COLUMBIA LIBRARIES OFFSITE HEALTH SCIENCES STANDARD HX00077950 *J\7^ I 899 Columbia ^Bnitiertfttp intljeCttpoflftugork College of ipfjpgictans ano burgeon* lUbrarp Digitized by the Internet Archive in 2010 with funding from Open Knowledge Commons http://www.archive.org/details/disinfectionindiOOster American public much misapprehension, and the agents which have been found to destroy bad odors — de- odorizers, — or to arrest putrefactive decomposition-antiseptics — have been confidently recommended and extensively used for the destruction of disease germs in the excreta of patient! with cholera, typhoid fever, etc. "The injurious consequences which are likely to result from such misapprehension and misuse of the word disinfectant will be appre- i The Mtditml S'rwi, Phlla.. Jan. 24, 1«*5, y 5 6 DISINFECTION. ciated when it is known that recent researches have demonstrated that many of the agents which have been found useful as deodorizers, or as antiseptics, are entirely without value for the destruction of disease germs. "This is true, for example, as regards the sulphate of iron or cop- peras, a salt which has been extensively used with the idea that it is a valuable disinfectant. As a matter of fact, sulphate of iron in sat- urated solution does not destroy the vitality of disease germs, or the infecting power of material containing them. This salt is, neverthe- less, a very valuable antiseptic, and its low price makes it one of the most available agents for the arrest of putrefactive decomposition in privy vaults, etc. "Antiseptic agents also exercise a restraining influence upon the development of these germs, and their use during epidemics is to be recommended when masses of organic material in the vicinity of human habitations cannot be completely destroyed, or removed, or disinfected. "While an antiseptic agent is not necessarily a disinfectant, all dis- infectants are antiseptics ; for putrefactive decomposition is due to the development of 'germs' of the same class as that to which disease germs belong, and the agents which destroy the latter also destroy the bacteria of putrefaction, when brought in contact with them in sufficient quantity, or restrain their development when present in smaller amounts. "A large number of the proprietary 'disinfectants' so called, which are in the market, are simply deodorizers or antiseptics of greater or less value, and are entirely untrustworthy for disinfecting purposes." 1 The offensive gases given off from decomposing organic material are no doubt injurious to health ; and the same is true, even to a greater extent, of the more complex products known as ptomaines, which are a product of the vital — physiological — processes attending the growth of the bacteria of putrefaction and allied organisms. It is therefore desirable that these products should be destroyed; and, as a matter of fact, they are neutralized by some of the agents which we recognize as disinfectants, in accordance with the strict definition of the term. But they are also neutralized by other agents — de- odorants — which cannot be relied upon for disinfecting purposes, and by disinfectants, properly so called, in amounts inadequate for the accomplishment of disinfection. Their formation may also be pre- vented by the use of antiseptics. From our point of view the destruc- tion of sulphureted hydrogen, of ammonia, or even of the more poisonous ptomaines, in a privy vault, is no more disinfection than 1 The Medical News, Apr. 18, 1885, p. 425. DISINFECTION. 7 is the chemical decomposition of the same substances in a chemist's laboratory. The same is true as regards all of the bad-smelling and little known products of decomposition. None of these are "infec- tious material," in the sense in which we use these words ; that is, they do not, so far as we know, give rise directly to any infectious disease. Indirectly they are concerned in the extension of the epidemic "filth diseases," such as cholera, yellow fever and of the fatal endemic filth diseases, such as typhoid fever and diphtheria, which in the long run claim more victims than do the pestilential maladies, first named. This because persons exposed to the foul emanations from sewers, privy vaults, and other receptacles of filth, have their vital resisting power lowered by the continued respiration of an atmosphere con- taminated with these poisonous gases, and are liable to become the victims of any infectious disease to which they may be exposed. Moreover, the accumulations of filth which give off these offensive gases furnish pabulum upon which certain disease germs thrive ; and it may happen that the bad smelling air carries something worse than the poisonous gas which makes its presence known by offending the sense of smell. It may waft to our nostrils infectious particles which are beyond recognition by any sense, unless it be the sense of sight with the aid of a good microscope. We desire, moreover, to have it fully understood that in restricting the meaning of the term disinfection within the limits given by the definition of the Committee on Disinfectants of the American Public Health Association, we do not wish to limit the practice of "disinfec- tion," in the popular sense of the word. It is but fair to say, also, that this popular usage is supported by good authority, and until quite recently has been the common ac- ceptation of the term among physicians and chemists. Indeed, it is but a short time since the nose test was the only test of "disinfection" recognized by many intelligent persons. Littre, in his Dictionary of the French Language, defines disinfec- tants as "substances which destroy, chemically, bad od< Vallin, the author of a valuable treatise upon "Disinfection Disinfectants," says, — Om a scientific point of view there is perhaps an impropriety in introducing i n t < > the idea of disinfection the suppression of 6d which offend the sense of smell. The had odor is not injurious in itself; it is an epiphenomenon, which does not I the measure of the hurtful properties of the air. or <>f any substance what- ever. The public, unacquainted with medicine, baa an unfortuu tendency to judge of insalubrity by the hail 0dOT| the ahsenre of this gives to it a deceitful security: when t DISINFECTION. it [the public] believes that all danger has been removed. Neverthe- less it is necessary to avoid violating the ordinary sense of words. 1 An atmosphere which does not in the least offend the sense of smell may certainly be insalubrious, and engender the gravest maladies ; but the fetid or disagreeable odors may reveal the presence of injurious prin- ciples, of toxic gases, or of organic matter in decomposition. We should not too much diminish the importance of these offensive odors in the eyes of the public ; everything which smells badly is to be sus- pected." 1 We agree with Prof. Vallin, that the bad odors should arouse suspi- cion, and lead to the use of deodorants, or of antiseptics, or of disin- fectants, if required ; but let us not leave the public to suppose that when the bad odors have been neutralized, the offensive material has been disinfected. Let us rather instruct the public that to deodorize and to disinfect are not synonymous terms. For our part we prefer to "violate the ordinary sense" of the word, and to restrict its signifi- cation within such limits as will prevent confusion, and, what is far worse, a reliance upon inefficient methods for the destruction of in- fectious material. In the present essay we shall use the words disinfection and dis- infectant, in accordance with the definition of the committee on disin- fectants already given. But, inasmuch as this is intended to be a practical treatise for popular use, we shall also give, in the proper place, directions for the use of deodorants and of antiseptics, so that "disinfection," in the broad sense in which the word is commonly used, may be fully considered. Tests of Disinfection. What means have we of proving that the infective power of infectious material has been destroyed? Evidence of disinfection may be obtained (a) from the practical experiments — experience — of those engaged in sanitary work; (b) by inoculation experiments upon susceptible animals ; (c) by experi- ments made directly upon known disease germs. (a) It is a matter of common experience, that when a room has been occupied by a patient with an infectious disease, such as small- pox, scarlet fever, or diphtheria, susceptible persons are liable to contract the disease weeks or even months after the patient has been removed from it, unless in the meantime it has been disinfected. If a second case does occur from exposure in such a room, it is evident that it has not been disinfected. But the non-occurrence of subse- quent cases cannot always be taken as evidence that the means of dis- infection resorted to were efficient. Negative evidence should be t Italics by present writer. * Op. Cit., p. 2. DISINFECTION. 9 received with great caution. In the first place, the question as to whether susceptible individuals have been fairly exposed in the disin- fected room must be considered. Then it must be remembered that susceptible persons do not always contract a disease, even when they are exposed in a locality known to be infected. A further difficulty in estimating the value of evidence obtained in practice arises from the fact, that, in connection with the special means of disinfection resorted to, such as fumigation, hanging up cloths saturated with a disinfecting solution, etc., it is customary to resort to additional pre- cautionary measures, such as washing surfaces with soap and hot water, white-washing plastered walls, and free ventilation. It is ap- parent that under these circumstances it would be unsafe to accept the fact, that no other cases occurred in a room treated in this way, as evidence that the particular disinfectant used is efficient for the destruction of the infectious agent of the disease in question. The fond mother who attaches a charm to her child's neck to protect it from evil, also takes the precaution of guarding it from contact with other children who are sick with any infectious disease. If her child fortunately grows to manhood or womanhood without having suf- fered an attack of scarlet fever or diphtheria, she may imagine that her charm has protected it, but the evidence upon which her faith is founded is not of a nature to convince those who are familiar with scientific methods of demonstration. "Well educated" persons are often ready to testify in favor of methods of disinfection, or of treat- ment, upon evidence which, from a scientific point of view, has no more value than that which the fond mother in question has to offer in favor of the little bag containing camphor or assafcetida, or some other charm of equal value, which she has attached to her child's neck to keep it from catching scarlet fever or diphtheria at school. On a par with these charms, so far as disinfection is concerned, we may place the saucer of chloride of lime, which it was formerly the fashion to place under the bed of a patient sick with an infectious disease, the rag saturated with carbolic acid, or chloride of zinc, suspended in the sick-room, and even the fumigations with burning sulphur, as some- times practiced by those who