Definition. - A volatile oil obtained by maceration and distillation from the bark of the sweet birch, Betula lenta L.

Dose. - 15 minims (1 Cc), U. S. P.

Allied Compounds

Aspirin, acetyl salicylic acid, is decomposed in salicylic acid in the intestines, and hence has no marked advantage. Its taste is less offensive and hence it can be taken by patients who have irritable stomachs. 30-45 grains (2-3 Gm.).

Mesotan is a methyloxymethyl ester of salicylic acid. It is a liquid and resembles oil of wintergreen without its agreeable (?) odor. It is readily absorbed by the skin and is thought to influence the joints more promptly than the oil of wintergreen. It is of value in lumbago also, and may be combined with olive oil and massage in some of the more protracted arthritides. It has the same indications as the other salicylates, and taken internally is ultimately broken down into sodium salicylate.