14 FOOD-GRAINS OF INDIA. 



a very considerable proportion of the actual energy derived from 

 the daily ration, the remainder being used to warm the body 

 itself, the air inspired, the food consumed, the water vaporised 

 from the skin and lungs, and the waste excreted. Of the energy 

 employed in or applicable to mechanical work inside the body or 

 external to it, a very large proportion is consumed in the work 

 done by the heart and in other automatic internal labour : this has 

 been estimated at 260 " foot-tons" that is, it is equivalent to the 

 work which a man does who raises 260 tons to the height of 

 i foot. The average amount of external work, expressed in the 

 same way, which an ordinary European labourer performs may 

 be set down as equal to 300 foot-tons ; a country postman walking 

 a daily round of 20 miles does work equal to 353 foot-tons ; it 

 has been calculated that the pedestrian Weston, travelling 50 miles 

 a day, did no less than 793 foot-tons of work per diem. Generally 

 speaking, ' one- fifth of the energy derivable from the food is 

 available for external work, and 2 foot-tons per i Ib. of the 

 body-weight is a fair day's work. 



It appears that a larger proportion of nitrogen to carbon (that 

 is, of albuminoids to starch and oil) is naturally demanded as the 

 stress and amount of labour required becomes greater. This 

 increase was formerly attributed to the greater waste assumed to 

 occur in the nitrogenous muscular tissue during increased exertion. 

 It is more probable that it is due to the comparative ease with 

 which albuminoids, especially those of meat, are assimilated during 

 strenuous labour, yielding urea as an excretory product on the one 

 hand, and on the other fat, which serves as a muscular fuel. 

 Another part of the nitrogenous food goes to augment the number 

 of the red corpuscles of the blood. These corpuscles have a 

 specially increased oxygen-carrying office to perform during violent 

 or strenuous labour. , 



Nutrient- Ratio and Nutrient-Value. The term "nutrient- 

 ratio" has been used in this Handbook to designate the proportion 

 of albuminoids to starch including with the starch the starch- 

 equivalent of any oil or fat present in the food. The expression 

 " nutrient-value " refers to the sum total of the albuminoids, the 



