ]., 1894, 1321. 5° ELECTROLYSIS. action to the Hermite solution.' Chemically, however, the two solutions exhibited very close resemblance." While the Hermite system was on trial in Worthing, Dr. Kelly,! Medical Officer of Health for West Sussex, investigated the process. Samples of the Hermite solution examined by him contained from 0.22 to 0.75 gram of chlorin per litre, but usually there was from 0.44 to 0.51 gram. M. Hermite claims that 0.30 gram suffices. Samples of sewage treated with the Hermite solution were examined by Dr. Klein. Ordinary sewage contains from 3,000,000 to 10,000,000 bacteria. These treated samples contained from 800 to 1,000. While there was a great diminution in the bacterial contents. Dr. Klein fotmd that the solution failed to destroy even all of the sporeless bac- teria. While the printed pamphlet descriptive of the process claims that the Hermite solution "instantly" destroys the bacteria of sewage when the two liquids are mixed, Klein found that, when bouillon cultures of typhoid bacillus, cholera vibrio, or colon bacterium were mixed half-and-half with the disin- fectant solution, none of the cultures were sterilized in twenty minutes. While Dr. Klein found the Hermite solution itself to be sterile, its disinfective action was small when added to sewage in much larger proportion than occurs in practice. Dr. Kelly concludes his report with : "Since there is no instan- taneous decomposition of fecal matter, and no sterilization of sewage, I am of opinion that the process, as far as the late trials have gone, has therefore failed to produce the results which are claimed for it by its inventor." The Hermite process was first tested in Havre, in 1893, and soon afterward in Lorient, France, and Worthing, and Ipswich, England. As stated by Konig and Remele,^ the commission which was sent to Havre by the Imperial Board of Health of Germany, and one sent from Paris by the Central Council of Hygiene, both reported adversely. Konig and Remele express the opinion that "the Hermite process has not as yet been shown to be practical, and appears to have been given up everywhere." Their conclusions, based upon their own experiments, are that processes of electrical purification are advisable only where other 1. Public Health, VI., 261. 1894. London. 2. Arohiv fur Hygiene, XXVIII., 185. 1897. ELECTROLYSIS. SI superior methods are out of the question, or where a natural power is available for the generation of electricity. Woolf Process. — This is also a process of electrolyzing sea- water, or a solution of salt in water, for the purpose of disin- fecting sewage, water supplies, etc. The exposed surfaces of the positive electrodes are of platinum, as in the Hermite proc- ess, and the chemical transformation wrought in saline solu- tions subjected to its electric current are undoubtedly identical with those in the Hermite process. The testimonials to the efficacy of "electrozone" and Hermite solution indicate a reawak- ening to the fact that solutions of the hypochlorites, or Labar- raque's solution, though old, are efficient disinfectant agents, as the report of the Committee of the American Public Health Association indicated. There is nothing to show that these solutions have any properties, disinfective or otherwise useful, further than those of the hypochlorite solutions prepared in the older ways. The first official test of this process was made by the Board of Health of New York City, in 1893, at Brewsters. The sewage of this village polluted the Croton water supply. A plant was erected and "electrozone" was run into the sewers with the sewage. The results were investigated by Mr. Martin, the chemist of the Board. When certain quantities of electrozone were run into the sewers, the sewage thus treated was said to have become odorless and almost sterile, after it had been fil- tered; and, when to the sewage in a looo-gallon tank, salt had been added until the sewage contained 2 per cent, of sodium chlorid, and the electric current was turned on until the fluid contained 40 grams of hypochlorite to the gallon, "the bacteria were reduced in an hour and a half from 10,000,000 per cubic centimetre to none."^ In 1894, Riker Island, which had been used as the dumping- ground for the garbage of New York City until it had become a serious nuisance, was effectively disinfected by the application of electrolyzed sea-water liberally and for a long time applied with hose and nozzle. These results, reported to the Board of Health of New York, are remarkable in view of some of the statements of those who 1. Engineering Record, XXIX., 110. l!j04. 52 ELECTROLYSIS. have investigated the disinfecting claims of electrolyzed sea- water in Europe, and of the conditions which have been pre- scribed as prerequisites to successful disinfection with the hypochlorites. One of these prerequisites is that the quantity of hypochlorite in a solution of chlorid of lime or hypochlorite of sodium shall be quite largely in excess of the organic matter to be acted upon, else the hypochlorite, while acting upon the organic matter, is itself destroyed before all of the infectious material is sterilized. Klein found that, mixed half-and-half with sewage or cultures of the cholera or typhoid germ, sterilization was never effected. In Hermite's method comparatively large quan- tities of the electrolyzed sea-water were allowed to act repeatedly upon the fecal matter in sewage, in small enclosed spaces, never- theless, under these favorable conditions the disintegration of masses of fecal matter was slow and incomplete, and steriliza- tion was not effected. It is stated that, at Brewsters, i part of hypochlorite to 100,000 of water was used to sterilize the sewage.^ Dr. W. J. Gillespie, Assistant Bacteriologist of the Bureau of Health of Philadelphia, carried out a series of experiments at the request of the Board with the view of determining the value of solutions of hypochlorites made by the action of the electric current. His report states : "An excess, or about 8 cc, of hypochlorites added to 5 cc. of a 4-day-old spore of anthrax in bouillon destroys them com- pletely in less than five minutes. "From I to 2 cc. of hypochlorites added to 10 cc. of a bouillon culture of diphtheria bacilli, entirely destroys them in less than twenty-four hours. "An excess, or about 8 cc, of hypochlorites added to 5 cc. of a 72-hour bouillon culture of diphtheria bacilli, destroys them completely in less than five minutes. "From I to 2 cc. of hypochlorites added to 10 cc. of an active culture of Staphylococcus pyogenes aureus, entirely destroys them in a very short time. "About 2 cc. of hypochlorites added to 10 cc. of urine pre- serve it indefinitely, free from decomposition or odor. "These experiments proved hypochlorite to be a powerful germicide, since it kills the most resistant of all organisms, (anthrax spores) in five minutes or less. 1. Electrical Engineer, XVIIL, 101. 1894. ELECTROLYSIS. S3 "The cheapness of the material, and the rapidity, and ease with which large quantities can be made, recommended it to me, and at the same time thinking that if its value as a disinfectant, germicide and antiseptic was all that was claimed for it, we had an ideal article — cheap, efficient and non-poisonous. As a municipal germicide and disinfectant it cannot be surpassed."^ Electrical Purification of Water. — In a paper with this title, Professor Drown,^ of the Massachusetts Institute of Technol- ogy, says : "The so-called electrical purification of water, by treating it with an electrolyzed solution of salt, is thus seen to be simply a process of disinfection by sodium hypochlorite; electricity, as such, has nothing to do with it. There is nothing peculiar in the sodium hypochlorite produced by electrolysis ; it has no dif- ferent properties from that made by the ordinary process of passing chlorin into a solution of caustic soda. That other com- pounds are formed in small amount by the action of chlorin on caustic soda is true, but it has not been shown, nor is it probable, that any one of them has as potent germicidal power as the hypochlorite. "It is unfortunate, I think, that the advocates of this system of purification of water and sewage are not content to attribute the purifying action of the electrolyzed solution of salt solely to the hypochlorite formed. There is nothing gained by calling it 'electrozone' or an 'electro-saline solution,' for there is nothing mysterious about its action, as these terms would lead one to suppose. Nor is it proper to speak of this system of purifica- tion in any sense as an "electricar one. "Finally, is it desirable in any case to treat a city's water sup- ply with a powerful disinfectant like the hypochlorites? When the question is put in this bald form I cannot think it will receive the approval of engineers and sanitarians." A review of the available evidence appears to justify the doubt whether electrolysis, or such products of electrolysis as have been under consideration, offer an efficient method of purifying sewage so as to make safe its admission into sources of public water supply. For some purposes, however, and in some places, it seems to have been shown that hypochlorite solutions pre- 1. From a copy of tlie report received tbrougli the courtesy of Dr. Gillespie. 2. Jr. of the N. E, Water Works Assoc, VIII., 13S. 1894. 54 ELECTROLYSIS. pared under the influence of the electric current, may be used with advantage. (See Ozone.) Chlorin Manufactured by Electrolysis. — In the paper to which reference has already been made, Professor Drown says : "When a solution of salt (chlorid of sodium) is decomposed by electricity, we have sodium liberated at one pole and chlorin at the other. The sodium is immediately oxidized and combines with the water present, and a solution of caustic soda results. By suitable mechanical contrivances the chlorin gas may be conducted away from the other pole as fast as liberated and col- lected as such. This method of making caustic soda, it may be said incidentally, is yet more or less in an experimental stage, but it seems not unlikely that the electrolytic production of caus- tic soda from common salt may become one of the world's great industries." The fuller elaboration of the idea of the municipal produc- tion of two very effective disinfecting agents, — caustic soda and chlorin gas, — by those cities which own an electric lighting plant, is given in a paper read before the Liverpool Polytechnic Society, by James Hargreaves, F. C. S.^ The following is an abstract of the paper : "Of all the chemical agents proposed for disinfection, the most effective, and at the same time the least injtxrious, is chlo- rin. The usual method of using it has been in the form of chlorid of lime or bleaching powder. In this form it adds to the alkalinity of the sewage, which is not desirable. It also adds to the solid matter. It has little or no action upon the walls and crown of the sewer above the level at which the liquid sewage flows, and its power of exterminating the zymotic 'colonies' on the walls and in the cracks and chinks of the sewers is almost nil. By passing chlorin gas directly into the sewers the sources of infection are at once reached, and the germs exterminated. When this is once thoroughly done there can be no further propagation, except by replanting with fresh germs from other sources. "The chief difficulty in the application of chlorin is its first cost. At present the most practical means of obtaining it is in the form of bleaching powder, in which the actual chlorin costs 1. Tlie Sanitary Record, XVII., 664. 1896. ELECTROLYSIS. 55 ixj to I20 per ton at lately prevailing prices. If made fully effective by liberation in the form of gas it would cost 50 per cent, additional for the acid used to liberate it. But the prob- lem is considerably modified when it can be produced in its most active form for fewer shillings than the pounds it now costs. In view of its more extended application it becomes of import- ance to examine its properties. "Chlorin, being gaseous, readily diffuses into cavities and openings which could not otherwise be reached, and also ensures that the zymotic growths will be exposed to its action, which is only very partially the case when bleaching powder is used. Its being 2^ times as heavy as air ensures that it will be in greater quantity near the floor of the sewer, and so dispose of rats and other vermin. Being soluble in about half its volume of water further ensures that the germ life in the sewage itself will also be attacked, and that by discontinuing the supply of chlorine for a short time workmen will be able to enter the sewers with- out injury or inconvenience. "What will the chlorin cost? The system of producing it, which I submit to your attention, employs the electric ctirrent, and is most easily applied where electric lighting is in use, and more especially where a corporation produces its own current. The electric plant is standing for more than half its time, so there is power enough to produce all the chlorin needed for the sewers many times over. "It is difficult to state precisely the cost of the power needed ; for every electrical engineer has his own notions on that subject. Hence I prefer to give the physical data, and leave the engineer to work out the cost for himself. 600,000 ampere hours with an electro-motive force of 3.5 volts, or 2,100 units, will decom- pose one ton of salt per hour, with ample allowance for contin- gencies. As there is no special outlay for generating plant, there is no need — except for book-keeping purposes — to charge interest on that. The only extra outlay for generation current is for the fuel and lubricants consumed, firemen's wages, and the quota for maintenance. With good engines and anything like a favorable price for fuel this should not cost more than J4d. per unit, or 43s. 9d. per ton of salt decomposed. With proper arrangements it can be done for less, but I give this as 56 ELECTROLYSIS. the highest cost that can be quoted where fairly good engines are used, and the other conditions are not exceptional. Where good effective heat engines are used, one horse-power can be obtained by the consumption of i pound of coal or even less per hour. Allowing lo per cent, for moisture and impurities in the salt, and for the salt remaining undecomposed in the alkali, the salt costing 12s. per ton, the cost of one ton of pure salt actually decomposed is 13s. 3d. One ton more fuel to produce steam and concentrate soda liquor is ample. "The alkali would make 44 cwt. of soda crystals, for which there is always a local market. If sold at j^d. per pound, or say 2s. per cwt., the value is £4 8s. The account for power and material is : Motive power £2 39 Salt o 13 3 One ton small coal o 80 : ^350 "Soda crystals sold, £4 8s, or a margin of 23s. to pay for labour, and interest, and maintenance of electrolytic plant. What this would amount to depends on the scale upon which the work is done. With a small installation, the above margin would be exceeded, while with a large one, such as one might expect to be erected for the sewage flowing to Barking Creek, the chlorin should cost less than nothing. "The chlorin from one ton of salt weighs 12 cwt., and in oxidizing or disinfecting power is equal to 33 cwt. of bleaching powder, which at present prices would cost £11 at makers' works. "The problem of sewage utilisation becomes considerably simplified when chlorin can be obtained at a practicable price. The perfect sterilisation of sewage gets rid of the danger of zymotic infection amongst the animals fed on the products raised from sewage manures, whether in the liquid or precipi- tated form. Chlorin also affords the means of getting rid of those disgusting smells which render sewage farms so undesir- able in vicinity of human habitation. The utilisation of sewage is a problem that somebody must solve some day. We cannot go on for ever throwing the elements of nutrition into the sea, and converting our watercourses into open sewers. Sewage is ELECTROLYSIS. 57 not pleasant either to smell or look at, but we must remember that it contains the elements of all nutriment. It is only a ques- tion of re-arranging its molecules to convert it into strawberries and cream. It was once thought to be a fine piece of sarcasm to charge one's political opponents with having a 'policy of sewage.' My opinion is that those who thoroughly solve the sewage problem will have done more for their country and their race than has been done by all the party politicians that have ever existed. "The distribution of the chlorin to the different parts of the district to be served is a matter that may be left to the engineer, and I will only state that as a general rule the bulk of the chlorin will be required at a point between the general confluence of the great mass of sewers and the final out fall. In the event of its being needed in or near centres of infection, it is a simple mat- ter to compress the gas into the fluid state, which only requires about four atmospheres of pressure. In this form it can be delivered at any desired point. Again, it may be converted into ordinary bleaching powder or into bleaching liquor, for spread- ing upon the ground, or in other cases where free chlorin is not desirable. In the gaseous state it is an immediate and effective exterminator of rats and other vermin by introduction into their underground runs. "In conclusion, I may point out another method by which the now unused day power may be employed and some profit made for the reduction of rates and taxes. Many users of bleaching powder, such as paper-makers, bleachers, etc., have their works, at or near towns, lighted by electricity. A good profit could be made by supplying bleaching liquor or bleaching powder and alkali for local use. The most costly part of the plant is already erected, but doing nothing for more than half its time, and it is well worth the expenditure of a little ingenuity to try to find a profitable use for it, more especially if a few factors of the 'unemployed problem' could be solved at the same time." 58 ESSENTIAL OILS. ESSENTIAL OILS. Some of the essential oils tested by Koch^ were found to have a marked antiseptic action, differing much in degree. While it required 1:5,000 of oil of cloves to check the development of anthrax bacilli, 1:33,000 of oil of peppermint, or 1:75,000 of turpentine-oil, sufficed to show a restraining influence. Oil of cinnamon, according to Behring,^ is about three times- as potent a germicide in blood serum or bouillon as carbolic acid. Thymol and eucalyptol are about four times weaker than car- bolic acid. The germicide qualities of the vapor arising from the essential oils were investigated by Omeltschenko,^ of Kiev. His con- clusions are, in part, as follows : Among the essential oils investigated by him, oil of cinnamon stands first in its germicide power, and after it in the order of their antiseptic action, are oil of fennel, lavender, cloves, thyme, peppermint, anise, eucalyptus globulus, etc. Bacteria in a dried condition are destroyed less rapidly than when in a normal condition. Anthrax spores were not destroyed by the action of these oils, but their vitality was distinctly weakened. The protoplasm of bacteria suffers a chemical change while under the action of the vapors of these oils so that its capability of taking anilin stains is lessened or destroyed, and the degree of the loss of its staining may be taken as an indication of the bactericide influence of the vapor. The popular use of the vapor of these essential oils has a rational basis. Onimus* determined that the oxidation products formed when solutions of essential oils in alcohol, particularly of oil of thyme, are passed over glowing platinum sponge, are capable of destroy- ing the bacillus of tuberculosis. It is, however, doubtful whether the essential oils as such had anything to do with the germicide action observed in the experiments of Onimus. It was more likely due to products analagous to formaldehyde, or possibly to ozonization. 1. Mlttlieil. a. cl. Kais. Ges. I., 271. 1881. 2. Zelt. fur Hygiene, IX., i28. 1890. 3. Centr. fur Bak., IS., 813. 1891. i. Le Bui. Med., 1890.— Centr. fur Bak., IX., 739. 1891. EUCALINE EXCRETA. eg EUCALINE. This is an American preparation for sale by Theodore Met- calf Co., which that firm claims is the best of the common dis- infectants. One gallon with loo gallons of water gives a mix- ture for large usage, and one teaspoonful to the pint of water is the usual domestic mixture employed. It is stated with regard to its chemical composition, that it is a residue of a number of manufacturing operations in which benzol and some of the coal- tar products are produced. It contains naphthalin, hydro- naphthol, resorcin, and beta-naphthol. I do not know that its germicidal capabilities have been determined. EXCRETA. The disinfection of excreta may be considered under two headings : Fresh Excreta, or Its Disinfection in the Sick-Room. — It is too often forgotten that time is an important element in disin- fection, but for fresh excreta, disinfecting agents should be chosen that do not require too much time. Another important consideration is that the disinfecting solution must be brought into intimate relation with the masses and particles of fecal mat- ter by stirring or otherwise. The 5 per cent, carbolic acid solution is widely used for the disinfection of excreta, and should, undoubtedly, be considered efficient. The preponderance of opinion among investigators, however, seems to be that some of the other coal-tar prepara- tions, — lysol, cresol, solutol — are more rapidly effective. Lime-wash, or milk of lime has been much used lately for the disinfection of excreta, but it is apparently less rapid in its action than chlorid of lime, carbolic acid, lysol, and some of the other preparations of cresol. Chlorid of lime, as determined by Nissen, destroys typhoid and cholera germs in stools much more rapidly than does caustic lime. The work of Sternberg and that of Vincent corroborate that of Nissen. On the other hand, Richard and Chantemesse found that 20 per cent, milk of lime, as recommended by Pfuhl, destroyed typhoid bacillus in stools in half an hour, while an hour was required for their disinfec- tion with a 5 per cent, solution of chlorid of lime. ■tlO EXCRETA. Vincent, Schottelieus, Pohl, and others have found lysol superior to carboUc acid for the disinfection of excreta. With Vincent cresol was an excellent disinfectant for fecal matter, and also an excellent deodorant. He states that in spite -of its quite active power, it is not one of the best disinfectants for the disinfection of typhoid fever stools, but the spirillum of •cholera is very easily killed with cresol. The investigations of Buttersack, Hueppe, Heider, and others indicate that solutol is a very suitable disinfectant for the rapid disinfection of excreta. Some of the authors state that it pene- trates into the interior of organic matter more rapidly than lysol and carbolic acid, and is more rapid in its action. It is also a good deodorant. Sternberg, Gerloczy, and Vincent recommend very highly solutions of sulphate of copper as very efficient disinfectants for •excreta, but both milk of lime and solution of chlorid of lime are cheaper, and the latter probably acts with greater rapidity. The conclusion of most investigators has been that mercuric •chlorid is unsuitable for the disinfection of excreta. Foote found that the simple solution of mercuric chlorid was ineffi- cient, but with the addition of sodium chlorid, it was the most efficient disinfectant tested by him. Ufifelmann also, while find- ing the simple solution inefficient, found that a i :500 solution with hydrochloric acid destroyed, with certainty, all germs in twenty-four hours. The results obtained by various investiga- tors in the application of corrosive sublimate to the disinfection of excreta are too discrepant to encourage its use for that pur- pose. Gerloczy, while recommending sulphate of copper highly for the disinfection of excreta, says that a still more efficient method for the rapid disinfection of stools in the sick-room, is pouring over them three times their bulk of hot lye, — one part of ashes to two of water. Wilchur^ states that a sure method of disinfecting cholera stools is pouring upon them four times their bulk of boiling water. For the disinfection of stools in the sick-room generally, it appears that we may safely advise a 5 per cent, solution of carbolic acid, a 3 per cent, solution of lysol or solutol, the 5 per 1. Sanitary Se-ws, Xri., S EXCRETA FERRIC SULPHATE. 6l cent, solution of chlorid of lime, or the 20 per cent, milk of lime. When either of the two last is used, its quantity should be largely in excess of the bulk of the stool, and ample time should be given for the action of the disinfectant. Ascoli is authority for the statement that solutions of formal- dehyde act readily and efficiently in the disinfection of fecal matter, and Walter corroborates this. Both of these experi- menters, as well as others, vouch for its rapid deodorizing action. Excreta in Bulk. — For the disinfection of excreta in bulk, a& in privy vaults, milk of lime prepared as described under "Lime," or chlorid of lime, preferably in solution, are to be recommended for their cheapness as well as for their efficiency when used in liberal quantities. The disinfection of excreta in bulk with the phenols is too costly ; the experiments with saprol, however, indicate that privy vaults of tight construction may be successfully disinfected with it, and this preparation is said to be cheap. Creolin, Little's soluble phenyle, lysol, saprol, solutol, and crude Carbolic acid are all good deodorants. Pulverized peat has been much used in the countries of Europe, as an application to excreta in vaults ; but, alone, it has no trustworthy disinfecting properties. FERRIC SULPHATE. In a recent paper on the value of ferric sulphate as a disin- fectant Riecke^ used a fine, dirty-white powder which, according to the manufacturers, contains about 70 per cent, of ferric sul- phate readily soluble in water, a few per cent, of ferrous sul- phate, and from 4 to 5 per cent, of free sulphuric acid. He says that it is probable that its germicidal properties are due to both the free sulphuric acid and to the metal combination. He cites the results obtained by various experimenters as an indication of the germicidal action of the several constituents of the salt. According to Koch, anthrax spores were killed in from ten to twenty days when exposed to i per cent, of sul- phuric acid. Kitasato found that the growth of typhoid bacillus was inhibited with 0.057 per cent., and from 0.073 to 0.08 per 1. Zelt. tur Hygiene, XXIV., 303. 1897. 62 FERRIC SULPHATE FERROUS SULPHATE. cent, destroyed it. The results obtained by Koch with chlorid of iron and the common sulphate of iron were unfavorable. Fromme found that metallic iron, at the instant of oxidation, has a marked germicidal action. Loffler found chlorid of iron to be an efficient disinfectant for the bacillus of diphtheria, and made it a constituent of the preparation for his local treatment. The experiments of Riecke indicate that typhoid cultures in bouillon were sterilized in one minute with 5 per cent, of ferric sulphate. A 5 per cent, solution of ferric sulphate added in equal quantities to typhoid bacillus and to cholera bacillus in acid urine, in alkaline urine, in acid feces, in alkaline feces, in acid mixture of urine and feces, invariably destroyed typhoid and cholera germs in one minute. The period of observation was from eight to twenty-one days, and controls were used in all cases. These germs are thus killed with certainty with a 2.5 per cent, solution in one minute. He states that it is also a good deodorant. He learned, also, that ferric sulphate is better than acids as an addition to pulverized peat. The price of ferric sulphate, he states, is, in Germany, 5 M. per 100 kilograms. FERROUS SULPHATE (SULPHATE OF IRON.) Sulphate of iron was formerly much used as a disinfectant, but its germicidal action is now known to be very slight indeed. Sternberg^ found that a saturated solution failed to destroy the growing power of any of the test-organisms. In Koch's^ exper- iments, anthrax spores remained in a 5 per cent, solution six days without harm. Applied to the disinfection of excreta, Vincent^ found that even when the mixture is 200 or 300 to 1,000, sulphate of iron fails to accomplish only a very incomplete disinfection of the material, even after forty-three hours. He ranks it below all other disinfectants tested by him. As a deodorant, sulphate of iron is still recommended by some persons who concede its worthlessness as a disinfectant. But Foote* states that, in his experiments, it showed itself totally 1. Tr. Amer. Public Health Aasoc, XI., 225. 1885. 2. Mitthell. a. d. Kais. Ge3., I., 234. 1881. 3. Annales de I'Inst. Past., IX., 9. 1895. i. Amer. Jr. Med. Sciences, XCVIII., 329. 1889. FERROUS SULPHATE. 63 inefficient, botii as a disinfectant, and as a deodorizer, and that there is no rational basis for its use for these purposes. He further says that it developed an odor considerably more dis- agreeable than that of the mixture of feces with sterilized water, and that the odor did not lessen in any appreciable degree in seventy-two hours when the flask was emptied. RideaP speaks of some of the undesirable qualities of sulphate of iron when used as a deodorant : "Virchow has pointed out one of the inconveniences of iron salts. The volatile fatty acids, butyric, valeric, etc., which cause a part of the offensive odor of putrefaction, are commonly com- bined with ammonia. When iron salts are added, the fatty acids are set free or turned into unstable iron compounds, so that the immediate effect of the projection of sulphate of iron into latrines is often an augmentation of the feior; this soon decreases, but usually reappears after a time. The same result would accrue on adding almost any acid or acid salt, and thus, as well as for other reasons, it is necessary to supplement the use of an acid or treatment with an iron salt by lime. Lake proposes iron salt, then lime, then filter; Lockwood, iron salt, then hot milk of lime. "Deposits of sulphide of iron in sewers may be a source of danger, since they are liable to produce sulphuretted hydrogen on the influx of any acid liquid. An oxidizing disinfectant like chlorin would, however, convert it into a sulphate and allow of its removal. All reducing disinfectants are open to the follow- ing objections: (i.) they permit the reduced organic matters to be oxidized again by the air; (2.) they are themselves in great part at first wasted by the free oxygen of the air and the water; (3.) unless kept out of contact with air they lose strength more or less rapidly by absorbing oxygen; (4.) the anaerobic bacteria are mostly reducing in their action and flourish readily in surroundings deprived of oxygen, whereas free oxygen is capable itself of killing them and destroying their food." Occasional reference to Rabot's method is noticed, which is recommended for the disinfection and deodorization of sewers, or mud, or ooze. (See Mud). It consists in the use of 500 grams of sulphate of iron followed by i kilogram of caustic lime, to each cubic metre of material to be treated. 1. Disinfection and Disinfectants, p. 118. 1896. London. 64 FLOORS. FLOORS. While under "Walls" it is stated that in typhoid fever the possibility of their infection is very slight, it may be assumed that the floors are infected. After all cases of infectious dis- eases, efficient methods of disinfecting the floors of the sick- room are required. It should be remembered that infection con- sists of particulate matter, vi^hich, like all matter, obeys the law of gravitation. The floor is, of course, the most extended hori- zontal surface in the room and receives a large part of the infec- tious dust or other matter. In disinfection processes, the cracks in the floors should receive especial attention, as recurr- ing cases in outbreaks of infectious diseases have been traced to neglect of this injunction. A rule of the Department of Health of Chicago is that floors of sick-rooms shall not be dry-swept. They must first be sprinkled thoroughly with tea leaves or sawdust wet with a strong disinfectant; the sweepings being burned immediately. They should then be wiped with a cloth wrung out of the disin- fecting solution. The recommendations of the Paris Commis- sion^ are that floors shall be washed with a solution of corrosive sublimate. If there is a carpet, it shall be cleansed with a brush dipped in the same solution. The practice in Berlin, according to Behring,^ is that floors shall have two washings in a 5 per cent, solution of carbolic acid, and if they are very dirty they shall be scrubbed with hot soap and water. Professor Loffler^ prefers sublimate to carbolic acid, and regrets that it is not used more. The danger from the former is very slight, and the smell of the latter lasts for weeks and is- very unpleasant to many persons. He even thinks that the trace of mercuric chlorid left in the air of a room may be prophylactic, and relates a corroborative experiment. Rosenberg recommends the thorough washing of floors with a solution of 100 cc. of holzin to ten litres of water before the formaldehyde apparatus is set in operation. His idea is that the liquid disinfecting solution softens any germs that may be present, for instance, those of tuberculous sputum, and thus facilitates their destruction with the gas. 1. Eevae D'Hygiene, XVIII., 968. 1896. 2. Bekampfung der Inf ectlonskrankheiten, I., 428. 1894. 3. Deutsche Viert. fiir off. Ges., XXIII., 149. 1891. FLOORS FORMALDEHYDE. 65 For floors which would not be injured by alkaline applications, a 3 or 4 per cent, solution of lysol would be an efficient wash ; for floors in natural finish, spraying or washing with a formal- dehyde solution would constitute an unobjectionable and prob- ably efficient method. There should be no carpet upon the floor of the infectious sick-room. If, however, there has been one, it should be disin- fected by steam, if practicable. Formaldehyde cannot be con- sidered an entirely trustworthy agent for the disinfection of carpets in place. Stood in loose rolls in a small cabinet or dis- infecting chamber, with impermeable walls, formaldehyde would, undoubtedly, prove efficient. Carpets that have been upon the floor of the sick-room of consumptives would better be burned by the owner when steam disinfecton is not available. Carpets were completely sterilized by Stahl by spraying them with a 5 per cent, and 2 per cent, solution of formalin, and main- taining the exposure to the vapor from fifteen to thirty minutes.'- In Paris carpets are taken up and sprayed plentifully on both sides with a i : 500 solution of mercuric chlorid.^ FORMALDEHYDE. About six years ago the interest of the compiler of these notes was temporarily aroused by occasional journalistic references to formalin as a disinfectant, but an adverse report came to hand some time afterward which indicated that its germicidal efficacy had been overrated. The appearance in a French journal of 1895, of a notable paper by Cambier and Brochet^ and another by Trillat* on the disinfection of rooms with formaldehyde gas, showed very clearly that this agent possesses disinfecting capa- bilities which deserved further study. At the Denver meeting of the American Public Health Association in the same year, in a discussion on railway hygiene. Dr. J. J. Kinyoun referred to experiments which had been begun in the bacteriological labora- tory of the Marine Hospital Service. The experiments, so far 1. Quoted from Walter. Zeit. tiir Hygiene, XXI., 476. 2. Annales de Mlcrographle, VIII., 285. 1896. 3. Revue D'Hj'glene, XVII., 120. 1895. i. lb., XVII., 7U. 1895. 66 FORMALDEHYDE. as they had then been carried, indicated that formaldehyde gas would prove to be a valuable agent for the disinfection of cars, rooms, etc. At that time the price of formalin, or solution of formaldehyde, was prohibitive of its general use as a source of formaldehyde gas, and no lamps or other apparatus were avail- able for its generation directly from methyl alcohol. In the autumn of 1895, Professor F. C. Robinson was requested by the State Board of Health of Maine to undertake an extended series of experiments for the purpose of determining the real value of formaldehyde in practical disinfection, and to devise, if practicable, a lamp capable of evolving large quantities of the gas in a short space of time. Many preliminary trials were made with lamps modeled after those which had been used by European investigators, — with incandescent cylinders or spiral coils of platinum or other material. The quantities of formal- dehyde delivered by any of the lamps of this type were found to be wholly inadequate in the disinfection of rooms. The platin- ization of asbestos and perforated horizontal disks of that mate- rial for the incandescent surface was a happy thought which made it practicable to generate formaldehyde gas rapidly and in large quantities and to popularize its application to the disin- fection of rooms. Germicidal and Antiseptic Value. — Many of the earlier exper- iments with formaldehyde were made with lamps that furnished comparatively small quantities of the gas. The later workers have, however, almost unanimously fixed the fact that formal- dehyde has remarkable disinfectant and antiseptic powers. The only questions at present are the methods of using and the limi- tations of this process. According to Blum,^ formaldehyde, even when strongly con- centrated, acts only slowly in destroying the vitality of micro- organisms. Weak solutions, however, suffice to prevent fer- mentation with gradual destruction of the bacteria. Vander- linder and Burk's^ experiments convinced them that a 5 per cent, solution of formalin (2 per cent, of formaldehyde") has no very pronounced action on bacillus typhosus, B. coli, strep- tococci, and staphylococcus. Strehl,' in his experiments, found 1. Munchener Med. Wooh.— Cetitr. fur Bak., XIV., 503. 1893. 3. Arch, cle Med. Experim., VII., 76. 1895. 3. Centr. fur Bak. XIX., 785. 1895. FORMALDEHYDE. 6/ that 50 cc. of Schering's formalin in a tight chest of one fourth cubic metre capacity did not suffice to sterilize silken threads with anthrax spores and staphylococcus in twenty-four hours at 20° C. These results are the only positively unfavorable ones which have been found in an examination of the work of fifty or more investigators. The results of the experiments of Philippe in the sterilization of the dust in dusty rooms, have assured him that formaldehyde vapor by far exceeds in value all other gaseous disinfecting agents. Formaldehyde, according to Aronson,^ when added in the proportion of i part to 20,000 of bouillon which contained an abundance of typhoid bacilli, preserved it in a sterile condi- tion. The action upon Staphylococcus pyogenes aureus was almost exactly the same. In his experiments, Ascoli^ used bits of blotting paper previously sterilized and then impregnated with an emulsion of the bacteria. Precautions were taken against carrying over traces of the antiseptic agent, and the culture tubes were kept under observation at a temperature of 37° C. for at least ten days. With formalin, anthrax bacilli were killed in fifteen minutes with a 10 per cent, solution, and anthrax spores capable of withstanding action of steam at 100° C. twelve minutes, were destroyed in less than five hours with a 10 per cent, solution. With a 5 per cent, solution, diphtheria bacillus was destroyed in ten minutes, anthrax bacillus in fif- teen minutes. Staphylococcus aureus in thirty minutes, and anthrax spores in five hours. In his experiments with i part of formaldehyde gas in 100 parts of air, pneumococcus was killed in fifteen minutes, Staphylococcus aureus in forty-five minutes, and anthrax spores in forty-five minutes. The organisms were confined in flasks of one litre and a half capacity. Lehmann* also found that even anthrax spores were destroyed with form- aldehyde gas, the time of exposure being twenty-four hours. In the opinion of Rosenberg,'^ formaldehyde is tenfold more effi- cient than corrosive sublimate as a disinfectant. Trillat^ says that formaldehyde is the most powerful gaseous disinfectant 1. Munchener Med. Wooh.— Centr. fur Bak., XVII., 499. 1895. 2. Berlin.klin.Woch.— Centr. tui- Bak., XII., 406. 1892. 3. Centr. tiir Bak., XVII., 849. 1895. 4. Munchener Med. Woch.— Giornale della Reale Soc. Ital. D'Ig., XVI., 151. 1894. 5. Zeit. luf Hygiene, XXIV., 488. 1897. 6. La Formaldehyde, p. 127. 1896. 68 FORMALDEHYDE. known. In Slater and Rideal's^ experiments, the growth of vigorous cultures was absolutely inhibited, with most of the bacteria, by i : 20,000 of formaldehyde. Staphylococcus pyogenes aureus, however, required i .-5,000. According to Walter,- a formalin solution of 1:10,000 prevents absolutely the growth of anthrax spores, cholera, typhoid, and diphtheria bacilli, and Staphylococcus pyogenes aureus. He observes that his results concur with those of most other observers, remind- ing them, at the same time, that i : 10,000 formalin solution con- tains one to 25,000 formaldehyde gas. The results of the experimental work, to which reference is made under other subheadings, make a more extended presenta- tion of this question unnecessary here. Besides its antiseptic and disinfectant properties, formalde- hyde appears to be an efficient deodorant. Trillat states that it is possessed of great deodorizing powers. Aronson^ says that formaldehyde combines readily with nearly all ill-smelling com- pounds, as hydrogen-sulphid, mercaptan, and ammonia, form- ing others that are non-offensive. Ascoli reports that formal- dehyde has the advantage of being an energetic deodorizing agent. It does not merely cover smell, but really destroys it. His experiments indicate to him that solutions of formalin may be trusted to disinfect the discharges from cholera and typlioid cases. Walter* states also that fecal matter is almost instantaneously deodorized with i per cent, of formalin, and is sterilized in ten minutes with 10 per cent, solutions. Available Sources. — One of the sources of fcirmic aldehyde, or formaldehyde gas, is "formalin,"' a 40 per cent, aqueous solu- tion put up by a German firm, but which may more economically be bought under the name of Solution of Formaldehyde as it is put up in this country. To prevent polymerization when this solution is evaporated, Trillat adds to it a solution of calcium chlorid and gives the mixture the name of "formochloral." A second method of obtaining the gas has been by the oxidization of wood spirit or methyl-alcohol by passing it over glowing platinum or other suitable metallic surfaces. The name "holzin" 1. Lancet, I., 1894, 1004. 2. Zelt. fur Hygiene, XXI., 421. 1S96. 3. Zelt. £Ur Hygiene, XXV., 168. 1897. 4. Zeit. fur Hygiene, XXL, 148. ISPn. FORMALDEHYDE. 