arc unfamiliar with the evidence as to the exact value of this agent, and the conditions necessary to ensure successful disinfection with it. Chloride of lime, sulphurous acid k r as, and carbolic acid are among our most useful disinfecting agents, out dis< not to DC charmed away by (hem any more than by a little bag of camphor. Having pointed out the fact that negative vx\<\v V ,f the infectious material to the surl ur cultui dium, or into a fluid which has been found to be suit growth of the particular organism which titivate. \ nil culture is in the d from the first, and io f, n indefinitely. Now it is evident that these "pure cultures" furnish I means for testiii be disinfected. The white-washing « Tni k 'r. mis to the ralloa 18 DISINFECTION. posed surfaces is a satisfactory method of destroying any disease germs which may have lodged upon such surfaces. g. Dry Heat. Dry heat is only to be recommended for the disinfec- tion of such articles as would be injured by exposure to moist heat, or to a disinfecting solution. A properly constructed disinfection cham- ber or "oven" is absolutely essential, if dry heat is to be used. The experimental evidence on record shows that the destruction of spores requires a temperature which would injure woolen fabrics (140° C. for three hours). In the absence of spores, however, articles which are freely exposed for two hours to a temperature of 110° C. (230° Fahr.) may with safety be considered disinfected. In practice it will be neces- sary to remember that the penetrating power of dry heat is very slight, and that packages, bundles, or even articles loosely thrown one upon another, cannot be disinfected in this way. io. Sulphur Dioxid (sulphurous acid gas). Fumigation with burn- ing sulphur has long been a favorite method of disinfection. The ex- perience of sanitarians is in favor of its use in yellow fever, smallpox, scarlet fever, diphtheria, and other diseases in which there is reason to believe that the infectious material does not contain spores. The ex- perimental evidence on record shows that under certain conditions it is effective for the destruction of micro-organisms in the absence of spores, but that it is quite impotent for the destruction of these repro- ductice elements. The presence of moisture adds greatly to the disinfecting power of this agent. It is freely soluble in water, one volume dissolving fifty volumes of the gas. It is therefore evident that a saturated aqueous solution is fifty times as strong as the pure gas — anhydrous. In aqueous solution, in the proportion of 1 : 2000 by weight, sulphur di- oxide kills micrococci in two hours' time. In gas-tight receptacle it destroys the infecting power of vaccine virus dried upon ivory points, when present in the proportion of one volume per cent., the time of ex- posure being six hours. The same proportion destroys anthrax bacilli, without spores, from the spleen of an animal recently dead, dried upon silk threads, in thirty minutes (Koch). These facts show that sulphur dioxid is a valuable disinfectant; but the conditions of suc- cessful disinfection, as established by the experimental evidence, are, that the material to be disinfected shall be freely exposed to its action for a considerable time, in a receptacle which does not permit the gas to escape. It must be remembered that disinfection of a thin layer of vac- cine virus upon an ivory point, or of anthrax blood upon a silk thread, exposed in a gas-tight receptacle, cannot be taken as evidence that thicker layers of infectious material, attached to the surface of bedding and clothing, or enclosed in folded blankets, bundles of clothing, mat- DISINFECTION. 19 tresses, *etc, can be disinfected by the same amount of sulphur dioxid generated in a room which is not gas-tight. It has been shown, by carefully conducted experiments, that the escape of sulphurous acid gas from a bed-chamb r or hospital ward is very rapid, in spite of the usual precautions for stopping up crevices when such a room is to be fumigated; and infectious material, enclosed in bundles or protected by folds of blankets, etc., may escape disinfection, after having been ex- posed for many hours in a tightly closed chamber containing ten vol- umes per cent, of this gas. ii. Copper Sulphate. This salt has been largely used as a disinfect- ant in France, and experiments show that in the proportion of one per cent, it is a reliable agent for the destruction of micro-organisms, in the absence of spores. It is much below mercuric chloride in germi- cide power, but is a better deodorant — not a better antiseptic — than the more poisonous salt. When we take into account its efficiency, it is comparatively cheap, and is to be recommended for certain purposes. 12. Zinc Chlorid. Solutions of chloride of zinc are largely used in this country and in Europe for disinfecting purposes. It is an excellent antiseptic and .deodorant, but its power to destroy disease germs has been very much overestimated. It may, however, be relied upon for the destruction of pathogenic organisms, in the absence of spores, in solutions which contain from five to ten per cent, of the salt. GENERAL DIRECTIONS FOR DISINFECTION. In the sick-room we have disease germs at an advantage, for we know where to find them, as well as how to kill them. Having this knowledge, not to apply it would be criminal negligence, for our efforts to restrict the extension of infectious diseases must depend largely upon the proper use of disinfectants in the sick-room. Disinfection of Excreta, etc. The dejections of patients suffering from an infectious disease should be disinfected before they are thrown into a water-closel or privy vault. This is especially important in cholera, typhoid fever, yellow fever, and other diseases in which there is evidence that the infectious agent is capable of self-multiplication, in suitable pabulum, external to the human body. Vomited matters, and the sputa of patients, with these and other infectious . should • lie promptly disinfected. This i> especially important in cholera, diphtheria, scarlet fever, whooping-cough, and tuberculosis. It is ad- visable, also, to treat the urine of patients sick with an infectn with a disinfecting s< >luti< in. for the disinfection of excreta, etc.. in the sick-room, a solution of ride of lime is to he recommended. This is an excellent ami prompt deodorant, as well as a disinfectant A quart of the standard 20 DISINFECTION. solution (No. 1), recommended by the committee on disinfectants, of the American Public Health Association, will suffice for an ordinary liquid discharge in cholera or typhoid fever ; but for a copious discharge it will be prudent to use twice this quantity, and for solid fecal matter a stronger solution will be required. As chloride of lime is quite cheap, it will be best to keep on the safe side, and to make the solution for the disinfection of excreta by dissolving eight ounces of chloride of lime in a gallon of water. This solution should be placed in the vessel before it receives the discharge. The material to be disinfected should be well mixed with the disinfecting solution by agitating the vessel, and from thirty minutes to an hour should be allowed for the action of the disinfectant, before the contents are thrown into a water-closet or privy vault. For the disinfection of liquid discharges in cholera, typhoid fever, dysentery, etc., a five per cent', solution of carbolic acid may be used. This was recommended by the committee on disinfectants of the Inter- national Sanitary Conference, which met in the city of Rome in 1885, of which committee the distinguished bacteriologist, Prof. Robert Koch, was chairman and the present writer a member. The solution should be used in an amount at least equal to the material to be disin- fected — better twice this amount. The time necessary to insure dis- infection was fixed by the committee at four hours. Milk of lime, made by slaking fresh quicklime with water and mixing the resulting hydrate of lime with eight parts of water, is one of the best and cheapest agents for the disinfection of excreta in the sick-room, on the surface of the ground, in open sinks, etc. This milk of lime should be used in an amount at least equal to the quantity of material requiring disinfection. Chloride of zinc in ten per cent, solution may be used to disinfect the dejections of those sick with cholera or typhoid fever, or sulphate of copper in a solution of the same strength (ten per cent.), the amount of solution used being equal to the amount of material to be disin- fected. It will be best to burn cloths used to wipe away the discharges of the sick, and especially those used in wiping away the infectious material from the mOuth and nostrils of patients with diphtheria or scarlet fever. Bits of old muslin may be used for this purpose, and should at once be thrown upon an open fire or gas stove aranged in the fire-place for this purpose. Infected sputum may be discharged directly into a cup half full of the solution of chloride of lime recommended for excreta, or of Labar- raque's solution. DISINFECTION. 21 Handkerchiefs, napkins, and towels used in wiping away infectious discharges, if worth preserving, should be at once immersed in one of the following solutions : Chloride of lime, 2 per cent. ; carbolic acid, 2 per cent. ; mercuric chloride, 0.1 per cent. (=1 : 1000). "Cloths used for washing the general surface of the body should also be disinfected with one of the above mentioned solutions ; and attend- ants should invariably disinfect their hands by washing them in one of these solutions, when they have been soiled by the discharges of the sick. Disinfection of the Person. Labarraque's solution, diluted with twenty parts of water, is a suitable disinfecting solution for bathing the entire surface of the body of the sick, of convalescents, or of those whose duties take them into the sick-room ; or a 2 per cent, solution of carbolic acid, may be used, or a solution of mercuric chloride (corrosive sublimate) of 1 : 1000. The poisonous nature of this solution must be kept in mind. The International Sanitary Conference of Rome gives the following directions with reference to the disinfection of the body after death from cholera : "The body should be enveloped in a sheet saturated with one of the strong disinfecting solutions, 1 without previous washing, and should at once be placed in a coffin." We see no objection to washing the body, if the strong solution of chloride of lime is used for this purpose. Washing with water would necessitate the careful disinfection of the water and cloths used for this purpose, and of the hands of the attendants. As the odor of chlorine or of carbolic acid would be objectionable under certain circumstances, we see no good reason for insisting upon the use of these agents, rather than on the odorless solution of mercuric chloride, which, in the pro- portion of 1 : 1000, would no doubt be equally effective. But when there is an odor of decomposition to be neutralized, the solution of chloride of lime will have a decided advantage on account of its de- odorizing properties. Disinfection of Clothing and Bedding. The cheapest and best way of disinfecting clothing and bedding, which is not injured by the ordinary operations of the