CONSTANTS 



563 



n. NXTTRITION. 



Such a body would require for daily food, carbon 

 270-300 grammes, nitrogen 20 grammes. 



Now proteins contain, in round numbers, about 15 per 

 cent, nitrogen and 53 per cent, carbon, while carbo- 

 hydrates and fats contain respectively 40 per cent, and 80 

 per cent, carbon. Hence the necessary amounts of 

 nitrogen and carbon, together with the other necessary 

 elements, might be obtained as follows (see p. 271) : — 



Proteids . . . 130 gmis. containing 20 grms. nitrogen 70 grms. carbon 



Carbo-hydrates 400 „ „ „ 160 „ 



Fats .... DO „ „ „ 40 „ „ 



Minerals . . 30 ,, „ „ — „ „ 



Water . . 2,300 „ 



2,910 



20 



270 



This might in turn be obtained, for instance, from : — 



Lean meat 

 Bread . 

 Potatoes 

 Milk. . 

 Fat . . 

 Water . 



230 grammes (h lb.) 

 480 „ (^y 1 lb.) 



. 660 

 . 500 

 . 30 

 .2,300 



(U lb.) 

 (I pint) 

 (1 oz.) 



(4 pints) 



This table, however, must be understood as being intro- 

 duced for the sake of illustration only. Many other 

 similar tables may be constructed by the use of various 

 kinds of food. 



III. Circulation. 



In such a body the heart would beat about 72 times in 

 a minute and probably drive out at each stroke from each 

 ventricle about 80 grammes (4 cubic inches or 3 ounces) 

 of blood. 



The blood would probably move in the great arteries at 

 the rate of about 8 inches (200 millimetres) in a second ; 



o o 2 



