174 COMPOSITION AND ORIGIN 



also on a certain quality of the substance of the brain, 

 spinal marrow, and nerves ; insomuch, that all the mani- 

 festations of the life or vital energy of these modifica- 

 tions of nervous matter, which are recognised as the 

 phenomena of motion, sensation, or feeling, assume an- 

 other form as soon as their composition is altered. The 

 animal organism has produced the brain and nerves out 

 of compounds furnished to it by vegetables ; it is the 

 constituents of the food of the animal, which, in conse- 

 quence of a series of changes, have assumed the prop- 

 erties and the structure which we find in the brain and 

 nerves. 



89. If it must be admitted as an undeniable truth, 

 that the substance of the brain and nerves is produced 

 from the elements of vegetable albumen, fibrine, and 

 caseine, either alone, or with the aid of the elements of 

 non-azotized food, or of the fat formed from the latter, 

 there is nothing absurd in the opinion, that other con- 

 stituents of vegetables, intermediate in composition be- 

 tween the fats and the compounds of proteine, may be 

 applied in the organism to the same purpose. 



90. According to the researches of Fremy, the chief 

 constituent, of the fat found in the brain is a compound 

 of soda with a peculiar acid, the cerebric acid, which 

 contains, in 100 parts, 



Carbon, . . . $%- 66-7 



Hydrogen, .. . . ''*'. 1() ' 6 



Nitrogen, . .' ^\ . 2-3 



Phosphorus, . . . . 0-9 



Oxygen, . . ,, f ^. . 19-5 



It is easy to see that the composition of cerebric acid 