laundry, is to immerse it in boiling water for half an hour or longer. It should be placed in boiling water as soon ;is moved from the person <>r the bed of the sick, and if it is : . to remove the articles from the room in order to accomplish this, they should be wrapped in a sheet or towel thoroughly saturated with a d infecting solution, if it is impracticable to disinfect such infected clothing and bedding immediately by boiling, it will he necessary to im- l Chlortd* of lima, 4 par c«nt., <>t. 22 DISINFECTION. merse it in one of the following disinfecting solutions, in which it should be left for four hours : Mercuric chloride, 1 : 2000 ; or the "blue solution," 1 of this salt and sulphate of copper, diluted by adding two fluid ounces of the concentrated solution to a gallon of water ; or a 2 per cent, solution of carbolic acid. The solution of chlorinated lime (2 per cent.) may also be used, but we give the precedence to the first mentioned solutions, because of the bleaching properties of this solu- tion. The blue solution does not injure clothing, and is to be preferred for domestic use to a simple solution of corrosive sublimate, which in the concentrated form is highly poisonous, and without odor or color. When diluted as directed, this solution may, however, be used without great danger. The metallic taste of the diluted solution could scarcely fail to prevent a fatal dose from being swallowed accidentally. Woolen garments and other articles which would be seriously in- jured by immersion in boiling water, or in one of the disinfecting so- lutions above mentioned, should be disinfected, in a properly con- structed disinfection chamber, by steam or by formaldehyd gas. Exposure to steam at 100° C. (212° Fahr.) for half an hour would be equivalent to exposure in boiling water for the same time, if the cloth- ing is hung up in such a manner as to be fairly brought under the action of the disinfecting agent. To be certain that the steam does not fall below this temperature in the disinfection chamber, a thermometer must be placed in a corner of the room, at a distance from the point of entrance of the steam, or " - an aperture from which the steam escapes. This should mark at least 100° C. for half 'an hour before the disinfec- tion can be considered complete. 2 To accomplish this, it is evident that the steam must come from the generator at a higher temperature, or, in other words, must be under, pressure. It must be remembered that in a majority of the infectious diseases in which disinfection is most frequently required the specific germ does not form resistant spores (cholera, typhoid fever, tuberculosis, diph- theria, erysipelas, pneumonia, yellow fever, smallpox). In these dis- eases therefore it would be a mistake to forbid the use of carbolic acid, sulphur dioxid, and other agents which enjoy the confidence of sani- tarians, and which have been proved by laboratory experiments to destroy pathogenic organisms, in the absence of spores. As disinfection by steam injures certain articles, dry heat may be used as a substitute for moist heat, but in this case a temperature of at least 110° C. (230° Fahr.), maintained for two hours, will be required. l Bichloride of mercury 4 oz. Sulphate of Copper 1ft. Water 1 gal. 8 The committee on disinfectants of the International Sanitary Conference of Rome fixes one hour as the time during- which steam should be made to pass over articles to be dis" infected. DISINFECTION. 23 In the use of dry heat, even greater care is necessary that the articles to be disinfected are freely exposed, — that is, not placed in the oven in bundles, or piled one upon another, but freely suspended in the disin- fecting chamber. For it has been shown by carefully conducted ex- periments that the penetrating power of dry heat is very slight. A properly constructed disinfection oven, such as that of Ransom, 1 will be required if dry heat is to be used. But it will, as a rule, be preferable to disinfect such articles in a steam disinfecting chamber of modern construction in which provision is made for exhausting the air before steam under high pressure is admitted, and in which after disinfection the clothing is rapidly dried before being removed from the steam chamber. Sulphur dioxid is a less reliable disinfectant than steam or dry heat, but when the necessary conditions are observed there is no doubt of its utility ; and the fact that it does not kill the spores of anthrax and of other bacilli is no reason for rejecting an agent which has been dem- onstrated by experience to be one of great value, which has been proved by laboratory experiments to be fatal to pathogenic organisms in the absence of spores, and to destroy the infecting power of vaccine virus. But in using this agent the conditions of successful disinfection, which have been established by experiment, should be borne in mind. The room which is to serve as a disinfecting chamber must be very thoroughly c 1 osed : every crevice and key-hole should be carefully closed by fastening paper over it. Even this precaution will not prevent the rapid escape of gas from cracks around doors, windows, etc. It is therefore desirable, when practicable, to use a disinfect- ing chamber which can be hermetically closed. The articles to be disinfected must be very freely exposi d, and should never be thrown into the room in bundles, or piled one upon another. We concur in the recommendations of the committee on disinfectant- of the Ameri- can Public Health Association, as to the amount of sulphur which mid be burned, and the method of effecting its complete combus tion: "To secure any result of value, it will be necessary to close the apart- ment to be disinfected as completely as possible, by stopping all aper- tures through which gas might escape, and to barn at least three pounds of sulphur for each thousand cubic feel of air-space in the mi. To secure complete combustion ulphur, it should be placed, in powder or in small fragments, in a shallow iron pan. which should be set upon a couple of bricks in a tub partly filled with water. 24 DISINFECTION. to guard against fire. The sulphur should be thoroughly moistened with alcohol before igniting it." 1 ' Since the above was written with reference to disinfection by sul- phur dioxid (SO2) the valuable germicidal properties of formaldehyd gas have been demonstrated, and satisfactory methods of .generating this gas for purposes of disinfection have been devised. Owing to its superior germicidal value and non-toxic properties it has to a con- siderable extent taken the place of sulphur dioxid as a gaseous disin- fectant. In making practical use of this agent a suitable apparatus will be required. For the disinfection of a room with its contents, freely exposed for surface disinfection, one pound of formalin should be volatilized for each thousand cubic feet of air-space — the time of exposure to the disinfecting action of the gas being not less than twelve hours. When paraform is used the amount required will be 60 grams to 1,000 cubic feet (Novy). In the absence of any apparatus satisfac- tory results have been obtained by the Department of Health of city of Chicago, as follows : "Ordinary bed sheets were employed to secure an adequate evapo- ratory surface, and these, suspended in the room, were simply sprayed with a 40 per cent, solution of formalin through a common 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 disinfection of 1,000 cubic feet of space. Of course, the sheets may be modified to any necessary number. * * * Surface disinfection was thorough, while a much greater degree of penetration was shown that that secured by any other method." Formalin may also be used in the disinfection of rooms and their contents by spraying all exposed surfaces. Experiments made by Kinyoun and others show that formalde- hyd gas does not injure the color or textile strength of fabrics of wool, silk, cotton or linen and that it has no injurious action upon furs, leather, copper, brass, nickel, zinc, polished steel or gilt work. Iron and unpolished steel are attacked by the gas. We would remark, that in the absence of suitable appliances for disinfection, and in general when the disinfected articles are of little value, consumption by fire furnishes the readiest and safest method of disposing of such articles. For articles of value, such as upholstered furniture, etc., which would be injured by any of the processes heretofore recommended, free exposure to the air (aeration) for three or four weeks is directed by the Committee on Disinfectants of the International Sanitary Con- ference of Rome. The same committee directs that "objects made 1 Preliminary report, 1. c, p. 427. DISINFECTION. 25 of leather, such as trunks, boots, etc., should be destroyed or washed several times with one of the weak disinfection solutions," — carbolic acid 2 per cent., or chloride of lime 1 per cent. The means heretofore recommended for the disinfection of woolen clothing, blankets and similar articles will not be sufficient for soiled mattresses. As a rule, they should be opened, and the contents disin- fected by steam, with subsequent free aeration, and the cover should be washed in boiling water after treatment with a disinfecting solution. Finally, the valuable germicidal properties of direct sunlight have been demonstrated by numerous carefully conducted experiments and the time-honored domestic practice of hanging infected clothing and bedding in the "open air" is to be recommended. This should supple- ment disinfection by formaldehyd or sulphur dioxid. Disinfection of the Sick-Room. Every effort should be made to pre- vent a room occupied by patients sick with an infectious disease from becoming infected. Carpets, stuffed furniture, curtains and other arti- cles difficult to disinfect, should be removed at the outset. Indeed, nothing should be left in the room which is not absolutely required, and all furniture and utensils should be of such a character that they can be readily disinfected by washing with boiling water or with a dis- infecting solution. Abundant ventilation and scrupulous cleanliness should be maintained, and a disinfecting solution should always be at hand for washing the floor, or articles in use, the moment they are soiled by infectious discharges. For this purpose a solution of chloride of lime may be used (4 per cent.). It is impracticable to destroy infectious material in an occupied apartment by means of gases < r volatile disinfectants, for to be effective these must be used in a degree of concentration which would make the atmosphere of a r om quite irrespirable. These agents are therefore useful only as deodorants. They are all more or less offensive to the sick, and will seldom be required, even as deodorants, when proper attention is paid to cleanliness and ventilation. Daily wiping of all surfaces — floors, walls, and furniture — with a cloth wet with a disinfecting solution, is to l>c recommended. For this purpose a dilution of chloride of lime (2 per cent.), or of carl" acid (2 per cent. i, or mercuric chloride ( 1 : L000), may In- used. By such precautit ms as ha\ e been indicated, th< >n ol the sick- room may b nted, especially in those diseases, such as chol and typhoid f< ver, in which the infectious agent is not given off