MANUFACTURED FOODS FOR AGRICULTURAL STOCK. 89 
be contained in the food supplied ; and no stimulant, or any 
other device, can substitute that necessary amount, if the 
animal is not to decrease in weight. If, on the other hand, 
the animal be required to increase in weight, as in the case 
of our growing and feeding stock, an additional amount of 
digestible and assimilable constituents is required beyond 
that which, under otherwise equal circumstances, would 
keep the animal at a fixed weight. In fact, no stimulus 
whatever can substitute the supply of the digestible and 
assimilable constituents in the food, whether it be required 
for the purposes of labour, or of increase in weight. In 
other words, the waste of matter in the body by respiration 
and perspiration, the loss by urine and faeces, and the gain 
in weight of fat, flesh, bone, &c., must all come from consti¬ 
tuents actually contained in the food* 
Some years ago an extensive series of experiments was 
conducted, at Rothamsted, on the feeding of oxen, sheep, 
and pigs, most of the results of which have been published, 
either in the ‘Journal of the Royal Agricultural Society of 
England/ or in the c Reports of the British Association for 
the Advancement of Science. 5 These experiments showed 
how much the character and productiveness of the foods 
employed depended upon the amounts they supplied of cer¬ 
tain digestible non-nitrogenom substances—such as starch, 
sugar, fatty matter, &c.; certain nitrogenous substances— 
such as albumen, &c.; and certain mineral matters. It was 
further found that the ordinary, or staple foods, when in 
proper admixture with one another, supplied the several 
constituents far more economicallv than when mixtures were 
attempted to be made, in which some of the constituents 
(starch, sugar, or oil, for instance) were employed in a com¬ 
paratively pure state, that is, after having undergone an 
expensive process of manufacture in their preparation. In¬ 
deed, unless fresh and cheaper sources of food can be 
discovered, so that we can be supplied with starch, sugar, 
oil, &c., at a cheaper rate than they are provided in hay, 
corn, oilcake, and the like, we cannot hope economically to 
replace the latter by special manufactured foods for stock. 
It may be asked—if we can with advantage employ con¬ 
centrated manufactured manures for our crops, why cannot 
we also economically employ concentrated manufactured 
foods for our stock? The answer is plain. In using the 
concentrated manufactured manure, containing a certain 
amount of nitrogen or phosphates, for example, the bulk of 
the crop is obtained from other sources —such as the atmo¬ 
sphere and water , not supplied by the farmer’s hand; the 
