SECRETARY'S REPORT. 113 



only in the presence of air and moisture. This is the condition of 

 freshly cut grass, free from dew or external wet. 



The question then presents itself, what are the changes occurring 

 in hay-making. 



1. The ferments begin, almost as soon as life ceases, to act on 

 the sugary matter. This is changed by a true fermentation into 

 carbonic acid and alcohol, accompanied by various ethers and 

 essences — dependant on the peculiarity of the ferment. This last 

 always undergoes change during its action on fermentable matter. 

 Both lose weight from the escape of gas. 



2. The starchy matter cannot ferment like sugar. Certain albu- 

 minous ferments rapidly convert starch without loss of substance 

 into gum, and ultimately this into sugar. This is effected by dias- 

 tase, a substance produced by fermentation. Hence malt quickly 

 changes the starch into gum and sugar in the brewer's mash. 



Starch is also changed into gum and sugar, by the long action 

 of weak acids, even by very weak vinegar, but we have no evidence 

 that carbonic acid evolved during fermentation so acts, nor that 

 vegetable acids, existent in plants, change starch to gum and sugar, 

 as they promote the conversion of sugar into alcohol. 



In loet hay, it is possible that the starch swollen by previous 

 heating may be converted to gum by exposure, an effect well 

 known to be produced on starched clothes in damp weather. They 

 iron limpsy. 



3. Gummy and jelly matters — these change not. Gum is already 

 food in a soluble state, but by prolonged wet, the gum becomes 

 acid. 



4. The woody fibre will undergo no change in hay-making, unless 

 by prolonged wet. In this case, ferments act on it, and it under- 

 goes change with loss of substance. 



5. The neutral bodies — fat, wax, and the green drapery suffer 

 change by converting grass to hay, even in the most favorable 

 weather. I do not know the nature of this change. It is quite 

 obscure. It is connected no doubt with the formation of alcohol 

 and ethers, during the fermentation of the sugar, and is attended 

 by a loss of fat and wax. 



6. The mineral matters change not in hay-making so as to cause 

 any loss of substance. 



These various changes occur in curing in the best manner grass 

 into hay. There is in this case, a certain loss of substance. Each 

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