WHEAT SUGAR. 99 



slightest decomposition : nevertheless, the sugar of milk was decom- 

 posed : it had a much more saccharine taste, and after saturation 

 with chalk it fermented very readily with yeast. 



It was necessary, therefore, to examine the decomposing action 

 of the sulphuric acid on the substances in question. For this pur. 

 pos\i the same experiment was begun afresh in close vessels, with 

 100 grs. of sugar of milk, 400 grs. of water, and four grains of sul- 

 phuric acid. During the process no gas was evolved, as in the 

 preceding experiment. 



The liquid was then concentrated in a dish accurately weighed, 

 after having added five grs. of potash to saturate the acid. 



The mass thus evaporated to dryness should have weighed 109 

 grs. in consequence of the 100 grs. of sugar of milk, 4 grs. of sul- 

 phuric acid, and 5 grs. of potash employed ; but it weighed only 

 98 grs. consequently there was a loss of 1 1 grains. This experi- 

 ment wat repeated twice more, and there was still a loss of 9 or 1 1 

 grs. giving a mean of 10 grs. 



This loss is too great to be ascribed to any error in the weighing, 

 which was conducted with the greatest care. 



Hence we may conclude, that this diminution of weight is occa- 

 sioned by a quantity of water formed at the expense of the sugar of 

 milk ; and this with the more reasojh, as no gas, no acid, and no other 

 volatile substance, was extricated during the boiling. 



All these experiments with the sugar of milk were equally repeat- 

 ed with starch, except that a much larger quantity of water was 

 added to prevent it from burning. The results were the same as 

 those obtained with sugar of milk. 



Conclusions. From all that has been said, it follows : 



1. That starch and the fecula of potatoes, boiled with water 

 acidulated with sulphuric acid, are converted into a liquid saccha- 

 rine matter, the quantity of which corresponds with the weight of 

 the starch employed. 



2. That this saccharine matter is susceptible of the alcoholic 

 fermentation. 



3. That the syrup of starch is composed of gummy matter and 

 saccharine matter in variable proportions. 



4. That ^he syrup evaporated slowly in a stove exhibits an elastic 

 substance, perfectly transparent. 



H2 