69 has been given by Oppermann to a 60 per cent, solution of form- aldehyde in methyl-alcohol. Adding to this solution a small quantity of menthol to lessen its irritating quality, Rosenberg^ calls it "holzinol." Another source is formaldehyde in its solid form, — trioxymethylin, paraformaldehyde, or polymerized form- • aldehyde. A trade name is "paraform." Formaldehyde Generators. — In the evaporation of the solution of formaldehyde in the ordinary ways, there is a considerable loss due to polymerization. A residue consisting of formalde- hyde in its solid, or polymerized form, is left. The French investigators sought to prevent this by adding a solution of cal- cium chlorid to the formaldehyde solution. Trillat invented an apparatus which he calls an autoclave for the vaporization of this formochloral, as he calls the solution of formaldehyde with calcium chlorid. It is supplied with a set of valves which auto- matically let the formaldehyde vapor escape when the pressure in its interior has reached that of three or three and one half atmospheres. The gas is conducted into the room from the autoclave by means of a small brass pipe which usually enters the room through a keyhole. The disadvantages of this appara- tus and others patterned after it are: first, its high cost; second, some danger of explosion due to the non-working of the valves, or the corrosion and obstruction of the metal pipe which conducts the gas into the room ; and, third, the want of uniform- ity in the quantity of gas delivered in a given time. This last objection was shown very plainly by the experiments of Professor Robinson^ with a generator patterned after the French apparatus. The apparatus in each test was run one hour with the following results : first, 500 cc. per hour ; second, 320 cc. ; third, 380 cc. ; fourth, 130 cc. ; fifth, 350 cc. The sixth experi- ment was interrupted after the apparatus had been running one half hour, when it was found that, practically, no formal- dehyde had been injected into the room. The advantages claimed for the autoclave and similar kinds of apparatus are that they can be placed outside of the room to be disinfected so as to be under the continual observation of the attendant. It has been found, however, that Trillat's method is more complicated and the apparatus more costly than is required. 1. Deutsche Med. Wocb., XXII., 626. 1896. 2. Tenth Ept. St. Btl. of Health of Maine, p. 156. It98. 70 FORMALDEHYDE. The addition of calcic chlorid or other salts which necessitates a subsequent troublesome cleaning out, and the system of valves and the subjection of the vapor to a pressure are all unneces- sary.i Under a sufficiently high degree of heat, the polymerized product is revaporized in the evaporation of the simple aqueous solution of formaldehyde. Though not uniformily successful in their workings, the results obtained with the various genera- tors of this type have been remarkably favorable in the hands of many investigators. (See Formaldehyde, Disinfection of Rooms.) In his experiments for the State Board of Health of Michigan, Dr. Novy^ found that the polymerization of formalin while undergoing distillation is largely a myth. If rapidly distilled, polymerization rarely occurs. The apparatus which he used was of a very simple kind, consisting of a copper tank shaped like an ordinary tin can. From this neck a small tube in two sections, connected by a short piece of rubber tubing, passes through a keyhole into the room to be disinfected. A funnel topped supply-tube at one side extends to near the bottom of the container. It may be heated with a Bunsen-burner, a gas or gasoline stove, or a kerosene burner. The doctor tells us that the formalin should be boiled as rapidly as possible. A good Bunsen-burner will distil five ounces of formalin, the amount necessary for i,ooo cubic feet of space, within ten or fifteen minutes. Should there be a tendency of the formalin to poly- merize, it can be prevented by the addition of five or ten grams of borax. The results obtained in using this apparatus were very favorable; decidedly more so than those which were had with sulphur fumigation, with the same organisms, under the same conditions, and in the same room. An apparatus devised by JJr. Kinyoun^ and used in the Marine Hospital Service consists of a metallic disinfecting chamber to which is attached a vacuum apparatus, a small boiler in which formaldehyde is generated by volatilization from a mixture of formalin and calcium chlorid, and a second sm»all boiler from which ammonia is turned into the disinfecting chamber by the evaporation of ammonia water. The ammonia 1. Tenth Bpt. St. Bd. o£ Health of Maine, p. 156. 1S9S. 2. Med. News, LXXII., 641. 1898. 8. Pub. Health Reports, M.H.S., XII., 100. 1S97. FORMALDEHYDE. ^j is used for the purpose of neutralizing the formaldehyde in the goods after the prescribed period of exposure. Among the lamps that have been devised for the production of formaldehyde by the oxidation of methyl-alcohol, I think it is safe to say that those in which flat platinized asbestos disks of considerable area are used are the only ones that produce large enough quantities of formaldehyde for the disinfection of rooms, and that, at the same time, are sufficiently simple and economical in construction for general use. Professor Robin- son's^ experiments indicate that the double Bowdoin Generator and the better class of generators which produce formaldehyde from its solution are of about equal efficiency. Dr. Dbty,^ Health Officer of the Port of New York, after making com- parative tests of various kinds of apparatus for the production of formaldehyde from formalin, from wood alcohol, and from paraform tablets, says that the Robinson lamp is also an effective method, as his experiments will prove. He adds that the lamp can be purchased for a comparatively small sum, is easily manu- factured, and is very satisfactory for house disinfection. The lamps for the revolatilization of paraform, or formalde- hyde in its solid form, are convenient for the production of small quantities of formaldehyde, as, for instance, for its con- tinuous antiseptic effect in the sick-room, ®r for the disinfection of small spaces. The prevailing high price of paraform is prohibitive of its use in general disinfection. The trade circular states that each one gram tablet of paraform contains one gram of formaldehyde gas. The experiments of Aronson^ indicate that it is practicable to disinfect rooms with paraform. He claims that one tablet suffices for the disinfection of each cubic metre of room space. He cites the fact that, in this method, the danger of explosion which accompanies the use of Trillat's autoclave is not present. Rosenberg* claims that holzin, a solution of formaldehyde in methyl-alcohol, is more efficient than formalin. For the vapor- ization of holzin a small apparatus is used which is not described. 1. Tenth Ept. St. Bci. of Health oj Maine, p. 153. 2. New York Med. Jr. LXVI., 517. 1897. 3. Zelt. fur Hygiene, XXV., 168. 1897. 4. Deutsche Med. Wooh., XXII., 626. 1896. 72 FORMALDEHYDE. Temperature. — The higher the temperature in rooms sub- jected to formaldehyde disinfection, say Abba and Rondelli/ the greater the disinfecting power of the formaldehyde. In the summer months, when the rooms are warm and dry, disinfec- tion with formaldehyde is more rapid and certain. The experi- ments of Dr. Wilson^ prove to him that temperature exercises a marked effect on disinfection with formaldehyde. In one experiment in which the temperature of the disinfecting cham- ber was low, sterilization failed to occur, although a large per- centage of gas was used. The same fact was also observed by Trillat,^ and he lays down the rule that disinfection is more efHcient if the rooms are previously warmed. Ivanofif* found that elevation of temperature increases the bactericidal activity of formalin. Van Ermengem and Sugg also state that formal- dehyde is more efficient at higher temperatures. For instance, anthrax spores which were not killed in from three to four hours at 15° C. were destroyed in fifteen minutes when the tem- perature was 37°.^ The experience of Professor Robinson® indicates that the range of temperature between 50° and 80° F. makes but little difference in the action of the gas. In a paper read at the meeting of the Massachusetts Medical Society, Dr. David D. Brough' gave the results of his investiga- tions for the Municipal Board of Health of Boston, in the use of formaldehyde in the disinfection of rooms. Referring to the question of the influence of temperature, he says : "Within the range of temperature, such as occurs in ordinary disinfection, the gas seems to act perfectly well. With a low temperature, below 35° F., my results were not so satisfactory, even using large amounts, as with a higher temperature. It would seem that very low temperatures interfere with the action of the gas." Dampness or Dryness. — Abba and Rondelli think that dry- ness of the atmosphere, in rooms subjected to formaldehyde disinfection, is conducive to efficiency in the disinfecting process. Trillat teaches also that disinfection is not so certain in the 1. Zeit. fur Hygiene, XXVII., 49. 1898. 2. BrooklynMecl. Jr., XL, 741. 1897. 3. La rormaldeliyae, p. 88. 1896. 4. Centr. fur Bak., XXlt., 50. 1897. 5. Quoted from Dleuclonne, Arbelten a. d. Kais. Ges., XL, 534. 1895. 6. Tenth Ept. St. Bd. of Health, p. 168. 1898. 7. Formaldehyde Gas as a Disinfectant, p. 14. 189S. FORMALDEHYDE. 70 presence of moisture. The experiments of StrehP lead him to conclude that formaldehyde acts more efficiently upon moist matter than upon dry. In the disinfection of rooms, Professor Robinson^ says that dampness is a disadvantage as it absorbs more or less of the gas and holds the odor in the rooms. Damp test-objects were, however, as easily sterilized as dried ones, but germs in liquids were not killed at any great depth. Novy found that infectious material is much more readily disinfected when it is moist. Even wet spore material is thoroughly disin- fected with formaldehyde, whereas such material is not affected by sulphur. He found that the walls and floor of the room to be disinfected, and whatever articles are present (previously spread out as much as possible) should be sprayed with water before exposure to formaldehyde vapor. Owing to the great solubility of formaldehyde, large vessels of water should not be kept in the room to be disinfected. When water is thus kept in the room, scarcely any odor of formalin will remain at the end of twenty hours, whereas, in the absence of such water, the odor at the end of the time mentioned will be intolerable. Dr. Brough finds that "the gas acts equally well on both wet and, dry cultures. This was my experience with silk threads and squares of gauze. Organisms growing in bouillon exposed in Petri dishes could not be killed." Action on Colors, Fabrics, Metals, Etc. — Experiments were made by Dr. Kinyoun'' by subjecting samples of wool, cotton, fur, and leather goods of every description to crucial tests, using solutions of various strengths and a saturated atmosphere of the gas. The results obtained were in every way satisfactory. Of over 225 different samples of wool, silk, cotton, linen, leather, and hair subjected, there was no change observed in textile char- acter, even when they were soaked in a strong solution of the gas. Little, if any change occurred in the colors of the fabrics ; only three of the number showed any change. These were two shades of violet and one of light red. These were coal-tar colors, and were also quickly bleached by the sun. Iron and steel are attacked by the gas, and more so by its solutions. Copper, brass, nickel, zinc, and gilt work are not acted upon. 1. Centr. JUr Bak., XIX., 785. 1896. 2. Ninth Report State Board of Health of Maine, p. 180. 18%. 3. Pub. Health Reports, M. H. S,, XII., 93. 1897. 74 FORMALDEHYDK. The experiments of Professor Robinson indicate that dry formaldehyde gas does not affect polished steel. Dr. Reik/ referring to the question whether or not the cutting edge of instruments is dulled when they are subjected to formaldehyde disinfection, says that Drs. Schweinitz and Burnett, of Wash- ington, state that, from the use both of the gas and of the liquid formalin, there has been no influence whatever upon the sharp- ness of the instruments. In a subsequent paper by Dr. Reik, detailing the experiments performed by himself and Dr. Watson for the purpose of determining the action of formaldehyde gas upon the cutting edge of instruments, he says : "As to the question regarding the edges of the knives, I tested very carefully their sharpness by means of the kid drum, both before and after sterilization, and I am not able to discover that the gas affects this in any way. To see whether or not the gas would affect instruments made of other material than steel, I repeatedly exposed the following instruments to the action of the gas; knives with aluminum handles, knives with ivory handles, a hard rubber syringe, soft rubber catheters, a Politzer air bag, and a nickel-plated syringe. None of these objects were in any .way affected by the gas." Formaldehyde gas, say Abba and Rondelli, is injurious to neither clothing, furs, paper, photographs, leather, india-rubber, woodwork, nor metals. It affects colors in nowise, with the exception of a few anilin colors which suffer a uniform change of color. The same is true of the colors of fresh flowers. It would appear from the testimony of recent experimenters in the disinfection of instruments with formaldehyde that this gas in its dry form, as it may be obtained from paraform, has but little, if any action upon steel instruments, and it is likely that the action of formaldehyde upon steel and iron, observed by Dr. Kinyoun, is due to the simultaneous presence of watery vapor which comes over with formaldehyde gas in the ordinary methods of its production. Fixation of Stains. — The observations of Rondelli^ show that formaldehyde gas fixes blood and pus stains so that they are not removable when subsequently washed. Fecal stains are also fixed, but in a slighter degree. This fact should be borne in mind in practical disinfecting work. 1. Bui. Jolins Hopkins Hospital, VIII., 26:. 1897. 2. Giornale della Eeale Soc. It. a'Ig., XIS., 510. 1897. FORMALDEHYDE. nc Toxicity. — Formaldehyde, when compared with sulphur diox- id, chlorin, and the other gaseous disinfectants, is very free from poisonous qualities. This idea is supported by a con- sensus of opinion among those who have sought to determine, this point experimentally. Aronson^ found that the inhalation of formaldehyde vapor is borne very well by animals. Guinea- pigs and rabbits left in rooms overnight during disinfection were found well and lively in the morning. After killing the animals, section showed in no case, as might be expected, evi- dences of serious irritation of the bronchial mucosa. Trillat^ states that formaldehyde is toxic only after inhalation many hours. Fairbanks,^ of Boston, while carrying on his experi- ments in Charlottenberg, shut mice and rabbits in the experi- mental room where they were left overnight exposed to form- aldehyde vapor. There were no injurious efFects and, particu- larly, no conjunctivitis. Referring to the question of toxicity. Dr. Charles Harrington* says that the results produced by the gas on the two rabbits used in his experiments were sufficiently certain to demonstrate the falsity of the theory that formaldehyde exerts no deleterious action on higher organisms and to render further experiments on his part in this direction unnecessary. "The experience of several others who are daily engaged in the work of house dis- infection, has shown that animals, such as cats and dogs, which have accidentally been confined in rooms undergoing formalde- hyde disinfection, rarely survive the operation when the latter is properly carried out." As to the influence of formaldehyde on animal life. Dr. Brough^ says : "Our opportunities for observation in this line have been limited. Dogs and cats which have been left in rooms were found killed. Flies were invaribly found dead. Bed bugs, which were exposed to the direct action of the gas, were likewise killed." While formaldehyde gas is irritating to the eyes and nose, the general testimony of those who have worked with it and have 1. Zeit. tur Hygiene, XXV., 168. 1897. 2. La rormaldehyde, p. 31. 1896. 3. Centr. fur Bak., XXIII., 20. 1S98. 4. Amr. Jr. Med. Sciences, CXV., 69. 1898. 5. Op. cit., p. 6. 76 FORMALDEHYDE. been much subjected to its influence is that no permanent ill results follow ordinary exposures to it. Disadvantages after Disinfection. — After the disinfection of rooms with formaldehyde, no poisonous substance remains, the odor is comparatively transient and but slightly disagreeable. A temporary airing renders the rooms habitable again. In a schoolhouse, which was disinfected with formaldehyde gas over- night and in which the fumes were very strong in the morning, the windows were thrown open for a while and the regular ses- sions of the school were held with but little trouble. Clothing, however, which has been subjected to disinfection with formaldehyde retains for some time quantities of irritating gas which renders it unfit for wearing until after it has been thoroughly aired for several days. But the vapor of formalin which remains in rooms or in clothing can be neutralized with ammonia. The Disinfection of Rooms. — Before formaldehyde generators were devised, capable of rapidly producing large quantities of the gas, doubts were expressed as to the practicability of suc- cessfully disinfecting spaces of large cubic capacity. The work of Trillat, however, did much to remove these doubts. Some of his experiments were made with an apparatus for the conversion of wood alcohol into formaldehyde : in others, he used his autoclave for the volatilization of formalin to which calcium chlorid had been added. In one experiment, the disinfection of several rooms with a capacity of 13,135 cubic feet, five litres of alcohol were burned. The temperature of rooms, 12° C. ; time of exposure of bacteria in the rooms, two to seven hours. Six animals inoculated with the test cultures of anthrax, diphtheria, and tuberculosis; none succumbed. The two inoculated with tuberculosis were killed in six weeks and found to be healthy.^ Other experiments were made with a series of seven rooms, on two different floors, connected by a stairway. Air space, 11,105 cubic feet; alcohol burned, six litres; time of exposure, nine hours ; temperature of rooms, 16° C. ; anthrax bacilli used as tests, no growth in twenty days ; three animals inoculated, all remained well. The same experiment was repeated with the 1. La Formalfleliycle, p. 83, 1S96. FORMALDEHYDE. 77 same cultures, and with the same results. Of the three animals inoculated, none were affected.^. In the experiments of Trillat and Roux for the city of Lyon, two connected halls, a large and a small one, with a combined capacity of 49,700 cubic feet, were disinfected. The tempera- ture of the rooms ranged from 4° to 10° C. Infected objects; paper, linen, wood, etc. ; germs ; pyocyaneus, pyogenes, anthrax spores, prodigiosus, coli ; autoclave placed outside the rooms ; in operation five hours; formaldehyde used, nine litres; test- objects were in various parts of both halls and at various heights; duration of exposure, thirty-six hours; growth in no culture in two, nor ten, nor thirty days ; sterilization of all these germs was absolute in spite of the dimension of the halls.^ In his report to the Hospital Commission of Montpelier, Dr. Bosc stated that, in one of his experiments, Trillat's autoclave was set up outside of a ward in a contagious disease hospital. This ward was more than 50 feet long, and had open doors lead- ing into two adjoining rooms at the end opposite to that at which the autoclave was placed. The combined air space of the three rooms was more than 26,000 cubic feet. Three litres of formalin were used; autoclave in action, two and one half hours; only the larger openings around the doors and windows were closed. The germs used were Staphylococcus aureus, B. coli, diphtheria, glanders, pyocyaneus, anthrax spores, etc., dried on pieces of linen, placed in various parts of the rooms and at various heights in the large and one of the small rooms ; some, covered ; some, open. At various places, also, dust from the Laboratory of Pathological Anatomy, earth from the courtyard, tuberculous sputum on linen, and mixed with sterilized sand, some dried and some only partially dry, or humid, were placed. Some of the samples were exposed five, others, twenty-four hours. The results were that all pathogenic germs exposed to the gas on pieces of linen, dried or partially dried, and in all parts of both rooms, large and small, were destroyed; the laboratory dust was sterilized, the earth from the pavilion developed only B. subtilis and B. mesentericus. Staphylococcus in the pocket of a coat was killed, but B. coli in the same pocket presented a 1. Op. oil., p. 80. 2. Op. cit., p- 98. 7^ FORMALDEHYDE. scanty growth on the fifth day. Staphylococcus under a pile of clothing, not destroyed ; and B. anthrax in the centre of a mat- tress was not destroyed; Staphylococcus between the layers of a folded mattress, sterile; B. tuberculosis, dried on linen, in sterilized sand, and in fresh sputum on clothing, was killed. The cultures were observed nearly two months; precautions were taken to neutralize the trace of formaldehyde gas.^ In his experiments in the disinfection of rooms, Strtiver^ used various kinds of apparatus for producing formaldehyde. In the disinfection of a room containing 1,252 cubic feet, he used in Moinke's autoclave, which is like Trillat's, 800 cc. of formo- chloral. This contained 200 grams of formaldehyde ; 160 grams of which were liberated. The room remained closed twelve hours. The results were : anthrax spores and typhoid bacilli in a tight closet, not destroyed ; anthrax spores between the seat and the back of an upholstered chair, not destroyed though their vitality was diminished; typhoid bacilli in the same place, and all of the other samples in the room, as well as the dust of the room, were sterilized; a guinea-pig inoculated with tubercle bacilli, remained well. In other experiments, rooms were disinfected by the evapora- tion of holzin. In a room containing 1,959 cubic feet of space, 250 cc. of the solution were used. Typhoid bacilli on linen and anthrax spores on threads were exposed, for twenty-four hours, in all parts of the room ; rinsed in weak ammonia solution ; anthrax spores all grew, typhoid bacilli killed except where cov- ered with several thicknesses of cotton flannel. In another experiment in the same room with fifty cc. of holzin, anthrax spores alone on threads were used. All were sterilized save those which were covered with three or four la}-ers of cotton flannel. For the disinfection of the floors of sick-rooms and of school- houses by washing them in it, Rosenberg'' reconmiends a solu- tion consisting of two tablespoonfuls of holzin to ten litres of water. In another paper, Rosenberg* gives the results of his experi- ments in the disinfection of rooms with holzin. In a small room 1. La Formaldehyde, p. 113. 189fi. 2. Zelt. £ur Hygiene, XXV., 357. 1897. 3. Deutsche Med. Wooh., XXII., 626. 1896. 4. Zeit. fur Hygiene, XXIV., 488. 1897. FORMALDEHYDE. 79 containing 468.7 cubic feet of air space, typlioid, cholera, diph- theria, and anthrax without and with spores, and streptococci were the test-bacteria. These germs were on silken threads, wrapped in blotting paper, and put in pockets of a vest and coat hung over the back of a chair, under coat collar, and in the coat sleeve. One hundred and ten cc. of holzin used ; exposure, one, two, and three hours; all were sterile. Repeated experiments gave the same results. Controls were used. In practical work, Rosenberg has the floors thoroughly- washed with a solution consisting of 100 cc. of holzin to ten litres of water before he sets the apparatus in operation. His object is to soften any germs that may be there, for instance, those in tuberculous sputum. In the experiments of Aronson,^ 200 one-gram tablets of para- form were volatilized in a room of 3,550 cubic feet capacity. The bacteria used were staphylococci, streptococci, B. pyocy- aneus, typhoid bacilli, diphtheria bacilli, anthrax spores, and B. tuberculosis on gauze, threads, etc. The room remained closed twenty-four hours ; most of the samples washed in weak solution of ammonia before transference to culture media or animals; controls the same; all test-objects were completely sterilized, as well as the dust from the floor. In another experiment in the same room only 100 tablets were used ; everything sterilized with the exception that anthrax spores were not with certainty. In the experiments of Gehrke,^ a room containing fifty-three cubic metres of air space was used. Two grams of paraform per cubic metre were used. They were volatilized in about four hours, and the room remained closed twenty-four hours. The test-organisms used were typhoid, diphtheria, anthrax, cholera, staphylococci, and bacillus pyocyaneus on pieces of linen and cotton cloth, and woolen, linen, and silk threads saturated with bouillon cultures of suspensions of agar cultures, some dry and others damp. In the experiments, all of the test-objects were completely sterilized when they were uncovered, with the exception of anthrax spores which were known to have a high power of resistance. A slight covering, however, sufficed to prevent sterilization of these objects. The results obtained by Fairbanks,' however, in the disin- fection of rooms with polymerized formaldehyde vaporized by 1. Zeit. fiir Hygiene, XXV., 168. 1897. 2. Deutaclie Mefl. Woch., XXIV., 242. 3. Centr. fur Bak., XXIII , 20, 1898. 8o FORMALDEHYDE. the action of the hot gases of combustion from a spirit lamp, did not constitute so unquaHfied a success though they may be termed fairly good. The room was rendered as tight as possible by chink- ing the windows and then pasting them. The test-organisms were diphtheria, typhoid fever, pyocyaneus, staphylococcus, and anthrax. The most of the samples infected with these germs were sterilized when freely exposed, but a slight protection sufficed to make their disinfection uncertain. The quantity of polymerized formaldehyde used by Fairbanks was much greater than that which is recommended by the manufacturers of the tablets and the apparatus for volatilizing them. In some of the series of experiments made for the State Board of Health of Maine, the rooms were such as are found in ordi- nary dwelling-houses, and no precautions, such as pasting and sealing, were taken. Test-objects were placed at different dis- tances from the floor where infection would be more likely to occur. But little difference in results was noted whether the objects were on the floor or several feet above it. In a room containing about 3,000 cubic feet of air space and with the period of exposure eleven or twelve hours, disinfection was done with generators using wood alcohol "and with others vaporizing formalin with calcium chlorid. The test-organisms, anthrax spores and diphtheria bacilli, were sterilized when upon cloth or soaked into bits of blanket, but when upon aluminum slips they were not sterilized with certainty. In the disinfection of a schoolhouse, one litre of formalin for each 3,000 cubic feet of air space was used. The test-objects used were bits of blanket saturated with the water from serum cultures of diphtheria, part of them wrapped in packets with two layers of cloth, and others free in Petri dishes and placed about the room. All the free bits of blanket were sterile; of the packets, one was sterile and five not sterile. For the detailed results of other experiments in the disinfection of rooms, see the Ninth Report, and this report, pages 136-160. The experience of Professor Robinson has shown him that, in large rooms, it is impracticable to kill virulent germs when cov- ered with one or two layers of cloth, but that the organisms freely exposed or soaked into the meshes of thick blankets are readily destroyed. In windy weather it was also shown that FORMALDEHYDE. gl disinfection is very difficult on the windward side of the house unless precautions are taken to seal the doors and windows. Formaldehyde, as a gas for disinfecting purposes, may be obtained from formaldehyde solution by exposing it in open ves- sels. This method Dr. Doty,^ the Health Officer of the Port of New York, justly characterizes as extravagant for general disin- fection. In the experiments of Professor Robinson,^ loo cubic centimetres of formaldehyde solution were poured upon a large pieces of cotton cloth and spread upon the floor. Less than half of the cultures of diphtheria bacilli and staphylococci in different parts of the room were destroyed after nine hours' exposure. The room was of 3,900 cubic feet capacity. As an alternative to spraying. Nils England' recommends, for the disinfection of rooms, the hanging up of sheets wet in one half litre of formalin in which 200 grams of calcium chlorid have been dissolved. The Department of Health of the City of Chicago reports that fully as good, if not better results have been obtained in a num- ber of disinfections made personally by Dr. C. W. Behm, Medi- cal Officer in charge of the Disinfecting Corps. "In these disinfections formalin was also used, but without the use of any apparatus. Ordinary bed sheets were employed to secure an adequate evaporating surface, and these, suspended in the room, were simply sprayed with a 40 per cent, solution through a com- mon watering-pot rose-head. A sheet of the usual size and quality will carry from 150 to 180 cc. of the solution without dripping, and this quantity has been found sufficient for the efficient-disinfection of 1,000 cubic feet of space. Of course, the sheets may be multiplied to any necessary number. "Cultures, both moist and dry, were exposed for five hours in these experiments — some in sealed envelopes, and others wrapped in three thicknesses of sheets, or folded inside of woolen blankets. Of the former, none showed growth after seventy-two hours' incubation, while the growth was but slight in those wrapped in the blankets. Surface disinfection was thorough, while a much greater degree of penetration was shown in these experiments than that secured by any other method. 1. NewTorkMed. Jr., LXVI., 517. 1897. 2. Klnth Report of the State Board o£ Health of Maine, p. 176. 1896. 3. La Salute Puhblica, IX., 261. 1896. 6 82 FORMALDEHYDE. "The evolution of the gas from the sprinkled sheets is exceedingly rapid — so much so that it behooves the operator to vacate the room within a very few seconds ; while, after starting the ordinary apparatus, he may remain ten minutes or more with- out serious inconvenience. When the room is opened after five hours, the density of the gas is still so great as to preclude respi- ration until after doors and windows have been opened some little time.i" Formalin has also been applied to the disinfection of rooms and their contents by spraying. (See Formaldehyhe, As a Spray.) Percentage, or Amount for Room Disinfection. — At the end of the first year's experiments, Professor Robinson^ stated that at least one litre of alcohol should be used for every 2,000 cubic feet of space to be disinfected, which would be about a quart for a room i5'xi3'xio'. At the end of the experimental work of the second year, he states that, for surface disinfection with the lamps using wood alcohol, at least two litres for 3,000 cubic feet should be used, and the room should be kept closed for ten or twelve hours. In the forms of apparatus which volatilize the 40 per cent, formaldehyde solution, at least 250 cubic centimetres for every 1,000 cubic feet should be used, and the room should be kept closed for the same length of time. In the work of Dr. Brough,' using an apparatus for the vola- tilization of formalin, he found that the results were not trust- worthy with the smaller quantities recommended by some experimenters, tie says that, "to get satisfactory results in house disinfection, I agree with Dr. Wyatt Johnston of Montreal, that at the very least one pound of formalin to 1,000 cubic feet should be used, and it would be better to use even considerably more. In this city it is the custom to use nearly a quart to the 1,000 cubic feet, and the varying and inconstant results with small amounts have not been repeated." As to the time of exposure. Dr. Brough says : "In my own tests I have found no difference in results from exposures of 5, 6, 7 hours and upwards. As good results were obtained in the shorter period of time as in the longer. If the results with a 1. Bureau and Division Reports, March, 1898. 2. Ninth Report, State Board of Health o£ Maine, p. 180. 1896. 3. Formaldehyde Gas as a Disinfectant, p. 15. 1898. FORMALDEHYDE. 83 certain amount of gas were not satisfactory with a short exposure they never were with a longer. It would seem that the work of the gas was accomplished quickly." Dr. Kinyoun's^ opinion is that not less than 500 cubic centi- metres should be used for each 1,000 cubic feet of space. These two investigators concur in the statement that the length of exposure is secondary to the amount of the gas used. A large per volume strength will accomplish the object better and in a shorter time than by using a smaller amount and prolonging the exposure. For room disinfection, under favorable conditions, fully twelve hours' exposure should be given. As the result of his experiments with various forms of appa- ratus Striiver^ came to the conclusion that for sporeless bacteria 1.6 grams of formaldehyde for each cubic metre of space suffices. In the vaporization of paraform, or polymerized formalde- hyde, Aronson^ states that each one-gram tablet suffices for the sterilization of one cubic metre of room space. In the experiments of Dr. Novy,* he found that two grams of paraform to each cubic metre (60 grams to 1,000 cubic feet) are sufficient to destroy, within twenty hours, all organisms regardless as to whether they are spores or vegetating forms, provided they are wet. For disinfection by the evaporation of formalin, he advises 150 cc. (5 ounces) of the 40 per cent, com- mercial solution for each 1,000 cubic feet of space, distilling it as rapidly as possible. In the use of holzin, Rosenberg^ recommends five cubic centi- metres to each cubic metre of space. This quantity usually suffices, but for the sterilization of anthrax spores he would increase the dose. The results of Rideal's^ experiments made for the purpose of determining the efficiency of paraform lamps, lead him to the conclusion that ten grams per 1,000 cubic feet suffice in all ordi- nary cases of disinfection, and if, in special cases, the walls and floors are in addition sprayed with a 0.5 per cent, formalin 1. Pub. Health Eeports, M. H. S., XII., 103. 1898. 2. Zeit. fur Hygiene, XXV., 357. 1897. 3. Zelt. fUr Hygiene. XXV., 168. 1897. 4. Med. News., LXXII., 641. 1898. 5. Zeit. fur Hygiene, XXIV., 488. 1897. 6. Public Healtb, X., 60. 1897. London. 84 FORMALDEHYDE. solution (2 ounces of formalin per gallon of water) before using the lamp, he believes that this would be the best practical means of disinfection. Power of Penetration. — In his report of the results of his second year's experiments, Professor Robinson states that form- aldehyde has some power of penetration. "Two layers of cotton cloth offer little resistance when the room is saturated with the vapors of the aldehyde, and even four or five layers of cotton can be penetrated with a fair degree of certainty. As regards woolens, test-objects have been frequently killed through one or two thicknesses of blanket in the ordinary time of exposure. But you cannot depend upon the certainty of the action of the gas through more than one thickness of cotton cloth. "^ Again, he says that, in small rooms, when wood alco- hol at the rate of two litres to 3,000 cubic feet of air space are used, or 250 cc. of formalin to 1,000 cubic feet are evaporated, "these amounts will penetrate one or two layers of cloth and sometimes several. But, in large spaces, no penetration can be depended upon with that proportion. This can be obtained by increasing the amount used. In small enclosed spaces of a few feet in capacity, with large amounts of the aldehyde, a marked degree of penetration can be obtained. Surfaces are rendered stenie in very short periods, ten or fifteen minutes, by concen- trated amounts in limited spaces."^ In a bell jar of 580 cubic inches capacity the formaldehyde derived from the volatilization of one tablet of paraform, or even one fourth of a tablet sufficed to sterilize all test-objects in twenty minutes. "Fifteen minutes were found to be ample time for the sterilization of diphtheria in thick woolen blanket."^ In this bell jar formaldehyde readily passed through a dia- phragm consisting of sixteen layers of heavy cloth held in place by a wire hoop. The possible spaces between the hoop and the glass were made tight with melted paraffin. The bacteria above the diaphragm were killed nearly as readily as those below, where the gas was admitted. In his experiments with formaldehyde in a gas-tight bag, diphtheria cultures and anthrax were almost invariably steril- ized, the time of exposure being nine or ten hours. 1. Tenth Ept. St. Bd. of Health of Maine, p. 135. 1898. 2'. Ibid., p. 168. 3. Ihia., p. 162. FORMALDEHYDE. 8$ These results, in their rapidity and certainty, are comparable with those obtained in the metallic disinfecting chamber with the aid of the vacuum system. Dr. Sprague's experiments were made with the Kinyoun-Francis disinfecting chamber, to which is attached a formaldehyde generator, an ammonia generator and a vacuum apparatus. The test-organisms were anthrax, diphtheria, and typhoid bacilli. A smaller percentage of form- aldehyde than 20 was found untrustworthy when used for short periods of time. Of twenty-one cultures exposed to 20 per cent, of formaldehyde for sixty minutes, seven gave growths and fourteen were sterile. The author says that "while surface disinfection was accomplished with 20 per cent, of gas after thirty minutes' exposure, as well as after one hour, the results in the interior of the mattress were not entirely satisfactory."^ In the experiments of Dr. Wilson,^ he found that 2 per cent. of formaldehyde gas with the vacuum process sufficed to disin- fect anthrax spores in the centre of a mattress in one hour and a half. The temperature of the disinfecting chamber was raised to 65°C. The conclusion of Dr. Doty^ is that we cannot depend upon formaldehyde for deep penetration in ordinary disinfection. It can, however, be relied upon to penetrate letters and other thin packages by placing them in an air-tight chamber. Abba and Rondelli* say that formaldehyde in the gaseous condition, pos- sesses, of itself, almost no power of penetration. Bedding, linen, clothing, etc., even when they lie lightly upon each other, cannot be efficiently disinfected, no matter how small the room is. The interior of the pile and the covered parts are not steril- ized. Gehrke^ says that formaldehyde is a very efficient agent for surface disinfection, but that it lacks power of penetration. Aronson also coincides with the opinion of the majority of experimenters that, in ordinary disinfection, the power of pene- tration of the gas is not great. Clothing must be hung up so that all surfaces are exposed. Though formaldehyde has some power of p^-.netration, the safest assumption in the present state of our knowledge of the 1. Med. News, LXXI., 763. 1S97. 2. Brooklyn Med. Jr., XI., 741. 1897. 3. New York Med. Jr.,LXVI., 517. 1897. i. Zelt. tUr Hygiene, XXVII., 49. 1898. 6. Deutsche Med. Woch., XXIV., 2i2. 1898. 86 FORMALDEHYDE. subject is that, in ordinary room disinfection, we cannot trust this gas to effect much more than a superficial disinfection. Clothing. — The evidence presented in the foregoing subtopic has an important bearing upon the applicability of formaldehyde to the disinfection of the articles which go under this subhead- ing. As to the disinfection of clothing, Doty says that, "for superficial disinfection — i. e., of hangings, furniture, clothing, furs, silks, and other articles which can be spread out and the surfaces exposed — formaldehyde is an agent of undoubted value."^ Abba and Rondelli^ found that clothing made from light stuffs, suspended freely, may be sterilized. Lehmann' says that when clothes were laid loosely in a trunk and cloths moistened with formalin were placed between them, it resulted that thirty grams of formalin disinfected a suit with certainty. According to Walter,* clothing upon which pus cocci had been dried was sterilized in six hours by spraying it with a 3 per cent, solution of formalin and wrapping it in oilcloth. Anthrax spores were destroyed in forty-eight hours by the same treat- ment ; the clothing remained entirely uninjured. In his very positive claims for holzin, Rosenberg^ holds that it is suitable, not only for the disinfection of surfaces, but that, through its power of penetration, it is well adapted to the dis- infection of clothing, etc. Kinyoun" reports : "I have not been able at all times to dis- infect the interior of pillows and mattresses with certainty, even when a very small room was used for this purpose and a large amount of methyl-alcohol consumed. The surfaces, dust, etc., were every time rendered sterile." The opinion of PfuhH is that for the disinfection of clothing, bedding, mattresses, and similar articles, formaldehyde is unsuit- able, and that they should be subjected to steam disinfection. In a paper read before the Montreal meeting of the British Medical Association, Dr. Wyatt Johnston,^ Bacteriologist to the 1. N.Y. Med. Jr.,LXVI., 526. 1897. 2. Zeit. fur Hygiene, XXVII., 49. 1898. 3. Miinchener Mefl. Wocli,— Ceutr. (iir Bak., XIV., 471. 4. Zelt. tur Hygiene, XXI., 421. 1^96. 5. Zeit. fur Hygiene, XXIV., 488. 1897. 6. Pub. Healtti Eeports, M. H. S., XII., 103. 1897. 7. Zeit. fur Hygiene, XXIV., 302. 1897. 8. British Medical Jr., Dec. 25, 1897. (Keprint.) FORMALDEHYDE. 8/ Board of Health of the Province of Quebec, said that he finds that clothing, in small enclosed spaces, may be disinfected with formaldehyde. "Placing the articles in a cupboard or trunk, and blowing in the vapour usually gave fair penetration, if excess of vapour was used. Pasting up minute cracks does not appear to make much difference. Though no large crevices or draughts should be allowed in the room we found it quicker and less troublesome to generate an excess of the vapour than to paste up cracks." Afterward he used a portable galvanized sheet iron disinfect- ing chamber, and still later, bags of "enamelled duck," though at the time of the meeting he had not had time to determine whether the best results are got by blowing in the vapor or by placing in articles which have been sprayed with formalin solu- tions. Dr. J. Petruschy,^ of Dantzic, refers to the unfavorable results obtained by the Dantzic Commission for the testing of formal- dehyde for the disinfection of clothing or the undisturbed con- tents of sick-rooms. Later experiments in the disinfection of clothing hung up in ordinary clothes-presses or wardrobes gave more satisfactory results. The test-organisms were anthrax spores on silken threads and diphtheria cultures and pieces of linen cloth infected with the cultures of the bacillus of diph- theria, saturated with blood or blood serum and then dried. For the generation of the formaldehyde gas, Trillat's autoclave was used, the gas being introduced through a gimlet hole bored in the back of the wardrobe. The door of the wardrobe did not close tightly, thus making the conditions of the experiment resemble disinfection with flowing steam, with the exception that a current of formaldehyde gas instead of one of steam was in operation. The test-organisms were wrapped in filter paper and then placed in the pockets of the clothing. Some were placed in the lower corners of the wardrobe and some in the toe of a long-legged leather boot. All of the packets in the pockets of the clothing and in the lower corners of the wardrobe were disinfected with certainty after the autoclave had been in operation one hour, but not with 1. Deutsche Med. Woch., XXIV., 527. 