92 OUTLINES OF PHYSICAL CHEMISTEY
Malic acid :
co 2 h— Ghoh— ch 2 — co 2 h.
The following modifications are known :
1. The Icevo-rotatory acid — obtained from the berries of the mountain ash.
2. The racemic acid (inactive by mixture) — obtained artificially :
(a) by reduction of racemic tartaric acid by hydriodic
acid.
(b) by the action of water on fumaric acid (boiling the
fumaric acid with a dilute solution of caustic soda).
8. The dextro-rotatory acid— obtained:
(a) by reduction of dextro-tartaric acid by hydriodic acid.
(b) by resolving the racemic form. A saturated solution of inactive cinchonine malate is induced to crystallise by sowing with a crystal of the lsevo- malate of the same base. In this way Bremer has, surprising as it may appear, induced a crystallisation of the dextro- malate (' Berichte,' 13, 351, (1880).).
Coniine : C
/ \
I i
H 2 GH — kj$±±i
\ /
N
H
1. Natural coniine is dextro-rotatory.
2. The racemic modification has been synthetically prepared by Ladenburg. a-methylpyridine heated with
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