HUMAN PHYSIOLOGY. 



To obtain the requisite amount of carbon from meat, 45,000 grains, or 

 about 6| pounds, containing 4,500 grains of carbon and 1,350 grains of 

 nitrogen would have to be consumed. Under such circumstances there 

 would arise an excess of nitrogen in the system, which would be equally 

 undesirable and injurious. By combining these two articles, however, in 

 proper proportion, the requisite amounts of carbon and nitrogen can be 

 obtained without any excess of either e. g. : 



2 pounds of bread contain 4,630 grs. C. and 154 grs. N. 

 f pounds of meat contain 463 grs. C. and 154 grs. N. 

 5,093 C. 308 N. 



The amount of carbon and nitrogen necessary to compensate for the loss 

 to the system daily would be contained in the foregoing amount of food. As 

 about 3 \ ounces of oil or butter are consumed daily, the quantity of bread 

 can be reduced to 19 ounces. In the quantities of bread and meat just men- 

 tioned there are 4.2 ounces albumin, 9.3 sugar and starch. 



The alimentary principles are not introduced into the body as such, but 

 are combined in proper proportions to form compound substances, termed 

 foods e. g., bread, milk, eggs, meat, etc. the nutritive value of each de- 

 pending upon the extent to which these principles exist. 



The following tables show the average composition of various articles of 

 food: 



COMPOSITION OF ANIMAL FOODS. 



