502 
and also in the number of the nuclei, or possibly in both causes 
together. The transformation of the nuclei of the 68°- and the 58°- 
acid in ethyl ether and benzene solutions, saturated at 25°, without 
crystals, did not take place even after they had stood in the dark for 
fourteen days. This is very probably due to the great concentration 
of the solutions. At 25° about 4.4 germs. of 58°-acid is soluble in 
1.6 grms. of ethylether, and about 4.6 germs. in 2.3 grms. of benzene. 
The 68°-acid dissolves to the extent of about 6.6 grms. in 3.2 germs. 
of ethylether and about + grms. in 3 grms. of benzene. 
An ether solution containing 2 grms. of 68°-acid in 5 ¢.c. and a 
benzene solution containing 2.4 grms. of acid in 3.6 grms. of solvent, 
gave a residue after standing for eight days in the dark which 
yielded the 42°-acid on crystallisation. After two months, standing 
in the dark a solution containing 2 grms. of the 58°-acid in 1.6 grms. 
of ether and a benzene solution with 1.8 grms. of acid in 2.5 grms. 
of solvent gave also -a residue which crystallised out as 42°-acid. 
An attempt to remove the nuclei from ethylether and benzene 
solutions, saturated at 25°, by filtration through cotton wool or 
filter paper was not successful, even-when the solutions had been 
kept for more than ten days free from crystals. 
From the foregoing it appears that the transition of the 58°-acid 
and the 68°-acid into the 42°-form in solution can take place inde- 
pendently of the melting of these forms, and that at 25°—30° they 
can form solutions which, apart from differences of concentration, 
are identical, provided that the nuclei are afforded an opportunity 
for transformation, and that atmospheric nuclei are excluded. When, 
however, the concentration of the solution is high, as may be the 
case with ether and benzene solutions, then it is not possible to 
break up the nuclei, or to remove them by filtration. In this case 
there exists most probably an equilibrium between the nuclei and 
the other molecules. 
One of the principal arguments of SroBBr and ScnHönBurG for the 
chemical isomerism of these acid forms is thus rendered ineffective, 
while the results are in complete agreement with the assumption of 
the trimorphism of the allo-cinnamic acids. 
In connection with what Stops and ScHöNBurG have communicated 
regarding the transformation of the 42°-acid and the 58°-acid into 
the 68°-acid at —14° (ice and salt), it was of importance to investi- 
gate if the same change also took place in solution. 
Various solvents were used. The most important results were 
obtained with water, so that these may be detailed first. 
An experiment was made with 68°-acid which had been freed 
