EUCALYPTUS 41 



are crushed. The taste of the dry leaves is aromatic, pungent, and 

 slightly bitter. 



The student should observe 



(a) The ensiform outline, 



(b) The coriaceous texture, 



(c) The similarity between the two surfaces. 



Constituents. Eucalyptus leaves contain, when fresh from 3 to 

 5 per cent, of volatile oil containing 50 or more per cent, of cineol 

 (eucalyptol, cajeputol). They also contain tannin, a bitter principle 

 which has not yet been investigated, and several resins, one of which 

 is crystalline. 



Uses. Eucalyptus leaves are used as an astringent ; they have 

 also been employed in the form of a cigarette for asthma. The 

 volatile oil has antiseptic properties. 



Note. The official eucalyptus oil may be obtained from E. Globulus, 

 E. dumosa, A. Cunningham, and other species. Much is imported from 

 Australia. Citron -seen ted eucalyptus oil is obtained from E. citriodora, Hooker 

 (Queensland). 



BEARBERRY LEAVES 

 (Folia Uvse Ursi) 



Source &C. The common bearberry, Arctostaphylos Uva-ursi, 

 Sprengel (N.O. Ericaceae), is a small procumbent ever-green shrub 

 distributed throughout central and northern Europe and North 

 America. It is indigenous to Great Britain, but is confined to Scotland, 

 the north of England, and Ireland. The plant sends out branching 

 stems that take root, and so forms small clumps. The drug was 

 probably in use long ago in this country but was first introduced 

 into the London Pharmacopoeia in 1788. 



Description. Bearberry leaves are small, shining, coriaceous 

 leaves, seldom measuring as much as 25 mm. in length by 12 mm. in 

 breadth. The upper surface is dark green or yellowish green, the 

 under surface paler. They are spathulate or obovate, the lamina 

 being rounded at the apex, but tapering gradually towards the base 

 to a short petiole. They are more or less rigid, and, when quite 

 dry, brittle. The margin is entire, slightly revolute, and in young 

 leaves ciliate with short hairs, but these are scarcely discernible in 

 the drug. The veins and veinlets, are depressed on the upper surface, 

 which thus assumes a chequered or wrinkled appearance ; the greyish 

 green under surface is reticulately marked with somewhat darker 

 veins, which are often slightly raised, but it does not show raised 



