232 BOARD OF AGRICULTURE. 



pectine, &c, with, reference to their digestibility, as well as 

 to their feeding effect. He determined the latter, not merely 

 by weighing the animal on trial before and after the feed- 

 ing period, which he proved (as had Voit and others before 

 him) to be in an unusual degree deceptive in the case of 

 short periods of feeding, but by analyzing quantitatively and 

 qualitatively the products and the residues of the digestion, 

 of the respiration, and of the transpiration, by improved 

 analytical modes, frequently new and original with him. 

 These observations were made unde'r similar conditions, 

 with different kinds of animals, and also with the same kind 

 of animals in different stages of growth, under differing con- 

 ditions, and when kept for different purposes. In summing 

 up the results of his investigations, in common with those 

 of others engaged in the same field of research (E. Wolff, 

 Scheven, Stohman, Henneberg, Gilbert, &c), lie arrived at 

 the following conclusions : a rational and economical system 

 of feeding farm live-stock in accordance with the extent of 

 our present experimental observations requires the following 

 kind of information : — 



First, How much of nitrogenous matter, how much of 

 saccharine or non-nitrogenous substances, how much of fatty 

 matter, and how much of mineral substances, in a digestible 

 form, does each kind of animal require, not only in its 

 various stages of growth, but also for every purpose it is 

 designed to answer ? And 



Second, How much of each of these four groups of sub- 

 stances are present, in a digestible state, in our various 

 articles of fodder ? 



The first condition rests on the physiological fact that 

 neither one nor another of the four kinds of nutritive sub- 

 stances alone can support animal life : it requires all four in 

 definitely varying proportions to accomplish specified results. 

 A violation of this physiological law re-acts more or less seri- 

 ously on the health of the animal, and leads, as a general 

 rule, to a bad economy in the use of fodder. Sufficient 

 experimental observation was already on hand to induce him 

 to specify, with a considerable degree of certainty, the parti- 

 cular amount of each group of substances which' is required 

 for different animals in their varying stages of growth and 

 in different conditions. 



