1893-94.] On Two Stereo-Isomeric Hydrazones of Benzoin. 201 
On Two Stereo-Isomeric Hydrazones of Benzoin. By 
Alexander Smith, B.Sc., Ph.D. 
(Read January 15, 1894.) 
While the theory of stereo-isomerism has been employed in the 
case of many carbon compounds, it has had but few applications in 
that of organic substances containing nitrogen. Its use has been 
almost confined to explaining the occurrence of isomers among the 
oximes. The addition of a new member to the small list of four or 
five pairs of hydrazones, whose isomerism can be explained only on 
the assumption of diversity in the disposition of the atoms in 
space, is therefore not unwelcome as giving additional weight to the 
theory. 
Werner (Berichte 23, 2333) has prepared the two stereo-isomeric 
ketoximes of benzoin, and, in accordance with Hantsch and Werner’s 
theory, assigns to them the formulae : — 
C,H,-C-CH(OH)-CA 
HO-N 
a-Benzoin-oxime. 
Stable, M.P. 151°. 
C,H,-C-CH(OH)-CA 
!l 
N-OH 
^-Benzoin-oxime. 
Unstable, M.P. 90°. 
The two phenyl-hydrazones described below will therefore possess 
the formulae : — 
C6H5-C-CH(0H)-C6H5 
C,H5-C-CH(0H)-CA 
II 
N - NHCgHs 
a-Hydrazone. y8-Hydrazone. 
Stable, M.P. 158-159°. Unstable, M.P. 106°. 
The following four paragraphs give briefly the reasons for 
believing that the substances isolated are really physical isomers. 
1. When benzoin and phenyl-hydrazine, in molecular propor- 
tions, are dissolved in alcohol and warmed on the water-bath for 
four hours, the solution deposits on cooling, first a substance melt- 