85 FORMALDEHYDE. certainty after one half hour's use of it. The packets of anthrax spores in the toe of the boot were not destroyed. What Professor Robinson says about the power of penetration of formaldehyde indicates that, in the disinfection of ordinary rooms, his belief is that it is impracticable to disinfect with cer- tainty their contents of clothing and bedding at the same time. Furniture. — Formaldehyde is, undoubtedly, a valuable auxili- ary in the disinfection of furniture for which there is no other available method. In the disinfection of upholstered furniture and bed-mattresses, the problem is usually that of surface dis- infection merely. For the disinfection of mattresses after cases of typhoid fever, the requirements are sometimes much more exacting. Kinyoun's experiments led him to conclude that it is doubtful whether the interior of articles, such as upholstered furniture, mattresses, and pillows, can always be disinfected unless a much larger percentage of the gas is applied than was used in his experiments. In the experiments of Professor Robinson^ to determine the penetrating power of formaldehyde with slips of filter paper soaked in typhoid cultures and placed in the interiors of mattresses, pillows, etc., and using from one half to one litre of alcohol to each 2,000 cubic feet of air space the experiments were all favorable. His later experiments, partic- ularly with the gas-tight bag, indicate the possibility of efficient disinfection when large quantities of formaldehyde are used in small, tight, enclosed spaces. Abba and Rondelli- think that the disinfection of the surfaces of furniture and of walls and floors, particularly of the cracks and crevices in them, cannot be done with certainty, even under favorable conditions. For the disinfection of furniture, as well as for surfaces of rooms and floors. Dr. RideaP advocates the use of the 0.5 per cent, solution of formaldehyde applied with a spray apparatus of proper construction. The apparatus to which he refers throws a profuse spray so that extensive surfaces can be pretty rapidly and thoroughly drenched. 1. Ninth Report, State Board of Health of Maine, p. 176. 1S96. 2. Zelt. fur Hygiene, XXVII., 49. 1898. 3. Public Health, X., 60. 1897. London. FORMALDEHYDE. 89 Books. — At the suggestion of Dr. J. S. Billings, E. G. Horton^ made an investigation in the Laboratory of Hygiene, University of Pennsylvania, to determine the value of formaldehyde for the disinfection of books. Formaldehyde vapor was obtained by evaporation from formalin. The books were sometimes stood upon end, and sometimes laid down upon their sides, but were always closed. The bacteria used were the bacillus of typhoid fever, of diphtheria, and Staphylococcus pyogenes aureus. The ■conclusions drawn by him from the experiments are, that : Books can be disinfected in a closed space, simply by vapor of -commercial formalin by using one cubic centimetre of formalin to 300 cubic centimetres, or less, of air. The vapor of formalin is rapid in its disinfectant action. The ■effect produced in the first fifteen minutes is practically equiva- lent to that observed after twenty-four hours. An increase in the amount of air to each cubic centimetre of formalin is not counterbalanced by an increase in the length of time of exposure. In case the disinfection has been incomplete, the vitality of the ■organisms has been so weakened that they survive only if trans- ferred in a few hours to media suitable for their development. In the experiments for the State Board of Health of Maine, 50 cc. of formalin poured upon a cloth in the lower part of a disinfecting chamber of 1,089 cubic inches capacity, disinfected books that were standing upon end in twenty-four hours and in forty-eight hours, but those lying flatwise were not disinfected.^ Surgical Instruments. — At the International Medical Con- gress in Moscow, Denter^ stated that a 2 per cent, solution of formalin sterilized instruments without injuring them. In some experiments made by Professor Robinson with paraformalde- hyde in a bell jar, the results indicate that surgical instruments may be rapidly sterilized by the evaporation of polymerized formaldehyde, provided the instruments are in a small and per- fectly tight enclosed space. In these experiments, bright pieces of steel suspended in the vapor and beyond the moisture from the alcohol were not coated or corroded. The repolymerization 1. Annals of Hygiene, XI., 754. 1896. 2. Ninth Keport, State Board of Health of Maine, p. 177. 1896. 3. Deutsche IVtecl. Wocb., XXIII., 188. 1897. 90 FORMALDEHYDE. of the paraform was prevented by pouring a small quantity of alcohol into the evaporating dish with the paraform. In the experiments of Rosenberg^ in the disinfection of instruments with holzin in a tight casket, he found that he was able to sterilize them in fifteen minutes. The fumes in the casket were still efficient four and one half weeks without renewal of the holzin. Dr. W. W. Alleger^ states that he has used ID per cent, solution of formaldehyde in alcohol for the disinfection of instruments, and that this, so far as he can see, had no bad effect upon the metal or the cutting edge. Dr. H. O. Reik^ investigated the value of formaldehyde for the disinfection of instruments. With the instruments in a closed chamber of i cubic foot capacity, he sought to determine the minimum quantity of paraform and the shortest time required to disinfect instruments. The paraform was volatil- ized with a Schering lamp. The micro-organisms used in his experiments were Staphylococcus pyogenes aureus and the anthrax bacillus. He concludes that, for practical purposes, ten or fifteen minutes is a short enough time for the sterilization of instruments, and that this can be done within this time with from three to five grains of paraform. In an interesting paper presented by Dr. Edward Martin,* of Philadelphia, he narrates his experiments with different agents and processes for the disinfection of instruments, partic- ularly of urethral instruments. Exposure of the instruments to formaldehyde vapor given off by paraform in a closed box at ordinary room temperatures proved absolutely efficacious. By this means, not only were new catheters, which are always infected, and old catheters, which had been dipped in putrid urine and thoroughly washed, disinfected, but also those which had been dipped in infected material, either urine or pure cul- tures of Staphylococcus pyogenes, or the colon bacillus, and had not been washed, were rendered absolutely sterile. This was proved by upwards of a hundred experiments. In the experiments half a dram of paraform was used, and this still preserved its disinfecting properties at the end of two weeks. He found also that all surgical instruments, even those 1. Zeit. fur Hysiene, XXIV., 48S. 1897. 2 Atner. Monthly Microscopical Jr., XV., 104. 1894. S Bui. Johns Hopkins Hospital, VIII., 261. 1S97. 4. Phil. Polyclinic, VII., 60. 1898. FORMALDEHYDE. 91 of intricate construction, exposed to the vapor for twenty-four hours were rendered thoroughly sterile. Disinfection of the Mails. — In the study of formaldehyde as a disinfecting agent, made by Dr. Sprague for the Supervising Svirgeon-General, M. H. S., in each experiment packages of let- ters, in the centre of which were placed dried cultures in sealed envelopes, were securely tied and thrown into the rack of the Kinyoun-Francis disinfecting apparatus. Growths occurred in all cases. The opinion is expressed that if the packages had been perforated, they would have been disinfected in some instances, but the trials were made with sealed letters for the express purpose of ascertaining whether or not it was possible to avoid mutilating them with the punch. In the experiments for the State Board of Health^ with para- form volatilized in a small enclosed space and with formalde- hyde driven from the generator into a gas-tight bag, the results indicate that this gas probably may be trusted to disinfect pack- ages of letters and other mail matter, especially if the precaution is taken to punch the envelopes. Without this precaution, how- ever, the interior of letters was not sterilized with certainty in experiments No. 5 and No. 7, page 166. Tuberculosis Sputum. — The well known action of formalde- hyde in hardening or coagulating albuminous matter is sugges- tive of doubt as to its suitability as a disinfectant for fresh tuberculous sputum. This, however, is a question which can be decided only by experimental work. Ascoli^ says that form- alin solutions can be used for the sterilization of those albumin- ous materials for which the bichlorid of mercury cannot be used. For example, the disinfection of the sputum of tuberculous and pneumonic persons. In the disinfection of a room, Striiver^ subjected tubercle bacilli to the action of formaldehyde and then inoculated them into a guinea-pig. The animal remained well. Tubercle sputum upon aluminum and tubercle sputum spread in Petri dishes, and swabs of cotton one half inch in diameter which had been rubbed with the false membrane in the throat of a diphtheria patient, were sterilized in the various experi- ments made for the State Board of Health. From 300 to 500 1. Tenth Ept. St. Bd. of Health of Maine, p. 161. 1898. 2. Giornale fl. E. S. Ital. D' Ig., XVI.— Centr. fur Bak., XVII., 849. 1895. 3. Zelt. fur Hygiene, XXV., 357. 1897. 92 FORMALDEHYDE. ■cc. of formalin had been driven into a room of 3,000 cubic feet with a Bowdoin vaporizer. The time of exposure was from nine and one half to fourteen hours. Tubercle sputum which PfuhP rubbed into cloth, dried twenty-four hours, and then exposed to formaldehyde in the ■disinfection of rooms was sterilized. Embalming.— IvsluoS^ sought to determine what power form- aldehyde has for penetrating organic tissues. Rabbits and guinea-pigs were infected with bacteria capable of producing general infections. After death, their livers were subjected to the action of formaldehyde gas. His results show that formal- dehyde gas penetrates organic tissues slowly. Its disinfecting influence extended only about five millimetres beneath the sur- face of the liver. The object of some experiments made by Burckhard' was the solution of the question whether human bodies and the bodies of animals could be penetrated with formaldehyde gas so as to destroy pathogenic germs, and thus remove the danger in path- ologic work. His experiments indicated that it is impractica- ble to do this. Formaldehyde mummifies the tissues so far as it acts, but it does not penetrate far. Trillat, on the other hand, says that formaldehyde diffuses itself rapidly through animal tissues, thus rendering them impu- trescible. Brushes, Combs, Etc. — Lehmann* recommends formalin for the disinfection of brushes and combs. He considers it a valu- able agent for household disinfection and, particularly, for dis- eases of the hair. Ascoli also recommends the vapor from formalin for the dis- infection of brushes, books, and other articles in small enclosed spaces, such as trunks, satchels, etc. As a Spray. — For the disinfection of small spaces, Striiver^ thinks that spraying with formalin is best. Nils England" recommends, for the disinfection of rooms, spraying with a solu- 1. Zelt. fur Hygiene, XXIV., 297. 1897. 2. Centr. fUr Bak., XXII., 50. 1897. 3. Centr. fur Bak., XVIII., 2.57. IS95. 4. Jluncliener Mefl. VVoch.— Centr. fiir Bak., XIV., 471, 1S93. 5. Zeit. tur Hygiene, XXV., 3.57. 1S97. ■6. La Salute Pubbllca, IX., 251. 1896. FORMALDEHYDE. g^ tion of formalin, or hanging up sheets wet in the solution. The room should be sprayed with a 2 per cent, solution and then closed for twenty-four hours. While at work, he states the workman can protect his eyes with goggles, and his nose and mouth with a mask lined with cotton. The hands may be smeared with vaselin. StrehP found that a 10 per cent, solution of formalin spray upon wall-paper sufficed to sterilize anthrax spores and staphylococcus, but that a 5 per cent, solution did not suffice. Dr. RideaP makes an argument, based upon his experiments, that a 0.5 per cent, solution of formaldehyde is strong enough to use as a spray when properly applied, but says, however, that the spraying with this solution should in all cases be followed by the use of a paraform lamp so as to insure the disinfection by vapor of crevices and parts of the room and furniture missed by the spray. The use, however, of so weak a solution as that recommended by Rideal can hardly be consid- ered trustworthy until further work in this direction has been done. Local Antiseptic and Therapeutic Action. — As a local anti- septic, Schleich^ has found that formalin-gelatin has very dis- tinct and valuable antiseptic qualities. It is prepared by the addition to 500 grams of purified gelatin in solution of twenty- five drops of pure formalin solution and evaporating over form- alin vapor. The resulting solid body is reduced to powder and preserved in the presence of a drop of formalin solution. Various authors have recommended formaldehyde as an agent for the local treatment of diphtheria, whooping cough, influenza, tuberculosis, and other diseases by inhalation, or otherwise. Aronson* recommends for this purpose and for the deodorizing of sick-rooms small lamps acting continuously. Wood= uses the Schering and Glatz lamp for this purpose. By keeping only one or two of the tablets in it, a gentle and constant antiseptic vapor may be diffused throughout the sick- room. In an emergency, and in the absence of this lamp, he has placed the tablets on a narrow, bent piece of tin laid across 1. Centr. fur Bak., XIX., 785. 1896. 2. Pub. Health, X., 60. 1897. Lonaon. 3. Therap. Monatsliefte— Med. News, LXVIIl., 381. 1896. 4. Zelt. fur Hygiene, XXV., 168. 1897. B. Medical Times, XXV., 264. 1897. 94 FORMALDEHYDE. the top of the common lamp-chimney in the treatment of influ- enza, diphtheria, etc. SoHs-Cohen has seen such good results in the treatment of tuberculosis of the larynx by means of formic aldehyde solutions that he is tempted to believe that we have in this agent a means of treatment superior to any other that he has ever used. He uses the commercial formalin, >4 to 4 per cent, of formic alde- hyde, that is, from i to 10 per cent, of formalin. The mucous membrane is cocainized before the application is made.^ In a discussion on formaldehyde at the meeting of the Maine Medical Association in 1897, Dr. W. B. Moulton, of Portland, was called upon to give his experience with the use of formal- dehyde in connection with an outbreak of diphtheria in his own family. He stated that he had kept formaldehyde vaporizing at a gentle heat in the room where the patient was and also from a lamp on the floor below. It was not uncomfortable to those continually breathing it, but would excite cough in one coming in from the outdoor air. Dr. C. D. Smith, of the same city, stated that he had made cultures from the throat of Dr. Moulton's boy before and during the use of the formalin vapor, and found that there was a marked inhibition of the power of the Klebs-Loeffler bacillus to grow in cultures. He was satisfied that constant breathing of formaldehyde vapor had been a valuable aid in preventing the extension of membrane in these cases, although antitoxin had been used early and in considerable doses to neutralize the toxin.^ Rosenberg** praises holzinol very highly in the treatment of whooping-cough and also in pulmonary tuberculosis. For internal use, when the systemic effect of formaldehyde is required, he recommends sterisol, which is a saturated solution of formaldehyde in a solution of sugar of milk. Experiments which he tried upon himself indicate that small doses of sterisol may be taken with impunity for considerable lengths of time, and that the urinary secretion contains formaldehyde for several days and is distinctly antiseptic. 1. The Therapeutic Gazette, XXI., 330. 1897. 3. Tr. Maine Med. Assoc., XII., 604. 1897. 3. Deutsche Med. Woch., XXII., 626. 1896. FORMALDEHYDE. gc Dr. Alexander,^ of Ohio, reports that he has, for a year, used formaldehyde in its various forms as a medical and surgical antiseptic with excellent results, — as a local application to specific and other ulcers, in diseases of the skin, and in diph- theria, and by inhalation in whooping-cough, hay fever, and other catarrhal troubles. According to F. J. C. Bird, the strength in which solutions of formaldehyde have been used for certain purposes is as follows : 1 :2,soo destroys the most resistant micro-organisms in one hour. 1 : 500 for the irrigation of catheters, etc., and as a mouth wash. 1 :2SO to 200 is a general disinfectant solution for washing hands, instruments, etc., in surgery, spraying sick-rooms, and as a deodorant. 1 : 100 in lupus, psoriasis, and skin diseases. One part of formaldehyde represents two and one half parts of the full strength, or the 40 per cent, solution of commerce.^ When solutions of formaldehyde are used locally, the obser- vations of Gagner and Ascoli should be borne in mind. Gagner^ found that when the hands were washed with a 2^ per cent, solution of formaldehyde no injury was perceptible, but when a rabbit's ear was touched three times daily with formalin, mum- mification appeared on the seventh day. As one of the disad- vantages of formalin, Ascoli* referred to its necrotizing and mummifying action upon the skin. If one applies formalin several times to the ear of a rabbit, or to a mouse's tail, indura- tion follows pretty rapidly and then necrosis of those parts without the existence of suppuration or pain. As a Food Preservative. — Trillat^ observed that one kilogram of beef, immersed five minutes in a i : 250 solution of formalin, was preserved twenty days. This is one of the many observa- tions which tend to show very conclusively that formaldehyde is a very efficient preservative. The most important question, however, from the point of view of public health is whether 1. New York Med. Jr., LXV., 53. 1897. 2. Pharmaceutical Jr.— Pittsburg Med. Eevlew, XI., 74. 1897. 3. Centr. fur Bak., XIV., 472. 1893. i. Giomale d. K. S. Ital. D' Ig., XVI.— Centr. tur Bak., XVII., 849. 1895. 5. La Pormaldeliyde, p. 47. 1896. 96 FREEZING. formalin exerts any harmful action. The experiments of Gott- stein^ tend to show that food products are hardened and spoiled after treatment with formaldehyde as a preservative. The investigations of Lederle^ teach him that the use of formalin for the preservation of milk should be prohibited. FREEZING. Upon most disease germs, the effect of low temperatures is too uncertain to permit their application to be considered as a trustworthy method of disinfection. In the experiments of Dr. T. M. Prudden/ carried out for the purpose of learning the effects of freezing in water, on vari- ous species of bacteria, the specimens were kept frozen for extended periods of time at a temperature of from 14° to 30° F. Water which contained Staphylococcus pyogenes aureus in innumerable numbers showed 49,280 to the cc. after sixty-six days, and a sample which contained the bacillus of typhoid fever in innumerable numbers still contained over 7,000 after one hun- dred and three days' freezing. Successive freezings and thaw- ings, however, were found more destructive of bacteria than the uninterrupted action of cold. In the paper of Dr. Weiss* giving the results of the experi- ments which he carried out in the Institution for Infectious Diseases in Berlin, he refers to some work which preceded his own. In connection with the winter outbreak of cholera in Nietleben in 1893, Professor Renk experimented for the purpose of determining the capability of the cholera spirillum to with- stand low degrees of temperature. He concluded that ice which is eight days old ceases to contain cholera germs capable of development. About the same time Uffelmann made a similar study of the question, using in some of his expei;iments sterilized water to- which cholera bacilli had been added, and in others bouillon cul- tures. He found that the cholera spirillum possesses a consid- erable degree of resistance to cold ; it survives a temperature of 1. Dentsolie Med. Wooh ., XXII. , 669, 797. 1896. 2. N. Y. Mea. Jr., LXVI., 626. 1897. 3. Medical Record, XXXI., 344. 1887. 4. Zeit. fur Hygiene, XVllI., 492. 1894. FREEZING FURNITURE. 07 — 24.8° C, but in none of his experiments did spirilla survive the freezing temperature more than five days. In Abel's experiments cholera spirilla were destroyed with certainty after eight days' exposure to the temperature of — 20°. On the other hand, Dr. Schruff found that cholera bacilli retained their vitality after they had been exposed to the freez- ing temperature at various times from September to May. The experiments made by Dr. Weiss indicate that the length of time during which cholera spirilla may survive freezing tem- peratures depends upon various circumstances. In bouillon, the vitality was retained much longer than in water which con- tained but a few drops of bouillon. They were rapidly destroyed in cholera stools, even more rapidly than in water. Weiss, therefore, concludes that under ordinary circumstances cholera spirilla in stools are rapidly destroyed during cold weather, and he apprehends no danger of the transmission of cholera through ice. Professor J. Forster,^ of Amsterdam, found that a variety of bacteria are capable of growth and multiplication and of dis- charging their vital functions when kept at the freezing point. FURNITURE. Upholstered furniture can be disinfected by thoroughly spray- ing it with a disinfecting solution, as is the official practice in Paris. The spray apparatus used should be more like the sprayers used by orchardists than those made by the manufac- turers of medical and surgical instruments. They should throw a fine, but profuse spray. In the absence of a spray apparatus, the disinfecting solution can be applied with a brush or a sponge, or washed or wiped thoroughly with a cloth squeezed out of the solution. For general use, a 3 or 4 per cent, solution of lysol is suitable. When formaldehyde is used for the disinfection of the rooms, this gas may be trusted to sterilize the furniture of the rooms provided it is freely exposed to it. When there is any doubt as to the efficiency of the disinfection of upholstered furniture it is a good plan to expose it for several days to the action of direct sunshine, when that is practicable. (See Light —The Real Value of Light as a Disinfectant. ) 1. Centr. fur Bak., XII., 431. 1893. 7 98 GUAIACOL HANDS. GUAIACOL. The disinfectant properties of guaiacol were investigated by Kuprianow.^ His conclusions are, in part, as follows : Guaia- col is not ^so powerful a disinfectant as carbolic acid and cresol. For this reason it is not suitable for external use as a disinfec- tant. The addition of 33 per cent, of alcohol increases the dis- infecting activity of guaiacol. Guaiacol and creasote have an especially energetic action when applied to the bacillus of tuber- culosis, but further experiments are needed to determine its value in this direction. Chemically pure guaiacol is much less irritating than carbolic acid and cresol. The absence of toxic and caustic qualities render guaiacol very suitable for internal use. HANDS. Probably no point relating to disinfection has brought out more discussion and has been the motive of more laboratory and clinical investigation than the question of how sterilization of the hands may be accomplished with the greatest certainty and rapidity. The loss of time involved in some of the methods calls for patience on the part of the surgeon, but a little trouble will not deter him who sympathizes with the words of Berg- mann, of Berlin, that "the touch of the surgeon's hands plays the chief part in the etiology of the spetic diseases of wounds, and the slightest touch of the skilled hand of the surgeon may bring the greatest harm." The older method of disinfecting the hands consisted in the preliminary scrubbing in soap and water, followed by soaking them in a carbolic acid, a mercuric chlorid, or other disinfecting solution. The investigations and recommendations of Fiir- bringer led to quite a wide introduction of his process which consisted, after the preliminary dry cleansing of the finger nails, in washing and brushing with soap and hot water two minutes ; the application of 80 per cent, alcohol, two minutes ; washing with a disinfecting solution (mercuric chlorid or carbolic acid) before the alcohol is fully evaporated ; drying in the air. 1. Centr. fur Bak., XV., 933, 981. 1894. HANDS. gg In testing Fxirbringer's method Roux, Jules, and Reynes^ found that the results were not perfect, but that they were better than the old process ; they, therefore, recommended it. The greater part of the discussion which has taken place in regard to the disinfection of the hands has related to the method of action and the efHciency of alcohol as a germicide. The orig- inal idea of Ftirbringer was that the role of alcohol in the disin- fecting process which bears his name is the removal of oil from the skin, thereby permitting the disinfecting solutions to pene- trate more easily. Reinicke^ went farther and claimed that alcohol has a germi- •^ cide action of its own. He found that by vigorous brushing of the hands with alcohol five minutes, with or without the preced- ing use of soap and water, followed only by rinsing in sterilized water, the culture media remain completely sterile. In his experiments with the Fiirbringer method, by extending the time, particularly in using the soap and water, colonies were very infrequent even when the sublimate was precipitated with a solu- tion of ammonium sulphid. Similarly good results were obtained when lysol was used instead of sublimate. Kroenig^ refers to Fiibringer's explanation of the action of alcohol and suggests that a partial or temporary sterilization of the hands may be due to the shrinking or contracting effect of the alcohol upon the epidermis, thereby imprisoning the micro- organisms and making their removal more difficult. Some of his experiments give some support to this supposition. Other experiments seem to indicate that the subsequent action of water by softening the epidermis has a tendency to release the bacteria. The disinfecting effects achieved by Fiirbringer are, therefore, in the opinion of Kroenig, only apparent. In conclusion, he states that the hands may be considered sufficiently disinfected when the adherence of the bacteria to the skin is not easily loosened and when the inhibitory action of the antiseptic con- tinues after the transplantation of the bacteria. In short, when the hand ceases to be able to infect. 1- Comptes rend, de I'Acad. etc.— Centr. fur Bak., V., 264. 1889. 3. Centr. fur Gynakol.— Centr. fur Bak., XVII., 916. 1895. 3. Centr. fur Gynakol.— Centr. fur Bak., XVII., 915. 1895. lOO HANDS. Ahlfeld/ who is the director of a large institution for the instruction of midwives, was in a position to test Reinicke s methods very thoroughly. The number of his experiments was far more than a thousand upon the hands of 215 different persons. In applying the alcohol he preferred, in his later work, pieces of flannel to the brush. The use of sublimate without alcohol gave disappointing results. Series A. The hands were scrubbed and cleansed five min- utes in very warm water and common toilet soap, cleansing and trimming the nails at the same time ; two minutes in alcohol of 96 per cent. ; three minutes in 3 per cent, soap-cresol solution (lysol?) ; five minutes rinsing in hot sterilized water. One hun- dred and sixty-two. experiments ; hands not sterile in 70 per cent. Series B. Five minutes in soap and water; two minutes in alcohol ; five minutes rinsing. Fifty experiments on the same number of students ; hands sterile in 90 per cent. Series C. Five minutes in soap and water; three minutes in cresol-soap solution; five minutes rinsing. No alcohol used. Forty-seven experiments : the hands sterile in 66 per cent. Series D. Five minutes with brush, soap and water. Three hundred and eighty-nine experiments: hands sterile in 14. i per cent. Upon his own hands, however, Ahlfeld had his fingers sterile in 82 per cent, of twenty-two experiments. Thus far, the best results were in series B, in which alcohol was used two minutes preceded by soap and water five minutes. Series E. In this series he sought to determine how far the process might be simplified without impairing its efficiency. The nails were shortened and cleansed without water. Then : one minute, washing in soap and water without brush; two minutes, in warm water ; two minutes, in alcohol ; five minutes, in sterile water. Fifty-four experiments upon the same number of pupils : all but one succeeded in sterilizing her finger, or 90.7 per cent. From this series he draws the conclusion that the brush is not absolutely necessary, and that the time for the pre- liminary cleansing can be reduced to three minutes. Series F. After the preliminary cleansing of the nails with- out water, three minutes, in hot water without soap ; two minutes, in alcohol; five minutes, in sterilized water. Eighteen 1. Deutsche Med. Woch., XXI., 851. 1895. HANDS. lOI persons, of whom twelve, or 66.6 per cent., sterilized their finger. The results, therefore, are not so good when soap is omitted. Series G. After the preliminary dry cleansing of the nails and trimming them; two minutes, in soap and water without brush; one minute, in hot water, rinsing in sterilized water; three minutes, with alcohol; five minutes, in sterilized water. Thirty-six pupils: 91.6 per cent, of successes or sterile fingers. Series H. In this series, the time for soap and water was lengthened one minute and the alcohol was applied with flannel instead of with gauze as in some of his experiments. After the preliminary dry cleansing of the nails and shortening them : three minutes, with soap and water without brush; three minutes, with alcohol applied with flaftnel; five minutes, in sterilized water. Fifty-two experiments on forty-seven persons with 98.1 per cent, of them successful. The only person who failed to sterilize her finger repeated the experiment a few days later and succeeded. In these experiments, extended through nearly a year, Ahlfeld thinks that he has shown that we may dispense with the brush and such disinfectants as carbolic acid and the cresols, all which tend to roughen the hands. As to whether his method suffices when it is known that the hands have been infected with pathogenic micro-organisms, he says that, in thirty-eight instances after his hands had been soaked in the petrifying discharges from disintegrating car- cinomatous and fibromatous growths, etc., they were rendered sterile thirty-seven times, or in 97.4 per cent, of the experiments. In the one instance in which there was a failure, the first experi- ment of the series, sublimate was used, but no alcohol. In most of his experiments Ahlfeld disinfected but one finger. The disinfection of the whole hand would, of course, occupy more time. In the investigations of Dr. Leedham-Green,i of Birmingham, England, he succeeded in only a small percentage of his experi- ments in completely sterilizing the hands with soap and water, followed with pure or 96 per cent, alcohol. The number of his experiments was only thirty-seven. With reference to the cause of Leedham-Green's unfavorable results, the details of the experiments are too brief to enable 1- Dentsclie Med. Woch., XXII., 360. 1896. 102 HANDS. , Ahlfeld^ to give an opinion as to the cause of his failures. In contrast with Green's results, he refers to those obtained with hot water and alcohol disinfection by the female pupils in the first course of that year. Of fifty pupils in their first practice, forty-six achieved a complete sterilization of a finger. Of the other four, three succeeded at the second trial, and the other one at the third. In eighty bacteriologic tests on the fingers of midwives or nurses, prepared for obstetric investigations, only four gave unsuccessful results, and in three of these they were the fingers of unskilled persons. Further, even when the hands of Dr. Ahlfeld and his assistant had been soaked in the secretions of a case of septic puerperal metritis, they were fully sterilized with the hot water and alcohol process, even after the septic fluid had been allowed to dry on the hands half an hour. He again refers to the fact that his experiments numbered far over a thousand before he published his results. In another series of experiments made by Ahlfeld^ and his assistant Vahle, their object was to determine how alcohol acts. Four explanations have been presented: i. Fiirbringer assumed that it freed the hands from oils and that thereby the action of the disinfecting solutions subsequently used was facil- itated. 2. Reinicke also believed that the solvent action of the alcohol on fats accounts largely for its value, but ascribes to it some germicide action. 3. Kroenig thinks that the disinfectant action of alcohol is a deceptive one, — it does not kill the bacteria, but by its absorption of water causes the epidermis to shrink and mechanically imprison them. 4. Alcohol is a true bacteri- cide, but only when the micro-organisms contain water. In the disinfection of the hands, the importance of the pre- liminary treatment with soap and hot water is shown in these later experiments of Ahlfeld and Vahle, in which dried threads with staphylococci were not sterilized in alcohol in five minutes, but moistened threads were absolutely sterilized in the same space of time. As to the strength of the alcohol, there were 88.8 per cent, of successes with 96 per cent, alcohol, and only 81.2 per cent, of sterilizations with 48 per cent, alcohol. 1. Deutsche Mefl. Woch., XXII., 861. 1896. 2. Deutsche Med. Wocti., XXII., 81. 1896. HANDS. 103 In still another communication, Ahlfeld,' referring to the results obtained by Poten, characterizes his methods as faulty and leading to faulty conclusions. In determining the efficiency of a method of hand disinfection, it is very essential that the scrapings from the spaces beneath the nails be tested. He claims that, thus tested, the hot water-alcohol method of disin- fection gives very nearly 100 per cent, of successes. Before making extended experiments with this method of disinfection, he had tested bacteriologically other methods for disinfecting the hands, carbolic acid, 3 per cent. ; soap cresol, 3 percent.; tricresol, 3 per cent. ; sublimate i : 1,000; sublimate- alcohol 1:1,000; washing with soap and hot water, etc. He found all these methods give results inferior to those with the method advocated by him. He states that Poten is in error in assuming that in his experi- ments Geppert's precautions were not observed. The alcohol disinfection is not only superior to all other methods for those who are experienced in its use, but it is the safest and most effi- cient to be put into the hands of persons who are inexperienced. As to the certainty of the method, he says that inexperienced persons in the disinfection of one finger can, in 98 per cent, of the experiments, secure absolute sterilization, and 87 per cent, in disinfecting the whole hand. In disinfecting his own hands, from 99 to 100 per cent, of absolute sterilizations can be attained in the experiments. He refers to a former work in which he states that 48 per cent, alcohol possesses quite a high degree of disinfecting power. Furbringer and Freyhan,^ referring to the experiments of Leedham-Green in which the hands were artificially infected with pure cultures, say : "Such conditions are too widely dif- ferent from the conditions in practice to serve as data for a con- clusion. These authors are convinced that in the inunction of cultures into the hands the bacteria penetrate rapidly into the numberless spaces of cuticular scales and that, furthermore, they enter the orifices of the hair follicles and the spiral sudori- ferous glands so that it may be impossible to sterilize the hands. 1. Deutsche Med. Wooh., XXIII., 113. 1897. 2. Deutsche Med. Wool)., XXIII., 81. 1897. 104 HANDS. They give the results of a series of new experiments from which the authors conclude that, after the alcohol treatment, it is desir- able to use a disinfecting solution as originally prescribed by Fiirbringer. Fiirbringer is now convinced that the antiseptic influence of the alcohol is not due principally to its solvent action upon the oily matter of the skin, but that Ahlfeld is right in assuming that alcohol is a strong bactericide for the micro- organisms of the hands. Fiirbringer and Freyhan think that alcohol acts in three ways : (a) it has a bactericide action of its own; (b) it prepares the way for other disinfectants by removing the oils and otherwise; (c) it removes the superficial epithelial scales and their bacteria and washes them away. Dr. Goenner,^ of Basle, repeated the experiments of Ahlfeld and Vahle and of Leedham-Green, supplemented by original experiments. His results are to the effect that alcohol is a dis- infectant, but its action is not so great as that of sublimate. The practical lesson is, therefore, that alcohol should be used in a bowl of sufficient size so that the hands may be wholly immersed for a specified time and that the sublimate disinfection should immediately follow. Epstein's^ experiments confirmed the conclusions of Reinicke and Ahlfeld that alcohol has a germicide action of its own, but he found that, as the strength of the alcohol is diluted down to 50 per cent., its disinfecting power increases, but that there is a diminution of this power as the dilution is carried below 50 per cent. In a paper by Dr. Menge,^ of Leipzig, he states that the opin- ion of Dr. Fiirbringer is more and more approaching the view taken by Reinicke and Ahlfeld and Vahle, although he does not go so far as these investigators have in their opinion as to the efficiency of mechanical disinfection of the hands, and, particu- larly, of the action of alcohol. According to Menge, 70 per cent, alcohol possesses advantages in the disinfection of the hands which no other agent has. It has a distinct germicide action against sporeless bacteria. A second advantage is that it saturates all of the superficial layers 1. Centr. tiir Gyn.— MUnchener Med. Woch., XLV., 337. 1898. 2. Zeit. fiir Hygiene, XXIV., I., 1897. 3. Miinchener Med. Wool)., XLV., 104. 1898. HANDS. 105 of the skin, thus having an advantage over watery solutions of disinfectants. A third advantage is that it does its work with- out injury to the skin. By virtue of the hardening influence of alcohol and its power of abstracting water, the more resistant forms beneath the epi- dermis are retained. If, however, the hands are subsequently soaked in water or the fluids of the body, the epidermic layer again becomes softened and enables these more resistant bacteria to escape. To meet the requirements of surgical gloves, Menge treats cotton or silk tricot, or stockinet gloves by immersing them in a solution of 100 cc. of xylol and 10 grams of a soft paraffin which melts at a temperature of 45° C. The gloves are allowed to remain fifteen minutes in the warm solution. They are then wrung out and dried in an oven. Water and acetic fluids flow from the surface of these gloves as they would from the feathers of aquatic birds. They are not, however, imper- vious to liquids under pressure. They present a comparatively smooth surface, are comfortable to the hands, and can be cleansed with soap and hot water and sterilized by steam. Menge has also used the paraffin-xylol solution as an appli- cation to the hands, after alcohol has been applied, for the pur- pose of preventing the subsequent softening of the epidermis and the liberation of bacteria. It also protects the skin from the penetration of infectious material. It can be removed by rub- bing the hands with ether and washing with soap and hot water. The method which Menge recommends for the disinfection of the hands is, — mechanical cleansing with hot water and soap applied with a brush, the nails having been carefully cleansed during the process ; disinfection of the skin with an aqueous or a v/eak alcoholic solution of sublimate ; soaking the hands with 70 per cent, alcohol and drying with a sterile towel ; application of the paraffin-xylol to the hands and again drying with a sterile towel. In the investigations of Dr. Howard A. Kelley,^ of Johns Hopkins University, soap and water were found to be utterly inadequate to remove the germs even when the scrubbing is very thorough and extended to from ten to twenty-five minutes. 1. Amer. Jr. of Oljstetrics, XXIV., UU. 1891. I06 HANDS. The use of mercuric chlorid solutions up to i .500, following the use of soap and water, leaves innumerable colonies after the precipitation of the mercuric chlorid with ammonium sulphid solution. A few experiments made with a 4 per cent, solution of lysol and with hydrogen peroxid were all unsuccessful. Some experiments were made with Fiirbringer's method (the number not stated). It was shown to be inefficient in almost every instance. He found the most efficient method of disinfecting the hands to be scrubbing them for ten minutes with soap and water at the temperature of 104° F. ; immersion in a saturated solution of permanganate of potash until the skin is stained a deep mahog- any red or almost black; immersion in a saturated solution of oxalic acid until they are completely decolorized and of a healthy pink color; rinsing the oxalic acid off in warm sterilized water. In fifty experiments with disinfection by this method, forty- four remained without growth. The remaining six yielded respectively 80, 20, 10, 9, 5, 4 colonies — enormous quantitative difference in favor of permanganate of potash and oxalic acid as contrasted with soap and water and corrosive sublimate. Dr. Roswell Park^ calls attention to the remarkably efficient properties of mustard as a sterilizing agent for the hands. His practice is to scrub his hands thoroughly with a mixture of green or other soap, corn meal, and mustard flour, using this about iive minutes. He has no hesitation in going from a necropsy to the operating room, if his hands are thus disinfected. He finds the mustard to be an admirable deodorant. Dr. L. S. McMurtry also recommends mustard for the dis- infection of the hands. The following method he has found to be efficient and simple : The nails are shortened and the spaces about them cleansed. The hands and arms are scrubbed with a liberal quantity of green soap and hot water with a stiff brush for ten minutes. The hands and arms are dried with a towel, the nails and under- lying spaces are again carefully cleansed. Ordinary mustard flour, mixed with warm sterilized water in the hands, is applied with friction for five minutes and then washed with warm steril- ized water. The hands are now thoroughly bathed in strong 1. Mea. News.— Pliilad. Polyclinic, V., 126. 1S96. HANDS HEAT. IO7 alcohol, 80 per cent. The hands receive a final washing in a stream of warm water running over them, brushing them again well.i It is not known to the writer whether the value of mustard flour for the disinfection of the hands has been determined bacteriologically. Koch,^ however, found that anthrax spores were not killed in ten days with oil of mustard, but there was only a weak growth. The development of anthrax bacilli, how- ever, was restrained in a marked degree with i : 330,000 of mustard oil, and i : 33,000 arrested their growth completely. For the disinfection of the hands, Loeffler recommends very highly a 3 per cent, cresol-anytol solution. It is very efficient and it affects the skin but little. ( See Anytin and Anytols. ) HEAT. As a disinfecting agent heat has been applied as dry heat (hot air), and as moist heat (steam and boiling). In their experi- ments with hot air, Koch and WolffhiigeP found that sporeless bacteria are destroyed in an hour and a half by hot air at the temperature of 100° C. (212° F.) ; that anthrax spores require for their destruction a temperature of 140° C. (284° F.) three hours. The impracticability of hot air disinfection is indicated by their statements that, in using hot air, the heat penetrates so slowly that with a temperature of 140° the interiors of quite small bundles of clothes, or of pillows are not disinfected in three or four hours ; and that the action of hot air of 140° injures most objects more or less. The experiments of Klein and Parsons* also show very conclusively the inefficiency of the hot air disinfectors which had been largely in use. These experiments and the practical experience of health offi- cers have gradually taught that, as compared with steam, hot air is much less certain and rapid in its action. It is, therefore, now but little used except in special work, on a small scale. 1. Medical Sfandard, XX., 53. 1898. 