Derivation.—Made by heating salicylic and carbolic acids with phosphorous pentachloride.

Properties.—A white crystalline powder; odorless, or having a faintly aromatic odor, and almost tasteless. Permanent in air. Insoluble in water, soluble in ten parts of alcohol and readily soluble in chloroform.

Dose.—Same as for salicylic acid.

Actions.—Salicylic acid, sodium salicylate and phenyl salicylate are powerful antiseptic, anti-rheumatic, diaphoretic, cardiac depressant, antiferment and antipyretic. Salicylic acid is in addition irritant and astringent, continued in large doses is apt to derange digestion; best to be administered on a full stomach.

Uses.—For acute rheumatism, influenza, strangles and purpura where there is much sloughing; also as a surgical wash, salicylic acid one part, borax one part to thirty or forty parts of water. Salicylic acid is a more powerful antiseptic than carbolic acid. Salicylic of soda is freely antiseptic. Salicylic acid is highly recommended in intestinal flatulence, given in two drachm doses with one ounce of aromatic spirits of ammonia. In gastric-flatulence give two drachms in capsule, repeat in half hour if necessary.