in the br< ath, or fr< m the general surface of the body, of the sick person. In smallpox and in scarlet fever there is greater danger that the infecti nt may remain attached to the surfaces in the room : for the atmos- phere becomi - infected from parti en < iff from tl e of the patient's bod 26 DISINFECTION. As already stated, the atmosphere cannot be disinfected while the room is occupied. There is much less reason for disinfecting it when the patient has been removed, and it is much simpler to renew it by throwing- open the doors and windows than to attempt to disinfect it. Indeed, there will be no infectious particles to destroy, except such as are dislodged from surfaces, window ledges, etc., where they have settled as dust while the room was occupied ; and if the precautions above recommended have been taken, the danger of such reinfection of the atmosphere will be reduced to a minimum. Disinfection of the vacated room, then, consists in the destruction of all infectious particles which remain attached to surfaces, or lodged in crevices, in interstices of textile fabrics, etc. The object in view may be accomplished by thorough washing with one of the disinfecting solutions heretofore recommended ; but most sanitarians think it ad- visable to "disinfect the room" with a gaseous disinfectant, such as formaldehyd or sulphur dioxid. If the "fumigation" with sulphur dioxid is resorted to, the directions given by the Committee on Dis- infectants of the American Public Health Association should be fol- lowed, i. e., three pounds of sulphur should be burned for every 1,000 cubic feet of air-space. But, as already stated, disinfection with for- maldehyd gas is to be preferred (see page 15). At the end of from twelve to twenty-four hours, doors and windows should be opened, and the room freely ventilated. After this fumiga- tion, all surfaces should be washed with a disinfecting solution (chlor- ide of lime 2 per cent., carbolic acid 2 per cent., or mercuric chlorid 1 :1000), and afterwards thoroughly scrubbed with soap and hot water. Plastered walls should be white-washed. Disinfection of Privy Vaults, Cesspools, etc. The contents of privy vaults and cesspools should never be allowed to accumulate unduly, or to become offensive. By frequent removal/ and by the liberal use of antiseptics, such necessary receptacles of filth should be kept in a sanitary condition. The absorbent deodorants, such as dry earth or pounded charcoal, — or the chemical deodorants and antiseptics, such as chloride of zinc, sulphate of iron, etc., — will, under ordinary cir- cumstances, prevent such places from becoming offensive. Disinfec- tion will only be required when it is known, or suspected, that in- fectious material, such as the dejections of patients with cholera, yel- low fever, or typhoid fever, has been thrown into the receptacles. In the Manual for the Medical Department of the U. S. Army the following directions are given : 92. When accumulations of organic material undergoing decompo- sition cannot be removed or buried, they may be treated with an anti- septic solution, or with freshly burned quicklime. Quicklime is also a DISINFECTIOA. 27 valuable disinfectant, and may be substituted for the more expensive chlorid of lime for disinfection of typhoid and cholera excreta, etc. For this purpose freshly prepared milk of lime should be used, containing about 1 part, by weight, of hydrate of lime, to 8 of water. 93. During the prevalence of an epidemic, or when there is reason to believe that infectious material has been introduced from any source, latrines and cesspools may be treated with milk of lime, in the proportion of 5 parts to 100 parts of the contents of the vault, and the daily addition of 10 parts for 100 parts of daily increment of feces. Hospitals. The directions already given in regard to disinfection of the sick-room and its contents apply as well to hospital wards in which patients with infectious diseases are treated. In addition to this, it will be necessary in hospitals to guard against such infectious diseases as erysipelas, septicaemia, puerperal fever, and hopital gangrene. The antiseptic treatment of wounds, in connection with a proper regard for cleanliness and ventilation, has practically banished these diseases from well regulated hospitals. Of the first importance in effecting this are the precautions now taken with reference to the disinfection of sponges, instruments, the hands of attendants, etc. Instruments of silver, such as probes and catheters, may be disin- fected by passing them through the flame of an alcohol lamp. In- struments of steel, gum catheters, etc., may be disinfected by immer- sion in a five per cent, solution of carbolic acid, or in a 1 :1000 solution of mercuric chloride. For instruments and vessels of copper, brass, and tin, boiling water, or the carbolic acid solution, may be used. Vessels of porcelain or glass may be disinfected by heat, or by either of the disinfecting solutions mentioned. Sponges should be kept per- manently in one of the disinfecting solutions, or, what is hotter, may be dispensed with entirely for the cleansing of wounds. In place of them, irrigation with a disinfectant solution may he resorted to, or the charges may be wiped away with some cheap absorbent material which can be burned after having been once used Patients in hospitals, with infectious diseases,, will of course be kept in isolated wards. Everything winch comes from such a ward should be disinfected, and the immediate attendants of the sick should not allowed to visit other parts of the hospital without first changing their outer clothing for a r< cently disinfected suit, and washing their hands in a disinfecting olution. When relieved from duty their un clothing should also be disinfected; and they should I bath with one of the weak disinfecting solutions h mended. Disinfection of Water and Articles of Food. The disiir drinking-water on a large scale, in reservoirs, wells, etc., ia imprad 28 DISINFECTION. ble. But it is a very simple matter to disinfect water which is sus- pected of being contaminated with the germs of cholera, typhoid fever, or any other disease transmissable in this way. This is readily ac- complished by boiling. As already stated, all known disease germs are destroyed by the boiling temperature maintained for half an hour. The importance of this precaution during the prevalence of an epi- demic of cholera or of typhoid fever cannot be over-estimated, when the water used for drinking purposes comes from an impure source, or is liable to contamination by discharges of patients suffering from these diseases. Those articles of food, and especially milk, animal broths, etc., which might serve as pabulum for disease germs, should, during the prevalence of an epidemic, be cooked but a short time be- fore they are eaten. And such food, if put aside for hours after it has been prepared, should always be again subjected to a boiling tempera- ture shortly before it is served. Food which gives evidence of com- mencing putrefaction is unfit for use, and in time of epidemics is es- pecially dangerous. Disinfection of Ships. It should be the aim of a physician attached to a passenger ship, or of the master of a vessel having no physician on board, to prevent the vessel from becoming infected when in an in- fected port, or when cases of infectious disease occur on board. This is to be accomplished by keeping the ship clean ; by disinfecting sus- pected articles, and especially the soiled clothing of passengers, before they are received on board ; by the isolation of cases of infectious dis- ease which occur on. board; and by the thorough execution of those measure of disinfection recommended for the sick-room. When a case of cholera or of yellow fever occurs upon a ship at sea, it cannot be taken as evidence that the vessel is infected unless at least five days have elapsed since the person attacked came on board. For he may- have contracted the disease from exposure at the port of departure, or in some other locality on shore. When, however, a longer time than this has elapsed, or when several cases develop in a particular locality on ship-board, either simultaneously or successively, the ves- sel must be considered infected, unless it is shown that the cases are directly due to the opening of baggage containing infected clothing. In practice, the sanitary officials at the port of arrival usually treat a vessel as infected if any case of infectious disease has occurred upon her during the voyage. This is a safe general rule, which should not be departed from unless a considerable time — five or seven days — has elapsed since the cases occurred, and they can be clearly traced to exposure before coming on board. In this case, if the ship is clean and the precautions relating to disinfection and isolation of the sick have been faithfully executed, the health officer may be justified in dis- DISINFECTION. 29 pensing with the general measures of disinfection which are required for an infected ship. These measures do not differ from those heretofore recommended for the disinfection of the sick-room and its contents ; but the special conditions on ship-board, and the great interests at stake, make it es- sential that the execution of these measures should be in the hands of sanitary experts. In the disinfection of ships, fumigation with sulphurous acid gas has been largely practiced by those in charge of quarantine establish- ments. The fact that the ship may be almost hermetically closed, and the escape of gas to a great extent prevented, makes this method of disinfection more trustworthy than in the case of dwellings and hos- pitals. The further fact, that certain parts of the ship are inaccessible for the application of disinfecting solutions, seems to make the use of a gaseous disinfectant imperative. Disinfection by means of steam, especially of an iron vessel, would no doubt be a difficult matter on account of the condensation which would occur from contact with the cool walls of the vessel below the water-line. But it will be well to fill the vessel with steam before in- troducing the sulphur dioxid ; for, as already stated, the disinfecting power of this agent is much greater in presence of moisture. A well equipped quarantine establishment should have an apparatus for gen- erating sulphurous acid gas, and injecting it into vessels, as this is the most expeditious and satisfactory method of fumigating a ship. An essential part of the disinfection of a ship will c< insist in the thorough cleansing of the bilge. The International Sanitary Confer- ence of Rome prescribed that the bilge water shall be pumped out and replaced by sea water at least twice at each disinfection of the vessel. Merchandise. Article V, of the Report of the Committee on Disin- fection of the International Sanitary Conference of Rome, says: "V. Disinfection of merchandise and of the mails is unnecessary. (Steam under pressure is the only reliable agent f"r the disinfection of rags — les chiffons en ^ros.)" We think this statement too broad, especially so far a- merchandise is concerned which has been on hoard a ship infected 'with yellow fever. The poison of this disease seems to he capable of self -multipli- cation on a foul ship in tropical latitudes, quite