2. Mlttheil. aus dem Kals. Ges., I., 234. 1881. 3. Mittheil. aus dem Kais. Gea., I., 301. 1S81. 4. Ept. of tlie Med. Officer of the Local Govt. Bd. for 1884, p. 218. I08 HEAT AS AN AUXILIARY. HEAT AS AN AUXILIARY. By heat as an auxiliary in disinfection, reference is made to temperatures below that of the thermal death points of the bacteria in question, and often far below. This increase in the activity of disinfecting solutions as their temperatures are increased is illustrated by Behring's^ observation that the bacil- lus of cholera and sporeless anthrax bacilli were destroyed with a 1:100,000 solution of mercuric chlorid at 36° C. (96.8° F.), but at 3° C. (37.4° F.), these bacteria were not destroyed with a lesser strength than 1 125,000. Again with a 1.4 per cent, solution of washing soda, anthrax spores were killed in ten minutes at from 80° to 83° ; in fifteen minutes at 'J'j° ; in twenty minutes at 75° ; and in from 30 to 60 minutes at 70° Remouchamps and Sugg^ found that pieces of linen soiled with cholera and typhoid dejections were completely sterilized with a I per cent, solution of carbolic acid, creolin, or lysol in thirty minutes when the solution had a temperature of 122° F., but that the sterilization required two hours when the solution was cold. In the experiments of Heider,^ the anthrax spores used by him in his tests resisted the action of a 5 per cent, solution of carbolic acid thirty-six days at the temperature of an ordinary room, but a solution of the same strength disinfected in from one to two hours at the temperature of 55° C. (131° F), or in three minutes when the temperature was 75° C. (167° F.). The same increased efficiency was observed with other solutions as their temperatures were increased. In his investigations of the value of soap solutions of crude carbolic acid, Nocht* learned that the germicidal action varies at different temperatures. Anthrax spores in a cold solution of carbolic acid were not destroyed in six days, but at the tempera- ture of 50° their destruction was complete in six hours. In practice he recommends the use of a 3 per cent, hot solution of soap into which up to 5 per cent, of crude carbolic acid can be poured and a clear solution can thus be obtained. This used at 1. Bekampfung der Infectionskranktieiteii, II., 15, 89. 1894. 2. Eevue D'aygiene, XIII., 640. 1891. 3. Centr. fur Bak., IX., 221. 1891. 4. Zeit. fur Hygiene, VII., 521. 1889. HEAT HYDROGEN PEROXID. lOQ temperatures from 40° to 50° C, he found to be efficient for the disinfection of clothing, leathern articles, etc. Experimenting with lutidin, Blyth^ failed to disinfect threads infected with bacterium termo in twenty-four hours with a 1.15 per cent, solution of this agent. The temperature was 15°, but at the temperature of 35.5° a 0.5 per cent, solution of lutidin dis- infected absolutely. Vrijheid's^ experiments show very plainly the advantage of using disinfectant solutions at somewhat elevated temperatures. He used anthrax spores in aqueous suspensions in which silken threads were soaked. After they had been dried, these threads were subjected to the action of a i : 1,000 solution of mercuric chlorid at various temperatures for certain lengths of time. In the experiments with the temperature of the disinfecting solution from 10° to 35° C. (50° to 95° F.) there was no cer- tainty of disinfection, whether the sublimate solution acted one minute or five, but when the temperature of the solution was from 40° to 48° C. (104° to 118.4° F-) sterilization was invariably perfect whether the threads were exposed five minutes or one. The cultures were kept under observation three months. Pane's^ experiments with carbolic acid led him to the follow- ing conclusions : A Yz per cent, solution of carbolic acid at a temperature of 37" destroys the Staphylococcus pyogenes aureus four or five times as rapidly as at 15°. A 5 per cent, solution of carbolic acid acts upon anthrax spores about sixty times more rapidly at 37° than at from 16° to 18°. Experimenting with mercuric chlorid, he found that solutions from 1 : 20,000 to i : 5,000 act four or five times more power- fully at the temperature of 37° than at 15°. HYDROGEN PEROXID. In a paper by Dr. B. W. Richardson," he refers to his study of this substance begun in 1858. He defines it as "an oxygen atmosphere in solution." It is not, however, a mere mixture, but a peculiar chemical compound. The oxygen can be made 1. Manual of Public Health, p. 313. 1890. 2. Nederlandsch Tldsoh., v., Geneesk. XSXII., 1074. 1896. a. An. deir Ist. D'Ig. Sper. dell' Univ. dl Eoma, II., 91. 1890. 4. The Lancet, I., 1891, 707. no HYDROGEN PEROXID. to accumulate voltime by volume, until the volume o£ water, say as much as would fill a pint measure, can rise to lo, 20, 30, and some say even over 100 volumes of oxygen before complete saturation is reached and a volatile body is formed. The combination of the added oxygen in hydrogen peroxid is stable in the presence of some substances, unstable and easily evolved in the presence of others. Dr. C. H. Brown,'^ of New York, makes the following state- ments relating to ozone and hydrogen peroxid : "It is considered that oxygen is capable of three allotropic modifications, viz. : "O2, ordinary (inactive) oxygen; O3, ozone; and Oj, active oxygen. "The latter form of oxygen (Oi), which only exists in status nascendi, is the most powerful oxidizing agent known, and is capable of combining with inactive oxygen (O2), and forming ozone (O3). Ozone is also a powerful oxidizer, in fact not much less so than O^, and as it is only formed in the presence of Oi, a distinction is in many cases difficult, and the chemical action is often ascribed to ozone, as for instance, as stated above, in the case of hydrogen peroxid (Hj Oj), the oxidizing agent of which is not ozone (O3), but nascent or active oxygen (Oi). "The following distinctions, arranged according to Baumann,^ still further show the difference between ozone and hydrogen peroxid, and the relation that O^ bears to each. "i. Active oxygen combines with inactive oxygen forming ozone, which is easily demonstrated in all cases in which its formation is not inhibited by the presence of easily-oxidizable bodies. "2. Active oxygen oxidizes water, and forms hydrogen peroxid. This does not take place when ozone acts on pure water. "3. Active oxygen oxidizes the nitrogen of the atmosphere forming nitrous and nitric acids. Ozone has no effect on nitrogen. "4. Active oxygen oxidizes carbon monoxid to carbonic acid.; this is affected by ozone. 1. Medical News, LVIII., 180. 1891. 2. Zeitschslttlur Physiol. Chemie, vol. V. (Quoted ty Brown) . HYDROGEN PEEOXID. Uj "Positive (Oi) and negative active oxygen (Oi) act essen- tially in a similar manner. It is certain, however, that the action of hydrogen peroxid (Hj O^), whose oxygen according to Schonbein is positive, is much less intense than that of ozone, O3. Ozone is a gas, hydrogen peroxid a liquid, and this fact alone necessitates a different action of the two toward various bodies. In both (apart from the positive or negative electricity, a difference which may be safely assumed) the oxidizing factor is O^; in the one compound bound to inactive (latent) water, in the other to inactive oxygen." He further proceeds to give the reactions which distinguish between ozone and hydrogen peroxid. The hydrogen peroxid tested by the Committee of the Ameri- can Public Health Association^ contained 5 per cent, of sulphuric acid, and the results are equivocal. Von Hettinga Tromp^ recommends hydrogen peroxid as a convenient, efficient, and harmless agent for the sterilization of drinking water. Ordinarily, it sufficed to add one part of hydrogen peroxid to 10,000 parts of water to insure its steriliza- tion in twenty-four hours, yet the rapidity of the action depended very much upon the number and species of the contained micro- organisms. A water which contained 19,600 germs per cubic centimetre, required 1 150,000, and a water that contained 34,- 850 germs required i : 10,000 to sterilize it in one day. Uffelmann^ repeating these experiments, did not find hydro- gen peroxid so efficient when largely diluted as Hettinga Tromp did. Even in the concentration of i :S,000 or 1 13,000, hydrogen peroxid was not so efficiently germicidal. At the suggestion of Uffelmann, Altehofer* made a careful repetition of the experiments of Hettinga Tromp. He found that neither 1:5,000 nor 1:2,500 of hydrogen peroxid sufficed to sterilize a water which had relatively few germs (560 to 1,800 per cubic centimetre) ; but the results were better with i : 10,- 000. A water to which typhoid and cholera germs had been added in considerable quantity required 1:1,000, and twenty- four hours' action of the disinfectant. n. Tr. Am. Public Health Association, XI., 207. 1885. 2. Quoted from Traugott. , ^ „ /■.„i,i„.-„ a^^ 3. Jahresberlcht iioerdle Fortschritte u. Lelstungen aut dem Geblete der Hygiene, VI., 48. 1888. 4. Centr. turBak.,VIir., 131. 1890. 112 HYDROGEN PEROXID lATROL. In Pane's^ experiments, a i per cent, solution of hydrogen peroxid destroyed spores within one hour, and staphylococci in from ten to fifteen minutes. Traugott's^ results indicate that i per cent, solution of hydro- gen peroxid destroyed the bacillus of typhoid fever and of diph- theria in five minutes; cholera germs and the streptococcus . of erysipelas, in two minutes; Staphylococcus pyogenes aureus in from fifteen to thirty minutes. This agent may, therefore, in the opinion of Traugott, be used instead of sublimate or carbolic acid, when it can have a longer time to act. When a rapid disinfection is required, as in the disinfection of the hands, it is inappropriate. Gibier,^ working with solutions containing 1.5 per cent, of hydrogen peroxid, destroyed within a few minutes B. anthracis, pyocyaneus, typhoid fever, cholera, yellow fever (?), megather- ium, prodigiosus, osteomyelitis, and Streptococcus pyogenes. Grandin* narrates the histories of cases of mammary abscess, suppurative pelvic haematocele, and puerperal endometritis, in which carbolic acid, sublimate solution, and tincture of iodin left him in the lurch, while suppuration or local sepsis ceased, and the patient went on to rapid recovery after the parts were washed out with undiluted hydrogen peroxid, or with it diluted in equal quantities of glycerin. HYPOCHLORITES. (See CHLORID OF LIME, SODIUM HYPOCH- LORITE, and ELECTROLYSIS. ) lATROL. This is said to be obtained by a synthetical process from cer- tain coal-tar derivatives, and to possess the combined properties of iodin, methylsalicylic acid, and phenol. It is a light, impal- pable, almost odorless, white powder, readily soluble in alcohol, and slightly soluble in warm water and glycerin. The manu- facturers claim that it is non-irritant and non-toxic. Dr. Theo- 1. Annali dell' l9t. fl'lg. dell' Univ. dl Eoina, II., 47. 1890. 2. Zelt. fUr Hygiene, XIV., 440. 1893. 3. Medical News, LVII., 416. 1890. 4. The Times and Register— Centr. fiir Bak., IZ., 769. 1891. INFLUENZA INSTRUMENTS. jj, dore Deecke, of Utica, N. Y., carried out a series of bacteri- ological experiments for the purpose of testing the antiseptic value of iatrol. He found that it has decided antiseptic prop- erties, but in the absence of published details relating to the experimental work, there is no ground for judgment as to the correctness of his conclusions. This name, "iatrol," should not be confounded with "itrol," mentioned under "Silver Salts." INFLUENZA. The researches of Pfeififeri have established the fact that the bacillus of influenza is easily destroyed by adverse conditions. It is rapidly destroyed by desiccation. Disinfectants of extra- ordinary strength are not required. The disinfection of all secretions from the mouth, nose, bronchial tubes, and of all objects that have been in contact with the sick is important. INSTRUMENTS. The most trusted process for disinfecting surgical instruments is by subjecting them to moist heat, — steam or boiling water. We are told by some authorities that boiling water is equivalent to steam at iOO° C. It is, however, more than equivalent in that it is more rapid and certain in its action. Some of the more resistant forms of pathogenic bacteria are supposed to be sur- rounded by protective envelopes which must be macerated and softened before the heat can penetrate their vital part. This is efifected more rapidly with hot water than with steam. The protective coat in some bacteria in a dried state is believed to consist of a series of minute bubbles or molecules of air. Referring to this theory, Ihle^ in a recent work, reminds us that gaseous or atmospheric bubbles are much more rapidly expelled from objects when they are in hot water than when in steam, due principally to the great difference between the specific gravity of water and of air on the one side, and the compara- tively slight difference between that of air and steam on the other. 1. Zelt. (ur Hyslene, XIII., 357. 1893. 2. Eine neue Methode der Asepsis. Stuttgart. 1895. 114 INSTRUMENTS. With the late improvements in gas and petroleum burners, water in covered, enamel basins can very quickly be brought to the boiling point. When boiling water is the sterilizing agent, rusting of the instruments is usually prevented by the addition of about a teaspoonful of bicarbonate of soda to a quart of water. We are cautioned by Ihle^ to have more soda in the solution for the sterilization of knives rather than too little; for solutions stronger than i per cent, have no unfavorable action upon cut- ting instruments. The smaller per cent, of soda fails to prevent knives from rusting. In sterilizing instruments by boiling, Levai^ recommends the addition of from % to i per cent, of caustic soda instead of the usual bicarbonate. So far as these processes are applicable, disinfection by boiling or with steam is preferable to the use of chemical agents. Carbolic acid has been widely used as a surgical antiseptic and disinfectant. Upon the recommendation of Scheurlen,* certain surgeons have used a J^ per cent, solution of ortho-cresol, with 12 per cent, of common salt, as a very satisfactory anti- septic. The rusting of instruments in it can be prevented by the addition of i :i,ooo of hyposulphite of sodium. The pre- ponderance of opinion among investigators is that the cresols, lysol, and solutol are more rapidly active when applied to pus- producing, and most other bacteria, than carbolic acid. Lysol has the disadvantage in surgical work of rendering instruments slippery. This is, of course, overcome if they are subsequently washed in sterilized water. Solveol, prepared as a surgical antiseptic, does not render instruments slippery, and is said to be more efficient than car- bolic acid. (See Solveol.) The field of use of mercuric chlorid is a very restricted one for the reason that it tarnishes instruments. According to Viquerat,* mercuric iodid has the advantage for this purpose over mercuric chlorid in that it does not tarnish instruments so quickly. With solutions of 1 : 1,000 of each, mercuric iodid does not begin to act generally before ten minutes, while the action of mercuric 1. Archlv tiir klinische Ohirurgie.— Centr. fur Bak., XVII., 9J9. 1895. 2. Jaliresberictit Uber die Forstsohltte u. Lel3t. aut dem Geblete der Hye. SIV., 278. 1897. 3. AroMv furBxper. Pathol, u Pilar., XXXVII., 74. 1896. 4. Centr. fur Bak., V., 536. 1889. INSTRUMENTS. "5 chlorid begins in one minute. In one hour, instruments that have been laid in mercuric chlorid have become black, while in mercuric iodid, in the same length of time, they have a yellowish coating that can be removed by a simple wiping. Dr. Deniges^ has combined Marechal's suggestion that instru- ments may be protected from rust indefinitely by the addition of a small quantity of some alkali with the use of a powerful anti- septic, and announces that instruments thus treated are abso- lutely sterilized, while they suffer no injury, even if left for months in the antiseptic solution. His formula is, mercuric cyanid two to five grams in one litre of water, to which is added five grams of sodium borate or carbonate. The experiments of Dr. Chas. T. McClintock indicate that the "germicidal" soap devised by him is a rapidly efficient surgical disinfectant and does not tarnish instruments, although contain- ing a mercurial salt. His opinion is confirmed by the work of Dr. F. G. Novy, and that of Dr. W. M. L. Coplin. Experiments that have been carried out during the last few years indicate that formaldehyde, as a gas and in solution, will prove a very convenient and efficient disinfecting agent for surgical instruments. (See Formaldehyde — Surgical Instru- ments.) For the disinfection of syringes, Hofmeister gives the follow- ing directions : The piston should be drawn from the cylinder and the lubricating material which came from the manufactory should be removed with ether or benzine (petroleumather) . The syringe should then be laid in a 2 to 4 per cent, solution of formalin for twenty-four hours. The formalin is generally all removed by rinsing, and the syringe is then ready to be disin- fected by boiling, care being taken previously to expel the air both before and back of the piston. Syringes should be such as consist only of metal, glass, and leather.^ For the disinfection of sponges, SauP recommends the use of 30 per cent, boiling propyl alcohol. Anthrax spores were destroyed in ten minutes. Fats and albumen did not interfere with the action. 1. Jr. Amer. Med. As30.— Therap. Gazette, XXI., 783. 1897. 3. Jahresbericlit uber die Fortschritte u. Lelst. aut dem Geblete der Hyg., XIV., 278. 1897. 3. Arohiv f. Klin. Chirurgle.— Munch. M. W'ocli., SLV., 759. 1898. Il6 lODIN TRICHLORID. lODIN TRICHLORID. Behringi says that this is the most efficient and many-sided of all the disinfectants. In another work^ he says that, beside iodin trichlorid, only corrosive sublimate, carbolic acid and cresol with acids, the halogens, and cholrid of lime, among the agents tested are capable of destroying anthrax spores in a short time. It may also be classed among the safe disinfectants, as it is poisonous only in a minor degree. Threads of bouillon with anthrax spores were sterilized in from two to four minutes with I per cent, of iodin trichlorid. Even in blood, where acid solu- tions of carbolic acid or cresol, and solutions of mercuric chlo- rid leave us in the lurch, this agent is efficient. In serum, anthrax spores on threads were devitalized in five minutes with 2.5 per cent, of iodin trichlorid, and in from thirty to forty minutes with i per cent. Behring recommends a 5 per cent. solution as a convenient stock solution that will keep unchanged for weeks. In the laboratory of the Imperial Board of Health of Ger- many, iodin trichlorid was subjected to a detailed investigation by RiedeP for the purpose of determining its antiseptic and dis- infectant powers. The test-organisms being on threads, a I : i^ooo solution invariably destroyed anthrax spores in nine hours, anthrax bacilli in thirty minutes. Staphylococcus pyogenes aureus, in fourteen minutes, and staphylococcus of osteomyelitis in one hour. In bouillon, anthrax 43acilli were killed in from eight to ten minutes with i : 1,000; staphylococci in from ten to thirty minutes with 1:4,000; and the cholera germ in frorti one half to one minute with i : 2,000. Tested as a surgical antiseptic, iodin trichlorid in a solution of the strength of 1:1,200 prevented the growth of staphy- lococci, streptococci, the most important bacteria of surgical diseases, while a i : 1,600 was not certain in its efifects. His experiments also showed that a complete sterilization of the hands may be effected with a i : 1,000 solution of iodin trichlorid after they have been cleansed one minute with warm water, sOap, and nail-brush. Riedel concludes that iodin trichlorid is an 1. Bekamptung aer Intectionskranklieiten, II., 27. 1894. 2. Zeit. fur Hygiene, IX., 455. 1890. 3. Arbeiten a. cl. Kais. Ges., II., 466. 1887. lODIN TRICHLORID IODOFORM. II7 efficient disinfectant and that its germicidal power is very much greater than that of carbolic acid and is surpassed only by that of corrosive sublimate. After investigating iodin trichlorid, Tavel and Tschirch^ report that this salt acts very energetically upon Staphylococcus citreus, S. pyocyaneus, and anthrax spores. With the last micro-organism it is superior to chlorin. The time of the action upon the bacteria was limited by the use of sodium thiosulphate solution. As a disinfectant, it makes no difference whether pure or the impure iodin trichlorid of commerce is used. Rideal, referring to iodin trichlorid, says : "It is well known in organic chemistry that the presence of a trace of iodin favors greatly the action of chlorin on organic bodies, hence it is not improbable that a small quantity of iodin, or of its chlorid, might be a valuable adjunct to chlorin disinfection.^" Traugott^ says of iodin trichlorid that a 5 per cent, solution keeps for months without any susceptible change, but that a 1 : 1,000 solution rapidly loses its disinfecting power. Accord- ing to his experiments, the germs of typhoid fever, cholera, diphtheria, streptococcus of erysipelas, Staphylococcus pyo- genes, and staphylococcus from osteomyelitis were all destroyed within one minute with a i per cent, solution, and were all destroyed in from one to ten minutes with a i : 1,000 solution. Diarrheal discharges, with the addition of typhoid fever and cholera bacilli mixed with an equal volume of a 2 per cent, solu- tion of iodin trichlorid, were disinfected in fifteen minutes. IODOFORM. The question of the antiseptic power of iodoform has called out much discussion. The favorable evidence derived from surgical practice has not been confirmed by the results obtained by many of the bacteriologists. Some light has, however, been thrown upon the rationale of the antiseptic and therapeutic action of iodoform by the work of some of the investigators. With the discovery of Scheurlen in mind, that the influence of 1. Oentr. fur Bak., Xnr., 736. 1893. 2. Disinfection and Disinfectants, p. 74. 1895. London. 3. Zeit. fur Hygiene, XIV., iU. 1893. Il8 IODOFORM. some of the ptomaines is to excite suppuration, and that this is particularly true of cadaverin, Behring's^ experiments taught him that iodoform prevents cadaverin suppuration. He injected a concentrated solution of cadaverin subcutaneously and thereby produced suppuration. When pure cadaverin is added to iodo- form, it is decomposed even in the cold. At the same time the iodoform is decomposed and free iodin is liberated. When cadaverin and iodoform in excess are simultaneously admin- istered subcutaneously no suppuration results. A large part of the beneficial action of iodoform is due to the destruction of the cadaverin molecules. Assuming that the pathogenic action of virulent pus is not due merely to the presence of the bacteria of suppuration, but also to the chemical products themselves; and assuming, further, that these chemical products are influ- enced in a similar manner as cadaverin is influenced, it becomes evident that the curative action of iodoform in virulent suppura- tion may be exerted without direct harm to the micro-organisms of suppuration. Writing at a later date of the action of iodo- form, he says, that it exerts its antiseptic action only when it is decomposed, and that from a surgical point of view this is a fortunate peculiarity of this agent. "Bacteria which have strong reducing characteristics decompose iodoform and render it active. ***** -pj^g more foul the secretions from the sur- faces of wounds, the more vigorously it acts. ***** Iodo- form is an antiseptic agent in the true sense of the word."= The experiments of Mattel and Scala^ confirm the results obtained by Behring, and teach them that, when iodoform or iodol comes in contact with certain reducing substances, iodin is liberated, and to this element in its nascent state is to be ascribed the antiseptic action of iodoform. They found that iodoform acts more energetically than iodol. In an editorial in one of our leading medical journals*, a brief review was given of the work of Lomry at the Lowen Univer- sity. He found that, in experimental wounds upon the opposite sides of animals, in every case the iodoform gave to the wound to which it had been applied a red, healthy appearance which 1. Deutsche Med. Woch., XV., 837. 1889. 2. Bekampfung der In£ectionskranklielten, II., 102-106. 1894. 3. Bulletin d'K. Acad. Med. dl Roma.— Centr. liir Bak., V. 492. 1889. 4. Medical News, LXX., 54. 1897. IODOFORM LIGHT. 119 was lacking in the wound on the opposite side. The iodoform reduced the amount of secretions, increased the diapedesis of the white blood corpuscles, and did not diminish their vitality, as shown by their ameboid movements. It also delayed the devel- opment of the microbes. In laboratory tests with gelatin, agar, and bouillon cultures, they found, just as others had found, that iodoform had practically no effect in delaying the growth of bacteria. The surface of a wound does not present the same conditions as does nutrient gelatin in a test-tube. In the wound it is soluble, hence its antiseptic action. It is insoluble in gela- tin, agar, and bouillon, and in these culture media it is inert. In serum, however, derived from various animals and in the fluid from hydroceles, blisters, pleurisy, and abscesses in man, the cultures in these media grew much less rapidly when iodoform was added. It may be stated, therefore, that the natural course of infection in a wound may be hindered by iodoform in three ways : by limiting the development of the microbes ; by lessen- ing their virulence ; and by neutralizing their toxins. LIGHT. In the study of the available means of destroying infection, light, and, particularly, direct sunlight should not be forgotten. The researches of recent years show that sunshine has a degree of germicidal value; and the bacteriologist who is not mindful of this fact may obtain very misleading results. Twenty years ago, Downes and Blunt observed that diffused daylight retarded the putrefaction of organic infusions, and that direct sunlight absolutely inhibited putrefaction. Their work, done before the days of pure cultures, did not receive the attention which the importance of the subject deserved. It was not until the pres- ent decade that general attention has been directed to the subject. It is found that the most resistant of pathogenic organisms may, under favorable conditions, be destroyed by the action of sun- light. Arloing observed that anthrax spores lost their power of development after two hours' exposure to sunlight; but to pre- vent the further growth of the anthrax bacillus in its vegetative form, twenty-seven or twenty-eight hours of sunshine were 120 LIGHT. required. Roux also observed that anthrax spores in bouillon, when freely exposed to the action of the air as well as that of light, were destroyed; but that the vegetative forms were still capable of development. In 1890, Pansini published the results of his experiments to determine the action of sunlight upon B. anthracis, prodigiosus, pyocyaneus, violaceus, murisepticus, cholera, and Staphylococcus albus. He found that even diffused light had' a marked effect in inhibiting the growth of bacteria after it had acted from twenty-four to forty-eight hours. Direct sunshine acting per- pendicularly upon the surface of the cultures sterilized them all within one day. When the sunshine acted obliquely, it was necessary to expose the cultures several days in order to steril- ize them completely. In liquid cultures from one half to two and one half hours sufficed to destroy all of the bacteria. The observations of Marshall Ward^ showed him that an- thrax spores are destroyed in a few hours by the action of sun- light. Transferred to fresh culture media, it was shown that, instead of a delayed development, their destruction was complete. Electric light had a germicide action weaker than that of sun- light. In the experiments of Momont,^ anthrax bacilli without spores, in dried blood, resisted the action of sunlight and air eight hours. Anthrax bacilli from bouillon, dried and then exposed to sunshine live about five and one half hours. Anthrax spores resist the action of sun and air more than one hundred hours when dry. In pure water they are not killed by the action of the sun in one hundred and ten hours in the absence of air ; but are destroyed by forty-four hours' exposure to the action of the sun and air. Sirena and Alessi^ experimented with the view of determin- ing the action of desiccation and of light upon various bacilli under various conditions. The bacillus of cholera dried in a dry room in the shade, or in sunshine exposed to air, or in sunshine hanging freely in the 1. Centr. fur Bak., XIII., 668. 1893. 2. Annales de I'lnst. Past., VI., 21. 1892. 3. La Eitorma Mefl., 1892.— Centr. fiir Bak., XL, 484. 1892. LIGHT. 121 room, was destroyed in one day ; but dried in a moist room, vital- ity was retained twelve days. Typhoid bacilli retain their vitality sixty-four days in a dry room in the shade, sixty-eight days dried in a damp room, one day exposed to the sunlight and enclosed in a reagent glass, and seven days when exposed to sunshine and hanging free in the room. Anthrax bacilli containing spores were not killed in 431 days when dried in a dry room in the shade ; but they were destroyed in 290 days in a damp room, in nineteen days when exposed to the sunshine in the reagent glass, or in forty-eight days when exposed to the sun and the air. The conclusions of the authors are that desiccation is a power- ful means of disinfecting ; that the varying effects of desiccation are due in part to the bacteria themselves and in part to the con- ditions in which the desiccation occurs; that sunlight itself is ■capable of destroying the most resistant micro-organisms. Typhoid Bacilli. — In a paper on the action of light upon bac- teria, Geisler,^ of St. Petersburg, refers to some of the works of his predecessors. Uffelmann noticed no injurious action of sunlight upon typhoid bacilli. Georges Gaillard, on the other hand, convinced himself that the action of direct sunlight, for from three to four hours, sufficed to destroy completely typhoid bacilli. He came to the following conclusions: The rapidity of the action of the light depends upon the medium in which the bacteria are ; the action of light is greater when the atmospheric air has free access to the cultures ; all parts of the solar spectrum have an action upon bacteria, but none so great as that of white light. Janowski experimented with typhoid bacilli. He came to the conclusion that light has a direct action upon bacteria irrespec- tive of any chemical changes in the culture media. Typhoid bacilli exposed to direct sunshine were nearly all destroyed in from six to ten hours. Diffused light had a germicide action, though weaker. Referring to the results of his own experiments, Geisler con- cludes that, a qualitative difference between the action of sun- light and electric light could not be observed, but the inhibitive 1. Centr. fur Bak., XI., Ml. 1S92. 122 LIGHT. action of sunlight upon the development of typhoid bacilli is distinctly greater than that of electric light. Not only the light and the chemical rays of electric light and sunlight act injuriously upon the growth of typhoid bacilli, but the heat rays have an auxiliary action in the same direction. All of the rays of the electric and solar spectrum, with the excep- tion of the red rays, inhibit the growth of typhoid bacilli. The unfavorable action of the electric light and sunshine upon the growth of typhoid bacilli on gelatin is due, not only to the direct action of the light upon the bacilli themselves, but depends also in some measure upon changes in the culture media. Dieudonne found that the bacillus of typhoid fever and B. coli were destroyed in one and one half hours' exposure to the action of the sunshine. Cholera. — In a first series of experiments, Palermo^ used bouillon cultures of cholera three days old as the most virulent. Tubes of lo cc. were used. While exposed to the action of the sun, precautions were taken against undue elevation of tempera- ture. In a second series, from 3 to 6 cc. of the culture were diluted with 30 cc. of sterilized distilled water. The results obtained by him indicate : that even after an exposure of six or seven hours to the action of the sunshine there was no diminu- tion in the number of bacilli, but their restricted motion indi- cated an attenuation of biologic functions ; that a comparatively shorter exposure to the action of the sun, — three or four hours, — sufficed to deprive the germs of virulence when tested on guinea-pigs; that the diminution of virulence is effected more rapidly when the media ai^e diluted. The results obtained by Buchner did not agree with those obtained by Palermo. He found that light has a very powerful disinfecting action upon aqueous suspensions of cholera spirilli. Tuberculosis. — In the experiments of Dr. Migneco,^ of the University of Catania, he found that, after ten or fifteen hours' exposure to sunshine, the bacillus of tuberculosis gradually lost its virulence, giving rise on inoculation to localized tuberculosis, and that, after twenty-four to thirty hours' exposure, complete 1. Annali flell'Ist. D'Ig. Sperlm. deUa K. Univ. di Roma, III., (Nuova Serie),463. 1893. 2. Annali D"Igiene Sperlmentale, V., 216. 1895. LIGHT. 123 Sterilization was eifected. The material used by him was tuber- cle sputum containing tubercle bacilli smeared on cloth. Before the International Medical Congress held in Berlin in 1890, Koch stated that the bacillus of tuberculosis is killed by the action of direct sunlight in from a few minutes to several hours, depending upon the thickness of the layer exposed. Dififused daylight has the same effect, but acts more slowly. Ransome and Delepine made a series of investigations with the object of determining how short a period of exposure to air and light would suffice to destroy the virulent action of the bacillus of tuberculosis. The experiments were made with both pure cultivations and with dried sputum, in some cases scraped and reduced to dust. Guinea-pigs were used for the inoculations. The experiments with the dried sputum are the most interesting, as they con- form most closely with what would be met with in practice. The specimens were exposed for short periods only — two, three, and seven days — though control specimens were kept for long periods of time in darkness, and with very slight access of air. It was observed that in all the specimens exposed in the dark, tuberculosis was the result even in free currents of air. All the specimens exposed to both air and light, even for two days only, and for one hour of sunshine, were found to have entirely lost their power for evil. Specimens of the same tuberculous dust gave tubercle to guinea-pigs after it had been kept in the dark, and with very little air, for thirty-five days.^ Diphtheria Bacillus. — In the experiments of Piazza,^ the action of sunlight is shown to attenuate the virulence of diph- theria toxin, slowly when the air is excluded, and much more rapidly when air is admitted. In the work of Ledoux-Lebard,^ it was found that sunshine has a distinct germicide action upon the bacillus of diphtheria, but that in his opinion sunshine can be depended upon only as an auxiliary to other methods of disinfecting in this disease. Bacteria of Suppuration.— Tht results obtained by Cheme- lewsky* were as follows : When subjected to the action of 1. Public Health, Vol. VII., 131. 1895. Lonflon. 2. Annali D'Igiene Sperlmentale, V., 521. 1895. 3. Kevue D'Hygiene,, XVI., 69. 1894. 4. Vrach.— Centr. fur Bak., XII., 174. 1892. 124 LIGHT. electric light for six hours the development of the bacilli of suppuration was checked. When the same bacilli were sub- jected to the action of sunshine for the same length of time they were destroyed. Not only the chemical and light rays, but the heat rays retard the development of bacteria. The development of Staphylococcus pyogenes albus, bacillus pyocyaneus, strep- tococcus erysipelatos, and S. pyogenes is retarded by all the rays ■of the spectrum with the exception of the infra-red rays. Staphylococcus pyogenes aureus proved the most resistant. The results showed that the virulence of bacteria of suppuration is diminished under the influence of light. How Light Acts. — The suggestion has been made that the germicide action of sunshine is due to its heat rays. Santorni/ however, investigated the simultaneous action of sunshine and the resulting heat from it. He found that the germicide action of sunshine was distinct when the accompanying temperature was not high ; that bacteria when dry withstand the action of light much longer; that no great difference exists between the power of anthrax spores and anthrax bacteria to withstand the action of the light; that the higher the accompanying tempera- ture, the greater the effect of sunshine or the electric light ; that the action of an electric light of 900 candle power is distinctly weaker than that of sunlight. Marshall Ward's^ experiments demonstrated that the actinic rays of the sun, independent of the heat, act germicidally. Kruse" also determined the fact that the disinfecting action of light is not due to the heat rays, but that the higher the accom- panying temperature the greater the germicide action of the light. The. noxious action of light upon bacteria has also been ascribed to changes in the medium in which they are found. In 1893, Richardson communicated his observation that, when fresh urine was exposed to the action of direct sunshine and air, there was invariably a formation of hydrogen peroxid which resulted in the destruction of the bacteria. Urine thus exposed to the action of the sunlight even showed an antiseptic action 1. Quotefl by Geisler. 2. Lancet, II., 1893, 3S3. 3. Zelt. tiir Hyg., XIX., 323. 1895. LIGHT. 125 when added to other urine that was putrefying and had not been exposed to the action of the sunshine. Dieudonne^ undertook a series of experiments for the purpose of determining the truth of this, and whether the sunshine also had a similar action upon other culture media. He found that,, when exposed to the action of the light, hydrogen peroxid is formed in agar and gelatin cultures in sufficient quantities to exert an antiseptic action. This action is due to the blue and violet rays. The red and yellow rays have no action of this kind. Hydrogen peroxid thus formed is rapidly decomposed when removed from the light. When the culture is again brought to the light, there is a re-formation of hydrogen peroxid. This can be repeated indefinitely with the same results. He further- more found that light had the same action upon ordinary water, — formation of hydrogen peroxid. In the different strata of water exposed to the action of light the quantity of hydrogen peroxid was unlike. It was most plentiful in the upper portion of the water. As to the manner in which sunshine exerts its bactericide action, this observation that light, in certain culture media and fluids, gives rise to the formation of hydrogen peroxid offers at least a partial explanation. In polluted water no reaction indicative of the presence of hydrogen peroxid is at first obtained, for the reason that hydro- gen peroxid, as fast as it is formed, is decomposed in its action upon bacteria. Further experiments by Dieudonne showed that, in the absence of oxygen, there is no formation of hydrogen peroxid. The experiments were made with various anaerobic bacteria. The formation of hydrogen peroxid through the action of air and light appears, therefore, to constitute a not unimportant factor in the germicide capabilities of light. The self-purifica- tion of rivers which, according to the investigations of Buchner, is to be ascribed largely to the action of light, receives a partially satisfactory explanation in the fact that hydrogen peroxid is formed under the influence of light. 1. Arbeilen a. d. Kais. Ges., IX., 537. 1894. 126 LIGHT. Dandrieu^ made a series of experiments which showed the part played by oxygen in the germicide action of Hght. In two flasks, one red and one clear, Dandrieu exposed dilute sewage to the action of the sun. The oxygen content of the water, before its insulation, was 5.6 mg. per litre; after it had been exposed to the action of the sunshine, there was a diminution of the oxygen in the red flask and a great increase in the water enclosed by clear glass. Oxygen before insulation. Oxygen after insulation. 8 days. U days. Bed flasli 5.6 5.6 3.6 17.92 2.46 23 96 In the water from the red flask, the bacterial flora was exceed- ingly rich, there being innumerable motile bacilli, vibrioni, and zoospores present ; in the water from the clear glass there were only cocci present. Dandrieu concludes that, under the influ- ence of sunlight, micro-organisms develop which have a reduc- ing action on carbon dioxid, and that the oxygen thus liberated destroys bacteria. As has been noted, Geisler found that light has a direct action upon bacteria, but that this action depends in some measure upon changes in the culture media. Kruse has shown that the intensity of the action of light upon bacteria depends upon the access of oxygen, and that while light has a direct germicide action the chemical changes in the media or the liquids in which bacteria are suspended are an important factor in the work. Sewage, and the Self -Purification of Rivers. — With the view of determining to what extent the action of the sun can be depended upon to disinfect sewage, and what part light plays in the self-purification of rivers, Procaccini^- carried out a series of investigations. The tables which he presents indicate that the action of the sunlight is strongly bactericidal. Sewao-e was 1. Annales d'Hyg.— Centr. fur Bak., V., 186. 1889. 2. Annali dell'Ist. D'Ig. Sper. deUa E. ITniv. Serie) 437. 1893. dl . Roma, III., (Nuova LIGHT. 127 exposed in glass vessels of a height of 60 cc. and a diameter of 25 cc. Selecting one experiment as a typical one, the number of colonies was reduced from 5,401 to 4 after six hours' exposure to the sunlight, while, in the duplicate experiment, the number of colonies increased from 5,493 to 9,419 in five hours, and to a much larger number in six hours. The two vessels were kept at practically the same temperature. In experiments to determine the depth to which the action of the sun was exerted, the cylinders were protected from all but the perpendicular rays. After three hours' exposure there were nine colonies at the top, ten at the center (30 cc. deep), and 2,115 at the bottom of the column of sewage (60 cc. deep). In a control experiment, in which the cylinder was protected from the sun, the numbers in the same order were 3,103, 3,021, and 3>463- Professor Buchner^ sought to determine the influence of light upon the bacillus of typhoid fever, B. coli communis, B. pyocyaneus, cholera spirilla, and various bacteria of decompo- sition. He found that when these bacteria are suspended in water, light has a very powerful disinfecting action. For instance, water containing 100,000 B. coli communis per cc. is rendered completely sterile by one hour's exposure to direct sunshine. Control samples kept at the same temperature, but not exposed to the light, showed a slight increase in the number of bacteria. Even diffused daylight effected a marked diminution in the number of germs after one hour's exposure. He believes that the action of light plays an important part in the self-purifica- tion of the water of rivers and lakes, although he alludes to the fact that certain species of bacteria are not prejudicially affected by the action of light. In another paper by Professor Buchner,^ referring to light as an important factor in the self-purification of rivers, he says that, even in September and November, diffused daylight sufficed to destroy, in five hours, bacillus of typhoid fever, B. pyocyaneus, and B. coli. 1. Centr. fur Bak., SI., 781. 1892. 