CHINESE AND AFRICAN SUGAR CANE. 
361 
The action of the ferment appears to depend on its being in 
a state of decomposition, consequently of molecular motion ; 
and this motion communicated to the molecules, or rather to the 
atoms of the sugar, suffices to destroy the existing equilibrium, 
and produces a new one, forming a grape sugar and subsequent 
fermentation. 
Grape sugar is distinguished from cane sugar by being less 
soluble and less sweet, and also by being easily decomposed 
into brown products by heating with diluted alkalies. It is the 
only kind of sugar which undergoes fermentation ; all the 
others are first converted into grape sugar, and then they fer¬ 
ment. 
When the ferment is yeast, or vegetable fibrine (proteine) in 
a state of decomposition, the vinous fermentation takes place 
in a solution of sugar. The juice of the grape, the infusion 
of malt, and the juice of Sugar Cane, all contain sugar and 
fibrine, and only require to be exposed to the air, and fermen- 
tion will take place. 
When caseine (the basis of cheese,) is the ferment, sugar, 
at the temperature of from 80° to 90°, is converted into lactic 
acid. With the same ferment at a higher temperature, lactic 
acid undergoes the butyric fermentation, especially if not neu¬ 
tralized. 
Sugar of milk has the same formula as grape sugar, and 
passes into it by contact with acid ; and then it ferments. 
Besides the kinds of sugar we have been noticing, all of 
which pass into grape sugar, and in that form undergo fermen¬ 
tation, there appears to be a kind which is uncrystalizable, but 
it is rendered so by impurities. Molasses, or the uncrystaliza¬ 
ble liquor from the Cane, is rendered so by a species of fermen¬ 
tation, or by the action of certain bases on the sugar during 
the evaporation, which produces two brown acids, glucic and 
melassic; the presence of which deprives a great part of the 
sugar of the power of crystalization. This formation of glucic 
and melassic acids, is the great obstacle the manufacturers of 
sugar from Sorghum have had to contend with. This difficulty 
