This section is from the book "Materia Medica And Therapeutics: An Introduction to the National Treatment of Disease", by John Mitchell Bruce. Also available from Amazon: The pharmacology and therapeutics of the materia medica.
Uvae Ursi Folia-Bearberry Leaves.-The dried leaves of Arctostaphylos Uva Ursi. From indigenous plants.
Characters.-Obovate, entire, coriaceous shining leaves, about three-fourths of an inch in length, reticulated beneath; with a strong astringent taste, and a feeble hay-like odour when powdered; the infusion giving a bluish-black precipitate with perchloride of iron.
Composition. -Uva ursi contains an inert crystalline gluco-side, arbutin, C12Hl607, yielding in the urine benzoic acid; an amorphous bitter glucoside, ericolin, C34H56O21; tannic and gallic acids; and a neutral body, ursone.
Impurities.-Leaves of red whortleberry; detected by being dotted and not reticulated on the under surface, with crenated margins. Also box leaves, which are not astringent.
Preparation. Infusum Uvae Ursi.-1 in 20. Dose, 1 to 2 fl.oz.
Uva ursi possesses much the same action as Pareira and Buchu, but is more astringent in virtue of the tannic and gallic acids which it contains. The arbutin appears in the urine partly as benzoic acid. Uva ursi is used as a remote astringent and stimulant in diseases of the urino-genital tract, such as chronic catarrh of the pelvis of the kidney, bladder, and urethra.