On Cafeme. 323 



racters of the principle, and the method of preparing it. M . 

 Garot, however, has recommended a new process for procuring 

 it, which consists in exhausting the unburnt bean, by successive 

 infusions in boiling water ; throwing down a quantity of colour- 

 ing and fatty matter from the filtered infusions, by the acetate of 

 lead ; removing the excess of lead by a stream of sulphuretted 

 hydrogen ; saturating the free acid with ammonia ; and evaporat- 

 ing the remaining liquid with a gentle heat. Long silky crys- 

 tals are thus procured, which are the cafeme in a state of impu- 

 rity, and which may be got quite pure, by a second solution and 

 crystallisation. The researches of Pelletier were directed chiefly 

 to determine whether this principle is of an alkaline nature ; be- 

 cause certain circumstances had led him to imagine, that its dis- 

 coverer was mistaken in denying to it alkaline properties. The 

 result has been, that M. Robiquef s views are substantiated ; for 

 cafeme dissolves in acids without neutralising them, crystallises 

 in a state of purity from the diluted acids, and does not affect the 

 vegetable colours. It must therefore be arranged with the class 

 of principles, of which Jiarcotme, one of the principles of opium, 

 is the most remarkable and best known. 



The most interesting fact contained in the researches of Pelle- 

 tiei* regards the composition of cafeme. It contains the largest 

 quantity of azote of all the vegetable principles hitherto ana- 

 lysed ; and contains more than even any animal principle, urea 

 and uric acid excepted. It is composed of 46.51 carbon, 27.14 

 oxigen, 4.81 hydrogen, and 21.54 azote. Although so highly 

 azotised, it is, like urea and uric acid, by no means prone to pu- 

 trefaction, — a fact which accords with a general law pointed out 

 by Robiquet, that azotised principles of the organic kingdoms, 

 although, in general, very liable to decay, are not so, if they are 

 crystallised. — Journal de Pharmacie, Avril 1826. 



7. Analysis of the Root of the Bryonia alba. 

 The root of the bryony possesses properties in relation to the 

 animal economy, which renders it an object of some interest to 

 the chemist. It is one of the most powerful of the vegetable 

 acrids, — of that order of poisons whose prominent character is the 

 power of producing diffuse inflammation, to whatever tissue they 

 are applied. Accordingly, it has been examined by several che- 



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