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gredieuts, as nitrogen, phosphoric acid, and potash. The stations work- 

 ■ ing in the interest of the buyers test their composition by analyses, and 

 thus farmers are enabled to guard against imposition and secure good 

 wares. The control thus exercised by the stations upon these prevents 

 a very large amount of fraud in the trade of these articles, and causes 

 a great improvement in the general character of the fertilizers sold in 

 the regions where the stations exist. The saving by this means to the 

 agricultural communities amounts to many times the whole cost of the 

 stations. 



The stations consist in general of a chemical laboratory, connected 

 with experimental fields, garden, or glass-house, for experiments in veg- 

 etable production, or, when the nutrition of animals is the object of in- 

 vestigation, with stables, and in some cases a respiration apparatus. 



By examining the character and results of some of the researches in 

 these stations we shall be best able to learn somewhat of the present 

 condition of the science of animaband vegetable production. 



Experiment stations for researches in animal physiology. — So far as the 

 writer is aware, almost no descriptions of the plan and results of the 

 most important of the later investigations in this subject have appeared 

 in the English language. An admirable resume of the subject, by Wolff, 

 of the station at Hohenheim, in Wiirtemberg, may be found in Mentzel 

 & Von Lengerke's Landwirthschaftlicher Kalendar, Berlin, 1872. Among 

 the stations which have been most active in this line of investigation 

 are those of Weende and Halle, in Prussia, Moeckern and Leipsig, in 

 Saxony, and Hohenheim, in Wiirtemberg. These experiments may be 

 divided into four classes : 



1st. Experiments in which chemical analyses are made of the fodder 

 given to the animals, and, in case of milch cows, of the milk produced ; 

 while the investigation of the excrement, urine, and gases given off in 

 respiration is omitted. Experiments of this sort are of great value in 

 •deciding wliat are the most economical kinds, mixtures, and amounts of 

 food for different domestic animals, as horses, cattle, sheep, and swine, 

 according as the production of meat, milk, labor, &c., are required of 

 them. They do not tell what proportions of the different foods are ac- 

 tually digested, nor do they give any direct explanation of the nutritive 

 processes that go on, nor of the ways of formation of fat and flesh in the 

 animal body. 



To this class belong many well-known feeding experiments, made by 

 Lawes & Gilbert in England, whose results have already been made 

 known to the English-reading public. 



Of still greater importance are the experiments made within a few 

 years past in the German stations, on the composition and amount of 

 ■food needful for the sustenance of cattle and sheep, and upon the effects 

 of different kinds and amounts of food given to milch cows upon the 

 amount and quality of the milk produced. 



Experiments on the effect of different kinds and quantities of food on the 

 amount and quality of the milk produced. — The most important investiga- 

 tions of this subject have been made since 1866 at the stations at Moeck- 

 ern by G. Kuehu and Hohenheim by Wolff & Fleischer, on cows, and 

 at the station at Halle, by Stohmann, on goats. 



The general plan is to feed the animals for a certain period with a cer- 

 tain ration ; then for another period with a different ration ; to make 

 accurate measurements and analyses of tlie food and of the milk pro- 

 duced, and thus note the effect of the different kinds and quantities 

 •of food upon the milk. 



In some experiments the rations fed out in the different periods are 



