306 THE ANIMAL AS A PRIME MOVER. 



been deinauded and still proved insufficient to supply the needed total 

 energy of the system. For a healthy and hard-working man. Dr. Pavy 

 gives 2 pounds of bread and 0.75 pound of meat as a fair ration for a 

 day. 1 Moleschott gives a total of 46 ounces or about 23 ounces in a dry 

 state, and 60 to 80 ounces of water in twenty-four hours. Yoit gives 500 

 to 800 grams, or about 17 to 27 ounces of nutrient matter in the food 

 taken; 2 and, on the same basis, eliminating wastes, the principal inves- 

 tigators give about 550 grams, nearly 20 ounces, as an average. Edward 

 Atkinson gives from 2 to 2.75 pounds per day of common foods as diet- 

 aries on which life can be sustained and ordinary work done without 

 strain ; but he allows 4 pounds for what may be termed " good living." 3 

 Much of the food included in the bill of fare of the well-to-do citizen has 

 no real value in nutrition; some of it is actually and often seriously 

 detrimental, and some, possibly a large proportion, is simply superfluity 

 and waste. 



The food of a working man contains about 15 per cent nitrogenous 

 matter; that of a young child 20 per cent. Milk contains 25 per cent, 

 uncombined water, as in the preceding cases, eliminated. Eighty-five 

 per cent of the food of the man is thus applicable to work, and 15 per 

 cent to muscle making. Three-fourths of the child's food is suitable 

 for work and production of fat; one-fourth for making muscle. An 

 egg contains 11 per cent fat, 17.6 per cent albumen, and 1.5 mineral 

 matter; or dry, 37 per cent fat, 58 per cent albumen, and 5 per cent 

 minerals; i. e., apparently nitrogenous matter constituted about 0.6 

 the total weight of the body. A large fraction of the food is thus 

 required for work and heat, a small proportion for building up the 

 machine, or for its repair. 



Wheat is usually considered the most perfectly compounded of the 

 grains adapted for the food of man. It contains, according to Scammel, 

 14.6 per cent muscle making elements, 66.4 per cent heat-producing 

 materia], 1.6 per cent nerve and brain food, and 17.4 water and waste. 

 Oatmeal contains, respectively, 17, 50.8, 3 and 30.5 per cent of these 

 elements. The meatscontain 20, 14, 2 and 64 per cent. Fish require little 

 heat, obviously, and as food contain 20 per cent muscle-making material, 

 1 per cent fat, 5 per cent brain and nerve food, and 74 per cent water 

 and waste. Oysters contain two-thirds as much solid matter of sub- 

 stantially the same composition. On the whole, 4 times as much energy 

 is supplied in good food for heat and work as for muscle repair and 40 

 times as much as for brain and nerve. 



Frankland finds the energy per pound of common foods to range 

 from 2,000 or 3.000 British thermal units in the case of the lean meats, 

 to about 7,000 with the grains and their flours, and to over 15,000 in the 

 case of the solid fats. The underground vegetables, which can hardly be 



1 Treatise on Foods. 



-Mott's Manual. 



:; Thurston's "Animal as a prime mover," page 76. 



