22 FOOD-GRAINS OF INDIA. 



the ration, but this reduction is small, and may be neglected. 

 In fact, we may be satisfied with the roughest approximations 

 to the standard or theoretical figures in spite of the appearance 

 of minute accuracy which three places of decimals give to our 

 tables and to our calculated examples of rations. And it should 

 be here mentioned that a margin of excess should be allowed 

 in all weighings to compensate for inferiority of the grains, for 

 casual impurities, and for the presence in an unavailable form 

 of some of the nutrients in the food-staples employed. It is 

 difficult to give any general rule, or to say what amount of 

 allowance should usually be made ; 5 per cent, will probably 

 suffice, except in the case of obviously inferior or dirty samples. 

 There are many ways in which such tables as the two 

 which we now give may be used in order to ascertain what 

 amounts, in ounces and decimals of an ounce, of two or more 

 foods, must be associated in order to furnish the necessary 

 quantities of the two chief nutrients for a day's ration. We 

 believe that the simple " inspection " method adopted in the 

 examples which follow will be generally preferred to elaborate 

 formulae and equations involving much calculation, many 

 references to tables, and the use of a number of coefficients. 



