COCA 



255 



Truxillo Coca. Pale green, thin, brittle and usually much broken, smooth 

 but not shining, shortly and stoutly petioled; blade 1.6 to 5 cm. long and one- 

 third to one-half as broad, obovate to oblanceolate, narrowed from near the 

 middle into the petiole, usually with a slight projecting point at the summit^ 

 the margin entire; underneath two irregular lines of collenchyma tissue, usually 

 incomplete or obscure, and frequently wanting, run beside the midrib; odor 

 more tea-like than that of Huanuco Coca; taste and numbing effect similar. 



Powder. Greenish. Characteristic elements: Calcium oxalate of parenchyma 

 in prisms, 5 to 10 ju in diam.; sclerenchyma, bast, and crystal fibers; small papillae 

 on under epidermal cells. 



CONSTITUENTS. A volatile liquid alkaloid, hygrine, and cocaine (CirHjiNOO, 

 which has been found to be a compound body represented in a methyl ben- 

 zoyl compound of another organic base, ecgonine (CgH^NOs). There are 

 also present in the leaves benzoyl ecgonine, a methyl compound of which con- 

 stitutes the alkaloid cocaine. This complex body cocaine is readily decomposed 



FIG. 138. Coca Leaves A, Upper side. B. Under side. (Photograph. Natural Size.) 



into its component parts, methyl alcohol, benzoic acid, and ecgonine, by heating 

 with HC1. Hydrochloric acid is, therefore, unsuitable for the extraction of 

 cocaine in the process of its manufacture. The percentage of cocaine varies 

 greatly, nence it is important to assay the leaves and its preparations. Assay 

 shows an average of 0.5 per cent, of ether-soluble alkaloids of the leaf. 