2. Archiv fiir Hygiene, XVII., 179. 1893. 128 LIGHT. The Influence of Light upon the Animal Organism. — A series of experiments carried out by Dr. Masella^ for the pur- pose of determining the influence of direct sunshine upon guinea-pigs inoculated, some with the bacillus of typhoid fever, and some with that of cholera, showed in both series of animals that their resistance against the action of the injections was diminished by exposure to direct sunshine, irrespective of the heat rays of the sun. Arnould,^ referring to these experiments which indicate that sunlight lessened the resistance of these animals to infection, is but little disposed to admit the opinion that sunlight is so impor- tant a factor of morbidity and of mortality. He finds that the number of experiments made by Masella was too small to have great value, and he thinks, furthermore, that he did not eliminate fully enough the influence of temperature. Arnould admits that sunshine occupies only a secondary place among the conditions which favorably influence human vitality. He believes that the indirect action, — the action in destroying and preventing the development of the morbific germs, — is the principal value of light as an essential element in individual health. The Real Value of Light as a Disinfectant. — Esmarch^ refers to the fact that Boubnoff has shown that the chemical action of the i-ays of the sun extends more or less deeply into fabrics, but it seemed to Esmarch that it was necessary to determine whether the direct sunlight may be used as a means of disinfecting cer- tain things, as cushions, mattresses, and upholstered furniture, which in many places cannot be subjected to other trustworthy processes of disinfection. His experiments show that the direct rays of the sun, under certain conditions, penetrate considerably below the surface of the articles to be disinfected. The action of the sun penetrated layers of linen cloth and destroyed cholera bacilli in from one to two hours upon the second and fourth layers of the cloth. To obtain the same effect with diphtheria cultures upon the first and third thicknesses of linen or of white woUen cloth, five hours' exposure to the direct sunshine was required. Staphylococcus pyogenes aureus, or Streptococcus 1. Annali D'Igiene Speiimentale, v., 73. 1895. 2. Revue D'Hygiene, XVII., 511, 668. 1895. 3. Zeit. fiir Hygiene, XVI., 257. 1894. LIGHT. 129 pyogenes was destroyed with no certainty after six hours' exposure. The light penetrated dark colored cloths much less deeply, and destroyed bacteria much less readily than in the case of white fabrics. In the interior of cushions, prolonged exposure to the action of the sun was powerless to destroy the diphtheria bacillus. These and other experiments convince Esmarch that in the action of the sunlight we have no trustworthy means of disin- fecting. When we can assume that the pathogenic germs are upon the surfaces of articles, as in most cases of diphtheria, it would suffice to expose the articles to the action of the sun for a few hours, but when, in cases of cholera or typhoid fever, the dejections of the patient may have penetrated to the interior of mattresses, the action of the sunshine cannot be trusted. For the purpose of comparing the action of the sunlight upon upholstered articles with that of spraying with carbolic acid, he carried on a series of experiments with the latter disinfecting agent. His results obtained with a 2 per cent, solution were untrustworthy, but with a 5 per cent, solution of carbolic acid, and spraying it plentifully over the surfaces of the goods until their surfaces were completely wet, the results were somewhat better, though not very encouraging. Dieudonne^ says that, unfortunately, sunlight acts only upon the surface of matter to be disinfected ; therefore, for clothing, bedding, etc., it is not a trustworthy means of disinfection. It is, nevertheless, a hygienic factor which should not be under- estimated. Kruse^ refers to sunshine as a universal and the cheapest means of disinfecting our houses and their surroundings, but at the same time, speaks of its limitations as a disinfecting agent. About and within our houses it must have access in the greatest abundance, but the attendant heat and ocular irrita- tion are often objectionable. In the disinfection of furniture, for instance, the difficulty of having direct sunshine gain access to every part is apparent. As to the action of light upon the tacteria of rivers or other bodies of water, it can be shown experimentally that it is not uniformly trustworthy. Its failure 1. Arbelten aus dem Kals. Ges., IX., 405. 1894. 2. Zeit. fur Hygiene, XIX., 332. 1895. 130 LIME. to sterilize is due sometimes to the slight intensity of the light, sometimes to turbidity of the water, and the absence in the water of a sufficient quantity of oxygen may contribute to the failure. The experiments of Procaccini, already cited, show that, in their action upon sewage, the disinfecting rays of sunlight do not penetrate to any great depth below the surface. LIME (caustic lime, CALCIUM OXID). In 1887, Liborius^ published a paper giving the results of his experiments with quick, or caustic lime to determine its disin- fecting power. He sums up his results in the following words : "A watery solution of lime of the strength of 0.0074 per cent, is sufficient to destroy typhoid bacilli in a few hours, and in the proportion of 0.0246 per cent, it will disinfect cholera bacilli in the same length of time. "Cultures of the cholera bacillus in unfiltered bouillon con- taining abundant albuminous precipitate, which offer at least as unfavorable conditions for the action of the disinfectant as are present in natural cholera dejections, are completely and per- manently disinfected in the course of a few hours by the addi- tion of 0.4 per cent, of pure quicklime, or by 2 per cent, of crude b\irnt lime in fragments. "Under more difficult conditions the most energetic action of the lime was obtained when it was used in the form of pure, pulverized, caustic lime, or as a milk of lime containing 20 per cent, of the same." To test the conclusions of Liborius, Sternberg^ made a some- what extended series of experiments. He says : "The above experiments suffice to demonstrate the fact that pure calcium oxid has no great value for disinfecting purposes, and show that the proposition of Liborius to give it the prefer- ence over chlorid of lime on account of its comparative cheap- ness is based upon a misconception of the practical value of the two agents for disinfecting purposes. Inasmuch, however, as calcium oxid has considerable germicide power when used in the form of lime-wash, especially after prolonged contact, the 1. Zeitschrift fur Hygiene, II., 15. 1887. 2. Disinfection ana Disinfectants, p. 172. 1888. Concord. LIME. i^i general use of lime-wash for sanitary purposes is to be recom- mended wherever it can be appHed to surfaces which are sup- posed to be infected by disease germs." Kitasato^ concluded from his own experiments that the typhoid bacillus is destroyed in nutrient gelatin and in bouillon by the addition of 0.0966 per cent, of lime, about thirteen times the proportion found by Liborius to be necessary. This differ- ence he deems to be due to the fact that Liborius diluted his bouillon with fifteen times its quantity of sterilized distilled water, while he used his culture media undiluted. Cholera bacilli were disinfected with caustic lime in the pro- portion of 0.1 per cent, against 0.0246 per cent, as given by Liborius. Liborius and Kitasato having determined the minimum quan- tity of caustic lime to be used for the destruction of typhoid and cholera bacilli, PfuhP set himself the task of learning in what quantity and in what forrh it is best to use caustic lime for the disinfection of typhoid and cholera stools. His experiments taught him that the action of the lime, when added in fragments to liquids to be disinfected, is slow and uncertain. When to the quicklime, as obtained in the market, one half its weight of water is added, it is slaked to a dry powder. If the hydrate of lime thus resulting is added in the form of powder to typhoid dejections, the powder has a tendency to collect in masses and not mix uniformly with the matter to be disinfected. Pfuhl found that the best way to use the lime is in the form of milk of lime made by the addition of one part of caustic lime to four parts of water, and thoroughly mixing. This gives a 20 per cent, mixture. Two per cent, of this milk of lime added to neutral typhoid discharges disinfected them completely in one hour. He therefore concludes that, in practice, it is best to add to the matter to be disinfected 2 per cent, by volume of the 20 per cent, milk of lime. It is self-evident, he says, that the addition of 2 per cent, of the lime-wash will be sufficient only when it is prepared from lime of good quality, and when used soon after its preparation. 1. Zeitsohrift fur Hygiene, III., iie. 1887. 2. Zeitsohrift fur Hygiene, VI., 98. 1S89. 132 LIME. or at least within a few days, having in the meantime been excluded from the atmosphere, and when the typhoid or cholera dejections, as is the rule, are of a liquid consistency. According to his experience, it is sufficient in the disinfec- tion of excreta to add the milk of lime until every portion of the matter to be disinfected gives a distinct alkaline reaction, that is, until red litmus paper is colored a deep blue when a drop of the mixture on a glass rod is touched to it. The results obtained by Liborius, Kitasato, and Pfuhl were so unexpected, and their practical application, if correct, would be of so much value in practice, that Richard and Chantemesse^ thought it worth while to repeat the work of their predecessors. They tested the comparative disinfecting power of lime, using Pfuhl's 20 per cent, milk of lime, and, for purposes of com- parison, a solution of corrosive sublimate i : 1,000 with five per cent, of hydrochloric acid added, and a 5 : 100 solution of chlorid of lime. As matter to be disinfected, they used typhoid and dysenteric stools in flasks, sterilized with heat, inoculated with typhoid bacilli or with the micro-organism thought by the authors to be the pathogenic agent of dysentery. Eight hours afterward the disinfectant was added and mixed with the pure cultures thus secured. The typhoid bacilli were not destroyed in forty-eight hours by the corrosive sublimate solution, neither were they by the acid sublimate solution. They were not destroyed by the chlorid of lime solution in one hour. On the other hand, the milk of lime effected complete disinfection in half an hour. The dysenteric stools were also thoroughly sterilized in half an hour by the milk of lime, while the acid corrosive sublimate solution failed to do it in twice that length of time. There is unfortunately a discrepancy, apparently a mistake of the printer, in the statement of Richard and Chantemesse of the quantity of the disinfectant solutions used in comparison with that of the matter to be disinfected. Schanz^ also tested the disinfecting power of caustic lime and was able to confirm the results of Liborius, Kitasato and Pfuhl X. Eevue D'Hyglene, XI., 641. 1889. 2. Deutsche Med. Wooh., XVI., 77. 1890. 133 as to its efficiency in the disinfection of liquids, but he doubts whether it would be suitable for the disinfection of excreta, on account of its lack of power to penetrate the more solid masses and particles of fecal matter. Karlinski^ gives his testimony also to the efficacy of lime as a disinfectant. Added to typhoid stools in the proportion of about 4 per cent., the bacilli were entirely destroyed within forty-eight hours. The foregoing statement of the results of experimental work with caustic lime, or milk of lime, was made for the Fifth Annual Report. Since then some further work has been done and "milk of lime" has received wide recognition as a cheap and trustworthy agent for the disinfection of excreta. In his experiments in the disinfection of stalls, cattle cars, etc., Jaeger^ learned that the specific micro-organisms of chicken cholera, hog cholera, erysipelas of swine, typhoid fever, glan- ders, and sporeless anthrax bacilli and Staphylococcus aureus are killed in two hours by the action of a thick milk of lime applied with a brush once. On the contrary, lime-wash failed to destroy anthrax spores, and the bacillus of tuberculosis was not destroyed in six hours, though three applications of the milk of lime were made. Giaxa' conducted a similar line of work, thereby determining that, in the disinfection of walls, even a 50 per cent, lime wash, acting forty-eight hours, failed to destroy anthrax spores, the bacillus of tuberculosis and the bacillus of tetanus. The typhoid and the cholera bacillus, sporeless anthrax bacilli, and Staphy- lococcus aureus, were destroyed, the cholera germ readily, and the staphylococcus with difficulty. He recommends white- washing as trustworthy for only cholera and typhoid fever. Beyer* carried out a series of experiments to determine whether lime water is an efficient and desirable disinfectant for clothing infected with the germs of cholera, typhoid fever, diph- theria, and with Bacterium coli and Staphylococcus pyogenes aureus. In nearly all of his experiments, complete sterilization was attained in twenty-four or forty-eight hours. His conclu- 1. Centr. fur Bab. und Par., VI., 73. 1889. 2. Arbeiten a. a. Kais. Ges., v., 251-273. 1889. 3. An.rleMlc.-GJonialeaellaRealeSoc. Ital. D'lg,, XII., 345. 1890. 4. Zeit. fur Hygiene, XXII., 228. 1896. 134 LIME. sions are that lime water is an efficient disinfectant for all these bacteria; but to insure complete sterilization, the clothing must be left in the lime water forty-eight hours, or to disinfect in twenty-four hours, the clothing must be washed in an excess of lime water and left in it a while, then be transferred to fresh lime water and soaked in that for twenty-four hours. As to the effects upon fabrics, he found, by many experiments, that woolens suffer changes in color and texture, but that cot- tons and linens suffer practically no change in textile strength, elasticity, or color. Beyer, therefore, recommends lime water as an efficient as well as cheap disinfectant for cotton and linen goods. Referring to his work in the disinfection of fecal matter, Vin- cent^ states that his results with caustic lime were less favorable than those obtained by other experimenters. To destroy the bacillus of typhoid fever in twenty-four hours at the tempera- ture of 15° C, a 25 to 30 per cent, milk of lime must be used. The comma bacillus in cholera stools is destroyed in seven hours at the same temperature with a 15 per cent, of milk of lime. In comparing the action of milk of lime with that of saprol in the disinfection of excreta, Scheurlen^ refers to Pfuhl's experiments which show that, when thrown into a vault contain- ing fluid or semi-fluid matter, the milk of lime sinks to the bot- tom of the liquids and is only partially mingled with the con- tents of the vault unless they are stirred mechanically. This mechanical mixing is practically impossible. Another objection to the use of milk of lime for this purpose is that the liquid contents of the vault are rich in substances which combine with the hydrate of lime, thus destroying its disinfectant proper- ties. We have here, not only the fixed and volatile phosphates, carbonates, and sulphates of the alkalies, but we have to take into account the large quantity of carbonic acid which is produced by the decomposition of urea (which amounts to about 40 grams per head per day), uric acid, and other products. Special Uses. — In the prevailing practice, milk of lime finds its most frequent use in the disinfection of excreta. For the disinfection of excretal matter in the sick-room, several quarts 1. Annales del'Inst. Past., IX., 15. ]895. 2. Archlv fiir Hygiene, XIX., 349. 1893. LIME. 135 of the milk of lime may be kept in a jug closely corked, in or near the room. Though in the opinion of Pfuhl, 2 per cent, of the 20 per cent, milk of lime suffices, the safer practice is to add to each stool a volume at least twice that of the discharge to be disinfected. As time is an important element in disinfection, each discharge thus treated should remain exposed to the action of the disinfectant ten or twelve hours, preferably, but three or four hours, at least, before the final disposition is made of it in the sewers or otherwise. Before each use of the milk of lime, the jug containing it should be shaken. For the disinfection of fecal matter in vaults, the contents should receive a thorough saturation, and in the case of privies in which the earth forms the catch-basin, the ground beneath should be thoroughly saturated with the milk of lime. Even then, the disinfection can be assured only after a complete mix- ture of the disinfecting fluid with the matter to be disinfected. The quantity of milk of lime prescribed by Pfuhl for the vaults of military barracks is 400 cc. (about i pint) per man daily. For the same purpose Behring^ says S to 7.5 litres daily for each 250 men. If the contents of the vault do not then give a distinct alkaline reaction with litmus paper, add more of the milk of lime until they do. The rule adopted in the infectious disease hospitals in Ham- burg is to mix the fluid excreta with lime and let it stand two hours before it is let into the sewers.^ Comparison with Other Agents. — For the disinfection of excreta and sewage, Behring^ prefers caustic lime to chlorid of lime as being more convenient to use and for retaining its disin- fecting powers better. The disinfecting power of lime, potash, and soda is equal when of the same degree of alkalinity. The Committee on Disinfectants of the American Public Health Association in 1885, showed a preference for chlorid of lime. Richard and Chantemesse had better results with milk of lime in the disinfction of excreta. For the same class of work Vin- cent ranks caustic lime lower than chlorid of lime. In his hands, copper sulphate was superior to either. 1. Zeit. fur Hygiene, IX., 410. 1S90. 2. Deutsche Viert. (ur off. Ues., XXVIII. (Sup.), 261. 1S97. 3. Bekampfung der Inf eotionskrankheiten, II., 93. 1894. 136 little's soluble PHENYLE LYSOL. Preparation. — Slake a quart of freshly burned lime in small pieces with three fourths of a quart of water, — or, to be exact, 60 parts of water by weight with 100 of lime. A dry powder of hydrate of lime results. To make milk of lime for ordinary use mix one quart of this dry hydrate of lime with four quarts of water. Air-slaked lime is worthless. The dry hydrate of lime may be preserved some time if it is enclosed in an air-tight container. Milk of lime should be freshly prepared, but may be kept a few days if stoppered closely. little's soluble PHENYLE. Hammer^ states that this is a solution of cresol in soap, or by means of soap. (See Creolin.) The experiments of the Com- mittee of the American Public Health Association show that it has considerable disinfecting power. It is an efficient deodorant. RideaP says that "it appears to be derived from wood-tar creasote." LYSOL. Lysol is a preparation containing about 50 per cent, of cresol rendered soluble with neutral potash soap. Frankel, Behring, and Hammer are at variance as to whether lysol is alkaline. Heider says that there is no free alkali. As to its disinfecting power, Remouchamps and Sugg,^ using typhoid and cholera bacilli as test-objects, found that, in the absence of albuminous matter, lysol was superior to carbolic acid, but when the liquids to be disinfected were albuminous, there was no appreciable difference in their action. For the sterilization of Staphylococcus pyog. aureus, Gruber* found a 2 per cent, solu- tion of lysol as effective as a 3 per cent, solution of carbolic acid. Buttersack'^ also concluded that lysol destroys this staphylococ- cus more promptly than does carbolic acid. In his experience, lysol is more efficient than carbolic acid for the disinfection of 1. Archlv fur Hygiene, XIV., 116. 1S92. 2. Disinfection and Disinfectants, p. 176. 1895. London. 3. Mouvement Hyg.— Hyg. Rundscliau, I., 436. 1890. 4. Centr. fur Bak., XI., 117. 1893. b. Arbeiten a. fl. Kais. Ges., VIII., 369. 1892. LYSOL. J ,_. fresh tuberculous sputum. Lingelsheim, as quoted by Pohl, learned that streptococci are killed in fifteen minutes by a 0.5 per cent, solution of lysol, while to accomplish the same results in the same time with creolin, the strength of the solution must be 1.25 per cent. Pohl's^ own judgment of lysol is that it is much more effective than carbolic acid or creolin. Behring^ says that lysol cannot be classed with the disinfectants for spore- bearing bacteria, since he determined that anthrax spores are not killed in twenty-four hours with a cold solution. When, however, the solution is warmed to 40° or 50° C, its power is considerably increased. Influence of Media. — Schottelius, as quoted by Behring,=' could find no difference in the germicide action of lysol, whether tested on bacteria suspended in water, bouillon, or serum. Behring criticizes the methods of Schottelius and states that, in the experimental work at the Hygienic Institute in Berlin, it has been found that the action of lysol is diminished by the presence of albumen. Excreta. — In the experiments of Vincent,^ liquid diarrheal stools, or fresh fecal matter diluted with urine were disinfected in twenty-four hours with lysol 6:1,000 or 7:1,000. Only a few innocuous microbes persist. If the fecal matter is of greater consistence, or has undergone fermentation, 10 or 11 per 1,000 is required. This quantity is needed for privy vaults. The action of lysol is continuous : the number of bacteria diminish from day to day. The bacillus of typhoid fever was killed in fifteen minutes with a 0.5 per cent, solution. The cholera bacil- lus in cholera dejections requires 3.5 per 1,000 at 15° C. for sterilization in seven hours. Schottelius, as quoted by Laser," recommends lysol particularly for the disinfection of excreta as more efficient than carbolic acid and creolin. Tuberculous Sputum. — In the experiments of Buttersack,^ lysol was shown to be a very efficient disinfectant for fresh tuberculous sputum, dissolving the albuminous masses and act- ing more promptly than carbolic acid. 1. Ein Beitrag zur Kentnis der clis. Eigenschaft lies Lysols. p. 36. 1893. 2. Bekampfungderlnfectionskrankhelten, U., 132. 1894. 3. Zeit. fur Hygiene, IX., 420. 1890. 4. Annalesdel'Inst. Past., IX., s:6. 1895. 5. Centr. tiir Bak., XII., 232. 1892. 6. Arbeiten a. d. Kals. Ges., VIII., 371. 1892. 138 LYSOL. Surgical Uses. — As has been stated, Gruber found that a 2 per cent, solution of lysol destroyed the staphylococcus of sup- puration as readily as a 3 per cent, solution of carbolic acid. For the disinfection of the hands, and for many other uses in surgical work, lysol has advantages over carbolic acid: it is probably a little more rapidly germicidal, it is less poisonous, and it is cheap. In Martin's clinic in Berlin, the statistical showing was more favorable after the use of lysol than after that of carbolic acid. In surgical work, Haenel^ says that lysol has no unpleasant action upon the hands unless it is used in stronger solutions than 2 per cent. Gerlach,^ speaking of the advantages of lysol in surgical practice, says that it is more effi- cient than carbolic acid; that the disinfection of the hands is assured by using a i per cent, solution without the previous use of soap; that a }i per cent, solution renders instruments sterile and does not attack the instruments ; and that it is eight times less poisonous than carbolic acid and much less so than corrosive sublimate. Dr. Vondergoltz' has used lysol and lakrol as antiseptics in obstetric practice with excellent results. Their detergent quali- ties also commend them to him. Solutions of lysol have the disadvantage in surgical work of rendering the hands and instruments slippery. This can, how- ever, be overcome by subsequent washing in sterilized (boiled) water. Under "Solveol" there will be some consideration of the question whether the combination of the saponaceous with the disinfectant property, as in lysol, is desirable. Toxicity. — The general testimony is to the effect that lysol is less poisonous than carbolic acid. Remouchamps and Sugg* rate the toxicity of lysol as less than one sixth of that of carbolic acid. Solutions and Uses.- — There appears to be ample reason for regarding lysol as a very efficient disinfectant for all ordinary species of contagion, — for all sporeless bacteria. It forms com- paratively clear solutions with water in every proportion, thus 1. D. M. Woch.— Centr. 1. Bak., XI., 608. 1892. 2. Zelt. fiir Hygiene, X., 167. 1891. 3. N. Y. Medical Times, XXIV., .S66. 1896. 4. Op. cit MERCURIC CHLORID. jog for many purposes having an advantage over creolin and carbolic acid. For the disinfection of clothing, a 2 per cent, solution, prefer- ably as hot as the hand will bear, or hotter, would apparently suffice. For the removal of blood stains and the disinfection of clothing at the same time, Heider^ proved lysol to be better than potash, solutol, soft soap, soda, or solveol. For the disinfection of tuberculous sputum or fresh typhoid discharges, a 4 or 5 per cent, solution would be required. MERCURIC CHLORID (CORROSIVE SUBLIMATE). Beginning with the work of Koch, in 1881, the many series of experiments made for the purpose of determining the bacter- icidal power of corrosive sublimate have given very diverse results. In Koch's^ hands, corrosive sublimate 1:1,000,000 perceptibly retarded the growth of anthrax bacilli, i :300,oo6 completely arrested their growth, i : 20,000 destroyed anthrax spores in ten minutes, and a single moistening with a solution of I ."5,000 sufficed to kill the spores of the same bacillus in a few minutes. Dr. George M. Sternberg,' as Chairman of the Com- mittee on Disinfectants of the American Public Health Associa- tion, says :' "My own observations are in accord with those of Koch, Jalan de la Croix, and others, as to the power of this agent in dilute solutions (1:1,000 to 1:10,000) to destroy the spores of bacilli, — B. anthracis and B. suhtilis, — and this con- stitutes the most difficult biological test known. Micrococci and bacilli in active growth, without spores, are killed by much weaker solutions (i :20,ooo to i :40,ooo)." On the other hand, working with the i : 1,000 solution, Gep- pert* found that, with neutralization of the mercuric chlorid, anthrax spores are never destroyed in half an hour. Behring^ states that an exposure of twenty-four hours is required, and Heider" had spores of the same bacillus which were alive after seventy-two hours' exposure to the solution. 1. ArcMv fiir Hygiene, XV., 385. 1S92. i. Mittbeil. aus dem K. Ges. I„ 269, 276. 1881. 3. Disinfection and Disinfectants, p. 41. 1888. Concord. 4. DeutsclieMed..Wocl)., XVII., 1066. 1891. 6. Zeit. fUr Hygiene, IX., 447. 1890. 6. Arcl). fiir Hygiene, XV„ 357. 1892. 140 MERCURIC CHLORID. The marked discrepancy observed in tlie results obtained by the various investigators admits of several explanations. One is that the media in which the test-organisms were suspended, or to which they have been attached, have been very different. Again, until within a few years, the inhibition of the growth of test-organisms by the exceedingly slight traces of mercuric chlorid which may adhere to infected threads or be transferred to liquid culture media, was undoubtedly mistaken for a germ- icide action. Further, a considerable variability in regard to the power of resistance of anthrax spores has often been noted. Influence of Media. — Schill and Fischer^ subjected fresh tuberculous sputum twenty-four hours to the action of solutions of corrosive sublimate. Mixed in equal proportions with the sputum, it made no difference whether the solution was i :i,ooo or 1 : 500 of water, the result was invariably the same ; a failure to disinfect the sputum. The well-known property possessed by corrosive sublimate of coagulating albuminous matter fur- nishes these authors with a ready explanation of the non-sterili- zation of the sputum, — the coagulation of the surface of the sputum, thus preventing the penetration of the disinfecting agent to the interior of the tuberculous matter. The suitability or unsuitability of corrosive sublimate for cer- tain disinfecting purposes is a question which has been widely discussed. For its elucidation much laborious laboratory work has been done, but the results are so contradictory that doubt must still rest on many points, — whether solutions of corrosive sublimate in all strengths coagulate albumen ; in what degree the disinfecting or antiseptic power of the solution is destroyed when the mercuric chlorid is changed into albuminate of mer- cury; as to the conditions under which albuminate of mercury may remain soluble; as to the best auxiliary agents to use for the purpose of preventing undesirable changes in them, or for the purpose of increasing the efficiency of mercuric solutions; etc. The work of Behring^ has shown him that, in disinfecting with corrosive sublimate, the success of the operation depends very much upon the character of the medium in which the infec- 1. Mlttbeil. aus dem Kals. Gesuntlb., TI., 142. 1884. 2. BekamDfung der InfecUonski-anklieiten, n., 4.3. 1894. MERCURIC CHLORID. 141 tious matter is suspended, whether water, bouillon, or liquids, like blood serum, which contain much albumen. Sporeless anthrax bacilli in water are killed by corrosive sublimate i :5oo,- 000 ; in bouillon, by i :40,ooo ; in blood serum, not with certainty by I :2,ooo. "When corrosive sublimate," he says, "comes in contact with the living tissues of the body it ceases to be HgClg, but it does not cease to have a germicidal action. * * * * When corrosive sublimate is precipitated by albuminous matter it does not lose its disinfecting power." Elsewhere, the same author says : "If, for the disinfection of blood and the fluids of animal tissues, we use a solution of corrosive sublimate stronger than I :4,ooo, albumen is precipitated and the penetration of the sub- limate into the deeper portions of the matter to be disinfected is hindered. In a still greater degree does this difficulty occur when we undertake the disinfection of the firmer organic tissues. Here,' in fact, only a superficial disinfection is observed. "The trouble is not, as was formerly assumed, that an inert albuminate of mercury results from the precipitation of the sub- limate, but the uniform penetration of the disinfecting agent is prevented by the precipitation."^ Some Recent Precautions. — Geppert,^ fearing that, in experi- ments with disinfectants, the trace of the disinfecting agent car- ried over on silk threads or other test-objects, even after they had been rinsed in sterilized water or alcohol, suffices to inhibit the growth of the bacteria attached to them, devised methods of precipitating or neutralizing the traces of the disinfecting agent. Though Koch taught that corrosive sublimate i : 1,000 destroys anthrax spores in one minute, and Frankel destroyed very resist- ant spores with sublimate i : 1,000 in thirty minutes, Geppert found that, after precipitating the corrosive sublimate with ammonium sulphid, anthrax spores are never destroyed in half an hour with a 1 : 1,000 solution and very seldom in one hour. Sometimes the action of this solution failed to sterilize the spores in several hours, and once they were not killed in twenty-four hours, as was shown by transference to culture media and by inoculations into animals. 1. Zeit. fur Hyg., IX., 400. 1890. 2. Deutsche Med. Wooh., XVII., 797. 1891. 142 MERCURIC CHLORID. In experiments of this kind, Geppert does not recommend threads, but prefers a filtered culture to which he adds a solution of corrosive sublimate i :500, half and half. Of the two innovations suggested by Geppert, Behring^ con- siders the chemical precipitation of the mercuric chlorid an improvement over past methods, but his second suggestion he believes is no improvement. In a series of experiments made by Dr. C. T. McClintock,^ pre- cautions like those suggested by Geppert were observed. The medium in which the bacteria were tested was bouillon. His experiments show that, experimentally at least, the germs with- stand the action of sublimate as follows : i:i,ooo. Staph, pyogenes aureus, 23 hours. I :ioo, Staph, pyogenes aureus, 11 hours. Saturated sol., Staph, pyogenes aureus, i hour. I : 1,000, B. subtilis, 41 hours. Saturated sol., B. subtilis, 85 minutes. 1 :200, Swine Plague, i hour. I : 1,000, Typhoid Germs, i hour. 1 : 1,000, Germs in feces, 24 hours. Saturated sol., Germs in feces, 24 hours. McClintock is forced to the conclusion that the germicidal power of solutions of sublimate has been enormously overesti- mated. He closes his work with the following summarv of results and conclusions : 1. The high rank heretofore given corrosive sublimate as a germicide is without warrant and was based upon faulty experi- ments. 2. The very varying power of resistance in different cultures, as pointed out by Esmarch, and insisted on by Gruber, is an all- important factor to be noted in determining the germicidal value of any agent. 3. Sublimate forms with cellulose, as in cloth, iilter paper, etc., with milk, with albuminous bodies, with some part of bac- teria, probably the envelop, a chemical compound that cannot be removed by any amount of washing with water. This sub- limate when acting on a germ, forms a capsule around it that 1. IWd., XVII., 893. 1891. 2. Medical News, LXI., 365, 397. 1892. MERCURIC CHLORID. jx, protects the germ for a time from the further action of the sub- limate, and, in turn forms an impenetrable barrier to the growth of the organism, unless removed. This barrier may be removed with salines, and is more rapidly removed in proportion to the renewal of the salines, conditions that are fulfilled in the circu- lating blood. While sublimate has no greater germicidal power, it does not follow that it is not a valuable disinfectant. Whether the germs contained in solutions treated with sublimate and disposed of as such material usually is, do or do not grow remains to be proved. In some recent work with the view to determining the germ- icidal power of mercuric chlorid, Rorkhoff,^ of St. Petersburg, sought to have the conditions of his experiments correspond, as nearly as possible, with those found in disinfecting work, particularly in the disinfection of dwellings. His conclusions are that, using the i :i,ooo solution, the most resistant spores are killed in six days ; anthrax spores, in nine to ten hours ; Staphylococcus pyogenes aureus, in two and one half to five hours ; typhoid bacillus, in fifty minutes ; diphtheria bacillus, in seventy to eighty minutes ; cholera bacillus and anthrax bacteria without spores, in fifteen minutes. Auxiliaries. — The addition of various chemical agents to solu- tions of mercuric chlorid has been recommended for the pur- pose of preventing the precipitation of albuminoids or of increas- ing the germicidal power of the sublimate solutions. In 1887, Laplace and Behring published the result of their work which indicated that sublimate solutions are much more active when 5 parts per 1,000 of hydrochloric acid or of tartaric acid are added to them. Behring^ and others have more recently recom- mended the addition of ammonium chlorid, of potassium chlorid, or of common salt, 5 parts to 1,000 of the sublimate solution. We are told that solutions thus made keep better, that the reduc- ing action of light is lessened, that the coagulation of albumen is avoided, and, as the carbonates and other alkalis then cause no precipitate, the solutions may be made with ordinary water after it has been boiled, instead of with distilled water. 1. Kevue D'Hygiene, XIX., 738. 1887. 2. BekampfungderInfectioii8krankheiten,II.,51. 1894. 144 MERCURIC CHLORID. Liibbert and Schneider^ claim that, from a chemical as well as from a practical point of view, sodium chlorid is a more suitable addition than tartaric acid or ammonium chlorid. It is better than the former to hold albuminate of mercury in solution, and better than the latter to prevent the precipitation of the mercury when the solutions are made with common well water. The proper quantity of sodium chlorid to acid is 1.3 parts to i part of mercuric chlorid. The addition of sulphuric acid, according to Panfili,^ increases the germicidal potency of disinfecting solutions more than the addition of either hydrochloric acid or tartaric acid, and he holds that the action of sodium chlorid is inferior to that of the acids. Garre^ agrees with Panfili that acids are superior to common salt as an auxiliary, and especially recommends acetic acid, 1-20 per cent. Pane'' found that the addition of tartaric acid to a i : 2,000 solution, whether in distilled water or in ordinary water, dis- tinctly increases its efficiency, and renders it equivalent to a I :i,ooo solution with the addition of sodium chlorid. He pro- nounces the I :i,ooo solution with tartaric acid very efficient. Beckmann^ and Vignon" add their testimony to that of others that the addition of common salt increases the effectiveness of sublimate solutions. Vignon recommends 10 grams of salt, or I ccm. of hydrochloric acid to i gram of corrosive sublimate. In his experiments to determine whether the disinfecting action of the i : 1,000 solution of corrosive sublimate is increased by the addition of acids, or common salt, Panfili^ used anthrax spores which were not killed in less than from ten to eleven hours by the simple solution. Geppert's precautions were observed. He found that the addition of from 5 to 10 per cent, of sulphuric acid to the sublimate solution increased its disin- fectant power very much, and that the addition of hydrochloric or tartaric acid increased the germicide action, but in a lesser degree. Sodium chlorid added to the solution increased its action somewhat, but not so much as the acids. 1. Deutsche Med. Woch., XIV., 828. 1888. 2. Revue D'Hyglene, XVr., 618. 1894. 3. Cor. Bl. f. Sch. Aerzts.— Deutsche Med. Woch., XV., 722. 1889. 4. An. deir Istituto D'Ig. Sperlmentale dell' Univ. di Roma, II., 88. 1890. 5. Centr. fur Bak., XX., 17. 1892. 6. Revue D'Hyglene, XVI., 618. 1894. 7. Annali dell' 1st, D'Ig. Sperim. della R. Univ. di Roma, III. (N. S.), 529. MERCURIC CHLORID. I^e Weyland/ however, claims that our most efficient disin- fectants, those which are destructive of spores, possess the prop- erty of precipitating albumen, — saturated solution of carbolic acid, corrosive sublimate, silver nitrate, and tricresol solutions. He says that the addition of sodium chlorid to comparatively weak solutions of carbolic acid increases the germicidal power of the solutions so that they precipitate albumen and destroy anthrax spores, while, on the other hand, the addition of com- mon salt to solutions of corrosive sublimate prevents their pre- cipitation of albumen and lessens their germicidal power. The results obtained by Rorkhoff,^ of St. Petersburg, tend to confirm the observations of the author last quoted, for, in his hands, the disinfecting value of solutions of mercuric chlorid are lessened by the addition of sodium chlorid (i per cent.), tartaric acid or hydrochloric acid (5 : 1,000), or carbolic acid (5 per cent.). Other Solvents^ Etc. — Solutions of mercuric chlorid in abso- lute alcohol, according to Lenti,' have no action on anthrax spores; but a 1:1,000 solution of sublimate destroys anthrax spores in twenty-four hours if it contains 2 per cent, of water. In glycerin mercuric chlorid is not effective until 40 per cent, of water has been added. As is well known, solutions of corrosive sublimate keep better in the dark than when exposed to light. Michaelis' made an experimental study to determine the influence of the color of the glass in which the solutions are preserved. His observations show that yellowish-brown glass prevents, better than any other color, the decomposing action of the light. Disinfection of Excreta.— Some time ago Dr. VV. B. Hills^ characterized the employment of corrosive sublimate for the disinfection of large masses of material, such as the contents of privy vaults, cesspools, etc., as absurd. He reminded us that albuminoids are coagulated, and that the resuhing albuminate of mercury is insoluble. If soluble, it would be changed imme- diately to inert sulphids in masses of fecal matter. Professor 1. Centr. fur Bak., XXI., 79P. 1897. 2. Revue D'Hygiene, XIX., 73S. 1897. 3. Hyg. Randscliau, IV., 2:M. 1«>-1. 4. Zeit. fur Hygiene, IV., 3i),i. iws. 5. Boston Med. iiiul Surg. Jr., CXIX., 1B9. I'S^^S- 10 146 MERCURIC CHLORID. Vaughan/ of Ann Arbor, answered Dr. Hill's criticisms, stat- ing that albuminate of mercury is soluble in solutions containing organic matter, and that it diffuses through them; that fecal matter contains but little albumen, — only 0.52 of i part in 1,000. Replying to this, Dr. Hills^ contends that albuminate of mercury is but very slightly soluble even in the presence of organic mattter, and he quotes authorities and adduces experiments, and reaffirms that the albuminate is decomposed by hydrogen sulphid and by other incompatibles in fecal matter. Behring^ also warns us that in putrefying material when sulphur compounds are liberated, mercuric chlorid is changed into inert sulphids. The Committee on Disinfection* of the American Public Health Association of 1885 recommended for the disinfection of liquid fecal discharges, a solution of i : 500 of sublimate with the same quantity of potassium permanganate, the time of exposure to be not less than two hours and the quantity of the material to be disinfected not in excess of that of the solution used. Among the disinfectants tested by Foote,^ the simple solution of mercuric chlorid was found to be inefficient, but the solution of this agent with the addition of sodium chlorid was the most efficient disinfectant tested by him. In the experience of Uffelmann," the simple solution of sub- limate 1 :5oo failed, while 1 1500 with hydrochloric acid destroyed with certainty all germs in twenty-four hours. "In an extensive series of tests made by Vincent,'' he found that sublimate i : 1,000 with hydrochloric acid, when added in equal volume to the matter to be disinfected and mixed intimately, failed to disinfect in four days. He concluded that mercuric chlorid is a very inefficient disinfectant for fecal matter. Antiseptic Value. — "There is a great difference," says Beh- ring,^ "between the antiseptic power of mercuric chlorid in albuminous, and in non-albuminous material. 1. Boston Mea. and Surg. .Tr., CXX., 1. 1S?9. 2. Ibicl.,p. 190. 1SS9. 3. Zeit. tur Hygiene, IX., 407. 1S90. 4. Disinfection and Disinfectants, p. 47. 188S. Concord. 5. .\mer. .Ir. of the Med. Sciences, XCVIII., 3-29. ISM'. 6. Berliner Klin. Wocli.—Centr. fiirBak., XII., 233. 1S92. 7. Annales de I'lnst. Past., IX., 11. ISfl.i. S. Deutsche Med. Woch., XV., 839. 