and in the Stack in Haymaking. 37 



existing circumstances. The elementary particles of the sugar 

 being disturbed in their previous arrangement, group themselves 

 according to their individual affinities ; and while the carbon 

 forms on one side, a compound containing all the hydrogen 

 (alcohol) it yields, on the other a compound containing the 

 greater part of the oxygen (carbonic acid). 



Alcoholic or vinous fermentation may thus be briefly de- 

 . scribed as the breaking-up of sugar under the influence of 

 ferments, and the reconstruction of the constituent elements 

 of sugar into alcohol and carbonic acid. 



Another condition favourable to fermentation is an elevated 

 temperature. If the thermometer ranges from 65° to 80° Fahr., 

 fermentation proceeds with rapidity, whilst at a lower tempera- 

 ture it goes on more slowly, and is stopped altogether at 32^ Fahr. 



In the absence of a sufficient amount of water many substances 

 otherwise capable of entering into fermentation remain appa- 

 rently unaltered for a long period. Too much or too little water 

 is alike unfavourable to the process. If one part of sugar is 

 dissolved in three or four parts of water, and yeast is added, and 

 the sugary liquid then placed in a warm room, no fermentation 

 takes place, although three of the essential conditions have been 

 fulfilled. Such a solution will require to be diluted with about 

 an equal weight of water, in order to set up active fermentation. 

 On the other hand, sugar dissolved in, say 16 to 20 parts of 

 water, after the addition of yeasts, either ferments but very 

 slowly, or rapidly turns acid in a warm place. 



These facts have a direct bearing on the proper conservation 

 of hay. As long as grass and clover are still quite fresh, the 

 proportions of water to that of sugar in the green plant are too 

 large to encourage fermentation ; the nitrogenous constituents 

 in newly-cut grass, moreover, only become ferments after the 

 vitality of the plant has been destroyed, and the vegetable cells 

 and vessels have become ruptured by partial drying, and their 

 contents have been mingled together. 



With the evaporation of water, and, to a certain extent, the 

 more or less complete destruction of the living organisation of 

 the plant, the conditions become more favourable for active 

 fermentation. By degrees the drying crop arrives at a stage when 

 the relative proportions of sugar and of the remaining moisture 

 are most conducive to fermentation. Should the weather unfor- 

 tunately turn showery at that stage of the haymaking process, and 

 the air become saturated for many days and weeks together, the 

 half-made hay often begins to ferment already in the field. 

 When this takes place the hay loses in quality, and becomes 

 much more liable to heat afterwards in the stack. If, on the 

 contrary, fine and warm weather sets in, and evaporation pro- 



