OF THE NERVOUS MATTER. 185 



vital process with a non-azotised compound (pro-, 

 bably, a fatty body). All that has been said in the 

 preceding pages on the various possible ways by 

 which the bile might be supposed to be formed, all 

 the conclusions which we attained in regard to the 

 co-operation of azotised and non-azotised ^elements 

 of food, may be applied with equal justice and equal 

 probability to the formation and production of the 

 nervous substance. 



We must not forget that, in whatever light we 

 may view the vital operations, the production of 

 nervous matter from blood presupposes a change in 

 the composition and qualities of the constituents of 

 blood. That such a change occurs is as certain as 

 that the existence of the nervous matter cannot be 

 denied. In this sense, we must assume, that from 

 a compound of proteine may be formed a first, se- 

 cond, third, &c., product, before a certain number of 

 its elements can become constituents of the nervous 

 matter ; and it must be considered as quite certain, 

 that a product of the vital process in a plant, intro- 

 duced into the blood, will, if its composition be 

 adapted to this purpose, supply the place of the first, 

 second, or third product of the alteration of the 

 compound of proteine. Indeed it cannot be consi- 

 dered merely accidental, that the composition of the 

 most active remedies, namely, the vegetable alka- 

 loids, cannot be shewn to be related to that of any 

 constituent of the body, except only the substance 

 of the nerves and brain. All of these contain a 



