The New International Encyclopædia/Antiseptic

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AN'TISEP'TIC (anti + Gk. σήπειν, sepein, to make rotten, to cause decay). In the arts, any substance which arrests fermentation and decay; in medicine, any agent which arrests the development and growth of micro-organisms. A germicide is a substance or agency which destroys these micro-organisms. A disinfectant destroys the organisms, and at the same time removes the noxious products of fermentation and putrefaction. The conditions which favor putrefactive change are a moderate degree of warmth, air, and the presence of moisture and microorganisms. Measures which tend to limit the action of any of these agencies are antiseptic in character. Cold acts as an antiseptic, by bringing the article to be preserved to a temperature at which the putrefactive bacteria can no longer act. In the preservation of canned goods another principle is employed, that of exclusion of air. The cans, with their contents, are heated, and when all air has been expelled the tops are soldered on. The principle of excluding moisture is employed in the processes of drying meats, fruits, and vegetables. The action of micro-organisms is often combated directly by the introduction into preserved foodstuffs of such antiseptic substances as boric and salicylic acids and formaldehyde. They are considered injurious, however, and their use is forbidden by law in many States. Besides the antiseptics proper, a number of the more common substances, such as connnon salt, sugar, alcohol, and saltpetre, are used in food preservation. On the other hand, antiseptics are used for other purposes besides the preservation of foodstuffs. Thus the preservation of sizes used in paper-making is effected by the addition of sulphurous acid, and the preservation of the commercial gums and pastes by such antiseptics as carbolic acid and oil of wintergreen. The preservation of wood from decay by impregnation with tar, creosote, carbolic acid, and corrosive sublimate is also practiced to a considerable extent.

In scientific laboratories antiseptics like alcohol and formaldehyde are largely employed in the preservation of anatomical and biological specimens. In surgery, the application of antiseptics, first introduced by Sir Joseph Lister, is a matter of greatest moment. It is an understanding of the use of antiseptic and germicidal agencies that has brought about the remarkable advances made by this branch of the healing art since 1880. The condition that is sought for in every surgical operation to-day is asepsis, or surgical cleanliness. When a substance is aseptic it is free from all septic micro-organisms. Such a state is made possible by the use of antiseptics and germicides. Instruments are generally rendered aseptic or sterile by boiling in water, by dry heat, by steam, or by washing with the chemical antiseptics, or by exposing them to moist formaldehyde vapors; dressings, by dry heat or by steam at ordinary atmospheres or under pressure; ligatures, by prolonged immersion in alcohol or other antiseptic solutions; and the skin of the patient at the site of the operation, by application, after mechanical cleansing, of a solution of carbolic acid or of corrosive sublimate. The chemical substances most commonly employed as antiseptics in medicine are carbolic acid, the bichloride and the biniodide of mercury, formaldehyde, free chlorine, iodine, potassium permanganate, iodoform, and boric acid, and to a lesser extent the vegetable substances thymol, menthol, and eucalyptol. Further consideration of antiseptics may be found in The Rules of Aseptic and Antiseptic Surgery (New York, 1888), by Gerster; and in tlie article “Antiseptics,” in Wood's Reference Handbook of the Medical Sciences. See Bacteria; Microbe; Koch, Robert; Pasteur; Wound.