BUCHU. 229 



from their more usual shape they have been distinguished as 

 obovate Buchu. In the British Pharmacopoeia they are briefly 

 described as follows : — About three-quarters of an inch long, 

 coriaceous, obovate, with a recurved truncated apex and sharp 

 cartilaginous spreading teeth. 



B. serratifolia (Bot. Mag., t. 456; Bentley & Trimen, Med. 

 Plant., t. 47), grows in the districts of George and Swellendam, to 

 the east of Cape Town, in damp situations on the mountain sides. 

 It forms a neater bush than the other species. It is readily 

 distinguished by the shape of its leaves. 



The leaves of Empleitrum serridcdum, Ait., a small shrubby 

 plant of the same ISTatural Order (Eutaceae), and inhabiting the 

 same district as Barosma, are not unfrequently substituted for the 

 true leaf, and sold as Buchu, but it is much longer and narrower, 

 with the sides parallel, the denticulations coarser, and the apex 

 much more acute; also they are of different odour, and terminate in 

 an acute point without an oil-gland, whereas the leaves of Barosma 

 serratifolia are blunt or somewhat truncate, and always provided 

 with an oil-gland at the apex. 



The leaves of B. serratifolia are not so liable to variation in size 

 and shape as are those of B. cremdata. From their length they 

 are known in commerce as long BucJm. In the British 

 Pharmacopseia their characters are given as follows : — " From an 

 inch to an inch-and-a-half long, linear-lanceolate, tapering at each 

 end, sharply and finely serrated, 3-nerved." From the shape of 

 the leaves this kind of Buchu is sometimes designated as linear- 

 lanceolate BucMi. 



The yield of essential oil from Barosma hctulina has been found 

 by Schimmel & Co. to be 2 per cent.,* " w^hich, even at the normal 

 temperature, was quite filled with crystals of Diosphenol." 



The yield from B. serratifolia was 1 per cent., sp. gr., 0"944, 

 which, even during the severe cold of the winter, separated only a 

 very little crystalline Diosphenol, and by treatment with lye only 

 small quantities of this body could be further extracted from it. 



The researches of Professor Fllickiger on the essential oil of 

 Buchu leavesf resulted, briefly, as follows : — On submitting 35 



* Bericht., April, 1891. 



+ Paper read at British Pharmaceutical Conference, Aug., 1880. 



