CIRCULARS, ORDERS, ETC.

MEMORANDUM ON DISINFECTION.

Fresh air and pure water, constant ventilation, and thorough cleansing, are natural means of preventing and destroying the causes of infection and disease. But there may be infected or foul places and things, and there are times of special necessity or sudden danger from the presence of infectious epidemic disease, which require the instant arrest or destruction of the infection and all its removable causes; this is disinfection. The clothing from persons with small-pox, scarlatina, or typhus, and even the air in the sick-rooms of such patients, is infectious; and the sick with typhoid fever or cholera discharge excremental matters which possess infective properties that should be immediately destroyed.

In this memorandum the words infection and disinfection are employed just as they are understood, as referring to the preventable causes that are concerned in repropagating specific kinds of disease; these causes are:

1. The specific infectious property or contagious substance of any one of the pestilential disorders.

2. The local impurities and moisture in the house and grounds where the outbreaks of disease have occurred or are liable to occur.

3. The foul exhalations and atmospheric impurities which injure health or help to propagate pestilential epidemics.

Experience has proved that it is possible, by certain chemical agencies (such as are described in sections 4, 5, 6, and 7 of this memorandum), wholly to destroy or prevent the operation of the specific infection or contagium of any disease; but to do this, it is necessary that precise rules should be observed in applying the disinfectants; and, as regards cholera and typhoid fever, it is especially important that the infective discharges from the sick should be disinfected as soon as voided from the body, and that whatever clothing or surfaces may have been soiled by such discharges should be disinfected as soon as practicable. The fact should also be borne in mind by all persons who have charge of infected things, that the infective property of virus of some diseases, and of cholera especially, is capable of rapid increase in filthy places and in a foul, damp atmosphere. Therefore, the cleansing and disinfection of such places should, if possible, precede the arrival or outbreak of any such pestilence. Every unclean and damp place about dwelling-houses, warehouses, factories, places of assemblage, passenger-vessels, railway-depots, and hotels, should be made and kept perfectly clean and dry. All drains, privies, and water-closets, should be kept as clean as possible, and should be thoroughly purified before cholera comes into the neigh. borhood. Such cleansing and disinfection give the surest protection against pestilential epidemics.

DISINFECTANTS AND THEIR USES.

There are three important classes of disinfectants, each having specific uses as mentioned above. Some of these purifying agents accomplish only one object, others accomplish two or more objects; some may be advantageously combined; others are incompatible with each other, and must not be used together.

CLASS I. Positive Disinfectants that quickly destroy or completely restrain every contagious and infectious virus.

This class comprises the caustic acids, the acid salts of metals (soluble oxide salts), such as sulphate of iron, sulphate of zinc, etc.; carbolic acid and cresylic acid; which not only destroy every communicable virus of disease, but also prevent those kinds of fermentation and decay that aid in propagating epidemics. Frost destroys some infections, but preserves many others, while boiling or high steam heat destroys all contagious matter. It will be observed that no one of these agents, singly, is applicable to every thing and every place that may require disinfection.

CLASS II. Antiseptics, comprising chemical agents that arrest or wholly prevent fermentation and decay.

This is a large class, and embraces carbolic acid and most of the agents of the first class; but not every antiseptic substance or gas (common salt or chlorine, for example) can absolutely prevent the fatal operation of epidemic infections.

CLASS III. Deodorants, absorbents, etc., comprises all the chemicals that deodorize or destroy putrid exhalations, or that absorb moisture and gases: charcoal, quicklime, and chlorine, are good examples of this group.

Each of these three classes, and each disinfecting agent, has its proper uses, and, as it is frequently important that these threefold means of disinfection should be applied at once to a given place or source of disease, the chemical properties of the several agents must be regarded. For example, it should be remembered that chlorine and the common alkaline compounds do not destroy the cholera infection; also, the fact that if permanganate salts, carbolic acid, and chlorine be used together, or if the first two of them be mixed, they will simply destroy each other, and leave the infection undestroyed.

