FOLIA UV^ URSI. 401 



decoction of the drug, on addition of sulphate of copper, lobeliate of 

 coppei' is precipitated. By decomposing the latter with sulphuretted 

 hydrogen, concentrating the solution and shaking it with warm ether, 

 Lewis obtained a yellow solution afibrding on evaporation a crystalline 

 mass of lobelic acid. 



Uses — Lobelia is a powerful nauseating emetic; in large doses an 

 acro-narcotic poison. It is prescribed in spasmodic asthma. 



ERICACEAE. 



FOLIA UViE URSI. 



Bearhen^ Leaves ; F. Feuilles de Busserole ; G. Bdrentraubenbldtter. 



Botanical Origin — Arctostaphylos Uva-ursi Sprengel {A.o^cincdis 

 Wimmer et Grabowsky, Arbutus Uva-ursi L.), a small, procumbent, 

 evergreen shrub, distributed over the greater part of the northern 

 hemisphere. It occurs in North America, Iceland, Northern Europe, 

 and Russian Asia, and on the chief mountain chains of Central and 

 Southern Europe. In Britain it is confined to Scotland, the north of 

 England, and Ireland. 



History — The bearberry was used in the 13th centuiy by the 

 "Welsh "Physicians of Myddfai," described by Clusius in 1601, and 

 recommended for medicinal use in 1763 by Gerhard of Berlin and 

 others.^ It had a place in the London Pharmacopoeia for the first time 

 in 1788. 



Description — The leaves are dark green, f to 1 inch in length by 

 f to f of an inch in breadth, obovate, rounded at the end, gradually 

 narrowed into a short petiole. They are entii-e, with the margin a little 

 reflexed, and in the young state slightly pubescent, otherwise the whole 

 leaf is smooth, glabrous, and coriaceous; the upper surface shining, 

 deeply impressed with a network of veins ; the under minutely reticu- 

 lated with dark veins.- The leaves have a very astringent taste, and 

 when powdered a tea-like smell. 



Chemical Composition — Kawalier (1852) has shown that a decoc- 

 tion of bearberry treated with basic acetate of lead yields a gallate of 

 that metal, thus proving that gallic acid exists ready-formed in the 

 leaves. When the filtrate, freed from lead by sulphuretted hydrogen, is 

 properl}'^ concentrated, it deposits acicular crystals of Arbutin, a bitter 

 neutral substance, easily soluble in hot water, less so in cold, dissolving 

 in alcohol, but sparingly in ether. 



By contact for some days with emuslin, or by boiling with dilute 

 sulphuric acid, arbutin is resolved, according to Hlasiwetz and Haber- 

 mann (1875), as follows : — 



CPH^0"+2 0ff rrC6Hi-20« OH^(0H)2 . C«H*(0H.0CH3) 



Arbutin. Glucose. Hydrokinone. Methyl-hydrokinone. 



Yet possibly arbutin is a mixture of the glucoside compounds of 

 both hydrokinone and methyl-hydrokinone. 



* Murray, Apparatus Medkaminum, ii. * Microscopic structure of the leaves, see 



(1794) 64-81. Pocklington, Phann. Journ. v. (1874) 301. 



2C 



