122 TIIK l'KL\L'Il'LE.S OF AGUICI LTLIIE. 



the amount of these substances that can be di(jested and 

 become useful to the annual. 



There are but few articles of food of which all the 

 albuminoids, fats, and carbo-hydrates can be thus di- 

 gested. The indigestil)le j)art is of no value for food. 



The table on the opposite page gives the jjcrccntage of 

 di'i/estible albuminoids, fats, and carl)0-hydrates contained 

 in the different articles of food, and the value of one 

 hundred pounds of each variety. 



In reckoning these values, the digestible albuminoids 

 and fats are, according to the usual custom, regarded as 

 worth 4^ cents per pound, and the digestible carbo- 

 hydrates as worth ^^ of a cent per pound. 



The results are, of course, only relative, and will vary 

 according to the market value of the standard articles 

 of food in any locality. If average hay is worth sixty- 

 four cents per hundred pounds, or $12.80 per ton, then 

 the other articles will be worth the sums given in the 

 table as compared with hay. 



If in any locality, or any year, the market value of liay, 

 corn, oats, or other articles connnonly used, is greater or 

 less, upon the average, than the tal)le indicates, then the 

 figures for all the articles mentioned must be increased 

 or diminished accordingly. 



The table affords a general guide for selecting and jiur- 

 chasing foods, but it must not be depended u})on for 

 great exactness. No article of food can, in reality, have 

 an absolute value of its own. The true value of any 

 article as food depends u]»()n its comliiuation with other 

 fo(jds, the nature of the animal to which it is fed, and the 

 purpose to be accomplished. In order to make an intel- 

 ligent selection, it is necessary to imderstand what partic- 

 ular kinds of food are needed in the •••iven case. 



