(from αντι and σεπτος putrid, of σεπτος to putrefy), an appellation given to such substances as resist putrefaction.

We have some curious experiments in relation to antiseptic substances by Dr Pringle, who has ascertained their several virtues. Thus in order to settle the antiseptic virtue of salts, he compared it with that of common sea-salt; which being one of the weakest, he supposes equal to unity, and expresses the proportional strength of the rest by higher numbers, as in the following table.

Salts, Salts, their antiseptic virtue.

| Salts | Antiseptic Value | |---------------|------------------| | Sea-salt | 1 | | Sal ammoniac | 1 + | | Tartar vitriolated | 2 | | Spiritus Mindereri | 2 | | Tartaris solubilis | 2 | | Sal diureticum | 2 + | | Crude sal ammoniac | 3 |

In this table the proportions are marked in integral numbers; only to some there is added the sign +, to show, that those salts are possessed of a stronger antiseptic virtue than the number in the table expresses, by some fractions; unless in the three last, where the same sign imports, that the salt may be stronger by some units.

Some resinous and other substances even exceed the antiseptic virtues of the neutral salts; thus myrrh, aloes, terra japonica, and aloes, are at least twelve times more antiseptic than sea-salt. Two grains of camphor is equivalent to sixty grains of that salt. An infusion of a few grains of Virginian snake-root, in powder, exceeds twelve times its weight of sea-salt. Camomile flowers have nearly the same extraordinary quality. The Jesuits bark has it also. Besides these, pepper, ginger, saffron, contrayerva-root, are twelve times more antiseptic than sea-salt. Dried sage, rhubarb, the root of the wild valerian, mint, angelica, ground ivy, fennel, green tea, red roses, wormwood, mustard, and horseradish, were likewise found more antiseptic than the standard.

To the clats of antiseptic medicines may likewise be added fermented liquors, acids, spirits, and even those plants called anti-acids, and erroneously supposed healers of putrefaction, particularly horseradish. Now vegetables, possessing this virtue, are the more valuable, in that being usually free of acrimony, they may be taken in much greater quantities than either spirits, acids, resins, or even the neutral salts.

Antiseptics are prescribed in all putrid, malignant, and pestilential cases. It is to be remarked, however, that different kinds of them are to be given in different diseases, and even in different stages of the same disease. Thus, the bark is specific in a gangrene, when the vessels are relaxed, and the blood resolved or disposed to putrefaction; but will fail, if the vessels are too full, or the blood be too thick. With the same caution is the bark to be used in wounds, viz. chiefly in cases of absorbed matter, when it infects the humours, and brings on a hectic fever.

By the great antiseptic virtue of alum, the bark, and other astringents, it should seem, that attrition had no small share in the cure of putrid disorders; and, indeed, the very nature of putrefaction consists in a separation or diffusion of the parts. But as astringents are improper to be administered in many cases, contrayerva-root, snake-root, camphor, &c. may supply their place; which, though highly antiseptic, have very little, or any, of an astringent quality.