CATTLE FEEDING. 



151 



Experiments were tried on a vigorous and healthy man, wliich 

 gave results that show conclusively that the fatty substances sutler 

 oxidation, and that alljuniin is not destroyed when at work, though 

 it be severe. The man performed mechanical work during nine 

 hours of the daj', and the following table gives the results while at 

 work or at rest, under different conditions of alimentation : 



* One gramme is equal to 15.43 grains. 



A glance at these figures reveals the fact that the quantity of 

 albumin decomposed while at rest or at work is about the same, 

 while it becomes evident that there is a great decomposition or ox- 

 idation of fat during work ; the quantity of carbonic acid expelled 

 bj' the lungs is greatly increased, as is the absorption of oxjgen ; 

 and there is also a larger quantit}' of water eliminated by the lungs 

 and skin. The quantit}- of carbonic acid expired is greater when 

 the bod}' is submitted to a fast than when it is being fed with nor- 

 mal rations. 



It has been stated by some, that during work a certain amount of 

 free nitrogen was expelled by the lungs, showing that the per cent. 

 of nitrogen in the urine was not a true indication of the decomposi- 

 tion of the albuminoids of the bod}'. A series of very exact experi- 

 ments has shown this not to be the case. 



Nobody at present contradicts the fact of the destruction of fat 

 and the formation of large quantities of carbonic acid. The simple 

 process of mastication increases the amount of carbonic acid formed 

 when compared with that expired by animals in a more perfect state 

 of inactivity. 



From the above facts it becomes very evident that, in order to 

 obtain the most rapid production of fat, animals must be permitted 

 as little muscular activity as possible. 



A veiy simple comparison has sometimes been made between 

 animals at work and a steam engine properlj^ fed with fuel and pro- 