independently of p sengers and crew. And there is ample evidence thai even when no case has occurred on an infected shij those who are enga| in discharging her cargo after arrival in port may he seized with yellow fever from breathing the infected atmosphere of the hold Evidently merchandise conveyed i n such a ship should he disin But it does not seem necessary to break packages which h 30 DISINFECTION. board in good condition, and a thorough fumigation with sulphurous acid gas will be sufficient if the unbroken packages are so distributed as to be fairly exposed to the action of the disinfecting agent. To ac- complish this, and to effectually disinfect the ship, it will be necessary to discharge the cargo at the quarantine station. The collections of the rag-man cannot properly be placed in the same category with other merchandise, such as agricultural products, hard- ware, new cotton or woolen goods, etc. An exception with regard to rags is indicated, but not stated with sufficient precision, in the article which we have quoted. There is evidence that smallpox has been not infrequently transmitted in rags, and sanitarians are generally agreed that it would be very imprudent to admit rags collected in or shipped from localities infected with cholera or yellow fever, without first sub- jecting them to thorough disinfection. PART SECOND. INDIVIDUAL PROPHYLAXIS AGAINST INFECTIOUS DISEASES. The state establishes quarantine stations, to guard against the intro- duction of infectious diseases of exotic origin ; and in enlightened countries, sanitary officials, under the direction of the central govern- ment, or of states and' municipalities, are charged with the duty of guarding the public against such diseases. It is generally recognized that this is to be accomplished by the isolation of the sick, the use of disinfectants, and by general measures of sanitary police. One way in which the individual may indirectly protect himself against such diseases is by using his influence to have this sanitary service placed in the hands of competent men, and in sustaining them in their efforts to exclude or stamp out infectious diseases by such measures as have been demonstrated by science and experience to be efficient for this purpose. But this is not the kind of "individual prophylaxis" which we have to consider here. The question is, What can the individual do to pro- tect himself and those immediately dependent upon him, under the various circumstances in which he may be placed, and especially in the presence of an epidemic? As the advice we have to give will differ greatly according to the disease, we shall pass in review the principal infectious maladies of man, and shall attempt to give for each such practical instructions as will enable an intelligent person to take all practicable precautions for his own protection, and for that of his immediate family. We have first, however, to make some general remarks. DISINFECTION. 33 Infectious diseases are contracted by contact with the sick, through the medium of infected articles — "fomites" — or by exposure in infected localities. The evident general rule of prophylaxis is, therefore, to avoid all of these sources of infection ; but there are circumstances in which this is either impossible or unjustifiable. Duty calls the physician and the nurse into the sick-room, and no argument based upon self-protection can keep the devoted mother from the bedside of her sick child, or the wife from giving her personal attention to her husband, or the husband to his wife, when stricken by pestilence. Humanity requires that dur- ing an epidemic the sick shall 'be cared for, the dead buried, and the foul places cleansed. All this calls for the active and intelligent efforts of persons who have the courage to face danger, and not only of those who by their profession are necessarily brought in contact with the sick — physicians, clergymen, sanitary officials, nurses — but often, also, of volunteers; for, during the prevalence of an epidemic of cholera, or of yellow fever, the number of physicians and trained nurses within the affected area is commonly insufficient for the care of the sick. The history of epidemics shows that brave men and women are to be found in every civilzed country, who are willing to volunteer for such perilous duties ; and also that physicians, and those whose legiti- mate duty it is to care for the sick, very rarely desert their post in time of 'danger; but the mortality among these brave men and women who stand by their guns, and among the volunteers who go to their assist- ance, is often very great. There is a wide-spread notion among people not familiar with the facts, that doctors enjoy a certain immunity from infectious diseases not possessed by other people, and that the absence of fear is a safeguard .-(gainst infection. Such a supposition is with- out foundation, and is an insult to the brave nun and wmu/n who fall at their post of duty in ev< ry epidemic. Courage is no more a por- tion against disease germs than against bullets. It is true, that in epi- demics, as in war, the sulkers and cowards often run into danger which the men in the rank's escape. The rashness which results from ignor- ance or from thoughtlessness is not courage, any more than the pru- dence which avoids danger when there is no gi on for facing it is cowardice. Those who rashly venture within the lines drawn by an epidemic, in the pursuit of litis i pleasure, on the supposition that they will escape the prevailing disease because they are "not afraid," often fall victims to their unreasoning temerity, ami not infre- quently heat a hasty retreat, with blanched face, when they are brought directly ipto the presence of the sick and the dying, Our advice t<> the brave IS, I'" nol put YOUr trust in your k'^\- for it is no armor againsl infection. Rely rather upon t! 32 DISINFECTION. tions which science and experience indicate as best suited to the special circumstances in which you may be placed, and do not hesitate to retreat before an invisible foe, when you are not required by con- sideratons of duty to remain upon the field of battle. If your services are not required, you are simply in the way ; and if you fall ill, you add to the labors of those who devote themselves to the care of the sick. And to the timid we would say let not your fear control your actions, but look the circumstances fairly in the face, and be guided by reason and knowledge, or by the advice of those competent to decide for you. A premature flight may bring you into ridicule, or into greater dangers than those you flee from. Do not let your fears exaggerate the facts, and weigh these in the balance of your reason, and not of your appre- hensions. The fact that Judge A or Col. B has fallen a victim to cholera or yellow fever is no more reason for deserting your home than is the fact that the humblest citizen of your town has died from the same disease. If courage is no protection against infection, it cannot be denied that fear, in the presence of the infectious agent, is a predisposing cause which frequently determines an attack, and which may turn the balance in favor of a fatal result. The depressing effect of fear is well known, and all influences which reduce the vital resisting power of the indi- vidual predispose to an attack when an epidemic is prevailing. Other predisposing causes of a general nature are those conditions of enfeebled resistance which result from ill-health, venereal and bac- chanalian excesses, etc. Of all these, it is probable that excessive indulgence in intoxicating drinks is the most potent factor in swelling the mortality returns dur- ing the prevalence of pestilential diseases. This predisposing cause acts in several different ways. The individual whose reason is befud- dled by drink, stumbles stupidly into all kinds of danger. He is "not afraid" to sleep upon the ground, exposed to the night air, when yellow fever is prevailing, or to quench his thirst with water which a prudent man would reject as unfit to drink in the presence of cholera, or to wrap himself in a blanket which has recently been in use by a patient with smallpox. Again, the debility, often attended with digestive de- rangement, which follows a recent debauch, constitutes a most favora- ble condition for the reception of the germs of cholera, of yellow fever, and of infectious diseases generally. Those who use intoxicating drinks habitually, but within the limits marked by that mental aberra- tion or loss of reason which constitutes intoxication, are less subject to infection than the man who is suffering from the effects of a recent "spree." But if they have any organic disease of the stomach, the kidneys, or of the liver, as a result of their habits, this constitutes a DISINFECTION. 33 predisposition to be attacked, and is a very serious complication when an attack is developed. Persons suffering from chronic wasting diseases, profuse discharges, or recent hemorrhage, are especially liable to become the victims of an infectious disease during its epidemic prevalence. The same is true of those whose vital resistance is below par from insufficient food, or from the continued respiration of vitiated air — crown poisoning, sewer- gas poisoning, etc In addition to the predisposing causes mentioned, which furnish in- dications of more or less value with reference to individual prophy- laxis, there are individual and race differences in susceptibility to cer- tain diseases manifested by those who are in perfect health. One man may be repeatedly exposed to an infectious disease without falling sick, while another may suffer several attacks of a disease, such as smallpox, in which one attack commonly confers immunity. Race differences in susceptibility are shown in the relative immunity of the negro from the effects of the yellow fever poison, and the great suscep- tibility of the same race to smallpox. We shall consider in detail the question of individual prophylaxis against certain infectious diseases, which, by reason of their fatality and occasional wide-spread epidemic prevalence, seem entitled to special attention in an essay of this nature. Cholera. In Asiatic cholera the danger of infection from association with the sick, in the capacity of nurse or physician, is very slight. This is amply demonstrated by experience. On the other hand, laun- dresses, who do not come directly in contact with the sick, but who handle clothing soiled by their discharges, are liable to contract the disease. Ey far the greater number of cases, however, result from exposure in infected localities, and fn >m drinking infected water. Out- side of the area in India where cholera prevails as an endemic disease, localities become infected and the water-supply contaminated as a re- sult of the introduction of infectious material from previously infected localities, either in f .mites, or through the medium of the discharge* of the sick. These facts furnish the indications for individual as well as for general measures of prophylaxis. In the sick-room the precautions to be taken are, to keep the room clean and well ventilated, to disinfect the discharges of the sick and all soiled articles as promptly as possible, and to wash the hands in a infecting solution when they have been in