Volatile Disinfectants.—Carbolic acid on any surfaces from which it will evaporate, or from which it may be vaporized by steam-heat, and the sulphurous acid fumes, are examples of disinfectants belonging both to the first and the second class. Bromine and nitrous acid have similar powers, but should be used only by medical officers.

Of the volatile deodorants in Class III., chlorine is the chief, and though useful for certain purposes in the other classes (I. and II.), if intensely concentrated, it is principally useful to destroy other gases and temporarily to arrest decay. It seems not to have power to destroy the infectious property of cholera, small-pox, and the cattle-plague, while the vapor, as well as the strong solution of carbolic acid, seems to destroy, or at least arrest, the infectious activity of all of them.

§ 1. QUICKLIME. To absorb moisture and putrid fluids, use fresh stone-lime finely broken; sprinkle it on the place to be dried, and in damp rooms place a number of plates or pans filled with the lime-powder; whitewash with pure lime, and not with kalsomine.

§ 2. CHARCOAL-POWDER.-To absorb the putrid gases, the coal must be dry and fresh, and should be combined with lime; this compound is the calx-powder, as sold in the shops.

§ 3. CHLORIDE OF LIME.-To give off chlorine, to destroy putrid effluvia, and to stop putrefaction, use it as lime is used, and if in cellars or close rooms the chlorine gas is wanted pour strong vinegar or diluted sulphuric acid upon plates of chloride of lime occasionally, and add more of the chloride.

§ 4. SULPHATE of Iron (Copperas), and CarboliC ACID.-To disinfect privies, cesspools, drains, and sewers, and especially the vessels, grounds, or places in which the discharges from the sick with cholera and diarrhoeal diseases are evacuated, dissolve eight or ten pounds of sulphate of iron in five gallons of water, and add a pint of fluid carbolic acid (if it can be had); stir or agitate it briskly, to make a complete solution. Use as follows:

To keep privies and water-closets from becoming infected or offensive, pour a pint of this solution into every water-closet pan or privy-seat, morning and evening.

To disinfect masses of filth, privies, sewers, or drains, gradually pour in the solution, hour by hour, until every part of the mass or foul surface has been thoroughly disinfected.

To disinfect the cholera-discharges, let a small quantity of this solution be constantly kept in all vessels into which the discharges are voided from the body, and let every privy and place where the discharges are cast away be thoroughly saturated with the disinfecting solution. Wherever cholera is present in a house or neighborhood, and wherever persons are arriving from infected places, the daily use of this disinfecting fluid should be maintained. Bed-pans and chamber-vessels are disinfected with this strong solution, using a gill at a time, and emptying and thoroughly cleansing as soon as used by the patient.

§ 5. PERMANGANATE OF POTASSA.-To be used in disinfecting clothing and towels from patients sick with cholera, scarlatina, typhus or typhoid fevers, during the night, or when such articles cannot be instantly boiled: throw the soiled articles immediately into a tub of water in which there has been dissolved an ounce of the permanganate salt to every three gallons of water. Boil the clothing as soon as it is removed from this colored solution, or boil them in it.

The Weimar Conference recommends that sulphate of zinc should be used precisely as we use permanganate of potassa. The zinc solutions need to be much stronger than those of the permanganate: use at least two ounces of sulphate of zinc to one gallon of water. It must be remembered that if any of these solutions are very strong they would destroy clothing. At the best, they are but temporary substitutes for disinfection by boiling.

