3 24 PLANT AND ORGANIC CHEMISTRY 
spectively gluconic and galactonic acids. By complete oxida¬ 
tion they both give saccharic acid. 1 
Conversely to the aldehyde sugars, fruit sugar is slowly 
attacked by bromine water. By the action of a more powerful 
oxidizing reagent it is decomposed into products containing 
fewer carbon atoms. 
The aldehyde and ketone character of these compounds 
is shown by the readiness with which the sugars form hy- 
drazone and osazone compounds. This reaction with phe- 
nylhydrazine is characteristic of all compounds containing 
aldehyde and ketone groups. 2 
The sugar varieties which to-day go to make up a magnifi¬ 
cent display of synthetic skill include many isomers, depend¬ 
ing upon the different arrangement of the atoms in space. In 
order to have a clear view over this field, it is important to as¬ 
certain the spacial relations or configuration of each member 
of the sugar groups. 3 
The latest publications by Emil Fischer on the Stereomers 
of the sugar groups show an admirable agreement between 
the conflicting facts pertaining to the sugars which have poured 
in from isolated researches during past years, when these are 
considered in the light of Le Bel and Van’t Hoff’s theory. The 
names of these investigators are especially identified with 
stereo-chemistry, although others have followed in the same 
lines. 
Among the writings of the past, the geometrical forms of 
matter were suggested by the Greeks, and later by Sweden¬ 
borg as a possibility; but it was Pasteur, in i860, who gave 
the underlying idea of grouping of atoms in space. 
1 When a solution of the alcohol mannite is heated for some hours to 42 0 C. 
with nitric acid, it is oxidized to mannose; if the reaction is continued with 
increased heat, the oxidation is carried on to the acid formation. 
2 CH 2 OH(CHOH) 4 CHO+ C 6 H 5 HN 2 H 2 =CH 2 OH(CHOH) 4 CH 
n 2 hc 6 h 5 +h 2 o 
CH 2 OH(CHOH) 3 CO . CH 2 OH+C 6 H 5 HN 2 H 2 =CH 2 OH(CHOH) 3 C.CH 2 OH 
+h 2 o I 
n 2 hc 6 h 5 
3 The configuration of a compound is the relative position of its atoms in 
space. The portion of chemistry treating on this subject is called stereo¬ 
chemistry. 