contact with the patient with soiled clothing. Attendants should not take their food in the room occupied by the sick, and should not drink liquids which have been exposed in the sick-room. 34 DISINFECTION. The general directions relating to diet, drinking-water, etc., which we shall shoitly give, apply to the attendants upon the sick, as well as to those at a distance from them ; and it should be remembered, in the interest of the sick, that these attendants do not run any special risks beyond those to which all persons within the area of infection are ex- posed. " Indeed, we may go further, and say that they run far less risk when they are in a well regulated hospital and under intelligent super- vision, than do those persons who dwell in the localities outside of the hospital from which the cases under their charge have come. Attendants upon the sick should have their meals at regular hours, should not be deprived of a fair allowance of sleep, and should never be allowed to become exhausted by protracted vigils or excessive fa- tigue. When cholera has been introduced into a country and is extending its limits from day to day, one of the first questions which will pre- sent itself to those who are able to change their place of residence will be, whether they shall attempt to keep out of its way, and if so, where it is best to go. The answer to this question must depend very much, upon circumstances. Those who are unfortunate enough to live in a city or town which has a bad sanitary record, which is not provided with an efficient health department, or does not provide money to ena- ble the officers appointed to do efficient work, had better decamp in good time, so as to evade the foe entirely, or to meet it upon a field more favorable for defensive operations. There should be no stampede, and no running away in haste without any definite idea of why and where. The time to go is before the disease has fairly obtained a lodgment. Consider that if the season is not far advanced, and the town is in an unfavorable sanitary condition, there is every reason to anticipate that the first cases will be followed by a severe epidemic, and decide at the outset whether you will put your castle in order to stand a siege, trust-j ing to well considered measures of individual prophylaxis, or whetherf you will beat a masterly retreat in advance of the first assaults of th<* enemy. Those who vacillate, in the hope one day that the epidemic is on the decline, and in the fear the next that it will sweep everything before it, in the end very often stay, when they could just as well havfi gone, and at the same time neglect those precautions which they^j should have taken at the outset if they had decided to stay. To those who are unable or unwilling to desert their homes, w would say, that when proper precautions are taken the danger is reall; not very great, and that sanitarians look for the day when cholera wil be practically banished from civilized countries. See that your prem-ij ises are in good sanitary condition, and do what you can to induce! your neighbors and the authorities in your town to prepare for th ' DISINFECTION. 35 storm. Look especially after the plumbing of your houses, and if there is a cesspool or privy vault upon your premises, see that it is kept in good condition by the use of antiseptics and deodorants. 1 Above all, see that no food comes into your house except such as is sound and good, and that the drinking-water used by your family is beyond suspicion. Well-water is always open to suspicion, and in general, during the prevalence of cholera, it will be advisable to boil all water used for drinking purposes. This is a prophylactic measure of prime importance, and there is good reason to believe that if faithfully executed it would, to a great extent, limit the ravages of the Asiatic pestilence. Tea and coffee recently made can be taken with impunity. Milk, «during the prevalence of an epidemic, should be boiled before it is used as food. Mineral waters, if bottled at places distant from the infected area, may be drunk in moderation. A moderate amount of sound wine, which was bottled prior to the epidemic, may be permitted to those who are in the habit of using it. Those not in the habit of using stimulants should not resort to their use during the progress of an epidemic. Those accustomed to them should restrict their liba- tions within moderate limits, and will find a little brandy and soda, or Apollinaris water, to be better than wines, and especially than the acid wines, which are apt to derange the digestion. Food should be plain and well cooked, and should be taken in mod- erate quantities. Intemperance in eating is quite as bad as intemper- ance in drinking. Soups, meats and vegetables should always be served hot, and should not be put aside for a future repast, or, if served a second time, should be brought to the temperature of boiling water shortly before they are eaten. Pastry and rich puddings, and all coarse and indigestible meats and vegetables, are to be avoided. Sound, ripe fruit, winch lias been brought to the house with the outer skin unbroken, may be eaten in moderation by those who know by ex- perience that it agrees with ihem. It should be carefully washed he- it is eaten. Melons, < ucumbers, unripe apples, peaches, or pe acid fruits generally, and, in short, .all those articles which are known to give rise to digestive d cuts in the absence of cholera, would ter be banished from the supply-list during the prevail this ise. I to the precautions relating ml drink, we would those relating to personal habits and clothing. '1 ' ted. and, <>n the I (thet hand, 84 to dian I ild al i >i tention. 1 1 greatest importance, and. inde lual prophyl; ht diet, and a d< >se or tv. 36 DISINFECTION. ciyne, or of Hope's mixture, or of any approved combination of an opiate and an astringent, will usually suffice to control a slight diar- rhoea, even if it is of a choleraic character. The clothing should be suited to the season, but great care must be taken that it is warm enough at all times to prevent the body from be- coming chilled. A broad flannel belt worn about the abdomen is rec- ommended by many physicians of experience, and is no doubt useful. Baths should be taken at frequent intervals, but should not be too pro- longed or too cold, and should be followed by a vigorous rubbing of the surface, to establish reaction. Excessive exercise and fatiguing labor of all kinds are to be avoided. One should never feel "done up," as a result of his exertions in the way of business or of pleasure, for the lassitude resulting from over-exertion, like that which results from fear, predisposes to an attack. Mental depression is, so far as possible, to be avoided ; "grief, despondency and "carking care" are recognized as predisposing causes in cholera and in other infectious diseases. The use of "sulphuric acid lemonade" — that is, of pure water acidu- lated with this acid and sweetened to taste — has been recommended as a prophylactic, and there is some evidence in favor of its usefulness. We would not advise its indiscriminate use, or that of any other pro- phylactic of this nature. When cholera has made its appearance in a dwelling or in a public institution, the inmates may be given this, to the exclusion of all other drinks. Yellozv Fever. This disease, like cholera, is contracted in infected localities, rather than by contact with the sick. Indeed, it is rarely, if ever, communicated directly by a sick person to his attendants. In in- fected places the poison seems to be given off from the soil, or from col- lections of decomposing organic matter, and we ha\e no definite evi- dence that it is communicated through the medium of food or drink- ing-water. The history of epidemics of this disease shows that when it obtains a lodgment in a city or town which is in an insanitary condi- tion, in southern latitudes and during the summer months, it extends its area and invades new localities similarly situated, until frost occurs, or at least until the weather becomes comparatively cool in the autumn. Those who remain in an infected area, unless protected by a previous attack, are almost certain to contract the disease, and much less can be done in the way of individual prophylaxis than in cholera. We therefore advise all those who can get out of the way of this fatal dis- ease to do so. As a rule, there will be plenty of time, after there is evidence that the disease has established itself in certain parts of a city, for those who live at a little distance from these centers of infection to get away, in a deliberate and well considered manner. The occur- rence of one or more imported cases cannot be taken as evidence that DISINFECTION. 37 an epidemic will follow, and is no reason for deserting one's home. If proper precautions are taken by the sanitary authorities, it is very probable that no evil result will follow such importation of the disease. But when these imported cases are followed by the occurrence of other cases in the vicinity where they have been sick, or when such local cases occur in the vicinity of wharves where vessels from infected ports discharge their cargoes, or in sailors' boarding-houses, etc., it must be taken as evidence that the disease has effected a lodgment, and that infected centers have been established, from which an epidemic will in all probability be developed, if the season is favorable and the city in an insanitary condition. An epidemic is not developed so rapidly as in the case of cholera, but the disease usually extends its limits in a very deliberate way, and while it is chiming its victims in one section of a city, other sections in the immediate vicinity might be quite healthy. But the territory invaded remains infected until cold weather puts an end to the epidemic. Fre- quently it happens that no new cases occur in an infected area for sev- eral weeks, or even months, for the simple reason that all those who re- mained to do battle with the pestilence have suffered an attack or are protected by a previous attack. The epidemic has ceased for want of material, but the infection remains, and will manifest itself if unpro- tected persons venture within the infected area from a mistaken idea that there is no more danger because there are no longer any cases. In this disease, then, the most important point in individual prophy- laxis is to keep away from infected localities, and from those places where the disease is epidemic— *. g., Havana, Veracruz, Rio Janeiro — during the season of its prevalence. Very many lives have been sacri- ficed by a misplaced confidence in the protection which courage is sup- posed to afford against this disease. "I am not afraid," says the mer- chant whose business calls him to an infected city, or the sea-captain who wishes to obtain a cargo of sugar in Havana during the summer months. But not being afraid does not prevent such persons from being attacked. And the mortality in Havana among sailors from northern latitudes is very great. There is a tendency in places where the disease is endemic to underrate its malignity, and to ascribe every fatal case to some fault nn the part of the unfortunate victim or his at- tendants. H<- was 'frightened to death." or "was not propcrlv nursed." or