Notice of Piperin. 353 



After the analysis given by Mr. Peletier piper nigrum, contains 

 a crystallizable substance (piperin) an acrid concrete oil, a volatile 

 balsamic oil, a gummy colored matter, an extractive principle, malic 

 and tartaric acids, amidon, bassorine, lignin and incidental salts. 



By following the methods of preparation heretofore given, I have 

 never succeeded without great pains in separating that acrid resino- 

 oleaginous compound so extremely embarrassing in the course of the 

 purification. 



It is evident from inspection that the greater part of the coloring 

 matter exists in the outer pellicle of the grain ; all attempts to make 

 the separation by mechanical or other means proved fruitless and 

 recourse to pulverization was found necessary. 



The pepper should be ground, and digested in alcohol at 37° or 

 40° (Baume) at a smart distilling heat, an alembic with its water-bath 

 is at once convenient and economical ; the whole should be agitated 

 from time to time, and the fluid changed if necessary. I know of 

 no better indication of the entire extraction of the Piperin, than the 

 want of taste in the mark, or insoluble residue ; although acridity (as 

 has been represented,) is by no means a property of piperin. The 

 alcoholic solutions being united should be reduced over a water-bath. 

 The distillation ended, there will be found in the bottom of the al- 

 embic, a deposit composed of a great deal of piperin, and a black 

 acrid resino-oleaginous substance ; the separation of this latter com- 

 pound from the piperin is difficult in the extreme, so much so that I 

 have seldom or never seen the preparation free from acridity, which 

 not only destroys, but produces a contrary effect to that desired when 

 employed as a remedy. The greater part of this viscous oil may be 

 separated by cold alcohol, piperin being much less soluble in this 

 menstruum when cold, than when warm and much less than the oil. — 

 The latter portion may be entirely separated by the addition of a 

 little lime to the warm solution of piperin with the oil, and leaving it 

 to crystallize in the same vase, which when cold may be separated 

 at leisure, redissolving the crystals thus procured with addition of a 

 little animal charcoal, and filtering when hot, which upon cooling 

 will afford crystals of a canary white, regular and free from acridity. 



Mr. Pontel has advised die use of caustic potash, and the effect is 

 certainly very marked. The solution should be weak, for caustic Pot- 

 ash has a tendency to alter the nature of the substance, and instead 

 of procuring piperin, I once found a compound that resembled very 

 much that of soap, and all subsequent attempts to procure the substance 



Vol. XVIIL— No. 2, 45 



