186 RELATION OF VEGETABLE ALKALIES 



certain quantity of nitrogen, and, in regard to their 

 composition, they are intermediate between the 

 compounds of proteine and the fats. 



93. In contradistinction to their chemical charac- 

 ter, we find that the substance of the brain exhibits 

 the characters of an acid. It contains far more 

 oxygen than tlie organic bases or alkaloids. We 

 observe, that quinine and cinchonine, morphia and 

 codeine, strychnia and brucia, which are, respectively, 

 so nearly alike in composition, if they do not pro- 

 duce absolutely the some effect, yet resemble each 

 other in their action more than those which differ 

 more widely in composition. We find that their 

 energy of action diminishes, as the amount of oxy- 

 gen they contain increases (as in the case of narco- 

 tine), and that, strictly speaking, no one of them 

 can be entirely replaced by another. There cannot 

 be a more decisive proof of the nature of their ac- 

 tion than this last fact ; it must stand in the closest 

 relation to their composition. If these compounds, 

 in point of fact, are capable of taking a share in 

 the 'formation or in the alteration of the qualities 

 of brain and nervous matter, their action on the 

 healthy as well as the diseased organism admits of 

 a surprisingly simple explanation. If we are not 

 tempted to deny, that the chief constituent of soup 

 may be applied to a purpose corresponding to its 

 composition in the human body, or that the organic 

 constituent of bones may be so emj^loyed in the 

 body of the dog, although that substance (gelatine 