[NOTE.-Rules for testing and Disinfection of Impure Drinking-Water.-To test for organic impurities in drinking-water, proceed as follows: For testing.—Make a solution of chemically pure permanganate of potassa, eight grains to one ounce of distilled water. Into a half-pint of the impure or suspected water, in a goblet or tumbler, put one drop of the red solution; if the red tint disappears from the glassful in half an hour, add more of the solution. For every drop that loses its color in the half-pint there will be found to be from one and a half to two grains of putrid organic matter in the gallon of water. To disin fect. To purify such water, if it must be used, drop in the permanganate solution until a slightly perceptible red tint remains in the water. This very weak solution of permanganate is not unwholesome; but for common purposes and among the poor it is better to depend upon the thorough boiling of impure water, if such water must be used. The permanganate quickly tests the presence of organic impurities. It destroys them by instantly oxidizing or burning them.]

§ 6. CARBOLIC ACID (FLUID).—This may be diluted at the rate of from forty to one hundred parts of water to one of the fluid acid. Use this solution for the same purpose as copperas is used; also to sprinkle upon any kind of garbage or decaying matter, and on foul surfaces, or in drains. When used to disinfect clothing, carbolic acid of a pure quality should be thoroughly mixed with its own quantity of strong vinegar, and next be dissolved in one hundred times its own quantity of water before the clothing is immersed in it. This mixture with vinegar insures such complete solution of the carbolic acid, that the clothing will not be burned by undissolved drops of acid when disinfected in the carbolic-water. This weak solution (one part to one hundred) will not injure common clothing, but the acid

must be of good quality and free from tarry matter. The clothing, etc., will long retain the offensive odor of the acid, except in articles that can be immediately washed out in a strong solution of soap-and-soda.

If it should be desirable to destroy certain articles and their infection together, without fire, then saturate them with the acid, or use it diluted in ten to thirty times its own quantity of water. The disinfecting and antiseptic power of good carbolic acid is so great that one part of it to one hundred parts of water is sufficient for ordinary disinfecting solutions. For ordinary purposes in disinfecting clothing, the zinc solution is preferable to that of carbolic acid.

For drains, sewers, foul heaps, stables, and privies, the cheap "dead oil" of coal-tar, or the crude carbolic acid, answers every purpose when freely applied. Coal-tar itself is available as a disinfectant or antiseptic paint for the walls of stables, privy-vaults, and drains. By mixing with saw-dust or dry lime, coal-tar or crude carbolic acid may be used on foul grounds or heaps of refuse.

The carbolic and cresylic "acids" are derived from coal-tar. Chemically considered, they are alcohols, and not acids. In market they are called by the first name-carbolic acid-and are frequently much adulterated or very impure in consequence of the naphthaline and tarry matters that dissolve in this kind of alcohol. The impurities do not dissolve in water. Coal-tar and the "dead oil" of coal-tar derive their disinfecting power from the "carbolic acid," of which the tar contains two or three per cent., and the dead oil contains five to twelve per cent. The impurities and adulterations of the crude "acids" make it desirable for sanitary officers to know the percentage of crystallizable acid in the carbolic fluids or disinfecting powder they use. Crude carbolic acid, containing fifty per cent. its weight crystallizable, costs less than a dollar per gallon, and is a good disinfectant for grounds, drains, or the air of a foul place in which cholera or any pestilential disease exists. Dilute or thoroughly agitate the acid in forty to one hundred parts water, and completely saturate grounds, the surfaces, and foul things in the infected neighborhood. Streets, court-yards, drains, and sewers may be quickly and effectually disinfected in this manner. The sprinkling of streets and gutters with a cheap solution of the acid has proved very useful in damp, hot weather. Add sulphate of iron whenever it is practicable.

7. BOILING OR HIGH-STEAM HEAT.-Whenever foul clothing and infected things can be boiled, or having a boiling heat steadily applied and kept up for an hour, this is one of the simplest and best modes of disinfection. But, until such high heat is actually applied to the infected things, some one of the disinfecting solutions must be used. A common steam tub (in a laundry, or elsewhere), with a tight cover, is a good disinfecting vat; but the temperature must be kept at boiling-point.

[NOTE. The methods of disinfection which are here described are preferred simply because they are effectual, safe, easily applied, and not expensive. They have been thoroughly tested, and are in accordance with the latest experience.

