APPENDIX. 



THE CHEMICAL BASIS OF THE ANIMAL P.nhY. 



Tin ;mim;il liody, from a chemical point of view, may be 

 led as ;i mixture of various representatives of three lai-e 

 ( la es of chemical substances, viz. proteids, carbohydrates ami 

 in association with smaller quantities of variou- saline and 

 other crystalline bodies. By proteids are meant bodies contain- 

 ing carbon, oxygen, hydrogen, and nitrogen in a certain proportion, 

 varying within narrow limits, and bavin:: certain general feature-; 

 they are frequently spoken of as albuminoids. I'.y carbohydrate.-, 

 are meant. Marches and sugars and their allies. \\V have al<o 

 seen that the animal body may be considered as made np on the 

 one hand of actual 'living substance.' sometimes spoken 

 protoplasm -ee 5), in its various modifications, and on the other 

 band of numerous lifeless products of metabolic a<ti\it\. \Ve do 

 pre-ent know anything definite about the molecular coin- 

 portion of the active living substance; but when we submit 

 living substance to chemical analysis, in which act it i- killed, 

 we always obtain from it a considerable quantity of the material 

 spoken of as protejd. And many anth' far as to speak of 



living substance or protoplasm as being purely pioteid in nature; 

 they regard the living protoplasm as proteid material, which in 

 Mom death to life has aSSUIll ill character- and 



>re-umahly has been changed in con-t ruction, but still is p: 

 matter; they sometimes speak of protoplasm as ' living pp-tcid 

 or 'living albumin.' It is worthy of notice. 1, 

 simple forms of living matter, like that constituting tin- b-dy ( 

 a white corpuscle, forms which we may fairly - "ii-id<T II tin- 

 nearest approach to native protopla-m. when they can be obtained 

 in ^utlicient quantity for chemical ana! found to contain 



