336 PLANT AND ORGANIC CHEMISTRY 
sugar chain may be increased and a higher synthetic com¬ 
pound formed. Upon the addition of prussic acid to sugar 
compounds, the further processes of saponification and reduc¬ 
tion are necessary before obtaining a higher sugar. By this 
method it is possible to pass from sugars containing a few car¬ 
bon atoms to sugars representing a higher synthetical series. 
However, this method can only be used with sugar compounds 
containing not less than 3 carbon atoms. Such compounds 
have the power of forming lactones, and sugars of a higher 
carbon percentage are obtained by reducing these lactones. 1 
By the use of this method Fischer has obtained some of his 
most brilliant achievements. 
The right, left, and inactive glucose and idose, which are 
Stereomers of glucose, have been obtained synthetically from 
their corresponding acids. Idose is named from the symme¬ 
trical form of its molecules, and is among the latest discovered 
compounds of this group. The acids of these last two sugars 
are isomeric with the sugar acids obtained by oxidizing glu¬ 
cose and mannose. 
Two other sugars, which may be mentioned as belonging 
to the hexoses, are galactose and talose. The right, left, and 
inactive galactose have been obtained. The d-galactose as 
well as the d-glucose may be derived from milk sugar by hy¬ 
drolysis. The latter may also be obtained by the same means 
from other carbohydrates. Galactose yields, on reduction, an 
alcohol called dulcite. These sugars belong to the second divi¬ 
sion of the hexose group, known as the dulcite grofip, and by 
oxidation yield mucic acid; whereas the sugars of the mannite 
division yield, on oxidation, saccharic acid. All these sugars 
may be separated from their solutions, in a solid form, by 
1 The lactones are gamma hydroxy compounds, which, by the loss of 
water, give an anhydride. 
ch 2 oh 
ch 2 
ch 2 
COOH 
Counting from the one above the bottom group, the carbons are known as 
the alpha, beta, gamma, delta carbons, etc. 
