MANUAL OF CATTLE-FEEDmG. 223 



Tins alternate storing np and giving off of ozygen by 

 tlie body has also been observed in physiological experi- 

 ments of an entirely different character, which can only be 

 alluded to here. 



That the storing up of energy is connected with tlie 

 storing np of oxygen is indicated by a few experiments by 

 Pettenkofer & Voit on two diseases in which the patient 

 is almost incapable of muscular exertion, viz., diabetes and 

 leukaemia. In these experiments the total excretion and 

 the total amount of food were not much different from 

 those in health ; but there was no such storing up of oxy- 

 gen as in the healthy organism, and there was also, as is 

 usual in these diseases, an almost entire lack of strength. 



But Pettenkofer & Yoif s and Ilenneberg's results mm 

 especially valuable for our present purpose because they 

 show that muscular power does not have its origin in a 

 simple oxidation but in the "explosive" decomposition, 

 independently of oxygen, of material ali*eady prepared in 

 the muscle, a conclusion to which we are also led by the 

 fact, already noted, that the muscle is able to perform 

 work for a considerable time independently of oxygen, 

 provided the resulting decomposition products are re- 

 moved. 



Conclusions. — We have learned in the foregoing pages 

 that, presupposing the existence of a healtliy and well- 

 nourished organism, muscular exertion is possible when 

 the chemical products of the action are removed from the 

 nniscles, and when the body has had the ability and op- 

 portunity to lay up a store of latent energy ; that this stor- 

 ing up of energy is effected by the entrance of oxygen 

 from the air into combination with the organic substances 

 of the nmseles ; that when work is performed this oxygen 

 reappears in combmation with carbon and hydrogen as ear- 



