502 PHYSIOLOGY. 



Expenditure : 



Expenditure 

 in calories. 



1. Mechanical work, 212.750 kilogram meters.. 500.00 



(425.5 gram meters equivalent to a calorie.) 



2. Heat lost in 2340 grams of excreta 58.500 



(Cooling from 37 C. to 12 C.; 2340x25.) 

 3 Heat required to warm 13,000 grams of air 



from 12 C. to 37 C 84.500 



Specific heat of air, 0.26 : 

 (13.00x25x0.26.) 



4. Evaporating 330 grams of water from lungs. . 192.000 



(1 gram requires .582 calories.) 



5. Evaporating 660 grams of water from skin . . 384.000 



6. Radiation and conduction from skin, about. . 184.000 



3,063.000 



Atwater concludes that the energy requirements of the diet vary as 

 follows : 



Calories. 



Man without muscular work 2700 



Man with light muscular work 3000 



Man with moderate muscular work 3500 



Man with severe muscular work 4500 



Chittenden made experiments upon soldiers and athletes for six 

 months. The 118 grams of proteid necessary per day, according to 

 Voit, means at least 16 grams of nitrogen in the urine, when this food 

 is metabolized in the form of urea, uric acid and purin bases. 

 Minkowski has shown that adenin, one of the purin bases found in the 

 breaking down of cell-nuclei, has a marked toxic action on dogs and 

 man. It has a local action on the kidneys, giving rise to deposition in 

 the kidney itself of spheroliths of uric acid or urate, which leads to 

 acute nephritis, albuminuria and speedy death of the animal. The 

 alloxuric bases also cause fever, when given by the mouth or sub- 

 cutaneously. It is evident that the products of proteid metabolism 

 are more or less dangerous to the body, especially so when there is an 

 excess of proteid food consumed. Chittenden reduced the food of the 

 soldiers one-half to one-third of the amount ordinarily considered 

 necessary. After the body had once adjusted itself to these new con- 

 ditions, the body-weight remained at a stationary condition. There 

 was a marked increase in physical strength ; there was no falling off in 

 physical or mental vigor, or any change in the hemoglobin or in the 

 number of erythrocytes. An excess of proteid over that which is^ 

 really needed for these purposes causes so much unnecessary strain upon 



