170 VEGETABLE PRODUCTS: CAFFEINE. 



bles, belonging to different natural families, and the 

 produce of different quarters of the globe, could hardly 

 have presented itself to the boldest imagination. Yet 

 recent researches have shown, in such a manner as to 

 exclude all doubt, that caffeine, the peculiar principle 

 of coffee, and theine, that of tea, are, in all respects, 

 identical. 



It is not less worthy of notice, that the American 

 Indian, living entirely on flesh, discovered for himself, 

 in tobacco smoke, a means of retarding the change of 

 matter in the tissues of his body, and thereby of mak- 

 ing hunger more endurable ; and that he cannot with- 

 stand the action of brandy, which, acting as an element 

 of respiration, puts a stop to the change of matter by 

 performing the function, which properly belongs to the 

 products of the metamorphosed tissues. Tea and cof- 

 fee were originally met with among nations whose diet 

 is chiefly vegetable. 



86. Without entering minutely into the medicinal 

 action of caffeine (theine) , it will surely appear a most 

 striking fact, even if we were to deny its influence on 

 the process of secretion, that this substance, with the 

 addition of oxygen and the elements of water, can yield 

 taurine, the nitrogenized compound peculiar to bile : 



1 at. caffeine or theine = C 8 N 2 H S O 2 



9 at. water = H 9 O 9 



9 at. oxygen = O 9 



C 8 N 2 H 14 20 = 

 == 2 at. taurine = 2 (C 4 NH 7 O 10 ) 



A similar relation exists in the case of the peculiar 

 principle of asparagus and of althaea, asparagine ; which 



