( 3S4 ) 
research junder the same conditions by Ladesburg and Doctor 1 ), I 
am of opinion that this research, although carried out fully and 
accurately, is attended with errors and that, therefore, the results do 
not represent the true state of affairs. 
Ladenburg and Doctor havd determined at different temperatures 
the solubilities of strychnine racemate and of strychnine /-tartrate 
and strychnine (/-tartrate together, and they are of opinion that at 
the temperature at which the solubility of the partially racemic salt 
became equal to that of the mixture of its two component parts, 
the transition point of the strychnine racemate was situated, that is to 
say, that below that temperature the said salt would be stable in 
presence of its saturated solution but that at a higher temperature 
it would be resolved under those circumstances, with simultaneous 
separation of the least soluble of its dissociation products. By this process 
that temperature was found to be 30°, whereas by the tensimetric 
method 29°,5 was found. Moreover, the said authors have always 
endeavoured to determine the content in d- and /- strychnine 
tartrate of the solutions saturated with both salts by measuring the 
angle of rotation of those solutions and calculating the respective 
proportions from the known specific rotatory power of each of 
the two salts. Their observations led to the result that at the tran¬ 
sition temperature the solution saturated with both components (these 
will in future be designated by D and L and their compound by 
R) would contain exactly 50% of both. 
Immediately after their publication Bakhuis Roozeboom 2 ) pointed 
out the improbability of their results and in the graphic representation 
given in his paper the way has been indicated how to set to work 
when studying the solubility phenomena in cases of partial racemism. 
The two components in the system L, D ancf water, in which R 
can be formed from D -f- X, have, as we are dealing here with 
biactive substances whose configurations are partly each other’s mirror 
images, at all temperatures a different solubility, which is shown by 
an asymmetric form of the solubility isotherms in this ternary system. 
This is elucidated by fig. 1. Suppose at a certain temperature the 
solubility of L= OL, of D=OD. If now L is dissolved in water 
already containing D, or D in solutions containing L, we obtain 
points situated on LC 1 or DC 1 , respectively, C l represents the 
solution saturated with both D and L. 
At the temperature of the transition point we obtain a similar 
0 Ber. d. d. chem. Ges. 32, 50. (1899). 
2 ) Zeitschr. f. physikal. Chem 28, 494 (1899). 