PLACES THAT MUST BE DISINFECTED, AND WHAT DISINFECTANTS TO USE. Water-closets, Privies, Close-stools, Bed-pans, etc.—Use either of the substances, 4 or 6, as described in the numbered sections of the foregoing directions.

Cellars, Vaults, Stables, or any Damp or Offensive Places.-Use 1, 2, 3, 4, or 6, in any manner suited to the objects to be attained, as described in these directions.

[NOTE. The permanganate salts must not be used with the carbolic or coal-tar disinfectants. It is also best that chlorine and the chlorides should not be used at the same time or in contact with the latter class of substances.]

Sick-rooms, Bedrooms, and Closets.-Ventilate and keep clean, and use substances described in sections 1, 2, or 3, according to directions.

To disinfect a Privy or a Quantity of Earth that is contaminated with Cholera-Excrement, or liable to be infected.-Use the mixed carbolic and copperas solution, saturated strength, as follows:

To every cubic foot of soil or filth give two or three pints of the strong solution.

To every privy and water-closet allowed at the rate of one pint of this solution, to be poured in daily, at evening, for every four persons on the premises. This practice to be kept up while cholera is in the district or country.

[This method of systematic disinfection would be useful in every household; but when cholera is present in any city or country, such thorough application of this means of protection cannot be safely neglected in any city to which persons may come from towns where cholera is epidemic. Sanitary chemists advise that the estimated quantity of these privy and sewer disinfectants required for each person daily, in the presence of cholera, should be one half an ounce sulphate of iron and one half a drachm or one half a teaspoonful of carbolic acid.]

THINGS TO BE DISINFECTED.

(a.) Beds, Bedding, and Upholstered Stuffs.-Expose to sunlight and ventilation freely and frequently. If actually infected, thoroughly moisten every part with a strong solution of 6 or 5.

(b.) Soiled Clothing, etc., from the Sick with Cholera or any Contagious Disease.-Use solution 5 or 6, precisely as directed, and as soon as the soiled articles are removed from the patient. Or immerse them at once in boiling water. In any case of infectious disease, the clothing must be boiled previous to washing or drying. Infected clothing must be thrown into the water at boiling heat. The boiling should be kept up for an hour.

(c.) Carpets, Sofas, Lounges, Mattresses, Floors, etc., infected by Cholera-Excrement, or by SmallIl-pox, Scarlatina, and other Contagions.

First.-Thoroughly moisten every infected thing with one of the carbolic or permanganate solutions (No. 5 or No. 6).

Second: Rules for Fumigation.—To give still greater completeness to the disinfection required for an infected apartment and thick woolen stuffs, carpets, etc., to which boiling heat cannot be applied, fumigate with sulphurous acid, thus: Arrange to vacate the room for twelve hours; close every window and aperture, and, upon an iron pipkin, or kettle with legs, burn a few ounces of sulphur; the quantity required for effectual work will depend upon cubical space of the apartment, and there should be enough to burn rapidly until want of oxygen in the air shall extinguish the flame. Instantly after kindling it every person must withdraw from the place, and the room must remain closed for the succeeding eight hours. If any other kind of fumigation is resorted to (as that by chlorine, bromide, or nitrous acids), a sanitary officer or a chemist should superintend the process. Fumigation should be resorted to in dwelling-houses only by official orders or permission, or under the personal superintendence of a competent medical man, as the disinfecting gases are very poisonous.

(d.) Finally, let fresh air and sunlight purify every place they can reach. Open and dry all cellars and vaults, and keep the grounds and surfaces about dwellings as dry and clean as possible. Use fresh lime or the "calx-powder" freely upon wet or offensive surfaces. Flush the water-closets and drains daily before throwing in the disinfectants as directed Domestic and personal cleanliness should be everywhere observed. There are no substitules

for pure air and water.