18S9. MERCURIC CHLORID. I47 "It has been demonstrated that albuminous culture media, those in which bacteria are already developing, are capable of converting HgClj into calomel, and even of reducing it to metal- lic mercury, thereby wholly destroying its antiseptic action. When we compare mercuric chlorid with iodoform, we find a remarkable difference in antiseptics. Iodoform of itself is an indifferent body, when brought into wounds, but, when it finds the material for its decomposition, can act as an efficient anti- septic. On the other hand, we bring an aqueous solution of sublimate with its remarkable antiseptic possibilities into wounds and see it become wholly inoperative. "The antiseptic value of mercuric chlorid is diminished not only by bacteria and their products, and by the albuminous con- stituents of the blood and secretions from wounds, but it is observed under the influence of the reducing action of light in the presence of organic matter even when the quantity of the organic matter is as small as in water which has not .been dis- tilled. Further it is diminished by fibres from bandages and by all strongly reducing chemical substances. "In practice all of these agents exert more or less influence upon the antiseptic value of sublimate, and, without an exact investigation and a careful consideration of the chemical changes which the sublimate undergoes when used in the treatment of wounds, one cannot correctly estimate its antiseptic value." Although, under the most favorable conditions, mercuric chlorid 1:1,000,000 will, as Koch learned, retard the develop- ment of anthrax bacilli, 100 times as much, or i : 10,000 is required to inhibit the growth of the same organism in blood serum as Behring points out. It has been noted by various observers that the Staphylococcus pyogenes aureus is not readily destroyed with mercuric chlorid. In the experiments of McClintock already cited, this micro- organism in bouillon was not destroyed in less than twenty-three hours. In the work of Dr. A. C. Abbott,^ this same bacterium in sterilized distilled water survived exposure to mercuric chlorid, i : 1,000, twenty minutes, while in bouillon, it was not killed in sixty minutes. When exposed twenty minutes in water 1. .Tohns Hopkins Hosp. Bill., II-, 50. 1891. 148 MERCURIC CHLORID. about one colony, on an average, developed; when in bouillon the average number of colonies was 1,103. He concludes that: "To the employment of sublimate solutions upon wound- surfaces it is plain that there are at least two serious objections. "First, the albumen of the tissues and fluids of the body tend to diminish the strength of, or indeed, render entirely inert, the solution employed. "And second, the integrity of the tissues is materially injured by the application of solutions of this salt." On account of the irritating qualities of the acids, Liibbert and Schneider"- prefer, in surgical work, the addition of com- mon salt to solutions of sublimate, 1.3 grams of salt to i gram of corrosive sublimate. Poisonous Qualities. — Corrosive sublimate is, of course, a dangerous poison, but, unless it is swallowed, there is little dan- ger from its use as a disinfectant. Of the i : 1,000 solution, there is little less than one sixteenth of a grain in one dram of the solution, hardly the equivalent of a maximum therapeutic dose for an adult. In this strength, it may safely be used for washing the hands, beard, hair, and face of the nurse, the attend- ing physician, or the disinfector after leaving infected rooms. The lethal dose for animals, administered hypodermically, is, according to Behring,^ from 1-100,000 to 1-80,000 of the weight of the animal. Comparing the i : 1,000 solution of mercuric chlorid with the 5 per cent, solution of carbolic acid, the degree of toxicity of the former is lower than that of the latter. Again, he says^ the toxicity of sublimate is not greater than that of other metallic salts, taking .into consideration their relative anti- septic powers. Dr. Holt,* referring to the introduction of corrosive sublimate as a disinfectant into the New Orleans Quarantine Station, says : "Our declaration at that time is confirmed by an experience of four years' trial on an immense scale, that our standard solu- tion, as used in sanitation, is absolutely harmless to persons unless it is swallowed, it matters not how extensive or constant the contact.'' 1. Centr. £. Bak., HI.,— D. 51. Wocli., XV., 7-22. ISSn. 2. Bekatnpfung der Infectionskranklieiteii, IL., 06. 1804. 3. Zelt.fiir Hygiene, IX., 407. 1890. 4. Ept. of Com. of Am. P. H. Assoc, p. 219. 18S8. MERCURIC CHLORID. I49 On the other hand, one of the public health journals^ reports that some of the disinfecting staff in the city of Paris have suf- fered symptoms of mercurial poisoning. Sjoqvist,^ of Stockholm, examined the urine of seven persons who had lived in houses from a few days to one year after their disinfection with mercuric chlorid. A trace of mercuric chlorid was found in the urine of two persons, both in the same house. Three to four grams per room had been used. He says that mercuric chlorid volatilizes very slowly in the temperature of an ordinary room, and that it was found in large quantity in wall-papers a year after disinfection. In German literature, the fear of poisonous results is often noted, but in a discussion before a meeting of the German Public Health Association, Professor Loeffler^ expressed the opinion that the danger to the inhabitants of rooms after the walls and floors have been disinfected with corrosive sublimate is very slight indeed, or absent. Solutions and Uses. — The addition of potassium permanga- nate to solutions of sublimate unfits them for other use than the disinfection of excreta, and their use in that direction is of doubtful value. The American Public Health Association's standard Solution No. 3, containing copper sulphate, has the disadvantage of slightly staining white goods even when reduced to I :i,ooo of sublimate. A large number of samples of cotton, woolen, and silk goods, soaked twenty-four hours in a cold I :i,ooo solution of corrosive sublimate in water, suffered no more from changes in colors than when soaked the same length of time in Kennebec River water. The quantity of the various chemicals to be added to the I :i,ooo solution of mercuric chlorid is more frequently stated as 5 plrts or more of common sah, or 5 parts of hydrochloric acid, or of tartaric acid, to 1,000 parts of the sublimate solution. The solution used bv the Board of Health of the City of New York is- corrosive sublimate (pulverized), 60 grains; common salt, 2 tablespoonfuls; water (hot), i gallon. Dissolve. Keep in glass, earthen, or wooden vessels. 1. Jr. of State Mecliclne, IV., 146. ISOIS. 2. Hygienische Ennclschau, IV., SIO. 1894. 3. Deutsche Viert.Kf off. Gesund., XXIII., 150. 18!)1. ISO MERCURIC CHLORID. Solutions of corrosive sublimate are wholly unsuitable to the "j disinfection of material containing much albumen, as tuber- culous sputum. Their use for the disinfection of excreta, fresh or in bulk, is of very doubtful expediency, as is indicated by the discrepant results obtained by various investigators. So far as there remains a legitimate sphere for the use of corrosive sublimate, it seems to be restricted to the disinfection of walls and floors, wood finish of furniture, upholstered furni- ture and clothing which cannot otherwise be disinfected, and the personal disinfection of hands, hair, beard, and face. Loeffler"^ regrets that corrosive sublimate is not more used for the disinfection of walls and floors. He deems it trustworthy and preferable to carbolic acid because it leaves no odor. Other Mercurial Salts. — In the experiments of Sternberg,^ mercury biniodid had a greater antiseptic power than mercuric chlorid. The work of Dr. G. Sims Woodhead^ indicates that the biniodid has the advantage over the bichlorid in that it does ; not coagulate albuminous solutions. As an antiseptic, I5J^ J grains of the biniodid with a slight excess of potassium iodid are to be dissolved in 34 ounces of distilled water. Such a solu- 'i tion is stable, but is not really one of biniodid of mercury, but is a double salt of potash and mercury. Dr. Woodhead's experi- ments appear to indicate that the biniodid is a more efficient antiseptic than the bichlorid, and that with the former salt there fl is not so much danger of toxic effects. J In a comparative study of the disinfectant powers of mercury bichlorid and mercury biniodid made by Viquerat,* these two agents were tried on B. typhosus, B. anthracis, B. pyog. fcetidus, I B. subtilis, B. strumitis, B. pyocyaneus. Staph, citreus, and S. aureus. The bichlorid i :i,ooo showed greater activity than the customary i :S,ooo solution of the biniodid. Even in the solu- tion of I :i,ooo, the biniodid was not so efficient as the bichlorid. For instance, anthrax bacillus could remain in the bichlorid only five minutes without being destroyed, while in biniodid, i :i,ooo, it could remain fifteen minutes, and in biniodid, i 15,000, it could 1. Op. clt., p. 149. 1891. 2. Disinfection and Disinfectants, p. 51. 1BS8. Concord. 3. The Medical News, LIV., 521. 1889. 4. Centr. fur Bat., V., 584. 1889. MOUTH. jrj survive two hours. The typhoid bacillus lived not longer than five minutes in bichlorid, but in biniodid, i :i,ooo, as well as in 1 :5,ooo, as long as a quarter of an hour. As to the comparative toxicity of the two salts, the author thinks there is no difference. The experience of Behringi teaches him that, disregarding the permanence of the solutions, it makes no difference which mer- curial preparation we choose, so long as we are able to bring it into solution, and this applies to albuminate of mercury as well. None of the mercurials, he says, possess higher disinfectant value than corrosive sublimate. MILK. (See TUBERCULOSIS-— Tuberculous Milk.) MOUTH. The study of the bacteriology of the mouth has developed the fact that a great variety of micro-organisms is habitually to be found there. Among these organisms, pathogenic germs are often found. Thus, in examining the mouths of children treated in hospitals for other diseases than diphtheria, Roux and Yersin found that 33 per cent., or more, of them contained the bacillus of diphtheria in an attenuated form.^ In 1880, Sternberg^ dis- covered the micrococcus of croupous pneumonia in the human saliva, and the investigations of many observers have since con- firmed the fact that the germ of pneumonia is a frequent inhab- itant of the mouths of well persons. Quite a large number of other pathogenic bacteria are found frequently, or at longer intervals, in the human mouth. Thus, at times, known or unknown, a rational indication for the disinfection of the mouth of a healthy person exists. During infectious diseases, or in the period of convalescence from them, disinfection of the mouth is more frequently needed. Dr. W. D. Miller, an American dentist long resident in Ber- lin, has probably done more than any other person in the study of the infectious organisms of the mouth and in testing accu- rately the suitability of various agents as disinfectant or anti- 1. Bekampfung der Infectionskranklielten, II., 53. 1894. 2. Revue D'Hyglene, XIV., 97. 1893. 3. Manual ot Bacteriology, p. 298. 1892. 152 MOUTH. septic washes for the mouth. Tests were made with nearly all the available antiseptics.^ Corrosive sublimate i : 2,000 effected a marked diminution in the number of the germs in one minute. Complete sterilization, however, required, on an average, over five minutes. The efficacy of the sublimate was increased in a surprising degree by the addition of benzoic acid. Trichlorid of iodin i : 2,000 was decidedly superior to the sub- limate. It is, moreover, not at all disagreeable, but its acid reaction unfits it for daily use as a mouth wash. In the strength ^ of 1 :2,ooo, sterilization was effected in one and one fourth min- utes; and in the strength of 1:1,500, sterilization was accom- plished in forty seconds. Some of the other antiseptics tested were : benzoic acid 1 :300 required two to two and one half minutes ; lysol i :200, five minutes; carbolic acid i :ioo, five minutes; boric acid i :50, eleven minutes ; thymol i :2,ooo, five and one half minutes ; hydrogen peroxid 4:100, six minutes; saturated alcoholic solu- tion of saccharin i :400, three fourths to one minute ; oil of ■ eucalyptus i 162^, eight minutes ; oil of cinnamon i :400, eight :| minutes ; oil of wintergreen i :35o, twelve minutes ; oil of pep- permint I :6oo, eleven minutes ; salicylic acid i :300, three fourths to one minute. His experiments and his experience indicate that there are very few substances at present in the dental materia medica which are available for disinfecting the human mouth. Mer- curic chlorid is much restricted by its exceedingly disagreeable taste and the possibility of toxic effects. Trichlorid of iodhi is hampered by its acid reaction which restricts its use to acute infectious diseases of the mouth or throat. Salicylic acid labors imder a similar ban. "We have, accordingly, only saccharin and benzoic acid left from which to construct antiseptic mouth washes for daily use, since a substance which requires over five minutes to devitalize .J bacteria cannot be expected to accomplish much in the short time during which a mouth wash is kept in the mouth. We may make an exception, however, in favor of the peroxid of hydrogen, which, on account of its non-poisonous and non- 1. Tr. Seventh Intern. Cong, of Hygiene, II„ 55. 1892. MOUTH. 153 irritant character, may be used more frequently and kept longer in the mouth than the great majority of other antiseptic liquids." Dr. Miller further says : "A mouth wash which I recom- mended years ago and which is decidedly superior to the best of the many so-called antiseptic mouth washes on the market, has the following construction : R Acid, benzoic 3,0 Tinct. Eucalypt 15,0 Alcohol, abs 100,0 01. menth. pip 0,75 "For the last year I have been making experiments with sac- charin, which manifests a very remarkable action upon the bacteria of the mouth. It appears also to be one of the least poisonous of the substances recommended for the treatment of the oral cavity, and has no deleterious action upon the teeth. "I have employed it in the following form : R Saccharini 2,5 Acid, benzoic 3>o Tinct. Rhatanae i.5,o Alcohol, abs 100,0 01. menth. pip 0,50 01. cinnam 0,50 "Three ccm. of this to 27 ccm. water kept in the mouth a full minute has a very marked effect upon the number of living bac- teria in the mouth. If instead of water we use a 4 per cent, solution of peroxid of hydrogen in connection with the tincture, we obtain a still more striking result." With a wash consisting of benzoic acid and saccharin in peroxid of hydrogen the num- ber of bacteria was reduced by i|ths. "In conclusion, I may therefore mention as antiseptic mouth washes trichlorid of iodin, i :2,ooo to 1:1,500; bichlorid of mercury, i :2,ooo, in conjunction with benzoic acid, i :300; sali- cylic acid, 1:300 to 1:250; benzoic acid, 1:300 to 1:250; sac- charin, I :400, preferably in combination with benzoic acid. The trichlorid of iodin and bichlorid of mercury are restricted to occasional use, particularly the trichlorid should be used with care; salicylic acid must likewise be kept under observation; saccharin has a disagreeable taste; only benzoic^acid appears to^ suffer from no pronounced undesirable qualities." .154 MOUTH OZONE. In the municipal laboratory of hygiene of Naples, Dr. Monte- fusco experimented with solutions of the essence of peppermint and other antiseptics. In his experience, they did not show a marked advantage over rinsing the mouth with sterilized water. Dr. Vallin, who reviews the work of Montefusco, says that cleansing the teeth with a brush and soap morning and evening, followed by prolonged rinsing with a weak solution of carbolic acid and the essential oils, or menthol, fulfils all indications.^ Weak solutions of formaldehyde have been recommended as mouth washes. They would, undoubtedly, be efficient disinfec- tants, but, used too strong, they cause intense smarting of the tongue. A solution of %. or, at the most, Y^ per cent, of formalin in water is as strong as the average mouth will bear. Behring, finding that chloroform, in quite weak solutions, is rapidly antiseptic in its action, recommends chloroform water as a mouth wash. MUD, OOZE, SLUDGE. The disinfection of material of this kind could be done with the hypochlorites, — chlorid of lime or hypochlorite of soda pre- pared by the electric current where that is available. Rabot's process has some repute in Europe. It consists in the use of 500 grams of sulphate of iron followed by i kilogram ■of caustic lime to each cubic metre of material to be .treated. NITRATE OF SILVER. (See SILVER and SILVER SALTS.) OZONE. Whether ozone in nature has any important influence in restraining or favoring the action of infectious agents, is still an unsettled question. In the quantities which may now be evolved by artificial means, it may act as an irritant poison to animal life, or rapidly destroy bacteria and all other low forms of plant growth, particularly in the presence of moisture. The results of some experiments which are available indicate that ozone has at least a slight destructive influence upon dry bacteria as they are found in the air of rooms. Dr. Mills^ 1. Revue D' Hygiene, XIX., 447. 1S97. 2. La Cllnique, X., 617. 1S96. OZONE. jcc :studied the germicide action of ozone artificially liberated in a medical ward of a hospital. The electric ozone generators ^vere -allowed to deliver ozonized air into the room, two hours each day, or every other day. The best results were attained when ozone was admitted every day. When ozonized every day, the total number of colonies in each Petri dish exposed to the air averaged ii8, when not ozonized, 182. The number of colonies of Bacterium coli commune, when the room was ozonized, was five ; when not ozonized, nine. Dr. Kowalkowsky^ gives a resume of some recent work which has been done in Russia. Dr. Krukowitsch, testing the action of ozone on the bacteria of putrefaction, found that the fresh, or moist bacteria, were much more easily killed than were dried bacteria. In a large flask 3 milligrams of ozone to the cubic metre sufficed to destroy fresh bacteria, but 8 milligrams were required to devitalize the dry bacteria. In a room of 25 cubic metres, 30 milligrams per cubic metre failed to destroy even the jnoistened germs. In the experience of Lukaschewitsch, even the large quantity of 1.5 grams per cubic metre was found insufficient to destroy anthrax spores or the bacteria of decomposition when dry, but, when damp, the latter bacteria were killed with one fifth that proportion of ozone. This last experimenter believes that the -explanation of the ease with which Krukowitsch destroyed his bacteria is that nitrogen dioxid is liberated with the ozone in the process which was used. In the Pasteur Institute, Paris, Christmas^ investigated the antiseptic action of ozone. From 1.5 to 2 milligrams of ozone per litre of air sufficed to prevent the development of sporeless anthrax bacilli, typhoid bacillus, diphtheria bacillus, and Asper- gillus niger. In forty-eight hours growing cultures -were strongly acted upon, and in ninety-six hours they were dead. Air which contained 0.5 milligram of ozone in each litre was almost irrespirable, but had no effect whatever on bacteria ; fruit and meat decomposed as rapidly as in ordinary air. As an anti- septic for inhabited rooms, its use is, he finds, entirely imprac- 1. Zeit. fur Hygiene, IX., 89. 1890. 2. Annales de I'lnst. Paat. 1893.-Ceiitr. fUr Bak., XV., 1016. 1894. 156 OZONE. ticable, on account of the irrespirability of air which contains quantities below that which has any antiseptic action. Purification of Water. — In the disinfection and purification of water, late experimental work and the improvement in apparatus for the generation of ozone promise much. At the meeting of the Electro-technic Society of Berlin, in 1891, Dr. Frolich^ reported the progress which had been made by the firm of Siemens & Halske in devising electric apparatus for the produc- tion of ozone, and in the technical application of ozone. Then, referring to the action of ozone on animals and plants, he stated that, in man, the breathing of air in which the generation of ozone has proceeded far, becomes unpleasant or injurious, and coughing results. Hospital wards containing patients cannot,, therefore, be ozonized. Insects are destroyed with ozone in twenty or thirty minutes. All water-bacteria are destroyed, as- well as all algae growing in water. This necessarily forbids the ozonization of water to be subjected to sand-filtration when the efficiency of the filtration depends upon the superficial layer of algae. The experiments in sterilizing water with ozone were always successful. Though pathogenic bacteria were not added, the fact that all of the water-bacteria were devitalized, indicated the destruction of pathogenic bacteria if they had been present. The ozonization of water destroys various offensive or harmful contents. Hydrogen sulphid is destroyed, ammonia is oxidized and transformed into nitrites and nitrates, iron is precipitated as hydroxid, and the bacteria of decomposition are destroyed. There were, he believed, good grounds for assuming that bad water may be converted into potable water by the ozone treat- ment. Oppermann^ studied the results of electrolyzing water, using" spiral platinum electrodes. He found that ozone was the potent factor in the purification or sterilization. There was the most abundant production of ozone when the water was kept at a low temperature,— 5°-6° C. Under the most favorable conditions, from 3 to 6 per cent, of ozone was produced. Changes in the water were : oxidation of the organic and organized contents, 1. Gesuncllielts-Ingenleur, XIV., 5d3. 1S91. 5. Weyl's Handbuch der Hygiene, I., 718. 1896. OZONE. 157 .and eventually of the ammonia and nitrites. Chlorin was liber- ated when the water contained chlorids and hjrdrogen peroxid in so slight quantities that its influence may be disregarded. The more polluted the ^^'ater the larger the quantity of ozone required. He found, further, that the electrolyzed water is free from germs, but its ozonized taste is unpleasant and its use for drink- ing purposes causes derangement of the stomach and vomiting. To render the electrolyzed water suitable for drinking, Opper- mann submitted it to a secondary electrolytic action, using alum- inum electrodes. This resulted in the formation of aluminum oxid and the precipitation of this as aluminum hydroxid clari- fied the water and removed the ozone. The resulting water was' free from germs, clear, pleasant to the taste, and possessed no undesirable qualities. The action of the ozonization was complete even when large quantities of typhoid and cholera bacilli had been added to the water. At the request of the Imperial Board of Health of Germany, Ohlmiiller^ made a detailed study of the disinfective power of ozone. His investigations showed that ozone has but little action upon dry bacteria, but that, suspended in water, they are strongly acted upon. Distilled, sterilized water to which 3,717,- 000 anthrax spores per cubic centimetre of water had been added was sterilized in ten minutes with 89.9 milligrams of ozone. With 58 milligrams of ozone, 57,000 anthrax bacilli were destroyed in ten minutes; 12,247,000 typhoid bacilli with 19.5 milligrams of ozone in two minutes; and 2,791,000 cholera bacilli with 16.7-19.5 milligrams of ozone in two minutes. Treating sewage, water from the Spree, and other polluted waters, he found that they were less easily sterilized than dis- tilled water. The water from the Spree was sterilized in ten minutes with 83.6 milligrams of ozone, but sewage was not sterilized in an hour with 156.3 milligrams. Ohlmiiller believes that his experiments show conclusively that, when water is not too grossly polluted, ozone exerts a destructive action upon the bacteria. He deems it likely that 1. Arbelten a. d. Kais. Ge^., VIII., 2-20 IS8 OZONE. ozone can be utilized for the purification and sterilization of river waters for drinking purposes. His investigations indicating the practicability of sterilizing water with ozone paved the way for its application on a large- scale to the treatment of water supplies with the same agent. It appears that this was first accomplished in Oudshoorn near Ley den, Holland. The sterilization of water in this place by means of ozone appears, according to Professor Ermengem,^ of Belgium, to have been a perfect success. Cold, dry air is subjected to the- action of an alternating electric current of great intensity. This, ozonized air is then driven under pressure into the sterilizers, where it comes in contact with the water to be sterilized. The source of the water supply is the Old Rhine. This ancient out- let of the Rhine with its many locks is converted practically intO" a canal. It receives the polluting matter from a populous coun- try and many towns, the refuse from factories, and it is trav- ersed by numerous boats. The water is of a dark brown color. It has an abundance of suspended organic and inorganic matter, and it has a repugnant odor. Chemically and bacteriologically,. it is a very bad water. Before this water is submitted to the action of ozone, it under- goes a preliminary filtration through sand. This filtration removes the suspended matter, the larger part of the bacteria,, but the chemical character of the water is but slightly improved, and its offensive taste and smell continue. The number of bac- teria in the unfiltered water varies from 5,000 to 100,000 per cubic centimetre; the filtered water contains from a few hun- dred to a few thousand bacteria. The result of the ozonization of this filtered water is to destroy all of the aquatic species of bacteria and all the most resistant, of the pathogenic bacteria that may find their way into the water. This sterilization is a constant and regular result of the pro- longed action of the process. The ozonized water loses all its disagreeable taste and smell, there is a considerable diminution in the soluble organic matter, and no harmful or undesirable changes result. We are told that the improvement in the char- acter of the water is extremely satisfactory from every point of view. 1. Annales (le I'Inst. Past., IX., G73. 1885. PEAT. J 2^ PARAFORM. (See FORMALDEHYDE— Available Sources.) PEAT. Dried pulverized peat (Torfnmll) has been used considerably as an absorbent and deodorant in dry conservancy systems. As being lighter and more absorbent, it may conveniently take the place of dry earth in earth-closets. As stated by Von Esmarch,i from 25 to 40 kilograms (60 to 88 lbs.) per head yearly are required, costing in Germany, from 31 to 50 cents, American money. Frankel and Klipstein^ carried out an extended series of experiments for the purpose of determining the germicidal action of pulverized peat, or peat meal. Their experiments indi- cate that, w^hen bouillon cultures are mixed with the powdered, peat so that the mixture remains damp, the cholera bacillus is. destroyed in two hours and a half. Under natural conditions,, when cholera bacilli are mixed with urine, as well as peat meal, the experiments indicated that the destruction of the bacilli is. not accomplished in less than eight or nine days. In some of the experiments under these conditions, the vitality of the bacil- lus was prolonged for fourteen days. These experimenters sought to determine whether the addi- tion of some of the chemical agents, which would not injtire the mixture for agricultural purposes, might not hasten the germi- cide action of the peat. Kainite had no beneficial influence in this direction. On the other hand, the addition of superphos- phate (Superphosphjjtgyps) increased the germicide action of the pulverized peat. These authors conclude that the opinion that pulverized peat has a conserving influence upon infectious matter is incorrect; on the other hand, their experiments indi- cate to them that the peat itself has a considerable power of dis- infection which may be greatly increased by the addition of superphosphate. The composition of the superphosphate used by them is given as: total phospheric acid, 15.35 per cent.; phospheric acid soluble in water, 12.06 per cent. ; phospheric acid soluble in alcohol, 8.51 per cent.; gypsum (Ca SO,-f2H2 0)„ 56.58 per cent. 1. Hygiensclies Tasolienbuch, p. 212. 1896. 2. Zelt. fiir Hygiene, XV., 333. 1893. l60 PEAT. The question of the value of pulverized peat as a disinfectant foi- excreta was also studied by Gartner/ of Jena. His conclu- sions are essentially those of Frankel and Klipstein, — that pul- verized peat alone has little disinfectant power, but that it acts quite efficiently, though somewhat slowly, in destroying cholera and typhoid germs when it contains 20 per cent, of superphos- phate or 2 per cent, of sulphuric acid. An intimate mixture of the disinfecting material and the excreta is essential to certainty of results. Loeffler and AbeP found that the disinfecting influence of pul- verized peat itself upon cholera bacilli is very slight, but that its action in this direction is decidedly increased by the addition of equal quantity, by weight, of superphosphate or 2 per cent, of sulphuric acid. When mixed with 50 per cent, of super- phosphate containing 2 per cent, of sulphuric acid, all of the cholera germs were destroyed in two hours. Further experiments showed that the typhoid bacillus in excreta required four days for its destruction with pulverized peat containing 2 per cent, sulphuric acid, and in some cases twelve days were required. This method of treating infected excreta is, therefore, applicable only when the matter may remain undisturbed for some weeks before it is removed. The results obtained by VogeP indicate that peat cannot destroy the germs of infectious disease. The origin of the peat makes no difiference. The destruction of these germs can be accomplished with peat to which 2 per cent, sulphuric acid, or ID per cent, phosphoric acid has been added. The experiments of Riecke* show that tlie disinfecting prop- erties of pulverized peat are very much increased by the addi- tion of ferric sulphate. Typhoid and cholera germs are de- stroyed in two minutes when mixed with 2 parts by weight of peat meal and i part of ferric sulphate. He found that ferric sulphate is a much better addition to pulverized peat than acid. 1. Zeit.lur Hygiene, XVIII., 263. 1894. 2. Centr. fur Bak., XVI., 30. 1894. 3. Deutsche Viert. fill- off. Ges. (Supplement), XXVII., 218. 1807. 4. Zelt. fur Hygiene, XXIV., 303. 1897. PERMANGANATES. l6l PERMANGANATES. Potassium Permanganate. — In Sternberg's^ experiments 0.12 per cent, destroyed the micrococcus of pus in culture solutions, but 2 per cent, were required to destroy the virulence of septi- cemic blood. Applied to a culture of anthrax bacilli, 1 1250 prevented development. A solution of the same strength act- ing four hours delayed the development of anthrax spores in the culture fluid, but did not destroy them; but they were destroyed in four days. In Koch's^ experiments a i per cent, solution did not kill anthrax spores in two days, but a 5 per cent, solution did within one day. Among the disadvantages enumerated by RideaP are that this agent must first expend itself in oxidizing sulphuretted hydrogen, nitrites, ferrous salts, and most organic matters before attacking bacteria. Furthermore, not being volatile, it can only act locally. A solution of two drams of corrosive sublimate and the same quantity of potassium permanganate to one gallon of water was recommended by the committee of the American Public Health Association for the disinfection of excreta, but the quantity of the solution suggested as requisite for the disinfection and deodorization of a normal evacuation, — one gallon,* — is hardly practicable, to say the least. Calcium Permanganate. — In a communication to the Academy of Medicine of Paris, Bordas and Girard'' state that perman- ganate of lime has a very destructive action upon micro-organ- isms in water. Its action is much superior to that of mercuric chlorid, and it, moreover, is neither caustic nor poisonous. The bacteria on which they tested its disinfective powers are B. coli commune, S. pyogenes aureus, streptococcus of erysipelas, bacil- lus of typhoid fever, anthrax bacillus, cholera bacillus, and others. A litre of water containing B. coli commune, 80,000 colonies per cubic centimetre, is sterilized in half a minute after the addition of 5 cubic centimetres of a solution of 2 grams of 1. Tr. Am. Public Health Assoc, XI., 204. 1886. 2. Mitthell. aus aem Kals. Ges., I., 264. 1881. 3. Disinfection and Disinfectants, p. 124. 1695. London. 4. Op. cit., p. 272. 1886. 5. Journal de Med. de Paris, VII., 622. 1895. II l62 PHENOL-ALCOHOLS. permanganate of lime to the litre, — sterilized with lo millegrams of permanganate to the litre of culture. All of the other bacteria were destroyed with lo millegrams of permanganate to the litre of culture or suspension in water, but some required its action five minutes. "To obtain imme- diate and absolute destruction of the most resistant germs, it suffices to add 20 millegrams of permanganate of lime to the litre of water." PHENOL-ALCOHOLS. When formaldehyde acts upon the phenols, a series of sub- stances are formed, whose therapeutic peculiarities are of inter- est. Dr. Georg Cohn,^ of Berlin, studied two of these, one of which is the reaction product of formaldehyde with phenol, and the other with eugenol. The fiirst, saligenin, was tested upon the cholera spirillum. Staphylococcus pyogenes aureus, and a short bacterium obtained from water. The growth of the cholera spirillum was prevented by 1 1500, and that of the Staphylococcus by i :50. Testing the germicidal action of sali- genin, it was found that the cholera spirillum was destroyed in three hours with 1:150, and Staphylococcus, in twenty-four hours with 1 150. The second agent tested by Cohn is eugenol formaldehyde or eugenoform. It forms a soda salt in long, white, needle-like crystals, which are readily soluble in water. It has a slightly bitter taste, but, unlike eugenol, the sodium salt is not caustic. Eugenoform, 1 1500, inhibits the growth of cholera, and i :200 that of pyogenes. In the proportion of 1 1500, it sterilizes cholera in three hours, and i :5o, pyogenes in twenty-four hours. Bouillon cultures were used in the experiments, and after twenty-four hours in an incubating oven, fresh bouillon was inoculated from them. Both saligenin and eugenoform act upon the bacillus of diph- theria almost as rapidly as upon the cholera spirillum. Eugeno- form exceeds saligenin somewhat in its antiseptic action. Eugenoform, even in large doses, is said to be harmless. Cohn refers to the fact that the anti-diphtheritic serum only neutralizes the toxins formed by the diphtheria bacillus, and that therapeutic 1. Zelt. tUr Hygiene, XXVI., 377. 1897. PHENOSALYL. iQ^ agents which have a marked antiseptic action when applied locally to the bacillus in the throat are much to be desired. He suggests these agents for this purpose. PHENOSALYL. A mixture which Christmas^ calls "Phenosalyl" has been tested and recommended by him as a desirable antiseptic. Its composition is : carbolic acid, 9 grams ; salicylic acid, i gram ; lactic acid, 2 grams; menthol, o.io centigram. Mix the three acids and warm until liquefaction is complete. This prepara- tion is soluble in water to 4 per cent. The following shows the comparative quantity of various disinfectants required to destroy Staphylococcus pyogenes aureus in one minute. Sublimate 2.5 Phenosalyl 7.5 Solveol 15. Lysol 15 . Creolin I7-S Carbolic Acid 25 . The degree of resistance of various bacteria to Phenosalyl is as follows, the figures indicating how much of the agent is required to kill each : sporeless anthrax bacillus, 3 ; pneumonia, 4 ; bacillus pyocyaneus, 4 ; tuberculosis, 4 ; typhoid fever, 5 ; diphtheria, 5 ; Staphylococcus pyogenes aureus, 7. Phenosalyl, as RideaP describes this preparation, is a mixture of phenol, salicylic, benzoic, and lactic acids, made by heating them together at 140° C, adding menthol and eucalyptol, and, after cooling, adding four times the volume of glycerin. It is a clear, syrupy liquid, of sweetish taste. It is easily miscible with water or alcohol, is not poisonous, and has a pleasant and non-persistent odor, which does not cling about the hands and clothes. The solutions have no corrosive action on the skin, the mucous surfaces remain smooth and slippery, and do not become dried up, as is the case after washing with carbolic acid or corrosive sublimate. Of course, this latter advantage belongs 1. Annales de I'Inst. Past., VI., 380. 1892. 2. Disinfection ana Disinfectants, p. 200. 1S95. London. 164 PHENOSALYL PLAGUE. to the glycerin, and would equally pertain to phenol or mercuric chlorid in the same medium. Prof. Frankel,^ in a series of bacteriological trials, found that phenosalyl possessed an antiseptic power superior to phenol in dealing with the micro-organisms of cholera, anthrax, pneu- monia, typus, diphtheria, tuberculosis. Bacillus pyocyaneus, and Staphylococcus pyogenes aureus. "It is well known that the last-mentioned bacterium is one of the most resistant, but even a I per cent, solution of phenosalyl is sufficient to kill it, while to produce the same effect with carbolic acid one must use a 2^/2 per cent, strength, and the exposure or contact must be con- tinued for a longer period." Phenosalyl has been used by Duloroy in the sterilization of instruments, of gauze, and of different organic substances like blood, as well as decomposing urine and the saliva of consumptives, with most encouraging results. It does not corrode nor discolor metals under ordinary circumstances of contact. This is an example of a mixture which seems to present great advantages. Of late years there has been a tendency to use complicated compounds, most of them only soluble in alcohol, which, apart from expense and other faults, is inadmissible as a medium for many purposes. It should be noticed that, while in mixtures the properties of the ingredients are mostly retained, in many of these compounds not only are the properties lost, but frequently new and objectionable ones are developed. For example, the desire to avoid the unpleasant odor of iodoform has led to the introduction of many "substitutes" which are costly, unstable, uncertain, and even dangerous in their action. However, phenosalyl may be reckoned as a convenient pre- paration of the above aromatic acids dissolved in lactic acid and glycerin, and scented with menthol and eucalyptus. The name is rather an unfortunate one, as leading to a wrong idea of its composition. PLAGUE. The preliminary investigations of Kitasato and Yersin indi- cated that the bacillus of plague is quite easily destroyed by physical and chemical agencies. Kitasato^ found that bouillon 1. Bacterienkuncle, Berlin, 1890. (Quoted by Rideal.) 2. Lancet, II., 1894, 428. PLAGUE. 165 cultures heated to 80° C. in a water-bath were sterilized. They were also destroyed in a few minutes by steam of 100° C. One per cent, of carbolic acid sterilized a culture in one hour, and Y^ per cent, in two hours. The bacillus was also destroyed by i per cent, of quicklime. Sunlight also rapidly devitalized the bacillus. In an important paper by Giaxa and Gosio,^ the results of their experiments are given in the investigation of the action of physical and chemical agents upon the bacillus of plague. Briefly summarized, they are as follows : Desiccation attenuates the virulence of the bacillus but little; respiration of dust containing it is dangerous. Pus and blood dried on bandages and kept in the shade thirty days at a temperature of 10° and 18° C. remained virulent. At the temperature 36,° 37,° they were not fully sterilized under five days. Direct sunshine requires from two to three and one half hours to sterilize, and then only the superficial layers of the culture are destroyed. Protected with a layer of linen or cotton, it requires from six to eighteen hours. At the temperature of 80° C, the bacillus being humid, it was destroyed in ten minutes ; when dry on linen, the germs were not destroyed in forty minutes. At 100° moist cultures were destroyed in five minutes, but it did not suffice for the steriliza- tion of the dry bacillus. Formaldehyde disinfects only the surfaces. Calcium hydrate, I per cent., destroyed in one hour. A solution of potash equal to 5 per cent, caustic potash killed in twenty minutes, the tem- perature being 60°. Green soap, 5 per cent, at 15° did not kill in twenty-three hours ; 3 per cent, at 35° sterilized. Hydro- chloric acid, 0.5 per cent., did not sterilize in three hours, but did in six hours. The same acid, i per cent., sterilized in three Tarbolic acid, l per cent., was efficient in three hours, and so was sublimate, 0.5 per cent., in five hours, and i per cent, m two hours. . A still later study of the action of disinfectants upon the bacil- lus is that of Kasanski.^ On silken threads, exposed to air and 1. Annan d'Igiene Sperirn., VII., 281. 1896. 2. Centr, lUr Bak., XXIII., 25. 18B8. l66 PLAGUE ROOMS. light, the bacillus retained its vitality from five to fifteen days, but cultures kept at a temperature of 58° C. in the water-bath were destroyed with certainty within one hour. In water from the public supply, it remained alive for from ten to forty-eight days ; on sterilized potatoes, sixty-two days. Dried upon silken threads, the bacillus was destroyed in from one to two minutes by from i :3,ooo to i : 1,000 of sublimate; by 1 :2,ooo of hydrochloric acid ; by 2}4 and 5 per cent, carbolic acid; by 5 and 10 per cent, formalin; and by 5 and 10 per cent, acetic acid. Potassium permanganate, lime water, and green soap were uncertain in their action. POTASH . (See ALKALIS. ) PRIVIES. (See EXCRETA.) PYOCTANIN. (See ANILIN DYES.) RESORCIN. After alluding to the experiments of Andeer, Callias, Dujar- din-Beaumetz, Lichtheim, and others, Rideal^ says that, "it is evident that i per cent, of this substance is efficiently antiseptic towards most micro-organisms." Pane,^ however, subjected Staphylococcus pyogenes aureus on threads to the action of a I per cent, solution of resorcin at 37° and they developed entirely normally. Thus he states that the advantages of resorcin in practice do not correspond with the results of laboratory experi- ments. ROOMS. Martin,^ of Paris, describes the methods of disinfecting rooms in Paris. There are four disinfecting stations in the city. These stations receive for disinfection mattresses, clothing, car- pets of small size, skins, furs, etc. The things disinfected with steam are bedding, cotton and linen clothing, and fabrics gener- 1. Disinfection and Disinfectants, p. 171. 1895. London. 2. An. dell' Istltuto D'Ig. Sperlm. dell' Univ. di Roma., II., 80. 1890. 3. Annales de Micrograpliie, VIII., 285. 1896. ROOMS. 