118 
SELECTED ARTICLES. 
Thus the acids before converting cane sugar into grape 
sugar, transform it into an uncrystallizable sugar, having a 
much sweeter taste than cane sugar, from which it is made. 
I also made a comparison of the alcoholic fermentations of 
two equal parts of cane sugar, one transformed into uncrys- 
tallizable sugar, the other not; the proportions of carbonic 
acid were alike in both cases. 
I subjected the uncrystallizable syrup arising from the fore- 
going experiments to a heat of 140° for four hours, after hav- 
ing added T -J T of sulphuric acid of 66°. The acid was diluted 
in a quantity of water equal to twice the weight of the syrup, 
and after being mixed with it, lime was added to saturation; 
the syrupy fluid lost much of its sweet taste on evaporation; 
it afforded sugar after having been left undisturbed for a few 
days; I separated the uncrystallized portions by means of 
alcohol; the remainder was a large proportion of well crys- 
tallized grape sugar. 
This operation succeeded equally well with the other acids, 
their quantity being increased or diminished according to 
their energy; if the temperature be raised above 140° great 
attention must be paid to the process for reasons presently to 
be stated. 
Acids also convert cane sugar into grape sugar, without the 
assistance of heat, but it requires a much longer time; this 
fact has been observed by all pharmaceutists in their acid 
syrups, and is noticed by M. Boullay in his dissertation on 
ulmine. 
If instead of T | T of sulphuric acid ~j be added to the un- 
crystallizable syrup, and the heat be raised to 212°, a liquid 
of a dark brown colour is obtained after a few minutes boil- 
ing; this liquid on being saturated with lime affords no signs 
of crystals; after being evaporated, it assumes the form of a 
brown molasses, having a bitter as well as sweet taste. It 
loses but little of its colour by the action of animal charcoal, 
and the syrup thus purified never crystallizes. The dark co- 
lour is not owing to a solution of ulmic acid in the syrup; for 
I have boiled this acid with sugar, and only produced a light 
