SCIENCE OF FEEDING ANIMALS. 223 



of crops, — winter and summer grain alternating with fallow, 

 — rendered it advisable to assign to stock-feeding, as a farm 

 industry, rather a subordinate position : there was, in fact, 

 but little use for scientific aid in making up fodder-recipes, 

 as long as grass or hay, straw, and a few varieties of grain, 

 represented the entire stock of fodder. 



On the other hand, analytical chemistry being still in its 

 infancy, and its modes of operation, consequently, open to 

 serious criticism, did not discriminate enough among the 

 various constituents of plants to carry conviction; whilst 

 a too exclusive chemical treatment of the question, " What 

 constitutes the peculiar value of the several articles of 

 animal food ? " met with but little support in practice. The 

 customary practice of chemists during the early period of 

 the present century, to ascribe to all the various soluble 

 organic constituents of plants an equal value in the animal 

 economy, and to determine their relative merits as food 

 merely by summing up the quantities of their soluble proxi- 

 mate constituents as starch, sugar, fat, nitrogenous matter, 

 &c, resulted in a classification which proved, when tested 

 on the farm, seriously deficient. 



Boussingault was the first chemist who advocated (1836- 

 38) a valuation of the food, based on its relative amount 

 of nitrogen, assuming at the same time that the entire 

 amount of nitrogen found was present in the form of so- 

 called proteine, or nitrogenous matter. Liebig soon after 

 followed with his classification of the constituents of vege- 

 table and animal food into plastic and respiratory substances. 

 The publications of both investigators, beginning about the 

 year 1836, and extending over a series of years, mark a new 

 era in the history of the science of stock-feeding. 



Whilst Liebig turned his eminent talents to account to 

 inquire into the composition of the liquid and solid constit- 

 uents of the animal organism, the chemistry of digestion, 

 the composition of animal and vegetable food, and their rela- 

 tion to the support of animal life, &c, to furnish suitable 

 material for the, development of an animal chemistry and 

 physiology, which he considered indispensable guides in farm 

 practice, Boussingault engaged, in 1836, in actual experi- 

 ments upon his celebrated Experiment Station at Bechel- 

 bronn, in the Alsace, to test the efficiency of his fodder 