167 ally. Those that are disinfected by washing or by spraying are skins, shoes and other leathern work, rubbers and rubber goods, as suspenders, caps, hats, trunks, furs, and wooden articles put together with glue. When a disinfecting carriage or van is sent to a house that needs disinfection, it is accompanied by three persons, a driver and two disinfectors. The van contains one or more spray apparatus, 12-litre flasks containing a i :5oo solution of mercuric chlorid; several is-litre jugs and packets containing 750 grams of copper sulphate; a can of cresol, cloths and sponges; cloth bags containing the working clothes of the disinfectors, and other articles to complete the working kit. Arriving at their destination, the two disinfectors remove their uniforms and put on their working clothes. After entering the room to be disinfected, the disinfectors spray the place which is, to receive their kit, bags, blankets, other clothing, etc. They carefully pack and place in the carriage, hermetically closed, the things that are to be removed to the disinfecting station for treatment. The sprayer is then filled, and ceilings, walls, wainscotings, large carpets left in the house, furniture, and particularly the bed, interior of commode, and all other things that are left in the room are thoroughly sprayed. Nothing is neglected. Mirrows and their frames, and pictures and other works of art are wiped with a cloth dampened with a disinfecting solution, or sprayed. The tacks are removed from the carpets and the carpets are sprayed plentifully on both sides. The rooms are usually sprayed twice with some minutes intervening, the dis- infectors always beginning at the top of the walls and proceed- ing downward. The vessels used by the sick person, water-closets, night cab- inets, and toilet-tables are carefully washed in a solution of sul- phate of copper. Disinfection with sulphate of copper is done after all intestinal diseases, and after diphtheria, croup, and angina where cloths, etc., have been thrown, and after brochial and pulmonary affections where the expectorations have been deposited. For large areas, as of cement or asphalted surfaces in cellars, stables, etc., a 5 per cent, cresol solution is used. After finishing their room, the disinfectors spray each other, descend from the house with their things, remove their working l68 ROOMS SALICYLIC ACID. suits, put them in the bag whicJi they have for that purpose, and with the van and driver return to their disinfecting station. At the station they carefully disinfect themselves. The sprayers are emptied and washed out each evening. During the course of infectious diseases, and before the time for the final disinfection, the disinfectors are often called to dis- infect other rooms than the sick-room. They do not then enter the sick-room. They remove infected clothing, and, after dis- infection, it is returned to the house. In Berlin the kit which is carried to the houses by the disin- fectors contains the numerous articles which they require in their work. As described by Merke,^ the method of disinfecting rooms may be summarized as follows : All furniture, pictures, etc., are placed in the middle of the room, the walls are rubbed with bread, unpapered walls with a 5 per cent, solution of carbolic acid, or are whitewashed; the raising of dust is carefully avoided. Polished furniture is rubbed with a cloth dampened in a 2 per cent, carbolic acid solu- tion, and then with a dry cloth ; the unfinished backs of pieces of furniture, and the upholstered parts are washed twice with a 5 per cent, carbolic acid solution ; wainscoting, doors, etc., are washed with a 2 per cent, solution; pictures not covered with glass are rubbed with a dry, soft cloth ; pictures covered with glass, with a cloth dampened in a 2 per cent, carbolic acid solu- tion ; toys of little value are burned ; toys of more value, leathern articles, metallic articles, glass, etc., are all washed carefully, or rubbed in a 2 per cent, carbolic acid solution. (See Walls, Floors, Furniture, and Bedding.) SALICYLIC ACID. Salicylic acid is, as determined by Behring,^ nearly twice as potent a germicide as carbolic acid. Peroncito observed that anthrax bacilli were destroyed in from ten to fifteen minutes with a saturated aqueous solution. In the investigations of Schill and Fischer,^ a saturated aqueous solution, mixed with tuberculous sputum in equal parts, 1. Deutscne Viert. t'Ur off. Ges., XXIII., 263. 1891. 2. Zelt. fur Hygiene, IX., 423. 1890. 3. Mittheil. a. d.Kais. Ges., II., 136. 1884. SALUBROL SAPROL. 169 destroyed the bacilli in twenty hours, thus acting more rapidly than did a 5 per cent, solution of carbolic acid which required twenty-four hours. Pane^ also used aqueous solutions of salicylic acid. A i : 1,000 solution at 39° destroyed Staphylococcus pyogenes aureus on threads in seven minutes; at 15° in thirty minutes. A solution of i :2,ooo, not irritating to delicate mucous sur- faces, had a distinct antiseptic action. At 37" it killed Staphy- lococcus pyogenes aureus on threads in twenty to thirty minutes. Typhoid and diphtheria at 37° were killed in from five to seven minutes with i : 1,000. Although salicylic acid acts so energetically upon sporeless bacteria on threads, it is less effective when tested after Esmarch's method. To kill Staphylococcus pyogenes aureus at 37" in from five to twenty minutes, a 3:1,000 solution must be used in the proportion of two parts of the solution and one of the bouillon. SALUBROL. As defined by Dr. Silber,^ of Breslau, salubrol is a combination •of bromin with methylenbisantipyrin. It is an entirely odorless powder. His experiments indicate that it is not poisonous. Applied to bacteria, he finds it an efficient antiseptic and that it has distinct disinfectant qualities. It not only prevents the growth of bacteria, but destroys them. In surgical practice he has found it to be an efficient antiseptic. Its only drawbacks are that, with some patients, when the powder is strewn upon fresh wounds, it produces a mild burning sensation. Some patients, however, do not complain of this smarting. It is absent when a 20 per cent, gauze is used. SAPROL. Saprol is a dark-colored, oily preparation with a smell like lysol or creolin. It is said to contain about 26 per cent, of phenol and cresol. It is recommended especially as a disinfectant and deodorant of privy vaults. 1. Annali dell' Ist. D'Ig. Sperim. dell' Univ. di Roma, II., 79. 1890. 2. Deutsche Med. Woch., XSII., 843. 1896. 170 SAPROL. The value of saprol as a disinfectant for human excreta has been investigated by Laser.^ It being lighter than water floats upon the surface of fluids which, from the supernatant layer dissolve phenol, cresol, and other coal-tar products which are soluble in water. The stratum of oil diffused uniformly upon the surface meanwhile prevents the rise of ill-smelling gases and, at the same time, prevents the deposit of germs from the air. The presence of ammonia in the fluids covered by saprol increases the solubility of the products of the coal-tar distilla- tion. This is, in brief, Laser's statement of some of the favor- able points in the use of saprol. Urine covered with a slight layer of saprol remained clear, without smell, and sterile for twenty-two days. One cc. of saprol sufficed to sterilize in six days 180 grams of a mixture of feces and urine, and 0.5 cc. of saprol sterilized 40 grams of cholera feces in twenty-four hours, and the same quantity of typhoid stools in forty-eight hours. Laser estimates that i per cent, of saprol suffices for the disin- fection of feces and urine, and since 150 grams of feces and 1,200 cc. of urine are reckoned daily for each person, 400 grams of saprol per month would be required to disinfect the excreta of one person. The price of saprol, as stated by Laser, is 60 pfennige (15 cents) per litre, or, in larger quantities, 40 pfennige per litre. It would cost, therefore, about 20 pfennige (5 cents) per person per month. Scheurlen^ found that the water below the layer of saprol was converted, in a short time, into about 0.5 per cent, of cresol solution. The deodorizing action of saprol is rapid and certain. According to the statements of the manufacturers, and his own analyses, he found saprol to consist of 20 per cent, of mineral oil and 80 per cent, of a 50 to 60 per cent, crude carbolic acid. Some persons had expressed fear of the danger of using saprol on account of its inflammability. Scheurlen tested this question. He found that the 50 to 60 per cent, crude carbolic acid, from which it is manufactured, flashes at 84° and burns at 93° C, vv'hile the mineral oil, which is a constituent of it, has a flashing point of 150" and burns at 171°. Saprol itself flashes at 90° and burns at 102° C. His conclusions confirm the statements of the manufacturers that saprol is a solution in round numbers of 20 per cent, min- 1. Centr. fur Bak., XII., 334-240. 1892. 2. Archiv fur Hygiene, XVIII., 35. 1893. SAPROL. 171 eral oil and 80 per cent, of a 50 to 60 per cent, carbolic acid. Its specific gravity is 0.98-0.99. It therefore floats upon the surface of watery fluids and spreads itself quite uniformly over their surfaces. Almost immediately after saprol is poured upon the surfaces of fluids, the solution of cresol begins. Even in twenty-four hours, when the quantity of saprol suf- fices, the underlying stratum of water is changed into a 0.34 per cent, cresol solution, and in four days, into a 0.43 to a 0.49 per cent. Saprol is an excellent deodorant, perhaps the best which we possess. Prodigiosus, cholera, and typhoid bacilli, and the vegetative forms of the bacteria of water and fecal matter are destroyed in from six to twenty-four hours. Spores (anthrax, megatherium) are not killed. The required quantity of saprol is i : 80. Watery solutions of cresol is made with very nearly equal facility, whether 100 per cent, crude carbolic acid or 50 to 60 per cent, carbolic acid is used. Formerly 100 per cent, crude carbolic acid was used by the manufacturers, but the lower grade is now employed. Keiler^ states that at least i per cent, of saprol is needed for the deodorization of vaults. His experiments show that 5 per cent, of saprol suffices to destroy typhoid fever bacilli in a few minutes, while one half that quantity destroys cholera bacilli in five minutes. He thinks, however, that there is no advantage in the oily constituent and the gradual absorption of the cresol, but that a soap solution of the disinfecting constituents of the crude carbolic acid would be preferable. Pfuhl,^ of Hanover, carried out a series of experiments for the purpose of determining the disinfectant action of saprol. He found that a small quantity of saprol added to putrefying urine removed the odor entirely within a few days. The num- ber of bacteria gradually diminished, and in three or four weeks disappeared entirely. Its action was also very marked when it was added to the pus due to urinous infiltration of tissues. Its 1. Archiv fur Hygiene, XVIII., 57. 1893. 2. Zelt. fur Hygiene, XV., 192. 1S93. 172 SAPROL. action upon solid and semi-solid excreta when the more elevated portions of the matter were uncovered was unsatisfactory. From 30 to 50 cubic centimetres of tuberculous sputum con- taining an abundance of resistant bacteria were mixed with one cubic centimetre of saprol and left forty-eight hours at ordinary room temperature. At the end of that time, the sputum was ■distinctly liquefied. A rabbit which received one cubic centi- metre in the peritoneal cavity died of tuberculosis. Staphy- lococcus aureus in bouillon covered with a layer of saprol was entirely disinfected in twenty-four hours. Pfuhl made some experiments to determine the degree of inflammability of saprol which indicate that it is not great, but that vaults containing paper, straw, or similar inflammable mate- rial into which lighted matches might be thrown might com- municate the flames to the saprol. Pfuhl's conclusions are as follows : Saprol has a strong antiseptic action, and, in the proportion of I to 100, is capable of sterilizing putrefying liquids. Excreta in a solid or semi-solid condition are not efficiently disinfected with saprol. Saprol is an excellent deodorant. For the disinfection of excreta, 300 to 500 grams of saprol per person per month suffice, but as the deeper portions of solid matter are not sufficiently penetrated by the saprol, mixing by mechanical process is required. For the complete disinfection of privy vaults, saprol is not suitable and possesses no greater value than the agents which have hitherto been in use. There is no special danger of inflammability, although in practice the danger is somewhat great on account of the possible presence of other inflammable material. His experiments indicate that saprol has a more energetic action as a disinfectant and as a deodorant than crude carbolic acid has. For the efficient treatment of excreta, the surface should be completely covered with a film of saprol. This disinfectant offers an efficient protection against the danger of the transpor- tation by flies of the infection of cholera, typhoid fever, and dysentery. In a second paper by Dr. Scheurlen^ he considers some of the objections to the use of saprol which had appeared in some 1. ArcMv tiir Hygiene, XIX., 347. 1893. SAPROL. J-, recent papers on the subject. Referring to Pfuhl's paper, he says that there are really only two disinfecting agents besides saprol which are practicable for the disinfection of privy vaults, — milk of lime and crude carbolic acid. Used as it was by Pfuhl for the disinfection of human excreta, when the liquids had been otherwise disposed of, he admits that milk of lime is an efficient agent. But this is far from the general condition of things. In ordinary vaults, with a mixture of the fluid and solid excreta, the milk of lime sinks to the bottom without mixine with the contents. This is what the experiments of Pfuhl have- shown. The mechanical mixing of the milk of lime with the contents of the vault is impracticable. Referring to a paper by Anschiitz, who recommends lysol instead of saprol for the disinfection of excreta, Scheurlen says that a comparison of the results obtained by Anschiitz with the two agents is impossible. He says that lysol is not a suitable disinfectant for excreta, for, when added to the contents of a vault that are in a fluid con- dition, the lysol is decomposed and an oily layer floats upon the surface. This finally condenses into a mass consisting of fatty acids and hydrocarbons soluble in ether and solutions of alkalis. He refers also to Keller's "soluble saprol" as another prepara- tion which is equally inappropriate for the disinfection of fluid excreta. Scheurlen made some experiments to determine the compara- tive value of saprol and of crude carbolic acid for the disinfec- tion of excreta, particularly when it is in a fluid condition, and he found that, -when not mixed mechanically, the fluids were capable of extracting a much larger proportion of cresol from saprol than from crude carbolic acid. Referring to the paper of Pfuhl, Scheurlen claims that Pfuhl's results do correspond with his, so far as the experiments are comparable. He says that for the disinfection of fecal matter from which the fluids have been separated, saprol is not superior to some other agents, but is their equal ; but when the contents of the vault are fluid or semi-fluid, saprol is greatly superior to any agent hitherto recommended for this purpose. 174 SILVER AND SILVER SALTS. SILVER AND SILVER SALTS. During his investigation of the antiseptic action of various filHng material in dental work, Professor Miller, of Berlin, was surprised to find that gold-foil, in some of the forms used by dentists, has a distinct antiseptic action. The correctness of this observation was confirmed by Behring,^ and he found that some other metals, notably metallic silver, possess a marked anti- septic action. Miller's theory, that their antiseptic properties were due to the condensation of oxygen or other gases upon their surfaces, is shown by Behring to be untenable, and that the antiseptic action is due to a slight degree of solubility of the metals and, consequently, to the presence in his cultures of a small quantity of the salts of these metals. Actol and Itrol. — In an address by Dr. Crede,^ of Dresden, he says that in common with his assistant. Dr. Beyer, they suc- ceeded in proving that metallic silver, when placed upon aseptic, sterile wounds, remains unchanged and does not at all irritate, so that it may be considered in every respect a thorough aseptic dressing material. In case the wound is not aseptic, but is in any part infected by bacteria, the products of the bacterial vital- ity oxidize the surface of the silver and enter into combination with the argentic oxid, forming argentic albuminates which have strong antiseptic properties ; in other words, a powerful antiseptic is at once formed by the aid of the aseptic metallic silver dressing as soon as the wound is already infected or becomes so. We succeeded in determining by a series of experi- mental researches that the bacterial secretion, acting upon silver and entering into combination with its oxids, are organic acids, preeminently lactic acid, and that the antiseptic which an infected wound, when dressed with metallic silver, generates of itself, is lactate of silver. Lactate of silver (actol) is a white, odorless, almost tasteless powder, which, when kept in a brown glass vial, remains unchanged; it is soluble in the proportion of i to 15 parts in water and in albuminous fluids. In its aqueous solution, in the proportion of 1:1,000, it destroys within five minutes strep- tococci, staphylococci, bacillus anthracis, etc. In blood serum. 1. Zeit. fiir Hygiene, IX., iS2. 1890. 2. Reported in Medical Review, XXXIV., 251. 1896. SILVER AND SILVER SALTS. 17c. it retards the development of -bacterial germs in a dilution of 1 : 80,000, while corrosive sublimate does so only in a solution of 1 : 20,000. It has, therefore, an antiseptic power at least four times as great as that of corrosive sublimate. He further states that the silver salts under consideration do not destroy cellular tissue as corrosive sublimate does while preventing the propagation of bacteria. As stated before, when lactate of silver is employed in powder form, it exercises some irritating action upon the more sensitive tissues, because it is rapidly absorbed on account of its ready solubility; a toxic effect, therefore, is not quite excluded after a liberal and long continued application of the dry powder. Of the other argentic salts, citrate of silver (itrol) proved to be the preferable and most efficient one in its action in bacteri- ological and clinical experimental researches. It forms a light, dusty, and stable powder without odor, and almost devoid of taste, and with the same antiseptic power as the lactate; but it requires 3,800 parts of water for solution. A solution of i part in 4,000 of water suffices to destroy all bacteria within ten min- utes; its antiseptic power, therefore, is amply sufficient in all cases commonly occurring. It occasions no unpleasant or pain- ful sensation in any kind of wound, and its scanty solubility secures for it a more lasting action with the advantage of a spar- ing application. Its use is, therefore, much cheaper than that of iodoform, although it is relatively about twice as dear. Marx'^ shows experimentally that actol cannot be used as an antiseptic for the whole body. Not only were his results anti- septically negative, but moderate hypodermatic doses produced febrile temperatures, due, he thinks, to the systemic action of lactic acid, following the decomposition of actol into lactic acid and metallic silver. As to the local action of actol and itrol, he believes that the work of Crede and Beyer has been so exact and faultless that there can be no doubt of the great value of these agents as local antiseptics. In another paper, Marx^ reviews several late works upon the antiseptic action of the silver salts : Zagontschkonski could observe no antiseptic action from silver gauze as recommended by Dr. Crede. He found that the 1, Centr. fur Bak., XXI., 573. 1897. 2. IWd., p. 711. 176 SILVER AND SILVER SALTS. gauze itself contained germs. Beyer, on the other hand, had always found the silver gauze sterile and thought it probable that Zagontschkonski had obtained an old preparation which was prepared by the old and incomplete methods. Meyer made careful and extended investigation of the action of the silver salts. He found that Staphylococcus pyogenes aureus was destroyed in forty-five minutes with a i : 4,000 solu- tion of itrol, and in thirty minutes with a i : 2,000 solution of actol. When in albuminous media, the silver solutions were slower in their action. The growth of sporeless bacteria was delayed with 1:20,000 in ascites bouillon, and in 1:10,000 in blood serum. They thought that the power of actol and itrol in preventing bacterial growth of albuminous media is very nearly that of sublimate, while in watery solutions the sublimate has a much greater action. Pilger considers the silver salts very efficient and harmless antiseptics that must supersede all other agents for this purpose. Commenting upon the recent literature on this subject, Marx thinks that the original statements of Crede and Beyer are con- firmed, and that among the numerous antiseptics itrol and actol are to take a prominent place. Tarnawski^ studied the disinfecting and antiseptic properties of actol and itrol, and, at the same time, carried on a series of parallel experiments with sublimate and nitrate of silver for purposes of comparison. The bacteria used were typhoid bacilli, Staphylococcus pyogenes aureus, and anthrax spores. The growth of anthrax and of the staphylococcus was inhibited by 1:20,000 of either of these salts; while the development of typhoid bacilli was prevented by 1:30,000 of actol, and 1:40,- 000 of itrol. The antiseptic action of sublimate, however, exceeded that of the silver salts. In his experiments to determine the germicidal action of these salts, he neutralized them with ammonium sulphid. Without this precaution, anthrax spores appear to be destroyed in from five to twelve hours with a i per cent, solution of silver nitrate or saturated solution of itrol, but when neutralization followed exposure to the disinfecting agent, they were not destroyed in 168 hours. Staphylococcus was destroyed in forty-eight hours with from i : 500 to i : 200 of actol solution, or in five hours 1, Centr. tiir Bak., XXIII., 618. 1898. SILVER AND SILVER SALTS. 1 77 with a I : loo solution. Some of the conclusions of the author are that: In blood serum, actol is inferior to the nitrate of silver as a disinfectant; in bouillon, the difference is slighter. In serum, sublimate is much superior to the silver salts in disinfecting power. Blumberg^ finds that, so far as their antiseptic action on ani- mal tissues is concerned, argentamin, actol, and itrol are superior to silver nitrate and argonin, and that mercuric chlorid is infe- rior to them. Protargol. — This antiseptic is composed of silver combined with protein material. It contains 8 per cent, of metallic silver and is easily soluble in cold water to 50 per cent. The solutions are entirely clear. It is also soluble in blood serum and solu- tions containing albumen, and in glycerin. Solutions of pro- targol are not precipitated by albumen nor by sodium chlorid. Benario^ tested the bactericide action of protargol upon vari- ous bacteria. An aqueous suspension of Staphylococcus pyogenes aureus was sterilized in twenty minutes with i per cent., and, suspended in bouillon, the germs were destroyed in ten minutes. In both bouillon and serum, sterilization was more rapid than in sterilized water. Typhoid bacillus, bacterium coli, and Siegel's bacillus and the pneumococcus were destroyed still more readily than staphylococcus,— a i per cent, solution destroyed them in from five to seven minutes. Anthrax spores were destroyed in one hour with a 2 per cent, solution. For installation into the conjunctival sac, or used otherwise, Benario found protargol devoid of irritating qualities. In his own hands, and in the hands of others, he states that protargol has been found to be a very desirable and efficient antiseptic. On the other side of the question of the antiseptic value of protargol, Kaufmann and Bloch^ subjected the methods of Benario to a severe criticism, and doubt the correctness of his '°'mr^rof Silver.-As regards the disinfectant power of nitrate of silver, Behring* places it next to that of mercuric chlorid, and in blood serum, in milk, or in albummous fluids, its "ITzelt. fur Hygiene, XXVI., 201. ISflS. 2. Deutsche Med. Woch.,XXin., 82 (Therap.Beil. 897. 3. Deutsche Med. Woch., XXIV., 27 (Tlierap. Ben.). 1898. 4. Zeit. fur Hygiene, IX., 406. 1890. 12 178 SILVER AND SILVER SALTS SOAP. action surpasses that of sublimate. Heider^ had not found this agent so efficient a germicide as Behring had. Anthrax spores subjected to the action of a i per cent, solution of nitrate of silver were not killed in fifty-four hours. In a foot-note, Heider refers to Savor's results in which anthrax spores were killed in fifteen minutes with a i per cent, solution, but he used nothing to precipitate the silver salt which adhered to the spores. In his tests of various disinfectants, Baer^ found that in bouil- lon, sporeless anthrax cultures were sterilized in two hours with from 1:30,000 to 1:20,000; diphtheria, with from 1:10,000 to 1 :2,50o; glanders, with from i : 15,000 to i :4,ooo; typhoid fever, with 1:4,000; cholera, with from 1:20,000 to 1:4,000. The first proportions were with freshly inoculated cultures; the second, with 24-hour cultures. In his experimental investigation of the disinfectant action of nitrate of silver, Jerosch^ found that anthrax bacilli on threads were destroyed in one minute by solutions of from 1:1,000 to 1 : 10,000. Similar results were obtained with Staphylococcus pyogenes aureus. He therefore rates the disinfectant action of nitrate of silver above that of carbolic acid. SOAP. The observations of Koch* that a i : 1,000 solution of potash soap in water prevented the development of anthrax bacilli, indi- cated that soap has a disinfecting as well as a cleansing action. Behring^ tested the disinfectant value of forty different samples of soap, usually in 10 per cent, solutions, and concluded that the germicide power of soaps depends upOn their degree of alkalinity. Some other experimenters, however, do not agree with him on this point. So far as I know, Behring has published no detailed results. The experiments of Nijland," in sterilizing with soap water in which the cholera bacillus was svtspended, yielded quite remarkable results. Suspensions of the bacillus were com- pletely sterilized in ten minutes with 2.4:1,000 of potash soap 1. Archiv fur Hygiene, XV., 357. 1892. 2. Zelt. fur Hygiene, IX., 482. 1890. 3. Centr. fur Bak., VII., 226. 189(1. i. Mittheil. a. d. Kais. Ges., I., 271. 1881. 5. Zeit. fUr Hygiene, IX., 414. 1890. 6. Archiv fur Hygiene, XVIII., 335. 1893. SOAP. 175 (green or soft soap). A soda soap (hard soap) in the same proportion did not fully sterilize in fifteen minutes, but a 3 : 1,000 solution sterilized within one minute. Jolles^ tested five kinds of soap, the degree of alkalinity of which varied from 0.02 per cent, to 0.05 per cent. His solutions ranged from o.i per cent, of soap to 10 per cent. He thinks that the results which he obtained justify the conclusion that there was very little difference in the disinfectant action of these soaps, when used in the same proportions, at the same tempera- ture, and acting for equal periods of time. At the temperature of 15° C, a 9 per cent, solution of either of these soaps destroyed cholera bacilli in from one to two minutes ; a 4 per cent, solution, in ten minutes ; and a 2 per cent, solution, in thirty minutes. A still more recent work is that of Reithoffer.^ The soaps used by him were the common soft soap, a white almond soap perfumed with nitrobenzol, and a hard patent potash soap. Suspensions of cholera bacilli were sterilized in one half minute with ID per cent., and in five minutes with 5 or 2.5 per cent. Suspensions of typhoid bacilli were sterilized in one minute with ID per cent, of soap, and in from three to ten minutes with 5 per cent. Staphylococcus pyogenes aureus was not killed in one hour with 18 to 20 per cent. Hence, in surgical practice, soap does not suffice as a disinfectant, but for the destruction of the typhoid bacillus and Bacterium coli commune, soap may be used when other disinfectants are not at hand. Reithoffer says that soap of good quality must be used, and that the common soft soap of the market is often impure and not worth much. The results obtained by Beyer^ were far less favorable than those of the preceding investigators. One of the official regula- tions in Germany for the disinfection of the clothing and bed clothing of cholera patients in 1893, was to immerse these arti- cles in a 3 per cent, solution of potash soap, a solution of car- bolic soap, or of carbolic acid, and let them remain twenty-four hours in it. To determine the germicidal value of the first of these solutions thus used, Beyer instituted a series of experi- ments in which soaps of various kinds were applied to the dis- infection of pieces of cloth infected with the cholera bacillus, 1. Zeit. £ur Hygiene, XV., 460. 1893. 2. Archlv fur Hygiene, XXVII., 360. 1896. 3. Zeit. fiir Hygiene, XXII., 238. 1896. l80 SOAP. typhoid bacillus, Bacterium coli commune, Staphylococcus pyogenes aureus, and the diphtheria bacillus. He sought to have the conditions approach as nearly as possible those in real practice. The soaps received from various manufacturers were sent in compliance with Beyer's request for green or potash soaps with an excess of alkalinity. Of the seven soaps exam- ined, the proportion of free alkali varied from o to 0.096, and, as Kitasato has shown that cholera bacilli in neutral bouillon will bear as much as 0.237 per cent, of free soda or potash before growth ceases, and typhoid bacilli as much as 0.18, it is evident that if disinfection should result it could not be due to the pres- ence of free alkali. The soap solution was used at various degrees of temperature, not exceeding 50° C. The results indicate that a 3 per cent, solution of potash soap (green soap, soft soap) cannot be trusted to destroy even the bacillus of cholera, unless the infected samples were kept in the solution at a temperature of 50° C. (122° F.) for one hour at least, and then were allowed to macerate in it twenty-four hours longer. The destruction of the other bacteria required gener- ally the maintenance of the temperature of 50° C. for a longer tiine and the prolongation of the period of soaking to forty- eight hours. In the treatment of soiled clothing, the tempera- ture of the solution cannot be raised above 50" without danger of staining it, and it is practically impossible to bring the solu- tion to the temperature of 50° in all parts of a boiler without exceeding that temperature in some parts. Applied to the destruction of the bacillus of plague, Giaxa and Gosio^ found that 5 per cent, of green soap at 15° C. had no effect in twenty-three hours ; but that 3 per cent, at 35° did kill the bacilli. Summary.— As may be seen under "Heat as an Auxiliary" and under "Alkalis," solutions of washing soda, when their temperatures are raised to 55° or 75° 0.(131° or 167° F.), become prompt and efficient germicides. On the other hand, the review of the experiments with soap solutions reveal results and con- clusions too discrepant to warrant the classification of such solu- tions as trustworthy disinfectants when the temperature is 50° C. (122° F.) or below. 1. Annali d'lgiene Sperlm., VII., 261. 1896. SOAP, ANTISEPTIC. l8l Solutions.— The Board of Health of New York City directs that one ounce of common soda be added to twelve quarts of hot soap (soft soap) and water, and for the present it will be on the safer side to prescribe, as that board does, that this solution is to be used for simple cleansing, or for cleansing after other methods of disinfection. SOAPS, ANTISEPTIC. Dr. Chas. T. McClintock^ gives an account of his experiments as to the possibility of making an antiseptic soap in which mer- curial salts remain in an active form and undecomposed. After narrating the results of various unsuccessful attempts in this line, he says : "Turning to the iodids I was more successful. For example, a solution of the double salt of mercury and potassium iodid will permit the presence of a weak alkali without precipitation of the mercury. In such a solution albumens are dissolved; further, nickel and steel are protected by the alkali from the action of the mercury. This seemed to be what I was looking fof, as it was a germicide more active than mercuric chlorid or iodid that would not tarnish instruments. But after making hundreds, even thousands of experiments with the material, it was not satisfactory. The trouble seemed to be in the amount of alkali needed : if too much was used, the mercury was pre- cipitated ; if too little, the metals were attacked. If the correct amount was employed at the outset, some of it might be used up uniting with albumens, for example, in disinfecting the skin. "I next took advantage of the well known fact rhat when neu- tral soaps are dissolved in water they are gradually decomposed into acid soaps and free alkali. By combining my mercury salt with the soap, when this was dissolved, I got a gradually increas- ing amount of alkali sufficient to replace any used up by albu- minous or other bodies present in the field of experiment. But some soaps, I found, liberated the alkali too rapidly, others too slowly. The amount of alkali and the rate of liberation depend, in part, on the nature of the oil from which the soap is made; also, to some extent, upon the amount of glycerin, free alkali, fatty acids, unsaponified fat adulteration, etc. After a long 1. Medical News, LXX., 485. 1897. l82 SOAP, ANTISEPTIC. series of experiments to obtain the right kind of soap, the proper amount of the mercury salts, etc., I obtained a combination that appears to be fairly satisfactory. At first, I used a soap con- taining Yi. per cent, of mercuric iodid ; but, by varying the com- position of the soap, I found I could use i per cent, and, later on, 2 per cent, of the mercury salt." A series of tables give the results of his bacteriological tests of this soap. The solution containing i per cent, of the soap or 1:5,000 of mercuric iodid, killed cholera, typhoid, and diph- theria and Staphylococcus pyogenes aureus in one minute. A solution containing 0.2 per cent, of the soap, or 1:25,000 of mercuric iodid killed the micro-organisms of pus in fifteen minutes. A solution containing % per cent, of soap, or i :20,- Goo of mercuric iodid, killed Staphylococcus pyogenes aureus in one minute. A solution of soap containing i :2,ooo of mercuric iodid destroyed anthrax spores in one minute. In these experiments, Geppert's precaution of precipitating with ammonium sulphid was observed. This antiseptic soap was tested after it had been exposed two months to sunlight. The results were as good as that of fresh material. This soap does not attack nickel or steel instruments under any ordinary exposure. They may be Dolled in a strong solu- tion of it without harm. If left in the soap solution for some days, however, the instruments may rust. The paper ends with the following conclusions : I. In proportion to the amount of antiseptic contained, this soap is at least five times as strong as any known germicide. A I per cent, solution of the soap, i :5,ooo of mercuric iodid, is at least equal to i : 1,000 of mercuric chlorid. 2. As it would ordinarily be used, it is at least as strong as any germicide in common use : i. e.. I believe that if a wet cake be rubbed over the hands, the layer of the soap next the skin will be at least a I per cent, solution, and as the tables show, this is at least as strong as i : 1,000 mercuric chlorid. 3. It does not coagulate albumens or attack nickeled or steeel instruments. It does not seem to have any action on lead, and so will not injure waste- pipes. 4. It will not attack silver and aluminum instruments. The correctness of the opinions of Dr. McClintock is con- firmed by the results obtained by others, among whom are Dr. SOAP, ANTISEPTIC. I83 F. G. Novy, of the University of Michigan, and Dr. W. M. L. CopHn, of Jefferson Medical College, Philadelphia. Dr. Novy reports : "The peculiar combination in which the mercury exists in the soap renders it decidedly more efficient than the common mer- cury solutions. A soap solution containing i : 5,000 of mercuric iodid, acting on common pus-producing organisms, destroys these in less than five minutes, whereas solutions of mercuric chlorid (i : 1,000, or mercuric iodid (i :i,ooo) require more than fifteen and sixty minutes, respectively, to accomplish the same result. "Another superiority of this soap solution, as compared with the common mercury solutions, is seen in the fact that steel and nickel instruments may be exposed to its action, at ordinary tem- perature or at steam heat for hours, without the slightest effect on such instruments. "An additional and important advantage of the soap solution is seen in its behavior to chemical compounds which ordinarily throw mercury out of solution. The mercury contained in the soap solution is not precipitated by proteid matter (such as blood serum), by phosphates (as in urine), or by hydrogen sul- phid. The soap solution can be used in the presence of such compounds, whereas ordinary mercuric solutions would be of little value. Thus, mercuric chlorid is not recommended for the disinfection of sputum in consumption, because it is precipi- tated by the proteid constituents. When the soap solution is added to tuberculous sputum the latter becomes gelatinous and in a short time perfectly liquid. The germicide can therefore act on the tubercle bacilli and does destroy these in a short time, as shown from experiments with guinea-pigs." In Dr. Coplin's experiments, the germicidal soap was tested on bouillon cultures of anthrax. Staphylococcus pyogenes aureus, prodigiosus, pyocyaneus, and on pus containing staphylococci. With I per cent, of the soap, which is equivalent to i : 5,000 of mercury iodid, all were destroyed in three minutes ; all but the pus in two minutes ; all but anthrax and pus in one minute; and all but anthrax in half a minute. With 1 : 1,000 of mercuric chlorid for comparison, the pus was not sterilized in eight minutes; only Staphylococcus pyo- 184 SODIUM HYPOCHLORITE. genes aureus and prodigiosus in five minutes ; and not one was sterilized in three minutes. With 5 per cent, carbohc acid, anthrax and pyocyaneus remained unsterilized after eight minutes; only the pus in five minutes ; and none in three minutes.^ SODA. (See ALKALIS.) SODIUM HYPOCHLORITE. Dr. Duggan,^ for the committee on disinfectants, finds this to be a rapid and efficient disinfectant. "A solution containing 0.25 of I per cent, (i part to 400) of chlorin, as hypochlorite, is an effective germicide, even when allowed to act for only one or two minutes, while 0.006 of i per cent. (6 parts to 10,000) will kill spores of B. anthracis and B. subtilis in two hours." One of the solutions of sodium hypochlorite used by Dr. Duggan, made by passing chlorin gas into a solution of sodium hydroxid, con- tained 6 per cent, of available chlorin. He says of this solution that "although rather concentrated and frequently exposed to the light and air, it has kept for a month without any appreciable change. A solution like this might be put on the market at a very reasonable price, and, as it should be diluted with 20 parts of water, it would be far cheaper and more eflfective than any of the proprietary disinfectants." The committee on disinfec- tion recommends a solution of chlorinated soda, diluted with 9 part of water, for the disinfection of the surfaces of the bodies of sick persons, or of their attendants when soiled with infectious discharges. Klein" made a series of experiments with sodium hypo- chlorite, using as test-organisms Bacillus coli communis, B. typhosus, B. diphtheriae, bacillus of swine fever, cholera bacillus. Staphylococcus pyogenes aureus, anthrax spores, and spores of Bacillus enteritidis. A 10 per cent, solution containing i per cent, of available chlorin destroyed all of the microbes in twenty 1. The reports of Drs. Novy and Coplin -were received through the courtesy of Parke, Davis and Co. 2. Tr. Am. Public Health Association, XI., 200. 1S86. 3. Lancet, II., 1896, 609. SODIUM HYPOCHLORITE. 185 minutes, and in ten minutes none of the sporeless bacteria were alive. A I per cent, solution with o.i per cent, of available chlorin destroyed all of the sporeless organisms, but the two sporing bacilli were not sterilized in twenty minutes. Added to sewage, I per cent, of sodium hypochlorite sufficed to devitalize the sporeless microbes of sewage in ten minutes. In his experiments for the determination of the value of dis- infectants for excreta, Vincent^ found that Labarraque's solution is a little less active than the saturated solution of chlorid of lime. To destroy the bacillus of typhoid fever in typhoid stools, a quantity equal to i8 per cent, of its volume must be added if the destruction is to be accomplished in twelve hours. Dr. Henry Leffman,^ of Philadelphia, made an investigation of chlorinated lime and chlorinated soda as they are found upon the market. Six samples of solution of chlorinated soda varied from 1.06 to 2.48 per cent, of available chlorin, and of eight samples of chlorinated lime, in packages, the available chlorin varied from 20 to 33 per cent. He says that in justice to the dealer it should be mentioned that these preparations are subject to steady deterioration, not only through the influence of the moisture and carbon dioxid of the atmosphere which forms carbonates and liberates the hypochlorous acid, but a slow conversion into chlorate also occurs in a manner not thoroughly understood, and this change also reduces the available chlorin. In hospitals and wherever there is intelligent aid available, it will be economical to prepare the sodium solution directly from the commercial chlorinated lime of good quality, using the fol- lowing formula, approximately that of the U. S. P. 1870: Chlorinated lime, i pound. Washing-soda, 2 pounds. Water, 2 gallons. In making solutions of chlorinated lime, it is best to triturate the article with water to the consistency of thick cream and then dififuse this mixture in a larger volume. If a mass of the mate- rial is simply shaken up with water it will not dissolve. In this 1. An. de I'Inst. Past., IX., 15. 1895. 2. Medical News, LXII., 595. 1893. ISO SOLUTOL. •connection it may be well to note that good chlorinated lime is a nearly inodorous powder. If it is lumpy or pasty, or has a strong chlorin odor, it is somewhat decomposed. SOLUTOL. This is a cresol preparation for general disinfection in which the cresol is rendered soluble by the addition of cresol-alkali. The manufacturer claims that it has a constant strength of 6o per cent, of cresol. For ordinary use, crude solutol is recom- mended as cheap and effective. Pure solutol may be used in •dwelling-houses or wherever the odor of the crude solutol would be offensive. In Buttersack's^ experiments for the Imperial Board of Health ■of Germany, solutol was found to be much more effective than carbolic acid, or lysol, or any of the other cresol preparations. Crude solutol was the only preparation tested by him which ■proved capable of destroying anthrax spores in one day. Buttersack, therefore, sa3's that, among all these agents, crude solutol alone answers the requirements of rapid and trust- worthy disinfection in the most difificult cases. According to Hueppe,^ solutol penetrates organic matter more rapidly than lysol and is a better deodorant. The destruc- tion of anthrax spores with creolin, lysol, solveol, or carbolic acid requires weeks : to destroy spores in twenty-four hours, or less, only corrosive sublimate, the acid solutions of cresol and the solutols are capable of doing it. The results of experiments in the laboratory of Hueppe have taught him that crude solutol answers all the requirements of gross disinfection, and is far more efficient than lysol. Taking everything into consideration, solutol, and particularly, crude solutol, is the best agent we have. Gruber,' while admitting that solutol has decided disinfectant power, could not observe so energetic an action as some experi- menters have reported. Solutol is deemed less efficient than "milk of lime" or soap solutions of cresol. Comparing solutol with lysol, H. Koch noticed that solutol penetrates more rapidly into the interior of masses of matter 1. Arbelten a. d. Kals. Gea., VIII., 369. 1S92. 2. Berliner Klin. Woch., 1893, No. 21. (Eeprmt.). 3. Centr. fur Bak., XV., 1021. 1894. SOLUTOL SOLVEOL. 187 and thus overcomes the foul odors more speedily. In twenty- four hours, solutol dissolved blood coagula more completely than lysol did. According to Koch, solutol is the preferable disin- fecting agent for slaughter-houses and stables. It is more •efficient and it is cheaper. A 0.5 per cent, solution is clear and sufficient for ordinary disinfection. Seifert,^ comparing the action of the various disinfectants, strongly recommends solutol on account of its efficiency and low- cost. Comparing the action of solutions of lysol, solveol, and of solutol, each containing 5 per cent, of cresol, and kept at a temperature of 55° C, Heider^ observed that anthrax spores were destroyed by lysol in five hours, by solveol in two hours, and by solutol in one hour. IlammerP says ; "In solutol the germicidal effect of the cresol is increased by the strong alkaline reaction of the preparation. It is well suited for gross disinfection." The work of Vincent* indicated that solutol is very similar in its action to that of solveol, and that possibly it is a little inferior in its action. Solutions. — The instructions of the manufacturer are to mix about half a pint of solutol with 2 or 3 gallons of water, pre- ferably using the solution hot. A solution containing i per ■cent, of cresol must needs have about 1.7 per cent, of solutol. SOLVEOL. Solveol is a preparation of cresol held in an aqueous solution ty means of cresotinate of soda. It contains 27 per cent, of cre- sol, and is prepared particularly as a surgical antiseptic. The •claims of the manufacturers are : that it forms clear and per- fectly neutral solutions in water; that solutions of the same effective strength are twenty times less poisonous and much less caustic than those of carbolic acid ; that its solutions do not roughen the hands as corrosive sublimate does, nor benumb them as carbolic acid does, nor render them slippery as lysol does, nor obscure the field of operation as the precipitate of 1. Deutsche Viert. fur off. Ges. (Sup.), XXVIII., 262. 