188 THEORY OF THE ACTION OF 



to quit, if she would really be of service to physio- 

 logy and pathology. The combinations of the che- 

 mist relate to the change of matter, forwards and 

 backwards, to the conversion of food into the various 

 tissues and secretions, and to their metamorphosis 

 into lifeless compounds ; his investigations ought to 

 tell us what has taken place and what can take 

 place in the body. It is singular that we find me- 

 dicinal agencies all dependant on certain matters, 

 which differ in composition ; and if, by the intro- 

 duction of a substance, certain abnormal conditions 

 are rendered normal, it will be impossible to reject 

 the opinion, that this phenomenon depends on a 

 change in the composition of the constituents of the 

 diseased organism, a change in which the elements 

 of the remedy take a share ; a share similar to that 

 which the vegetable elements of food have taken in 

 the formation of fat, of membranes, of the saliva, of 

 the seminal fluid, &c. Their carbon, hydrogen, or 

 nitrogen, or whatever else belongs to their compo- 

 sition, are derived from the vegetable organism ; 

 and, after all, the action and effects of quinine, mor- 

 phia, and the vegetable poisons in general, are no 

 hypotheses. 



95. Thus, as we may say, in a certain sense, of 

 caffeine or theine and asparagine, &c., as well as 

 of the non-azotised elements of food, that they are 

 food for the liver, since they contain the elements, 

 by the presence of which that organ is enabled to 

 perform its functions, so we may consider these ni- 



