WASTE AND REPAIR FOODS 



nitrogen. This not only implies a waste of food substance, but 

 also that a great deal of extra work is thrown on certain organs. 



Next, let us suppose that he feeds on lean meat only. Then, 

 in order to obtain the necessary quantity of carbon, he must eat 

 no less than 6-^ Ibs. daily, as this weight of lean meat contains 



Carbon 4,500 grs. 



Nitrogen .... 1,350 grs. 



In this case we notice a similar waste of nitrogen, the removal of 

 which would also give an undue amount of work to the organs 

 concerned* 



But it is possible to take such a mixed diet of bread and meat 

 as will supply all the requirements of the system, and at the same 

 time yield but little waste material. In doing this we also reduce 

 the total amount of food taken. Thus : 



2 Ibs. of bread contain 

 f Ib. of lean meat contains 



Total . 



carbon 4,500 grs., and nitrogen 150 grs. 

 carbon 500 grs., and nitrogen 150 grs. 



. . 5,000 grs. 300 grs. 



So that by eating no more than zf Ibs. of solid food daily we 

 should be enabled to repair all the waste of the body, taking an 

 excess of 500 grains of carbon only. This clearly shows the ad- 

 vantage that may be gained by a mixed diet which is selected with 

 due regard to the requirements of the body. 



A model food is one which contains nitrogenous, non-nitro- 

 genous, and mineral food substances in the proportions in which 

 they are required to make good the waste of the body. Among 

 such foods may be mentioned (i) milk, on which young animals 

 entirely subsist ; and (2) eggs, which provide all the nourishment 

 to young birds till they are hatcned. The following tables give 

 the exact composition of these : 



Cow's 



858 

 68 

 38 



3 6 



Water 



2. The Composition of Fowl's Eggs. 



White 

 . . 78 



Nitrogenous matter . 



Fatty (non-nitrogenous) matter 



Salts . ... 



20 -4 



IOO-O 



Yelk 



52 

 16 

 307 



i-3 



IOO-O 



