342 PLANT AND ORGANIC CHEMISTRY 
land moss, and inulin, from many composital plants, act the 
role of starch in the plants wherein they occur. 
A brief reference may be given here to compounds like 
dextrin and laevulin, which stand intermediary between the 
starches and sugars. Dextrin is formed from starch by treat¬ 
ing with dilute acids, or by diastase. According to the con¬ 
ditions, several dextrin kinds may be separated. A crystal¬ 
line form, produced by the action of dilute mineral acids on 
starch for months, has been isolated. Dextrin gives with 
iodine a red coloration. 
Glucosides are compounds of grape sugar or glucose with 
another substance, and naturally find place in a study of car¬ 
bohydrates. Grape sugar, on account of its containing an 
aldehyde group, is capable of uniting with different kinds of 
chemical bodies to form these compounds. The compound 
which results on decomposing a glucoside is frequently of a 
complex nature. Glucosides are very widely spread in nature. 
In many cases the chemical constitution of glucosides is well 
known, and some of these compounds have been made syn¬ 
thetically. 
Recently, Fischer has described a method of obtaining glu¬ 
cosides synthetically. By the action of hydrochloric acid on 
sugars, alcohols, oxyacids, and phenols, he obtained conden¬ 
sation products of the nature of glucosides. These compounds, 
like other glucosides, do not react with Fehling’s solution or 
with phenyl-hydrazine. But they are decomposed by acids. 1 
1 Also ketones, by warming and treating with hydrochloric acid, are changed 
into glucosides. Ketones combine with sugar; rhamnose with one molecule; 
arabinose, fructose, and glucose unite with two molecules of acetone; sarbose, 
with a ketosane, yields a beautiful crystalline compound. By employing a very 
weak solution to work with, in contradistinction to the former work with strong 
hydrochloric acid, a-and j8-stereomers were obtained, also a third product, an 
acetal compound, analogous to the glucose mercaptans. In the beginning 
these are in excess, then they go over into glucosides. 
The ketose sugars react with alcohol, in presence of HC 1 , more quickly than 
aldosans. 
Fischer has also discovered, as a between-product, glucose-acetone, which 
is separated in fine, colorless needles. This compound is distinguishable from 
the glucose di-acetone. 
A new glucoside, similar to amygdalin, but of a simpler formula, named 
amygdonitril glucoside, has been recently described by Fischer. 
