132 PHYSIOLOGICAL CHEMISTRY. 



mainly upon grass or hay, in which the proportion of nitrogenous to 

 non-nitrogenous matter is not more than 1 to t.14 ; but when employed 

 in active labor they require a liberal supply of oats, in which the pro- 

 portion is as 1 to 5.49. In Play fair's diet tables, which were collected 

 from a variety of sources, including those of prisons and infirmaries, 

 those of the American and European armies during peace and in active 

 service, and of certain hard-working laborers, the increase of albuminous 

 matter, with increased labor, is a marked feature. While in a bare 

 subsistence diet the proportion of albuminous to non-nitrogenous matter 

 is as 1 to 4.52, in that of active laborers it is as 1 to 3.34. The follow- 

 ing table will show the relative increase of the two kinds of food under 

 different conditions of exercise, as calculated from Playfair's data. 



EELATIVE INCREASE, UNDER DIFFERENT CONDITIONS, OF ALBUMINOUS AND NON- 

 NITROGENOUS MATTERS IN THE FOOD. 



Albuminous Non- nitrogenous 



matter. matter. 



Bare subsistence diet ... 100 100 



Full diet with moderate exercise . . 180 147 



Diet of active laborer .... 232 155 



Diet of hard-worked laborer ... 242 169 



Thus, in passing from a bare subsistence diet to that of the hard- 

 worked laborer, the non-nitrogenous matter of the food is less than 

 doubled, while the albuminous matter is considerably more than 

 doubled. 



As these diet tables were adopted by various civil and military 

 authorities as the result of experience in the practical adaptation of 

 food to the amount of work performed, they may be regarded as ex- 

 pressing with great approximation to certainty the physiological 

 requirements under different conditions. They are corroborated by 

 the variation in diet adopted in the convict establishments of Great 

 Britain, as given by Pavy.* In the change from " Light-labor Diet *' 

 to '" Hard-labor Diet," while the non-nitrogenous food is increased only 

 13.37 per cent., the albuminous food is increased 16.15 per cent. 



It is also a matter of interest to determine the quantity, source, and 

 destination of the different chemical elements entering into the compo- 

 sition of the food. Taking the average composition of albuminous 

 matters, fat, and carbohydrates, we find that a man under ordinary full 

 diet takes into his system daily the constituents of the food, in round 

 numbers, as follows : 



DAILY CONSUMPTION IN THE FOOD. 



C H O N S 



Albuminous matter, 130 grammes, containing 70 10 29 20 1 



Starch . . 300 " 134 18 148 



Fat . . . 100 " " 76 12 12 



280 10 189 



*On Food and Dietetics. Philadelphia edition, 1874, p. 433. 



