MICRO-ANALYSIS. 845 



from the figure it seems that the obhquity of such individuals is 

 nearly constant. These individuals may all be lying upon a 

 definite brachydome instead of upon the base. 



PiPERINE (Ci.HigNOg). 



Occurrence : See pp. 573, 574. 



Piperine is rather easily prepared from white pepper as 

 follows : The ground pepper is mixed with an equal weight of 

 lime and a small quantity of water is added. The mixture is 

 heated to boiling for about 15 minutes, and is then evaporated 

 and carefully dried upon a water-bath. The residue is powdered 

 and extracted with ether. The ethereal solution contains the 

 piperine, which separates in the form of crystals. It is purified 

 by re-crystallization from hot alcoholic solutions.* 



Piperine is a weak base, dissolving in dilute acids without 

 forming salts and on this account may be separated from acid 

 solutions with petroleum ether. It forms crystalline double salts 

 with platinic chloride, mercuric chloride and iodine-potassium- 

 iodide. At 25 C. one part of piperine is soluble in 15 parts 

 of alcohol; 36 parts of ether; and 1.7 parts of chloroform. It 

 is nearly insoluble in water. The individual crystals formed on a 

 microscopic slide from hot alcoholic solutions of piperine vary 

 in length from o.i mm. to 1.5 mm. (Fig. 340). Isolated 

 aggregates are also formed. As in cubebin we find numerous 

 oily-looking drops of the amorphous substance, but with piperine 

 they often have the outline of crystals, as if the latter were first 

 formed, and later transformed by fusion or otherwise into the 

 amorphous material. On the other hand the crystals grow, on 

 long standing, at the expense of the drops. In sections of the 

 crude drug it is not at all uncommon to find in the oil secretion 

 cells the characteristic crystals of piperine. Molisch f has given 

 a number of methods for the micro-detection of piperine in 

 sections. 



* Briihl, Die Pflanzen-Alkaloide. 



t Hans Molisch, Grundriss einer Histochemie der Pflanzlichen 

 Genussmittel. (1891), pp. 27-29. 



