A Manual of the Chemistry of the Carbon Compounds

260 THE CHEMISTRY OF
into /S chloropropionic arid, which forms fibrous crystals smelling like
creosote and melting at 65°.
Amidoglycerie Add or Serine (C3H,O8NH^.—This oompound has
been obtained by boiling sericin or silk-gelatin (see SUk) with dilute
sulphurio acid. It crystallizes from a hot solution in hard brittle
crystals, and forms metallic salts, but combines also with acids. By
the action of nitrous acid it is converted into glyceric acid.
The constitution of glycerio acid and its derivatives is generally
represented by the following formulae:—
Qlycerio Acid. 0 lodopropionle Acid. Hydrnerylio Acid.
CHj.OH
CH.0H CH2 CH2
CO.OH CO.OH CO.OH
If hydracrylic acid had this constitution it would be identical with
ethene-lactic acid, which on oxidation is converted into malonic acid.
But hydracrylic acid does not yield a trace of this compound, but is
resolved into carbon dioxide, glycollic acid, and oxalic acid, and no
acetic acid informed, showing that hydracrylic acid does not contain
the group methyl, and therefore its constitution is also quite different
from that of common lactic acid.
When an alcohol is oxidized, the oxygen entering the molecule
is attracted by that carbon atom whioh is already combined with
oxygen. Now in glycerin each of the three carbon atoms is combined
with oxygeu, and consequently the oxygen whioh replaces
the hydrogen will be attracted as much by the second carbon atom
as by the first. From this it appears very probable that the above
compounds have the following constitution :—
Glyeerio Acid. & lodopropionio Actd. Hydrncrylio Acid,
CHj.OH CH,I CH8.0H
i.OH OH ,CH
°