34 



kofer, iu JMunicli. A second one, constructed on the same plan, but large 

 enougb for an ox to live in while being experimented upon, was put up 

 some nine 5 ears ago in the station at Weende. A third was added in 

 1870 to,the equipments of the station in Halle; and a fourth was put in 

 operation about a year since at the station in Leipsic. 



Tlie apparatus consists essentially' of a large chest or compartment 

 with air-tijiht walls, in which is placed an animal, for instance an ox. 

 The interior is furnished with arrangements for supplying food and 

 water and collecting the excrement and urine. By appropriate ma- 

 chinery a current of fresh air is introduced through openings provided 

 for the purpose, and, after it has supplied the wants of the animal for 

 respiration, is conducted out, bringing with it the gaseous products of 

 respiration, into a gasometer, where it is measured. It is then analyzed, 

 and a comparison of its com[)Osition with that before it had passed 

 through the apparatus shows what material has been added to it by the 

 respiration of the animal. 



We have thus from the analysis of the food, and of all the ultimate 

 products of its transibrmation, a means of following out the processes 

 of the transformation of the food in the body of the living animal, and 

 can infer what i5arts the different food-ingredients play in building up 

 the diUerent tissues as flesh and fat, and what materials of the food and 

 body (onti'ibute to the supply of animal heat and muscular force. 



The last three classes of experiments belong almost exclusively to the 

 last decade. The researches of the last class are, it may be said, only 

 begun, and thus far the results have not assumed so definite a form as 

 is the case with others. The experiments are extremely laborious and 

 con)plicated. One of the experimenters at Weende lately remarked to 

 the writer that after several years of work with the respiration appa- 

 ratus, they had only learn«'d how to manage the api)art)tus, the animals, 

 and the food, and were just ready to commence a series of researches, 

 which gave promise of success. 



We hope to be able hereafter to give accounts of the details and re- 

 sults of these researches. 



Sufficient has been said to show that although much has been done, 

 yet the science of animal nutrition is still in its infancy. It is by such 

 researches as these that the theory of the feeding of domestic animals 

 is brought into the form of an exact science. 



It is greatly to the credit of the German stations and a very high ^ 

 compliment to the wisdom of the agricultural public, by whose voluntaiy 

 contributions they are largely supi)orted, that so much labor is spent 

 upon abstract scientific investigation. But the value of the application 

 of the results of these researches to practical agriculture is recognized, 

 and the German farmers put their hands in their pockets and take out 

 the money to support these experiments, for the very simple reason that 

 they know that " it pays." 



Experiments in vegetable production. — These may be divided into two 

 general classes: • 



1st. Field experiments, whose object is to determine the effects of 

 different manures and methods of culture ujjon different crops in differ- 

 ent soils. 



One common plan for conducting these experiments is to lay off a 

 field in plots, and on these to put different manures, and note the effects 

 upon the crops raised thereon. The number of experiments of this sort 

 made within the i)ast two decades is very great. In general, howjever, 

 while they are quite interesting, yet, as many of the investigators in the 

 German stations say, the different factors of the experiment, as temper- 



