Online Encyclopedia
Search over 40,000 articles from the original, classic Encyclopedia Britannica, 11th Edition.
DISINFECTANTS
Online EncyclopediaEncyclopedia Home :: DIO-DRO
del.icio.us it!
|
DISINFECTANTS , substances employed to neutralize the See also:action of pathogenic organisms, and prevent the spread of contagious or infectious disease. The efficiency of any disinfectant is due to its See also:power of destroying, or of rendering inert, specific poisons or disease germs. Therefore antiseptic substances generally are to this extent disinfectants. So also the deodorizers, which See also:act by oxidizing or otherwise changing the chemical constitution of volatile substances disseminated in the See also:air, or which prevent noxious exhalations from organic substances, are in virtue of these properties effective disinfectants in certain diseases. A knowledge of the value of disinfectants, and the use of some of the most valuable agents, can be traced to very remote times ; and much of the Levitical See also:law of cleansing, as well as the origin of numerous See also:heathen ceremonial practices, are clearly based on a See also:perception of the value of disinfection. The means of disinfection, and the substances employed, are very numerous, as are the classes and conditions of disease and contagion they are designed to meet. Nature, in the oxidizing See also:influence of freely circulating atmospheric air, in the purifying effect of See also:water, and in the powerful deodorizing properties of See also:common See also:earth, has provided the most potent ever-See also:present and acting disinfecting See also:media. Of the artificial disinfectants employed or available three classes may be recognized: -1st, volatile or vaporizable substances, which attack impurities in the air; and, chemical agents, for acting on the diseased See also:body or on the infectious discharges therefrom; and 3rd, the See also:physical agencies of See also:heat and See also:cold. In some of these cases the destruction of the contagium is effected by the formation of new chemical compounds, by oxidation, deoxidation or other reaction, and in others the conditions favourable to See also:life are removed or life is destroyed by high temperature. Among the first class, aerial or gaseous disinfectants, formic aldehyde has of See also:late years taken foremost See also:place. The vapour is a powerful disinfectant and deodorant, and for the See also:surface disinfection of rooms, fulfils all requirements when used in sufficient amount. It acts more rapidly than equal quantities of sulphurous See also:acid, and it does not affect See also:colours. It is non-poisonous, though irritating to the eyes and See also:throat. With the exception of See also:iron and See also:steel it does not attack metals. It can be obtained in paraform tabloids, and with a specially constructed spirit See also:lamp disinfection can be carried out by any one. Twenty tabloids must be employed for every x000 cubic ft. of space. Disinfection by sulphurous acid fumes is of See also:great antiquity, and is still in very See also:general use; for the purpose of destroying See also:vermin it is more powerful than formic aldehyde. Camphor and some volatile See also:oils have also been employed as air disinfectants, but their virtues See also:lie chiefly in masking, not destroying, noxious effluvia. In the 2nd class—non-gaseous disinfecting compounds—all the numerous antiseptic substances may be reckoned; but the substances principally employed in practice are oxidizing agents, as See also:potassium manganates and permanganates, " Condy's fluid," and solutions of the so-called " chlorides of See also:lime," soda and potash, with the chlorides of See also:aluminium and See also:zinc, soluble sulphates and sulphites, solutions of sulphurous acid, and the See also:tar products—carbolic, cresylic and salicylic acids. Of the physical agents heat and cold, the latter, though a powerful natural disinfectant, is not practically available by artificial means; heat is a power chiefly relied on for purifying and disinfecting clothes, bedding and textile substances generally. Different degrees of temperature are required for the destruction of the See also:virus of various diseases; but as clothing, &c., can be exposed to a heat of about 250° Fahr. without injury, See also:provision is made for submitting articles to nearly that temperature. For the thorough disinfection of a sick-See also:room the employment of all three classes of disinfectants, for purifying the air, for destroying the virus at its point of origin, and for cleansing clothing, &c., may be required. Additional information and CommentsThere are no comments yet for this article.
» Add information or comments to this article.
Please link directly to this article:
Highlight the code below, right click, and select "copy." Then paste it into your website, email, or other HTML. Site content, images, and layout Copyright © 2006 - Net Industries, worldwide. |
|
|
[back] DISEASES OF THE |
[next] DISMAL |