THE CHEMICAL CONSTITUTION OF THE 

 ANIMAL BODY. 



J One visiting the ruins of a vast and elaborate building, 

 which had been entirely pulled to pieces, would get an amount 

 of information relative to the original structure and uses of 

 the various parts of the edifice largely in proportion to his fa- 

 miliarity with architecture and the various trades which make 

 that art a practical success. The study of the chemistry of 

 the animal body is illustrated by such a case. Any attempt 

 to determine the exact chemical composition of living matter 

 must result in its destruction ; and the amount of information 

 conveyed by the examination of the chemical ruins, so to speak, 

 will depend a great deal on the knowledge already possessed of 

 chemical and vital processes. 



It is in all probability true that the nature of any vital pro- 

 cess is at all events closely bound up with the chemical changes 

 involved ; but we must not go too far in this direction. We are 

 not yet prepared to say that life is only the manifestation of 

 certain chemical and physical processes, meaning thereby such 

 chemistry and physics as are known to us ; nor are we prepared 

 to go the length of those who regard life as but the equivalent 

 of some other force or forces ; as electricity may be considered 

 as the transformed representative of so much heat and vice versa. 

 It may be so, but we do not consider that this view is warranted 

 in the present state of our knowledge. 



On the other hand, vital phenomena, when our investiga- 

 tions are pushed far enough, always seem to be closely asso- 

 ciated with chemical action ; hence the importance to the stu- 

 dent of physiology of a sound knowledge of chemical princi- 

 ples. We think the most satisfactory method of studying the 

 functions of an organ will be found to be that which takes into 

 consideration the totality of the operations of which it is the 

 seat, together with its structure and chemical composition ; 