he was "imprudent," etc., etc. The mortality is no doubt largely influenced by these secondary causes, but yellow fever is a malignant disease, which under the most favorable circumstances is very fatal to unacclimated strangers within the limits of its endemic prevalence, and which in its epidemic extension in new territory often claims from 30 to 35 per cent., or even more, of those who fall sick, as its victims 38 DISINFECTION. This being the case, we repeat our advice to all those whose duty does not require them to stay on the field of battle, to make an orderly re- treat to some place of safety. The precautions relating to food and to personal habits do not differ materially from those recommended in the case of cholera. The diet should be simple, and excesses should be avoided. Less care will be necessary with reference to the use of fruits and vegetables — indeed, they are rather to be recommended, as better suited than animal food to the warm latitude in which this disease prevails. Constipation should, above all things, be avoided ; and if there is evidence that the functions of the liver or kidneys are imperfectly performed, suitable medication should be resorted to. There is no special danger from the use of water, if it is from a source which insures it from contamination with organic impurities. Spirit- uous liquors, if used at all, should be taken in great moderation. Nothing is more likely to develop an attack than alcoholic excesses, and the habitual drunkard is almost doomed to death if he falls sick with this disease. Exposure to the direct rays of the sun, excessive fatigue, and venereal excesses are all predisposing causes which it is within the province of individual prophylaxis to avoid. Exposure to the night air, and especially sleeping out of doors near the ground, is recognized by experienced physicians in yellow fever regions as an in- vitation to an attack. Great care should be taken to avoid chilling of the body, and it is well to sleep as far from the ground as possible. The Creoles of Louisiana and of the West Indies generally insist upon closing the windows of a sleeping-room at night. The mortality among natives of tropical climates, and especially among those whose habits are good, and who are accustomed to a frugal mode of life, is very much less than among the natives of north- ern latitudes, when these come, without any previous "acclimation," within the influence of the yellow fever poison. Those who are habit- uated to life in the extreme South enjoy a certain immunity from the effect of the poison, which is shown by a lower death-rate rather than any exemption from being attacked. One attack of this disease, as a rule, confers immunity from a subsequent attack. Individual prophylaxis in an infected city will include the. avoidance of those localities which give special evidence of being infected, and especial care not to visit such localities at night. The liberal use of disinfectants in cesspools and water-closets, and a perfect state of sanitary police in and around the premises, will consti- tute a most important part of the precautionary measures which every individual should take for his own protection and that of his family. A state of mental equilibrium, and an intelligent appreciation of the DISINFECTION. 39 special circumstances in which he is placed, and of the various meas- ures of prophylaxis heretofore indicated, will enable an individual to look the facts fairly in the face, and to be goverened by the light of reason and of science. Unfortunately it too often happens, among the ignorant and degraded, that a spirit of bravado, attended with a neg- lect of the simplest sanitary precautions, and a disposition to deny the presence of the dreaded foe, prevails during the earlier stages of an epidemic, and that this is followed by a disorderly stampede and a dis- graceful neglect of the sick, when the presence and malignant nature of the pestilence are recognized. Smallpox. This disease is contracted by exposure to emanations from the body of the sick, or from articles which have been in use by them, or exposed in their vicinity. There is no evidence that the small- pox poison multiplies external to the human body, and the indications for prophylaxis are therefore quite different from those already given for cholera and yellow fever. One may eat what he pleases, and wal- low in filth, when smallpox is prevailing, without contracting the dis- ease, so long as he keeps away from the sick, and is not brought in con- tact with any article infected by them. In this disease, however, as in the infectious diseases generally, previous^personal habits will greatly influence the result when exposure does occur ; and the disease is more fatal to the victims of alcoholism, to those who are poorly nourisl and, in general, to those whose vitality is reduced by i > to noxious effluvia from putrefying material, by living in overcrowded and ill-ventilated apartments, etc. As it is now the universal practice to isolate smallpox patients as soon as the disease is recognized, the danger of coming, accidentally. in contact with them is not great. There is but little danger of inl tion from passing within a few yards of a patient with smallpox in the open air. or from passing a building in which c; under tr< ment. Unprotected persons who enter the sick-room ai extremely liable to contract the disease; and the inf materia] given off from the patient's body clings mosl to clothing, etc.. and may give rise to an attack- after many monl unless destroyed by disinfection. It is evident, then, that individual prophylaxis will include ' ano which have been occupied by the side, and of art i used by them, unless there is a ceii linty that t! i disinfected, it is probable that an unprotected person, who f< obliged, for special reasons, to enter th iom, ma) in fection by the use of an air filter pi the mouth and I This should be constructed on the principal oi the "Tyndal in which all inspired air is made to pass through a 40 DISINFECTION, ding, which arrests suspended particles. It would be necessary im- mediately on coming out of the room to burn the cotton filter, to bathe the hands and face in a disinfecting solution, and to change the outer clothing. It is a general rule in regard to infectious diseases that those who are necessarily exposed to them should take the precaution of not going into the sick-room with an "empty stomach," or in a condition of ex- haustion from any cause. A cup of coffee, or a glass of wine and a cracker, may be taken if a considerable interval has elapsed since the last regular meal. It is well-known that against smallpox we have a special measure of prophylaxis, which has restricted the ravages of this disease within the limits which are left to it by carelessness in regard to the application of tli is measure, or ignorance of its value. Since the famous discovery by Jenner, vaccination has become the prophylactic par excellence. The immunity conferred by vaccination is, as a rule, complete ; but there are exceptions to this rule, and vaccinated persons occasionally suffer from a modified form of the disease. The statistics of the Lon- don smallpox hospital show that the mortality among unvaccinated persons received into that hospital with smallpox, is 35.55 per cent. ; while the mortality among vaccinated persons is less than 7 per cent. No doubt a large proportion of the cases of post-vaccinal smallpox might have been prevented by revaccination. It is now recognized that the protective influence of vaccination is not always of a permanent character, and children who have been success- fully vaccinated in infancy should be revaccinated when they reach the age of puberty, or sooner, if smallpox is prevailing in the neighbor- hood. The operation is so trifling that it is customary to vaccinate old and young, with the exception of those who have been successfully vaccinated within a year or two, whenever an outbreak of smallpox occurs. This practice is to be recommended, but when the operation has been performed in a proper manner, with virus which is known to be reliable, it is folly to insist upon a frequent repetition of the vaccina- tion, because "it didn't take." If the first vaccination has been com- pletely successful, a perfect result from revaccination is not usually ob- tained ; and the fact that no result is obtained must be taken as evidence that the person is protected. The prophylactic value of vaccination practiced after exposure to smallpox has been demonstrated, and one who is not entirely certain that he is protected by a recent successful vaccination will do well to resort to this important prophylactic meas- ure at once, if he has reason to suspect that he has been exposed to smallpox. DISINFECTION. 41 Scarlet Fever. In this disease, as in smallpox, the poison is given off from the bodies of the sick, and is not reproduced independently of them. As we have no knowledge of any means of protection corre- sponding with vaccination, prophylaxis consists solely in keeping out of the reach of infection by the sick, or by articles infected by them. The sick person may communicate the disease during the whole period of his illness and convalescence, — a period which often extends to five or six weeks, or even longer than this. Infected clothing, which has been packed away for months, may communicate the disease ; and there are numerous instances on record of its transmission to children at a distance from the sick, by healthy persons who have recently come in contact with scarlet fever patients. The lower animals, and espe- cially pet cats and dogs which may have visited the sick-room unno- ticed, or which are thoughtlessly given to convalescent children for their amusement, constitute a great source of danger. Persons who have suffered a attack of the disease, or who have but little suscepti- bility to it, may have a slight sore throat as a result of exposure to the scarlet fever poison, and may communicate the disease in its more severe form to^inprotected children. One great difficulty in arresting the progress of an epidemic by isolation of the sick and disinfection, results from the fact that these slight and often unrecognized cases are frequently allowed full liberty. Infection has been traced to milk which had been standing in the sick-room, or to the same liquid which had become infected in a dairy where scarlet fever had prevailed, and where recent convalescents were permitted to milk the cows. All of the facts point to a most rigid exclusion of susceptible children from every possible source of infection. The susceptibility of adults is very much less, and, when attacked, they usually have the disease in a mild form. But their responsibility extends far beyond the point of avoiding the sick for their own protection. Those who are associated with susceptible children have no right under any circumstances to visit the room of a scarlet fever patient without taking the most thor- ough precautions with regard to the disinfection of their person and clothing immediately upon leaving it ; and even with these precautions, such a visit cannot be justified when it is made simply out of curiosity or friendship. ( )nly those who are in attendance upon the siek should be allowed in the sick-room, and they must he regarded U infected persons, who are not to he permitted to come in contact with unpro- 1 children while they are engaged in this duty. Piphtheria. 