Food for Agricultural Stock. 201 



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 constituents actually 

 contained in the food. 



Some years ago an extensive series of experiments was con- 

 ducted at Rothamsted, on the feeding of oxen, sheep, and pigs, 

 znost of the results of which have been published, either in tlie 

 Journal of the Royal Agricultural Society of England, or in the 

 Reports of the British Association for the Advancement of 

 Science. These experiments showed how much the character 

 and productiveness of the foods employed depended upon the 

 amounts they supplied of certain digestible non-nitrogenous sub- 

 stances, such as starch, sugar, fatty matter, &c., certain nitro- 

 genous 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 economically than when mixtures were 

 attempted to be made, in which some of the constituents (starch, 

 sugar, or oil, for instance) were employed in a comparatively 

 pure state ; that is, after having undergone an expensive process 

 of manufacture in their preparation. Indeed, unless Iresh 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 concen- 

 trated 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 manu- 

 factured manure, containing a certain amount of nitrogen or phos- 

 phates, for example, the bulk of the crop is obtained from other 

 sources — such as the atmosphere and loaier, not supplied by the 

 iarmer's hand ; the natural constituents existing in his soil, and 

 the residue from previous mama'es and crops. The application 

 of a small quantity of ammonia and mineral matter will often 

 yield as great an increase of vegetable produce, as if 20 or 30 

 times the weight of farmyard dung had been employed. This is 

 not to be wondered at when it is considered, that by far the 

 greater bulk of the dung consists of water and other constituents 

 which the plant can obtain either from the air or the soil. We 

 thus get, by the use of concentrated manures, a much greater 



