INDUSTRIAL PROGRESS DURING THE YEAR 1873. cvii 



the kingdoms of Prussia and Saxony alone. The work of 

 these stations consists for the most part of experiments on 

 the nutrition and growth of animals and plants, and investi- 

 gations of soils, fodder materials, and especially commercial 

 fertilizers. 



In animal nutrition, important series of experiments have 

 been andare still being made by Henneberg, director of the 

 station at Weende, in Hanover; Kiihn, of the station at 

 Mockern, in Saxony; Stohmann, of Leipzig; Wolff, of Ho- 

 henheini ; Hoffmeister, of Dresden, and others. Some of the 

 principal subjects are the digestibility of different kinds of 

 food by different domestic animals; the effects of different 

 kinds and quantities of food upon the quantity and quality 

 of milk produced by cows and goats, and the functions of 

 the various food ingredients in the animal economy. 



The experiments on the digestibility of food are made by 

 analyzing the food and solid excrement, the difference being 

 the amount disjested. At the station at Weende there have 

 been completed up to the present time nearly seventy feed- 

 ing experiments with oxen, involving observations of this 

 sort. In general about half of the hay and straw consumed 

 by the animals was digested. The difference in digestibility 

 of hay and straw is much less than has been supposed. The 

 greater value of the hay as fodder depends chiefly upon its 

 fi^reater content of diG:estible nitros^enous matters. 



The experiments on milk production have been made by 

 feeding cows and goats with rations varying in amount and 

 composition, the food given and the milk produced being ac- 

 curately measured and analyzed. A large number have been 

 made, and with the utmost care and accuracy. It is found 

 that, in general, while the total quantity of the milk is in- 

 creased up to a certain point by large and rich food rations, 

 and while as the milk increases in quantity it also grows 

 somewhat richer, and contains a larger percentage of dry mat- 

 ter, yet beyond this limit a further increase in the quantity 

 or richness of the food is without effect on the milk. 



It is further found that attempts to change the composi- 

 tion of the organic substance of the milk, the relative amounts 

 of caseine and fat, by increasing the amounts of fats or albu- 

 minoids in the food, are of no avail. The practical inference 

 from these experiments is that, as regards milk production, 



