80 VEGETABLES. 



had a stove filled with wood and dry faggots. It may 

 have been so filled a long time. But no heat is evolv- 

 ed. The stove is no warmer than the objects around 

 it. If now you apply a torch, a chemical action takes 

 place in the stove. Oxygen combines with the wood. 

 A transformation of the air and wood into other sub- 

 stances takes place. A real chemical experiment is 

 performed, one that would seem very wonderful, if 

 we had not seen it so often ; and much more heat is 

 produced, than was in the torch, which you applied. 



132. Just so is it with the seed. There were mate- 

 rials deposited, as in the stove ; not to burn, it is true, 

 but to be transformed ; and, in the transformation, to 

 evolve heat in the seed, much more than is applied 

 from the soil. As the stove, so the seed, heats itself, 

 when the operation is once started. 



Upon this evolution of inward heat, a portion of 

 vinegar is formed in the seed. As cider, by excessive 

 fermentation, turns to vinegar, so a portion of every 

 germinating seed turns into vinegar, or acetic acid. 

 This IS believed to attract bases from the surrounding 

 soil, and to form with them acetates (123), which are 

 known to be very soluble, and may be regarded as a 

 sort of pap for the embryo plant, while yet it can 

 neither reach after, nor could digest other food. 



133. Simultaneously with the formation of vinegar, 

 another substance is formed in the seed, called diastase. 

 This diastase has the power to transform starch into 

 sugar. That this is the object there can be no doubt ; 



