242 MXNXJA-L OF CATTLE-FEEDIlSrG. 



tions of complex substances from simpler ones), of which 

 many have been shown to take place in the body, also de- 

 mand a supply of force for their performance. Thns the 

 production of the trne "contractile substance" of the 

 muscles (see p. 224), if such a substance exists, from pio- 

 teui and non-nitrogenous matter, must absorb and render 

 latent large amounts of force coming from the simultaneous 

 oxidation of other materials. 



Such processes, however, have no significance to the 

 feeder, since the force thus rendered latent is not with- 

 drawn fi'om the body, but is set free again in it when the 

 complex substance is decomposed. 



Influence; of SmruLANrs. — The influence of stimulants 

 upon the chemical processes in the body has been but little 

 investigated. 



Volt's experiments on coffee * seem to indicate that this 

 substance, at least, has practically no effect upon the pro- 

 tein consumption in the dog. On the other liand, it would 

 seem that the oxidation of non-nitrogenous matters may be 

 considerably affected by nervous influences, such as cold, 

 stimulation of the skin, light, sound, etc. The fact that 

 the excretion of carbonic acid is less during sleep also 

 points in the same direction. 



There appear to be no experiments on farm animals 

 touching this point, but we may safely conclude from the 

 facts known concerning other animals, as well as from 

 practical experience, that nervous excitement, produced 

 by rough treatment, noise, etc., is unfavorable to the best 

 results of feeding. 



* " XJntersuoTnitigen uber den Emfluss des Koohsalzes, Kaffee's, etc., 

 auf den Stofiwechsel." 



