( 161 ) 
The results of these determinations are reproduced in the accom- 
panying figure. The line ACB represents the beginning, ADB the 
end of the solidification. To begin with, it is to be remarked that, 
setting out from the end points, the first line at once rises on addition 
of the active compound of opposite sign. 
There is therefore only one meltingpoint line and, consequently, 
the solid mass must consist of mixed erystals, and the inactive 
substance (50 pCt. d of /) is not a racemic compound but a pseudo- 
racemic mixed crystal. 
It were however conceivable that from A or B a small fall occurs, 
which escapes observation, because the rise begins at a very 
smal! concentration of the second 
oxime. If this were the case the 
inactive oxime would really bea 
racemic compound. The matter 
can, however, be readily decided. 
If it is a racemic compound the 
solidification of all mixtures, from 
0 to 50 pCt. dor /, must terminate 
at the temperature of the eutectic 
point, which exists where the 
short falling lines from A and B 
meet the line of the racemic 
compound. 
In our case therefore the solidi- 
fication of all mixtures between 
O and 50 pCt. would have ter- 
minated just below 72°, 
The final solidifying points, which were susceptible of very accurate 
observation, lie however on the line ADS and change continuously 
with the concentration. 
For some concentrations the end point was determined by obser- 
ving the course of the cooling as a function of the time in a bath 
at constant temperature. By this means the time, and therefore also 
the temperature, at which the solidification is complete may be 
observed with great accuracy. 
The curve ADB confirms the view that mixed crystals are formed 
on solidification at all concentrations. 
Thirdly it is supported by the analysis of crystals which were 
deposited from a fused mixture containing 20 pCt. of /-oxime. If 
the line ACB were the melting point line of a racemic compound, 
this compound would be deposited from the fused mass; if mixed 
| Pi, 
