ARBUTIN

C 12 H 16 O 7 . A substance obtained by Kawalier from the leaves of the red bearberry Arctostophylos uva ursi , and by Zwenger and Himmelmann from the leaves of a species of winter-green, Pyrola Umbellata . It is prepared by precipitating the aqueous decoction of the leaves of either of these plants, with basic acetate of lead, filtering, removing the exce of lead with sulphuretted hydrogen, and either treating the filtrate with animal charcoal and leaving it to crystallise or evaporating and digesting the residue with a mixture of eight parts of ether and one part of alcohol, which di olves out the arbutin, and deposits it on evaporation in the crystalline state.