518 POWDERED VEGETABLE DRUGS 



198. (Fig. 190.) THEOBROMA. Cacao. 



Paste, fine powder. 



Cocoa, E. Kakao, G. Cacoa, Feves du Mexique, Fr. 



The seeds of Theobroma cacao L., Sterculiacese. 



Deep reddish brown; chocolate brown. 



Mildly fragrantly aromatic. 



Bitter and astringent. 



Epidermal cells of seed small, polygonal, filled with deep brown 

 coloring matter. A few multicellular deep brown trichomes. Thin- 

 walled, collapsed parenchyma; selerenchyma layer. Endosperm cells 

 thin-walled, polygonal, filled with fat and some compound starch. 

 Hull remnants showing mechanical tissue of rather thick- walled, mostly 

 elongated, porous cells. Spiral duct remnants and some crystals. 



Cocoa and chocolate are variously adulterated with ground cocoa 

 shells, starch, rice, flour, cocoa butter, lard, and other substances. 

 Shells should not exceed 3.5 per cent. Shell adulteration may be 

 determined quantitatively by the method described in Part I. 



