150 ANATOMY FOR NURSES. [CHAP. XIII. 



142.9 



5.1 



The human body, from a chemical point of view, may be 

 regarded as a compound of three large classes of chemical sub- 

 stances ; viz. proteids, fats, and carbo-hydrates associated with 

 water and mineral salts. 



In our first chapter we said that protoplasm was the basis of 

 the life of the body, and from that point of view we may look 

 upon the human body as an assemblage of variously modified 

 protoplasm. But it comes to the same thing, for the chemical 

 composition of protoplasm, so far as it has been possible to 

 analyze it, has been found to agree closely with that of the 

 fully developed organism. 



The processes of nutrition that take place in the protoplasmic 

 cell are essentially the same as those which take place in the 

 fully developed body, with this exception, that in the one case it 

 is a very simple, and in the other a very complex, process. In 

 both cases, non-living chemical substances are taken in from 

 without, and converted into material which is endowed with 

 that mysterious property we call life. 



To support life, the different food-stuffs must be taken in 

 proper proportion ; and, in order that -all the tissues and fluids 

 of the body may continue in good condition and perform their 

 functions properly, they must be supplied with all the ingredi- 

 ents necessary to their constitution. A man may be starved to 

 death at last by depriving him of lime phosphate as surely, 

 though not as rapidly, as if he were deprived of albumin or fat. 

 Many a patient in less well-instructed times has been slowly 

 killed by deprivation of water, or by exclusive feeding on beef- 

 teas and jellies. 