1897. 2. AroMv fur Hygiene, XV., 370. 1892. 3. Arohiv fiir Hygiene, XXI., 198. 1894. i. Annales de I'Inst. Past., IX., 29. 1895. 180 SOLVEOL. creolin does ; that its odor is less persistent than that of carbolic acid; and that, diluted with calcareous waters, precipitates are not formed as with corrosive sublimate and lysol : hence its solutions may be made with water from wells and cisterns. These claims seem to have been fairly well substantiated by various investigators. In a comparative examination of the disinfectant powers of the cresols, Hammerl found that they are more efficient when rendered soluble by cresotinate of soda (solved). In a later- work,^ he has compared solveol with other cresol preparations and with carbolic acid and finds that it is superior to all of them. In his experiments with cresol rendered soluble with creso- tinate of soda (solveol), Hammer^ determined that solutions- containing 0.5 per cent, of cresol act more energetically than 2.5 per cent, solutions of creolin, lysol, or carbolic acid. He recommends it as a surgical antiseptic to supersede car- bolic acid which is not always trustworthy. Vincent^ refers to the work of Hueppe, Hammer, Von Hey- den, Koch, and Hagen, which indicate that solveol is a little more active than lysol and the other preparations of cresol. He states, however, that solveol appears to him to be a little inferior to lysol and cresol. It may be added that his experiments were in the disinfection of excreta, a use to which the manufacturers never intended solveol to apply. Nevertheless, Vincent says, that the bacillus of typhoid in fecal matter was destroyed in seven hours with a i per cent, solution. Another mistaken use of solveol was apparently, that Buttersack* when he employed it for the disinfection of fresh tuberculous sputum. He, how- ever, found that a 6.6 per cent, solution was very efficient and that it acted more promptly than carbolic acid. He might have used solutol for that purpose, another preparation of the same manufacturers intended for gross disinfection. After using solveol nine months for all purposes as an anti- septic in medical and surgical practice, Hiller^ says that it is the most desirable antiseptic that has yet come to his hands. In. 1. Archiv fur Hygiene, XXI., 198. 1894. 2. Arohiv tiir Hygiene, XII., 359. 1891. 3. Annales de I'Inst. Past., IX., 27. 1895. 4. Arbelten a. &. Kals. Ges., VIII., 371. 1892. 5. Deutsche Med. Woch., XVIII., 841. 1892. SOLVEOL. 189 making a i per cent, solution, he mixes 37 cubic centimetres with I litre of well or hydrant water. In surgical work, one half of this strength suffices, for it is equal to a 2.5 or 3 per cent, solution of carbolic acid. This solution is at first clear, but after standing some day§ becomes slightly opalescent. It is entirely neutral, mixes with blood or pus without coagulating them, and produces no precipitate with other fluids or secretions. Its irritation of the skin or serous or mucous membranes is slighter than that of solutions of carbolic acid or corrosive sublimate of equal effectiveness. With his experience with it, Hiller holds that solveol is eminently suitable for use in connection with operations in the thoracic or abdominal cavities, and in gyneco- logic and obstetric practice. On account of its slight irritation, its relatively slight toxicity, and the certainty of its antiseptic action, no antiseptic hitherto used equals or exceeds it. Hueppe,^ under whose direction solveol was tested by Ham- mer, recommends it as an antiseptic, and thinks it may well replace those more toxic and irritating agents, carbolic acid and sublimate. Comparing it with lysol in the disinfection of the hands, when lysol is used the soap and the disinfectant con- stituent must act at the same time and for an equal length of time, then the hands must be rinsed in sterilized water, then dried. Water and soap are found everywhere for the primary cleansing but not sterilized water. If, however, we choose solveol, the hands are first washed in soap and water, solveol is used, and the hands are immediately dried as with carbolic acid or sublimate. In a communication by Dr. Freund^ on the use of solveol as an antiseptic in obstetric and gynecologic work, he states that for the past three months he has used solveol as the only anti- septic. Pouring 37 cubic centimetres of solveol into 2,000 cubic centi- metres of water gives us a solution containing I/2 per cent, of cresol. This solution is almost as clear as water itself, and is in no way injurious to instruments. On the other hand, lysol and creolin mixed with water do not give clear solutions. In connection with fifty births and a long series of gyneco- logical cases, no fact has been encountered which has a tendency Berliner Klin. Woeh., 1893, No. 31. (Repi-lnt.). Arclilv (ur off. Gesund. In Elsass-Lotlivingen, XV., 19. 1893. 190 SOLVEOL — SOZOIODOL PREPARATIONS. to throw any doubt upon the certain and energetic disinfecting- power of solveol. One test of its use is that, used freely, no toxic symptoms have appeared. It causes no precipitates. One disadvantage only has been noticed: when the hands are in contact with this solution for some time, the skin is roughened as in using solutions of carbolic acid, and slight sen- sations of numbness have sometimes been observed. Solutions.— A i per cent, solution can be made by mixing 37 cc. of solveol with i litre of water, or approximately i per cent. by adding 2 ounces of solveol to 3^^ pints of water. The >4 per cent, solution generally used can be formed by adding 18.5 cc. of solveol to 1,000 cc. of water. SOZOIODOL PREPARATIONS. Dr. Spirig,^ of Bern, found that mercury-sozoiodol was more efficient as an antiseptic and a germicide than any of the other sozoiodol preparations. In all of his tests it ranked as the equal of sublimate. His conclusions are that the antiseptic action of potassium-sozoiodol upon wounds is better than in reagent glasses. One of the advantages of its use is that it is odorless, that it irritates the tissues but little, that on account of its slight degree of solubility it covers the surfaces for some time, and that the danger of poisoning during its use is slight. He thinks, however, that this agent does not equal iodoform in open wounds, but that it is worthy of a more extended testing. Draer^ made a study of the antiseptic action of the various sozoiodol salts when applied to the bacillus of diphtheria. His results indicate that the mercury salt is the most efficient. A i per cent, solution sterilized in one half hour a well developed bouillon culture of this bacillus. An aqueous solution of the only slightly soluble mercury salt was made by adding common salt in the proportion of 7.5 : 1,000. In another table he shows that mercury sozoiodol sterilized a twenty-four hour bouillon culture of the diphtheria bacillus in five minutes with only 1 : 10,000 of the disinfecting agent. Draer recommends this agent as a topical application in the treatment of diphtheria, particularly when applied in powder 1. Zeit. fur Hygiene, XIII., 1.5. 1893. 2. Deutsche Med. Woeh., XX., 667, 583. 1894. SOZOIODOL PREPARATIONS SPRAYING. 191 form in the mixture hydrarg. soz., natr. chlorat. ana i.o, sulph. praecip. ad 50.0. Next to the mercurial salt, acid sozoiodol was the most active, then the zinc and the soda salt. The potassium salt was the least effective. Professor Sormani^ reports that the agent which was found by him in his experiments to destroy the bacillus of diphtheria the most rapidly is mercury-sozoiodol. As a stock solution to- be applied to the throat, he dissolves 2 grams of this salt, with I gram of saccharin, and 50 grams each of alcohol and distilled water and adds 20 drops of hydrochloric acid. A single drop of this mixture sterilizes in less than a minute two cubic centi- metres of very resistant cultures of the diphtheria bacillus. As a local application to the throat, he applies this solution- pure, or diluted in from five to fifty times its volume of water. Professor Sormani found the mercury salt much more active than the other sozoiodol salts. ' Schwarz^ also finds the mercury salt much more efficient than the other sozoiodol preparations, applying it locally with a pow- der blower. His statement, that mercury sozoiodol i : 10,000 quickly destroys the bacillus of diphtheria, confirms that of Draer. SPRAYING. As a disinfecting process, spraying with solutions of various disinfectants has been recommended and used, especially for walls, floors, and upholstered furniture. In 1884, under the advice of Dr. Joseph Holt,^ President of the State Board of Health of Louisiana, spraying with a i : 1,000 solution of corrosive sublimate with muriate of ammonia to render the mercurial salt more soluble, was adopted as an important part of the sanitary treatment of vessels in quarantine. The solution was applied through a hose and rose to all of the available surfaces of the vessel, excepting cargo, but including bilge, ballast, hold, saloons, forecastle, decks, etc. Since then this practice has been widely extended in maritime quarantine work. For the disinfection of the walls of rooms Guttmann and Merke, of Berlin, recommended spraying with a i : 1,000 solu- 1. Atti deir Assoc. M. Lomb.-Revue D'Hygiene, XVIII., 74.- 1896. 2. Wiener Klin. Woch.—Centr.fiirBak., XIX., 19. 1896. 3. Bpt. of Com. on Disinfectants of A. P. H. Assoc, p. 215. 1888. 192 SPRAYING. tion of corrosive sublimate. They used anthrax spores on threads. Their results were not an absolute sterilization of the walls ; but the test was a severer one than is found in real work.^ Later Merke expressed the opinion that Esmarch's method of rubbing with bread is more trustworthy.^ Cronberg' refers to Guttmann and Merke's method as effec- tive, cheap, and easily applied. He says it does not injure the walls and is not dangerous to the operator or the inhabitants of the room. In various European countries, spraying with corrosive subli- mate solution has been revived with satisfactory results, partic- ularly in some of the English, French, and Italian cities. "In Paris, for instance, spray disinfection has been substituted for sulphur fumigation for some time; and last year the late M. Dujardin-Beaumetz, who at an earlier period had supported the use of sulphur fumigation, pointed out that the spray process gave a security to municipal disinfection which it had never previously had. Using a solution of i in 1,000 of mercury perchlorid, with either 2 per 1,000 of salt or from 3 to 5 per 1,000 of tartaric acid, it was found that house epidemics and reinfection were practically abolished. This result was first stated after over 100,000 disinfections had been carried out with the spray; and it was stated at the same time that prior to its adoption house epidemics and reinfection had been extremely common."* Gerlach^ experimented with lysol as a spray. In forty instances only two were unsatisfactory. Of late, spraying with solutions of formaldehyde of various strengths has been recommended. Nils England uses a 2 per cent, solution, and a 2 per cent, or 2.5 per cent, solution. is used by some of the English medical officers of health. Dr. Rideal recommends a 0.5 per cent., and Dr. Wyatt Johnston^ a. y^ to I per cent. 1. Jahresberloht ueber die Fortsch. und Leistung. a. der Geb. d. Hyg.,V., 172. 1687. 2. Deutscbe Vlert. fur off. Ges., XXIII., 269, 274. 1891. 3. Arohlv fiir Hygiene, XIII., 294. 1891. 4. Jr. of state Medicine, IV., 21. 1898. 5. Deutsche Vlert. f. off. Ges., XXIII., 148. 1891. 6. Reprint from Brit. Med. Jr., Dec. 25, 1897. STEAM DISINFECTION SULPHUR FUMIGATION. I93 STEAM DISINFECTION. Nothing is liere given under this important heading for the reason that time has not been available for arranging the notes which have been collected on this subject. For a statement of the results obtained in some experiments with steam disinfec- tion up to 1889, see pages 261-269 of the Fifth Annual Report of this Board. Evidence will there be found that pressure steam is not an essential of trustworthy steam disinfection. All pathogenic germs may be destroyed with certainty with current steam under very slight, or no pressure. The non-recognition of this fact has done more than anything else to defer the general use of steam disinfection in country districts, villages, and small cities. SULPHATE OF IRON. (See FERROUS SULPHATE.) SULPHUR FUMIGATION. The experiments of Koch^ show that, in a practically gas- tight casket, I per cent, by volume of sulphur dioxid will kill dry anthrax bacilli in twenty minutes when on threads and exposed to the direct influence of the gas, and that, under the same conditions, the bacilli are destroyed in two minutes when the threads are damp. Anthrax spores, however, were wholly uninjured by a four days' exposure to 6 per cent, of the gas. When dried cultures of sporeless bacteria, not more than from one tenth to one half millimetre thick, were exposed in a room fifty hours to sulphur dioxid, none were killed. One hour after the sulphur was lighted the percentage of sulphur in the air was about 3 ; one hour later it was only 1.25 ; and twenty hours later, 0.015. The very extensive and careful experimental work of Wolff- hiigeP presented results similar to those of Koch. The action of the gas was only superficial, and in the disinfection of ordi- nary rooms its action, even upon sporeless bacteria, was very unfavorable. The German Cholera Commission prescribed 069; von Pettenkofer, 1.04; Mehlhausen, 1.39; and Wernich, 4 per cent, as the required proportion of the sulphur dioxid gas. 1. Mittheil. a. d. Kals. Ges., I., 252- 1881, 2. Ibid., p. 191-232. 13 194 SULPHUR FUMIGATION. In some of Wolffhugel's experiments more than 8 per cent, was present in the room at first, but in from two to four hours the air contained only 1.25, and in from twenty-one to twenty-seven hours it had only 0.02 per cent, by volume. Basing his opinion upon his experiments, the conclusion reached by him is that the idea of disinfecting goods with sulphur dioxid without injury is illusory. In Sternberg's experiments,^ sporeless bacteria were destroyed under favorable conditions, but he admits that "the conditions of success are such that it appears almost impracticable to con- form with them in practice on a large scale, and it is evident that much of the so-called 'disinfection' with this agent is a farce." A suggestion of the reason why the Committee on Dis- infection of the American Public Health Association retained sulphur fumigation as a disinfecting process may undoubtedly be discovered in this sentence from Sternberg's report : "We must not then be too exacting with reference to this agent until we are able to recommend something better in its place for the purposes to which it is commonly applied, viz., for the disinfec- tion of apartments and ships." Since the investigations of Koch and Wolffhiigel were made, sulphur dioxid has been used but very little in Germany as a disinfectant; but in England and in France and some of the other Continental countries, its use has continued. Among the French investigators there has been no unanimity as to the effi- ciency of sulphur fumigation. The experiments of Thoinot^ were conducted in a room of 50 cubic metres capacity, the cracks and crevices being closed as tightly as possible with putty. The infectious material used was partly in the form of pathological secretions and pieces of organs, and partly pure cultures. The results showed that path- ogenic bacteria, so far as regards the action of sulphur dioxid, may be divided into two groups. One group,— bacillus of malignant edema, sympathetic anthrax, and anthrax,— showed absolute resistance to the most concentrated and prolonged action of sulphur dioxid; while in the other group, — tuber- culosis, glanders, typhoid fever, cholera, diphtheria,— sulphur dioxid has a disinfectant action. 1. Dlsinteotlnn anfl Disinteotauts, p. 64. 1888. Concord. 2. Etude 9U1- la Disinfection par I'Aolcle Sulfureux, p. 7. isgo. SULPHUR FUMIGATION. I95 The required quantity for successful disinfection varies in different cases, but 60 grams of sulphur burned for each cubic metre of space, and allowed to act twenty-four hours in a well- closed room, gives, according to the author, absolute security. This quantity is, therefore, recommended in practice. (Wolff- hiigel found that twice this quantity cannot be trusted to destroy even sporeless infection in room disinfection. — Y.) The tubercle bacilli used by Thoinot were partly in pure cul- tures, and partly in tuberculous sputum, and the latter was in a moist as well as in a dry condition. The subsequent inoculation into guinea-pigs gave negative results. The thickness of the layers of sputum subjected to the action of sulphur dioxid is not stated. The conclusions of Dubief and Briihl^ are favorable to sulphur dioxid as a disinfectant, but their methods were faulty and did not conform with the conditions found in actual practice. In his paper on sulphur fumigation, Richard^ adduces some testimony from the records of the military and naval surgeons *in favor of the practice. By its use outbreaks of various dis- eases appear to have been stayed. Nevertheless, he affirms that, as sulphur dioxid occupies an inferior position in the list of the disinfectants, it should be employed only in those cases where other disinfectants are inapplicable, and he says that we con- tinue to use sulphurous acid where other more trustworthy pro- cedures are absolutely impracticable. In the discussion which followed the reading of Richard's paper, Vallin supported the use of this process of disinfection, but would prescribe the previous liberation of a large quantity of steafh in the room to be disinfected, by boiling water in open vessels of large area for one hour. In an investigation of the comparative merits of sulphur and formaldehyde fumigation, made by Dr. Novy' for the State Board of Health of Michigan, the resuhs were decidedly in favor of formaldehyde as the more efficient. The room used was designed as the disinfection room at the time the laboratory was built, and it was intended to have a capacity of 1,000 cubic feet, but slightly exceeded that. In order to make the room 1. Comptes Rendua.— Centr. tiir Bak., VI., 91. 2. Revue D'Hygiene, IX., 273. 1887. 3. Medical News, LXXII., 641. 1898. 196 SULPHUR FUMIGATION. perfectly tight, the aim in the construction of it was to have it gas-tight as nearly as possible, and was, therefore, much more nearly so than in the rooms found in ordinary disinfecting work. It was found that formaldehyde does not tend to pass out of the rooms so rapidly as sulphur dioxid does, and therefore has a distinct advantage over sulphur in the disinfection of crowded tenement-houses. As to the germicidal powers of the two gases, it was found that sulphur fumes possessed little or no action on most bacteria when in the dried state. If, however, the speci- mens are actually wet, they will be destroyed except in the state of the resistant forms, such as the spore stage and tubercle bacilli. For tubercle bacilli or spore-containing material, wet or dry, it is of no value. It can be used for the diisnfection of rooms which have been infected with ordinary disease organisms. From three to six pounds of sulphur must be burned in each 1,000 cubic feet of space. The evaporation of water in the rooms where the articles are to be disinfected does not suffice. The walls, floors, and articles in the room should be sprayed with water. The room should be made perfectly tight, and should be kept closed at least twenty hours. While sulphur fumigation under certain conditions is of value, it is, nevertheless, evident that it is more obnoxious to persons in adjoining rooms, more injurious to fabrics, and certainly less effective than formaldehyde. Professor Robinson made a single comparative experiment with sulphur in one of the rooms used in the formaldehyde experiments. The results were decidedly unfavorable to sul- phur dioxid.^ The citing of a larger number of works on the subject would serve in no degree to change what must be considered the just verdict, — that, though sulphur dioxid has some germicidal power when tested on sporeless bacteria, it is an untrustworthy agent in the disinfection of rooms and their contents. Other Objections. — The action of sulphur dioxid is increased by having the goods to be disinfected moistened by the diffusion of watery vapor in the air. At the same time its injurious action upon many articles is increased. Some of the ill effects observed in the extensive practice of the Marine Hospital Service, as 1. Tenth Ept. St. Bel. of Health of Maine, p. 167. 189S. SULPHUR FUMIGATION SURGICAL ANTISEPTICS. I97 record by Surgeon Carter,^ are: It injures the colors of many woolen goods, being especially hard upon greens and bright reds. A red flannel shirt, for instance, always comes out yellow. The dark blues are generally uninjured, but sometimes turn a red- dish brown. Articles containing starch, if not washed soon, are corroded, especially true of handkerchiefs. Blankets and hair pillows will retain, for about a week, a smell so disagreeable, in no sense like that of burning sulphur, that they are unpleasant to use. Flour in ordinary barrels will not rise with yeast for some days after exposure. Tea and coffee are permanently ruined. Apples and other fruits are made worthless. Metals are tar- nished. Further objections to the use of this gas are that it is an active poison, and it is dangerous to inhale it even when not highly concentrated ; that it leaves an unpleasant odor in rooms in which it has been used ; and that, in its use, there is some risk of fire. Comparison with Other Gaseous Disinfectants. — While the disinfectant power of chlorin gas is somewhat greater than that of sulphurous acid gas, the corrosive action of chlorin is greater, and it bleaches and destroys fabrics in a greater degree than sul- phurous acid. The disadvantages of chlorin are so great that it has filled but a small place in general disinfecting practice. On the other hand, formaldehyde has distinct advantages over sulphur dioxid, in being a much more efficient germicide. Many investigators have demonstrated that, when well exposed, anthrax spores are destroyed by formaldehyde. Formaldhyde appears to have, also, a somewhat greater power of penetration, it is practically without injurious action upon the colors or tex- tures of fabrics, its inhalation in any quantity likely to be received, is free from danger, and its odor is much less disagree- able than that of the fumes of sulphur. SURGICAL ANTISEPTICS. Carbolic acid, the chief reliance in the early days of antiseptic surgery, is now largely replaced by other agents of greater germ- icidal activity, or less toxic, or for other reasons deemed more desirable. Scheurlen, Beckmann, and Romer have shown that the antiseptic action of solutions of carbolic acid and the cresols 1. Jr. Amer. Med. Assoc, 367, XIV., 618. 1890. 198 SURGICAL ANTISEPTICS. is increased by the addition of common salt to them. (See Car- bolic Acid.) The cresols, so the results got by most of the experimenters indicate, are superior to carbolic acid. In his experiments, Gru- ber discovered that an aqueous solution of cresol made by shak- ing crude carbolic acid with water has remarkable antiseptic powers. (See Cresol — Surgical.) Some recent investigations made by Loeffler indicate that solutions of anytols of carbolic acid, or of the cresols, are more energetic in their action than the simple solutions. (See Anytin and Anytols.) The preponderance of evidence indicates that lysol is more effi- cient than carbolic acid and, in common with the other cresol pre- parations, is less toxic. An inconvenience in its use is that hands and instruments are rendered slippery. Solveol, a somewhat recent addition to the list of cresol prepa- rations, is designed particularly as a surgical antiseptic. It forms clear solutions in water, it is less toxic than carbolic acid, it does not render objects slippery, and it is more efficient than carbolic acid. (See Solveol.) Phenosalyl, according to Christmas and Frankel, is a desirable antiseptic and superior to carbolic acid. The work of Pane indicates that thymol is a valuable antisep- tic. Its action when applied to Staphylococcus pyogenes aureus is especially energetic. He recommends a i : 1,000 solution. Mercuric chlorid, a very energetic antiseptic in non-albumin- ous solutions, is untrustworthy when brought in contact with albuminous matter, as occurs in most surgical work. The addi- tional disadvantages, that it is highly toxic and that it corrodes instruments, still further impair its value as a surgical antiseptic. (See Mercuric Chlorid — Antiseptic Value.) Boric acid is very feeble in its action. It is often used where agents with more distinct antiseptic qualities are required. Though antiseptic soaps generally are of doubtful value in general surgery, a "germicidal soap" containing mercuric iodid and prepared by Parke, Davis & Co. appears, according to the tests of Drs. McClintock, Novy, and Coplin, to be a rapidly effi- cient and valuable antiseptic. (See Soaps, Antiseptic.) Iodoform, though showing very little of the qualities of a germicide, exerts its antiseptic action in those classes of wounds SURGICAL ANTISEPTICS THYMOL. 199 where antiseptics are most needed, as is stated under "Iodo- form." lodin trichlorid acts rapidly as a germicide. A i : 1,200 solu- tion inhibits the growth of pus bacteria. The fact has been well established in laboratory and clinical work that some of the chemically pure anilin colors have a dis- tinct antiseptic action even in weak solutions. (See Anilin Dyes.) The work lately done by Crede and others makes it probable that itrol, actol, and other silver salts are to take a prominent place among the numerous surgical antiseptics. (See Silver Salts.) Formaldehyde is a very energetic antiseptic. In addition to its anti-germicide action, distinct antitoxic affects probably fol- low its application to septic surfaces ; but the range of the appli- cability of the various fonnaldehyde preparations, solid and liquid, is still to be determined. Thomalla, of Berlin, adds 5 per cent, polymerized formaldehyde to iodoform and finds the mix- ture much more efficient than iodoform alone. (See Formalde- hyde — Local Antiseptic and Therapeutic Action.) THYMOL. According to Koch,^ i :8o,ooo of thymol begins to check the growth of anthrax bacilli. Behring^ found that thymol is not a trustworthy disinfectant,- — that it is about four times weaker in its action than carbolic acid. Perroncito learned that a saturated aqueous solution of thymol killed anthrax bacilli in from six to ten minutes, but that it had no action upon anthrax spores. Pane^ found that, other than a retardation of their growth, anthrax spores were uninfluenced by a solution of 2 : 1,000, acting seven days at a temperature of 35°. Staphylococcus pyogenes aureus, however, was more sensi- tive to much weaker solutions : indeed, this bacterium dried on threads was sterilized in from ten to fifteen minutes with a solu- tion of 1 : 1,000 at a temperature of 37°, and a solution of i :2,ooo 1. Mltthellungen aus dem Kais. Ges., I., 271. 1881, 2. Zelt. fUr Hyg., IX., m. 1890. 3. An. deU' Istltuto D'Ig. Sperimentale deirUniv. dl Eoma, II., 81. 1890. 200 THYMOL TUBERCULOSIS. produced the same effect at the same temperature in thirty min- utes, and at the temperature of 15°, in one hour. With the method of Esmarch, the i : 1,000 solution is still more efKcient, for at 37° sterilization is effected in from a minimum of two to five minutes to a maximum of ten to fifteen minutes. This result is superior to that obtained by the same method with sublimate solutions in equal proportions. This energetic action of thymol upon Staphylococcus pyogenes aureus, and its acting more efficiently upon the germs in Esmarch's method than when they are upon threads,Pane deems worthy of note. Pane's solutions of thymol were made with distilled water. He says that when ordinary water is used the solution must be stronger to obtain equal effects. In view of the energetic action of thymol upon Staphylococ- cus pyogenes aureus. Pane thinks that the use of the i : 1,000 solution merits a wider adoption in surgical practice, particularly in the major operations, laporotomies, etc. When it is used the solutions should be warmed. It has the advantage, also, of cheapness and absence of unpleasant odors. TUBERCULOSIS. The principal problems presented in the disinfection required under this heading are the treatment of fresh tuberculous sputum; dried tuberculous sputum, or tuberculous dust; and tuberculous milk. The difficulty in destroying the tubercle bacillus under these various conditions differs considerably. Fresh Tuberculous Sputum. — The experiments of Schill and Fischer^ led them to conclude that but very few chemical disin- fectants are capable of destroying fresh tubercle bacilli. In fresh, moist sputum, they were killed in fifteen minutes by flow- ing steam at 100° C. ; in ten minutes by boiling in water ; in twenty-four hours with a 5 per cent, solution of carbolic acid in equal quantities. The bacilli were not killed in twenty-four hours with a i : 1,000 nor with a i : 500 solution of corrosive sublimate. Dried sputum, however, was destroyed with i : 1,000 corrosive sublimate. For the disinfection of clothing, bedding, etc., which have become infected with tuberculous sputum, they J. Mittliell. a. d. Kal3. Ges., II., 131. 1884. TUBERCULOSIS. 201 recommend subjection to steam for one hour. With steam, fresh, moist sputum is more quickly disinfected than dry sputum. Boiling with water one half hour is certain. In the opinion of Schill and Fischer, sublimate is unsuitable for the disinfection of fresh sputum, but they recommend the use of a 5 per cent, solu- tion of carbolic acid mixed with the sputum, half and half. Yersin^ states that a 5 per cent, acid solution of carbolic acid sterilized tuberculous sputum in one half minute, and a i per cent, solution in one minute. Grancher and Gennes^ sought to determine the most efficient methods for disinfecting tubercular sputum. The chemical agents tested by them were 5 per cent, solutions of carbolic acid, potash, copper sulphate, zinc chlorid, and i per cent, solutions of corrosive sublimate. Ten parts of the disinfecting solution were mixed with two parts of sputum and shaken. The effi- ciency of the sterilization was determined by inoculation into animals. Of the animals thus used all died, either very soon of septicemia, or after some weeks with tuberculosis, with the exception of those which had been inoculated with sputum to which sublimate had been added. None of these latter animals died of septicemia nor of tuberculosis. On account of the poisonous nature of sublimate, the authors did not deem this a suitable disinfectant for general use. They then proceeded to experiments with heat as the disin- fecting agency. The sputum was floated in sterile water, the temperature of which was raised to 60°, 80°, and 100°. That which had been heated to 60° and 80° was not destroyed with certainty, but, on the other hand, that which had been subjected to a temperature of 100° was sterilized without exception. When soda is added to the water in spittoons it facilitates their cleansing when they are disinfected with heat. For the disinfection of spittoons in hospitals they recommend a small, netallic disinfecting chamber inside of which the spit- toons with their contents are placed and into which steam is turned. Kirschner's' conclusions, based upon his own experiments, are that hot water coagulates the sputum and thus sterilization 1. Eevue D'Hygiene, XII., 76. 1890. 2. Kevue D'Hygiene, X., 193. 1888. 3. Centr. liir Bak., IS., 41. 1891. 202 TUBERCULOSIS. would not ensue. He has not found that the temperature of 70° C. for ten minutes will destroy the bacillus, as Yersin claims. But he thinks that streaming steam is needed for rendering the sputum harmless. In his hospital he has in operation an appara- tus for the disinfection of the sputum in cuspidors something like that advised by Grancher and Gennes. He lets the glasses containing the sputum remain a full half hour in the steam appa- ratus after the thermometer registers 100° C. Incidentally it may be mentioned that, in his hospital, he has cuspidors for tuberculous patients held on iron supports at the height of about one metre. The Health Department of the City of New York^ advises that tuberculous sputum should be received in covered cups con- taining a 5 per cent, solution of carbolic acid or milk of lime. As regard the use of the latter agent for this purpose, it would be well to bear in mind that Jaeger found that lime-wash is an inefficient disinfectant for the bacillus of tuberculosis. As the results obtained by most investigators indicate that cresol, lysol, and solutol are generally more rapid and certain in their action than carbolic acid, they probably may well be substituted for carbolic acid. In Buttersack's^ experiments with the cresols a 10 per cent, solution of two of them sterilized fresh sputum which contained an abundance of bacilli. There is some doubt as to the applicability of chlorid of lime to the disinfection of tuberculous sputum. The unpleasant and irritating odor is at least objectionable. Since it has been determined that iodin trichlorid has germ- icide powers of the highest order, and that this action is but little influenced by the presence of albuminous matter, it is prob- able that this agent may be found very efficient for the disinfec- tion of fresh sputum. Its irritating vapor, however, bars it from the immediate presence of the patient. Corrosive sublimate is entirely unsuitable for the disinfection of fresh sputum. Ascoli states that formaldehyde solution acts efficiently in the disinfection of sputum, but its action, some what like that of sublimate in coagulating albuminous matter, furnishes a good 1. Circular, Disinfection and DlsinfectantSil Form L, p. 8. 2. Arbelten a d. Kals. Ges., VIII., 369. 1S02. TUBERCULOSIS. 203 reason for doubting the adaptability of this agent to this purpose. Further experiments should determine the question. The experiments of Christmas, Rideal, and Frankel, stamp phenosalyl as a compound that merits a thorough experimental trial in the disinfection of fresh tuberculous sputum. Dried Tuberculous Sputum. — In the disinfection of dried tuberculous sputum, or tuberculous dust, some chemical disin- fectants may be used which are not suitable for the disinfection of fresh sputum. In the disinfection of a room which has been occupied by a consumptive, the same general rules may be fol- lowed which are given under "Rooms," "Walls/' and "Floors." All dust should be removed very carefully from furniture, walls, and floors, with a cloth squeezed out of a disinfecting solution, — lysol, 4 per cent. ; carbolic acid, 5 per cent. ; or mercuric chlorid, I : 1,000. If the disinfection of the room is to be completed with the liquid disinfectants, the washing should be repeated, the time intervening between the two washings not necessarily exceeding half an hour. Floors and the cracks in them should be thoroughly treated with the solution. If the room is to be disinfected with formaldehyde gas, a preliminary spraying or washing with a 2 per cent, solution of formaldehyde (5 per cent, of formalin) of floors and the lower parts of the walls that may have been soiled with expectorations, is advisable. The clothing and bedding of tuberculous patients are prefer- ably disinfected with steam. (See "Bedding," "Clothing," and ''Furniture.") The rooms of consumptive patients, during their illness, should receive quite frequent disinfections — every two or three weeks — preferably with formaldehyde gas as being the most convenient. When formaldehyde is not available, the infectious dust should be removed with a dampened cloth as already advised. Tuberculous Milk. — The principal recourse for the steriliza- tion of milk is by heating it. The bacillus of tuberculosis when suspended quite uniformly in a fluid, as in milk, is much more readily destroyed by heat than when in tuberculous sputum, fresh or otherwise. The thermal death-point of the tubercle bacillus in milk is variously stated by different authorities. 204 TUBERCULOSIS. Yersin says that the temperature of 75° C. (167° F.) maintained ten minutes, sterilizes milk so far as the bacillus of tuberculosis is concerned. Bitter^ concludes that the temperature of 155° F. continued thirty minutes suffices. He found, however, that the whole mass of the milk must be raised to the required temperature, and that those forms of sterilizing apparatus in which the milk ilows over heated surfaces, or in which it is delivered in a con- tinuous flow, are not to be trusted. The investigations of De Man^ in the laboratory of Professor Forster in the University of Amsterdam, made for thq purpose of determining this point, appear to have been careful and extended. That his experiments might approach as nearly as possible the conditions found in the actual process of Pasteurizing milk, the material used was milk demonstrated to be virulent, or milk rendered virulent by the addition to it of secretions from tuberculous udders. After the milk had been brought to the required temperature, it was rapidly cooled by running water which had a temperature of from 10° to 12° C. His experiments showed him that the tubercle bacillus in tuberculous milk is destroyed in four hours at the temperature of 55" C. in one hour at the temperature of 60° C. in fifteen minutes at the temperature of 65° C. in ten minutes at the temperature of 70° C. in five minutes at the temperature of 80" C. in two minutes at the temperature of 90° C. in one minute at the temperature of 95° C. As to the changes which occur in milk during Pasteurization or sterilization, it is generally stated that they begin at 68° C. and that they increase from this point on, with the elevation of the temperature and the duration of its action. His own experiments with various persons show that the change in taste is rarely detected when the temperature of 70° C. is maintained ten minutes. Only one person out of a con- siderable number was able to distinguish the Pasteurized milk from the unpasteurized at this temperature. The results of the investigations of De Man coincide with those of Bitter ; that those 1. Zeit. fiir Hygiene, VIII., 255. 1890. 2. Arcblv fur Hygiene, XVlIt., 133. 1S93. TUBERCULOSIS VETERINARY PRACTICE. 205 processes of Pasteurization in which the milk passes over a heated surface are not trustworthy. The bacilli are not destroyed. To ensure sterilization, the whole bulk of the milk must be brought to the required temperature and maintained at this point for the required length of time. The observations in the Amsterdam laboratory show that many samples of Pasteurized milk upon the market contain many bacteria; some of them as much as a million per cubic centimetre. At the recently held International Hygienic Congress in Madrid, Lehmann of Wiirzburg, stated that heating milk or cream to 65° C. for five minutes does not suffice to destroy all the pathogenic bacteria, but it is accomplished by heating it to from 82° to 85° C. for ten minutes. It appears, therefore, that the temperature of 167° F. (75° C), continued for twenty minutes, is none too high a requirement for safety, and this is now quite generally accepted as the proper temperature and time for the Pasteurization of milk. VETERINARY PRACTICE. The rules of the various cattle commissions and veterinary authorities relating to the disinfection of stalls, cattle cars, etc., are not well defined. — I-n^most cases the spaces to be disinfected are too open in their constructionto permit any part of the work to be done with gaseous disinfectanEgr- Usually the work must be done wholly with solutions applied with a brush or otherwise. The period of exposure of infectious matter to the disinfectant in its liquid form is necessarily brief, and disinfecting agents whose action is rapid and vigorous should, be used. - Jaeger's^ investigations weremore extended than those of any other worker known to me. HiTv^fefkJDrought out very clearly the necessity of adapting the disinfecting agent to the specific kind of infection to be destroyed. For instance, while brush- ing the surface with a 1 : 3 milk of chlorid{ of lime destroyed anthrax spores, it was untrustworthy as a disinfectant for the 11^^ of tuberculosis and c^rt^iar that of glanders. For the destruction of the bacillus of tuberculosis he found carbolic acid and the other coal-tar phenols very efficient, especially when acidulated with hydrochloric acid. For this purpose he recom- 1. Arbelten a. tl. Kais. Ges., A'., 247. 1S89. 206 VETERINARY PRACTICE. mends especially Laplace's 4 per cent, solution of crude carbolic acid with 2 per cent, of hydrochloric acid. In the hands of Jaeger, the power to destroy anthrax spores with certainty has been shown only by solutions of carbolic acid and the thick chlorid of lime mixture. It is probable that so ne of the newer preparations of cresol will be found to be very efficient in veterinary 'work, particularly solutol and crude solutoll the latter of which is h^aid to be a cheap as well as efficient disinfJjctant. (See Solutol.) A thick milk of lime applied once with a brush, Jaeger found efficient in the disinfection of the micro-organisms of chicken cholera, hog cholera, erysipelas of swine, typhoid fever, glanders, anthrax bacilli without spores, and Staphylococcus pyogenes aureus. Giaxa,^ in a similar line of work to that of Jaeger's, found that, in the disinfection of walls, even a 5 per cent, lime-wash acting forty-eight hours failed to destroy anthrax spores, the bacillus of tuberculosis, and the bacillus of tetanus. A strong solution (xJjzeLoi chlorid of lime may be classed as one of the rapidly acting disinfectants for most bacteria, but Jaeger's report of its failure when applied to the infection of tuberculosis and glanders should be borne in mind. For the cleansing of cattle cars, Gruber^ acivises scrubbing them out with hot water or washitig with a 2 per cent, solution of soda at 50° C, although this has no particular disinfecting power. If the cars are infected, he sprays with a 5 to 10 per cent, solu- tion of formaldehyde. ^T.increas(. in their numbers, and they are plentiful in forty-eight hours. It is a very good deodorant, he says, but a very inefficient disin- fectant for fecal matter. ZINC SULPHATE. . . ,j The experiments of Koch, Sternberg, and others show that this salt has no practical value as a disinfectant, and but very slight value as an antiseptic. Pane,* experimenting with a 5 per cent, solution, found that staphylococcus on threads, even when exposed to the ' solution one hour at the temperature of 30° C, was unaffected by its action save a slight retardation in the development of the bacteria. 1. MittlielL a. d. Kals. Ges., I., 26L 1881. 2. Am. .Ir. M. Se.^pr. 1883. p. 3.>il. 3. Annalea ile I'Inst. Past., IX., 10, 18%. i. -An. deir tstituto D'Ig. Sperlmentale dell' Univ. di Roma, 11., 93. 1890. Pamphlet Binder Gaylord Bros. Inc. Makers V Syracuse, w. »• Ml. JAM 21, ISIB