504 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



brought comparatively little that is new in principle or of 

 special popular interest. The German experiment stations, 

 where the bulk of the most accurate work is done, are occu- 

 pied mainly in pushing the inquiries referred to in previous 

 reports. In this country the analysis of foods and experi- 

 mental tests and application of the later theories of feeding 

 are among the most interesting topics we have to note. 



FEEDING EXPERIMENTS. 

 Digestion of Foods by the Horse. 



In continuation of the experiments by Wolff and asso- 

 ciates at Hohenheim, on the digestion of foods by the horse, 

 reported last year, an ingenious apparatus has been con- 

 structed by which the animal can be kept regularly at work, 

 and the amount regulated at will and accurately measured. 

 Thus far the digestion of the foods has not been materially 

 affected by the amount of work done. As was found in pre- 

 vious experiments, the horse digested less from hay than 

 sheep did. It was further noticed that the decrease in diges- 

 tion which comes with decrease in the amount of nitrogen 

 in the hay was greater in the horse than in the sheep. The 

 experiments indicate that the horse digests somewhat less 

 from coarse foods hay, straw, and the like than sheep ; but 

 about as much from concentrated foods grain, etc. as oth- 

 er domestic animals. 



Source of Muscular Force. 



In the experiments of Wolff above referred to, it was found 

 that as the muscular exertion of the horse increased, the se- 

 cretion of nitrogen in the urea increased also, thus implying 

 a greater consumption of muscle an observation contrary to 

 those of Voit, Pettenkofer, Fick and Wiblicenus, and others. 

 Steps have been taken to verify the experiment. It is no- 

 ticeable, by the way, that though the source of muscular 

 force, whether from consumption .of the nitrogenous or the 

 carbonaceous tissues and food ingredients, is far from beimr 

 settled, yet, of late, numerous chemists and physiologists are 

 inclined to ascribe it to the nitrogenous materials. 



