280 



SUGAR OF STAECH. 



with sugar of 

 Hiilk. 



Tlie sugar of 

 milk decom- 

 posed, not the 

 acid. 



Experiment 

 repeated in 

 close vessels. 



Water appa- 

 rently formed. 



receiver a hundred grammes of sugar of milk, four of sulphuric 

 acidj and four hundred of water. To the neck of the retort 

 was adapted a tubulated receiver, from which proceeded a sig- 

 moid tube, opening under a jar filled with water. 



After boiling for three hours, no gas had come over, except 

 the air contained in the vessels. A pi'ece of blue paper intro- 

 duced into the neck of the retort was not reddened. The wa- 

 ter that had passed into the receiver was without taste, did not 

 redden litmus paper, had no smell of sulphurous acid, and did 

 not precipitate lime-water, muriate of barytes, or acetate of lead; 

 consequently it contained no sulphurous, sulphuric, acetic, or 

 carbonic acid ; in short, it was nothing but pure water. 



Barytes-water traversed by the bubbles, extricated during the 

 process, wafi not rendered turbid in the least, and the gas that 

 had passed into the jars was nothing but the air of the vessels. 



It is evident, that the sulphuric acid had not undergone the 

 slightest decomposition : nevertheless, the sugar of milk was 

 decomposed ; 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 purpose the same experiment was begun afresh in close 

 vessels, with iOOgrs.of sugar of milk, 400 grs. of water, and 

 4 grs. of sulphuric 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 5 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 sulphuric acid, and 5 grs. of potash employed ; but it 

 weighed only 98 grs. consequently there was a loss of 11 grs. 

 This experiment Vv'as repeated twice njore, 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 errour in the 

 weighing, v.'hich was conducted with the greatest care. 



Hence we must conclude, that this diminution of weight 

 is occasioned by a quantity of M'ater formed at the expense 

 of the sugar of milk } and this with the more reason, as no 



gas. 



