Antiseptics are medicinal agents capable of arresting fermentative processes, preventing the development of bacteria, thereby preventing or arresting the decomposition of organic substances, and the process of putrefaction. When these agents are brought in contact with disease germs they destroy their vitality. Included in this class are carbolic acid, creasote, salicylic acid, eucalyptus oil, iodoform, benzoic acid, boracic acid, pepsin, bromine, iodol, hydronapthol, peroxide of hydrogen, pyrozone, aristol, bichloride of mercury, essential oils, etc.

Forms of Antiseptics for Use: Dr. Black on this subject says: "In regard to the use of antiseptics in different cases and for different purposes, I should divide them into three forms, each of which has especial advantages.

"These forms are: the solution in water, the oil, and the powder.

"The solution in water is especially useful for cleaning infected surfaces of wounds, washing abscesses, and, indeed, in any case where there is something that can be removed by washing. In the performance of this act the antiseptic is diffused to all parts of the wound or abscess mechanically to the best advantage. It is more likely to reach every part in this form than in any other; and this is an advantage that can hardly be overestimated; for it is very difficult to reach all parts of an abscess by any mode of procedure now known to us on account of the very tardy diffusion of liquids. And in case the liquid containing the antiseptic in solution does diffuse, its very diffusion and mixture with the surrounding fluids soon dilutes it below its range of antiseptic value. It is therefore necessary that the washing be continuous to obtain the continuous effect of the drug. This is generally impracticable, and for this reason the watery form of antiseptics is very much limited in usefulness. The continuous drip, or the application as often as every fifteen or twenty minutes, gives effective results in some favored localities; but it is very difficult to carry out and occasions much trouble. The continuous bath is still more limited in its range of application. Neither of these can be used in dental practice. With us the watery form of antiseptics should be limited to the cleaning of infected parts. They cannot be trusted to prevent septic action for any length of time, for the reason that they so soon become diluted below their range of antiseptic value by mixing with the secretions, or the juices of the flesh. Since studying the powers of antiseptics and disinfectants more closely, my feeling is that it will not do for us to expect to do too much disinfectant work in connection with the soft tissues except in cases in which some tissue destruction can be borne; and that antiseptics only retard the growth of microbes during their presence in effective proportion; hence the necessity for continuous and oft repeated application. In using these for the purpose of cleaning, much aid may be had by making use of the solution in peroxide of hydrogen instead of water, so as to obtain the mechanical effect of the ebullition of the oxygen evolved in mixing the antiseptic with the secretions. There is possibly some antiseptic virtue in oxygen itself as well; but I am apt to think that its principal use is the mechanical one. And that is a very important use. Thorough cleaning is excellent antiseptic work, and the peroxide of hydrogen will do this in many positions where nothing else will, and at the same time carry the antiseptic proper to the more remote parts of the wound or abscess."

Sir Joseph Lister is the originator of the antiseptic treatment in surgery. He first employed carbolic acid as an antiseptic for surgical dressings, but abandoned it on account of its slow action as a germicide and its volatility. He then employed bichloride of mercury, which was stable and acted promptly, but caused irritation, and was precipitated by the albumen contained in the serum of the blood. He then employed the sero-sublimate gauze, consisting of gauze saturated with a solution of bichloride of mercury, in the serum of the blood; but this being harsh and non-absorbent he substituted for it a combination of chloride of ammonia and chloride of mercury, known as sal-alembroth, which was not only less irritating, but was soluble in blood serum. Later he presented the double cyanide of zinc and mercury as the best antiseptic, on account of its being non-volatile, unirritating, insoluble in water, and only soluble in 3,000 parts of blood serum, with an inhibitory power so high that a solution of 1:1200 is sufficient to keep animal fluids permanently free from putrefaction. The Listerian method consists in applying over the line of the wound six or eight layers of the gauze, out of which the bichloride has been washed by wringing it out once or twice in a solution of 1 to 20 carbolic acid. All zymotic diseases are at the present time generally attributed to bacteria or to their ptomaines, and for a number of years the theory that all contagious and epidemic diseases are caused by micro-organisms has been received by the medical profession. Many diseases are now regarded as contagious which were not so considered before the discovery of bacteria. Bacteria are found in great numbers and different varieties in the air, earth, water, and in every part of the body of man and animals, and multiply very rapidly by division and by spores. Some varieties are subject to change, others appear to be permanent. New varieties are supposed to be produced by the same laws by which the different kinds of vegetables, plants and animals are generated. The discoveries in bacteriology have brought about a revolution in the treatment of many diseases, namely, tuberculosis - as the Koch treatment - typhoid and other fevers, carbuncle, erysipelas, diptheria, pneumonia, influenza, malaria, tetanus, etc., etc. (See Use of Antiseptics in Dental Practiced)