COCA 27 



ether until 100 c.c. have been collected or the drug is exhausted. Shake out 

 with 2 per cent, hydrochloric acid till exhausted. Mix the acid solutions, wash 

 once with ether, make alkaline with ammonia, and shake out with ether. Allow 

 the mixed ethereal solutions to evaporate, dry at 100 and weigh. 



Uses. Coca is a stimulant tonic and restorative, and is used during 

 convalescence. Cocaine hydrochloride, when administered hypo- 

 dermically, or applied to an exposed mucous surface, rapidly paralyses 

 the sensory nerves and thus produces local anaesthesia. It is therefore 

 of great value and much used in minor surgical operations of the 

 eye, nose, ear, &c. 



BUCHU LEAVES 

 (Folia Buchu) 



Source, &C. The official buchu leaves are obtained from Barosma 

 betulina, Bartling & Wendland (N.O. Rutacece), a small shrubby plant 

 indigenous to Cape Colony. The drug, the use of which appears 



FIG. 16. Buchu leaves (B. betulina), showing the shape, margin, 

 and recurved apex. Natural size. 



to have been learnt from the Hottentots, was introduced in 1821 

 but this was probably not derived from the species now official. The 

 branches, collected while the plant is flowering and fruiting, are dried, 

 and beaten to separate the leaves which are exported from Cape 

 Town. 



Description. The leaves of Barosma betulina, commercially known 

 as ' short ' buchu, average from 1 to 2 cm. in length, and are of a pale 

 green colour. They have a very characteristic, rhomb oid-ob ovate 

 outline, and a blunt, strongly recurved apex. They are rigid and 

 brittle when quite dry, but cartilaginous when moist. The surface 

 is glabrous or very nearly so, short hairs being often present on the 

 midrib near the base ; the upper surface presents small wart-like 

 prominences due to the elevation of the epidermis by subjacent 

 oil-glands ; the lower surface is finely wrinkled. The margin is 

 provided with numerous, minute, sharp teeth. When examined 

 with a lens by transmitted light the lamina exhibits scattered oil- 

 glands, one being situated at the base of each marginal indentation. 



