178 MODE OF ACTION OF NITROGENISED 



chemical character, be capable of taking the same 

 share as the nitrogenised products of the animal 

 body do in the formation of the bile ; that is, it 

 must play the same part as a product of the vital 

 process. On the other hand, a non-azotised medi- 

 cinal agent, in so far as its action affects the secre- 

 tions, must be capable of performing in the animal 

 body the same part as that which we have ascribed 

 in the formation of the bile, to the non-azotised 

 elements of food. 



Thus, if we suppose that the elements of hippuric 

 or uric acids are derived from the substance of the 

 organs in which vitality resides ; that, as products 

 of the transformation of these organs, they lose the 

 vital character, without losing the capacity of under- 

 going changes under the influence of the inspired 

 oxygen, or of the apparatus of secretion; we can 

 hardly doubt that similar nitrogenised compounds, 

 products of the vital process in plants, when intro- 

 duced into the animal body, may be employed by 

 the organism exactly in the same way as the nitro- 

 genised products of the metamorphosis of the ani- 

 mal tissues themselves. If hippuric and uric acids, 

 or any of their elements, can take a share, for ex- 

 ample, in the formation and supply of bile, we must 

 allow the same power to other analogous nitro- 

 genised compounds. 



We shall never, certainly, be able to discover 

 how men were led to the use of the hot infusion of 

 the leaves of a certain shrub (tea), or of a decoction 



