Dose, 1/40 - 1/6 gr.; 2 - 10 mgms.

An alkaloid obtained from morphine by the substitution of two H. groups by acetyl groups, diacetyl-morphine-hydrochloride. White crystals, soluble in water, 1 in 2, in alcohol 1 in 9. (Trade-name, Heroin.)

Acidum Cresylicum. Cresylic Acid. (Cresol.) Dose, 1 - 3 min.; 0.05 - 0.2 c.c.

A mixture of ortho-, meta-, and para-cresols. Crude cresol is a yellowish liquid, darkening on keeping, with a characteristic odour resembling phenol. Soluble 1 in 80 of water, readily in alcohol, ether, chloroform, glycerin, olive oil. Pure ortho-cresol is a colourless, deliquescent, crystalline solid.

Acidum Acetyl-Salicylicum. Acetyl-Salicylic Acid. Dose, 8 - 15 grs.; 1/2 - 1 gm. (Salacetic Acid). C6H4(COOH)OCOCH3. A white crystalline powder, or colourless crystals. Soluble 1 in 400 of water. Soluble 1 in 5 of alcohol. Both aqueous and alcoholic solutions do not keep on standing. (Trade names, Acetysal, Aletodin, Aspirin, Saletin, etc.)