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SELECTED ARTICLES. 
diabetes not entirely pure, the calcareous deposit was of a very 
beautiful rose colour. 
Action of Sugars on Sugars. — There is an experiment 
which has been much more thought of by adulterators than by 
chemists. This is crystallizing cane and starch sugar together, 
so as to present an uniform appearance. But the following ex- 
periments show that this cannot be done. 
On the 23d of May, I dissolved 20 grammes of sugar ob- 
tained from starch in 32 grammes of water, and left the syrup 
to evaporate spontaneously in a hot and dry place; ten days 
afterwards there was no trace of crytallization. On the 20th 
June, crystals similar to those of cane sugar were visible in 
the midst of a viscous fluid, but the quantity was small. 
I also boiled equal parts of cane sugar and grape sugar with 
animal charcoal, and obtained a perfectly clear syrup, of a 
pleasant taste, but not as sweet as before the operation; the 
mixture was left undisturbed for two months; crystallization 
gradually took place, and at last the whole formed a solid mass. 
In this case it was not the cane sugar that crystallized, but the 
grape; and the quantity of uncrystallizable sugar that remain- 
ed, did not equal one-fifth of the cane sugar added; hence, by 
the mere effect of boiling, the cane sugar was transformed into 
grape sugar. Numerous experiments have proved to me, that 
the uncrystallizable sugar which remained, was a mixture of 
the two sugars. 
APPLICATION OF THESE EXPERIMENTS TO THE MANUFACTURE 
OF SUGARS. 
Manufacture and Refining of Cane and Beet Sugar. — I 
have shown that lime, even at the boiling point of syrups, ex- 
ercises no injurious effect on cane sugar; these experiments 
clearly explain the advantageous use of it in sugar works. I 
have also ascertained that the soluble calcareous salts in like 
manner exercise no deteriorating influence; but this is not the 
case with acids in a state of great dilution; they first convert 
crystallizable sugar into an uncrystallizable white sugar, and 
