276 The Sugar-Beet in America 
given because these compounds are made up of carbon 
combined with hydrogen and oxygen in the ratio in which 
these elements are found in water. This makes the carbo- 
hydrates in reality carbon-water compounds. The sugars 
are as a rule crystalline, soluble in water, less soluble or 
insoluble in alcohol, and insoluble in ether and other sol- 
vents that are immiscible with water. They all have a 
more or less sweet taste, but vary considerably in sweet- 
ness. Most sugars have the property of rotating the 
plane of polarized light. This property is of great aid to 
the chemist in making rapid determinations of the quantity 
of sugar present in any substance. 
The commercial sugars are divided chemically into two 
classes: monosaccharids and disaccharids. The mono- 
saccharids have the formula C.sHwO. and include dex- 
trose, or grape-sugar, and levulose, or fruit-sugar. The 
disaccharids have the formula CyH.O1 and include su- 
crose, or cane-sugar, lactose, or milk-sugar, and malt- 
ose, or malt-sugar. They may be considered as con- 
densation products of the monosaccharids and derived 
from two molecules by the elimination of water thus: 
2 CeH,205 —H.O =CyHe2O0u. The sugars of the disac- 
charid group are hydrolyzed when heated in solution with 
dilute acid; in the case of sucrose a mixture of dextrose 
and levulose results, the change consisting of the addition 
of a molecule of water and a bisection of the sucrose 
molecule. This action is called “inversion.” 
Sucrose, or cane-sugar, is the most important of the 
sugars; it is the ordinary sugar of commerce. It is about 
two and one-half times as sweet as grape-sugar. The 
name cane-sugar was given because it was first obtained 
