PROTEIDS. 



139 



ical dietary, being not only admirably selected, but also properly 

 proportioned." 



The ideal ration for an army of United States soldiers on duty 

 in the tropics is therefore suggested as being of the composition 

 given in the table on page 137. 



Most valuable, instructive, and revolutionary are the experiments 

 conducted by Prof. R. H. Chittenden, of the Sheffield Scientific 

 School, during 1903, and reported by him in a book entitled Physi- 

 ological Economy in Nutrition, published in 1904. These experi- 

 ments were made on three classes of men professional men, 

 soldiers, and college athletes. We can but give a r6sum6 of the 

 most important facts established by Prof. Chittenden, referring 

 our readers to the book itself, with the opinion that it is the most 

 valuable contribution on the subject of which it treats which has 

 been made in recent years. 



The experiments on the professional men showed that, taking 

 the Voit standard (p. 130) as a general average of accepted dieta- 

 ries, this is entirely too generous for a man whose occupation does 

 not involve excessive muscular work, but whose activity is mainly 

 mental ; that such a man can live on a much smaller amount of 

 proteid or albuminous food than is usually considered essential for 

 life, without loss of mental or physical strength and vigor, and 

 with maintenance of body and nitrogen equilibrium. Prof. Chit- 

 tenden himself, whose body-weight was 57 kilos, showed for nearly 

 nine consecutive months an average daily metabolism of 5.7 grams 

 of nitrogen. His wants were met by the metabolism of i33.75 

 grams of proteid per day, instead of the 118 grams of Voit. At 

 the same time non-nitrogenous food was much reduced below Voit's 

 standard. A fuel-value of 2000 calories per day was adequate to 

 meet the ordinary wants of the body. By experiments upon him- 

 self and others Prof. Chittenden has shown that the minimal pro- 

 teid requirement for professional men is from 0.093 to 0.130 gram 

 of nitrogen per kilo of body-weight. These results were not 

 obtained on a restricted diet, each individual being allowed perfect 

 freedom of choice. The food of a single day is an illustration of 

 this : 



Breakfast 7.45 A. M. 



Grams. 



Coffee 103 



Cream 30 



Sugar 10 



Lunch 1.30 P. M. 



Creamed Codfish 64 



Potato balls 54 



Biscuit 44 



Butter 22 



Tea 120 



Sugar 10 



Wheat griddle-cakes ... . 133 



Maple syrup 108 



Dinner 6.30 p. M. 



Grams. 



Creamed potatoes 85 



Biscuit 53 



Butter . . . 15 



Apples celery lettuce salad 50 



Apple pie 127 



Coffee 67 



Sugar 8 



Cheese-crackers 17 



