298 FERMENTATION OF NEW MADE HAY. 



from dillureut sides, or near the center of the stack, to prevent 

 packing the hay on one side more than on the other. The top 

 slioukl be finished with long, straiglit, coarse grass or sedges. 

 In the okl country stacks are thatched. 



Feriiieutatiou of New-Made Hay. — Concerning this point, 

 tlie following is from the pen of Prof. F. 11. Storer in the Rural 

 Xeiv Yorker: 



''There are several facts, long famihar to practical men, which 

 show clearly that the process of hay-making is something more 

 than a mere drying-out of moisture from the grass. New liay 

 will ' sweat ' somewhat in the mow or stack, no matter how dry 

 it seemed to be at the moment of storing ; and many horse-keei)- 

 ers believe it is not fit for food for horses until after this sweat- 

 ing fermentation has thoroughly run its course. 



" Even at the ordinary temperature of the air a good deal of 

 carbonic acid, with traces of hydrogen and hydrocarbons, are 

 given off during fermentation. 



"In the beginning of an experiment, the oxygen of the air 

 was rapidly absorbed and changed to carbonic acid. But even 

 after the oxygen had been completely removed in this way from 

 the confined volume of air employed in the experiment there was 

 still evolution of carbonic acid from the hav, the oxvffen for 

 which must have come from the grass. The atmosjihere sur- 

 rounding the grass had but little influence on the volume or the 

 composition of the grasses produced. The evolution of carbonic 

 acid took place about as rapidly in the artificial atmosphere as it 

 did in air. It Avas more rapid at a temperature of 97 degrees 

 than at GO degrees. Where corrosive sublimate was used in the 

 hay, or where the tube containing the hay was exposed to steam- 

 heat for several hours and tlien left to itself, no gases at all were 

 evolved ; hence the conclusion that the fermentation and the ev- 

 olution of gas must be dejiendent upon the presence in the hay 

 or grass of low forms of organic life. In confirmation of this 