'I his is a i!im-«<-c in which the infectious material it given off from the surfaces affected, and not from the general surface of the body. As the usual seat of the disease is the throat and the iusal 42 DISINFECTION. mucous membrane, it is the discharges from these surfaces which are especially dangerous. Although adults are much less susceptible to the disease than children, there have been numerous instances in which they have contracted diphtheria by the accidental reception of a bit of infectious material directly into the fauces. This is especially liable to occur during the operation of tracheotomy ; and several physicians have lost their lives in this way, in their efforts to save those of their patients by aspirating through the tracheotomy tube. It seems extremely prob- able that the diphtheria bacillus is capable of increase independently of the sick, in damp, foul places, such as sewers, damp cellars, and es- pecially under old houses in which the floors come near the surface of the ground, leaving a damp, ill-ventilated space. At all events, the disease often clings to such houses in spite of the application of the usual means of disinfection. There is no doubt as to the influence of bad hygienic conditions in maintaining the infection when. the disease has been introduced, and it is possble that such conditions may, in cer- tain cases, originate it. Insufficient nourishment, the malarial poison, aricl^ insanitary sur- roundings are predisposing causes to the disease. Those suffering from scarlet fever, measles, whooping-cough, and tuberculosis are also especially liable to be attacked. As in the case of scarlet fever, mild cases, which is the absence of others more pronounced it would be difficult to recognize as true diphtheria, may give rise to malignant diphtheria in more susceptible individuals, or in those whose vital re- sisting power is reduced by any of the causes mentioned. Prophylaxis will demand complete non-intercourse with the sick, avoidance, of infected localities, and care to exclude all persons and arti- cles coming from such houses from contact with yourself or children. The disease is often spread by thoughtless persons who visit the sick- room, and even kiss the infected patients, and then, without any pre- cautions in the way of disinfection, fondle healthy children in other places, and perhaps transmit by a kiss the infectious material which has adhered to their lips. The possibility of transmission by pet animals is also to be borne in mind. It has been demonstrated by the bacteriologists connected with the health departments in our large cities that the diphtheria bacillus is often found in the throats of patients convalescent from this disease for three or four weeks after the attack, and exceptionally for a much longer time than this. The time when it will be safe for a convalescent from this disease to associate with susceptible children can therefore not be determined with certainty except by a bacteriological examina- tion made by an expert. DISINFECTIi The most important method of prophylaxis for children who are una- voidably exposed to the danger of infection is the use of protective in- oculations by sub-cutaneous injection, of the diphtheria antitoxin. The value of this method has been amply and repeatedly demonstrated in children's hospitals, in asylums, and in private practice. The pro- tection afforded by such inoculations is not permanent, and probably, as a rule, does not last longer than a few weeks. Tuberculosis. Scientific researches have demonstrated that tubercu- lar consumption is an infectious disease, and that the sputa of those affected with it, injected into susceptible animals, reproduces in them the same disease. This sputum is therefore infectious material, and should be destroyed by burning, or by the use of chemical disinfectants. There would be little danger of infection from the moist masses of sputum, but in a desiccated condition this material is liable to reach the lungs of susceptible individuals, and to induce the disease. It is well known that there is a great difference in susceptibility to pulmonary consumption, and that in certain families this disease carries off one member after another, while it is unknown in other fam- ilies. Those who have this hereditary predisposition should pay spe- cial attention to individual prophylaxis. They should avoid intimate association with consumptive persons, should live under the best hygienic conditions, in dry, well-ventilated apartments, and should se- lect an occupation which will keep them in the open air, rather than one which keeps them confined to the house. Above all, they should avoid the respiration of an atmosphere loaded with organic impurities, or with irritating inorganic particles — dust of various kinds. Out of door life on the high and dry plains in the center of tin- continent, or in the mountains, will in most instances enable them to overcome the predis- position, if commenced before infection and the resulting tubercular lesions have occurred. Those who are engaged in occupations which require •' pass some hours each day in an atmosphere loaded with dust will do rator for filtering the suspended particles from the air it is demonstrated that, independently of hereditary predisposition, the respiration of such an atmosphere predisposes to tubercular d the lungs. Typhoid Fever. [n # this •' - in cholera, the infectious agent is contained in the alvine discharges of the sick. In the int< preservation as well as in that ->f the public good, every individual who has charge of cases should see that the evacuatii ma from th< thoroughly disinfected before they are thrown out. The drinking of water contaminated with such inf< is recognized as a very frequent I 'inn ; and individual • phylaxis demands an intelligi 44 DISINFECTION. a supply of drinking-water is obtained for personal or family use. If there is the least reason to suspect that this supply may be contaminated by typhoid material, or if it contains an undue amount of organic im- purities, it should be rejected entirely, or boiled shortly before it is used. Typhoid epidemics have in several instances been traced to using milk which had been contaminated by infected water, added to it di- rectly, or used at the dairy for washing the vessels containing it. The remedy in this case is to verify the purity of the source of supply of all milk used for drinking, or to boil it immediately before it is used. The water of wells located within the limits of a city or village should not, as a rule, be used for drinking purposes, for the soil is almost cer- tain to be polluted ; and it often occurs that the contents of privy vaults and cesspools pass into the same porous stratum of sand or gravel from which the well-water is obtained, or that surface drainage finds its way into shallow wells. It will be necessary, also, to regard with suspicion the water of small streams and ponds which are so situated that they may receive the drainage from collections of filth upon their margin. Next to impure water we must place impure air as a factor in the eti- ology of typhoid fever. There is good reason to believe that the germs of the disease may be carried by the foul gases which are given off from sewers, privies, etc., when these become infected, and that the disease may be induced by the respiration of such a contaminated atmosphere. At all events, the breathing of a vitiated atmosphere, and insaintary sur- roundings generally, constitute predisposing causes which should ba avoided. There can be no doubt that typhoid fever, cholera, and other infec- tious diseases are not infrequently transmitted through the agency of insects, and especially of flies. These domestic pests are likely to light upon the excreta of persons suffering from infectious diseases, if it is left standing in receptacles of any kind, or is thrown without previous disinfection upon the ground or in shallow pits. From these foul places, with their feet and legs soiled by contact with material contain- ing typhoid or cholera germs, they may fly to a neighboring kitchen and there light upon articles about to be served as food, or may fall into the milk jug, etc. This mode of infection is to be prevented by clean- liness, prompt disinfection of all infectious material and the use of suit- able screens to exclude these carriers of infection from human habita- tions. In typhoid fever, as in yellow fever and cholera, depressing mental emotions, such as grief, despondency, or fear, and physical exhaustion from excessive fatigue, insufficient food, etc., are predisposing causes which may induce an attack in the presence of the infectious agent. DISINFECTION. 45 Malarial Fevers. One of the latest and most important achieve- ments of scientific medicine is the demonstration that malarial fevers are due to infection by a microscopic parasite which is found in the blood, and that the usual way in which such fevers are contracted is by the stings of infected mosquitoes. Fortunately not all mosquitoes are infected with this parasite. A certain species, found in marshy regions in tropical or sub-tropical countries, has been proved to be chiefly con- cerned in the transmission of these fevers to man. The evident meas- ures of prophylaxis consists in avoiding the marshy regions where these noxious insects abound, and especially at night, when they are most active ; or in the use of mosquito bars and other means of protec- tion from the stings of these infected mosquitoes when in the vicinity of the places infected by them. In addition to these precautions it is best to take from five to ten grains of quinine daily as an antidote to infection, when exposed in a decided malarious region. In giving these directions it must be re- membered that they refer only to the typical malarial fevers which are contracted in marshy regions. The so-called "malaria" of cities is, as a rule, due to entirely different causes. Concluding remarks. This chapter might be greatly extended, but, having passed in review the principal measures of individual prophy- laxis against those infectious diseases which are most fatal, we shall not dwell upon precautions to be taken in other contagious diseases, such as measles and whooping-cough. These precautions will not differ from those already recommended in the cases of smallpox and scarlet fever. So, too, in regard to the infectious skin diseases. These are communicated by personal contact, and rarely occur except among those who neglect personal cleanliness, as well as other Military laws. Soap and water will generally suffice for individual prophylaxis. By avoiding filthy persons as well as filthy places, the danger of contract- ing these and certain other unmentionable infectious diseases will be reduced to a minimum. 1 COLUMBIA UNIVERSITY LIBRARIES This book is due on the date indicated below, or at the expiration of a definite period after the date of borrowing, as provided by the rules of the Library or by special arrange- ment with the Librarian in charge. DATE BORROWED DATE DUE DATE BORROWED DATE DUE C2S(l14l)M100 r6i Sternberg 3t4 1399