508 
In this experiment it frequently happened that the melt first erystal- 
lised to the 42°-acid and afterwards was transformed back into the 
68°-acid. This was also noticed by SroBBr and ScnönBure. This 
phenomenon is therefore not due to atmospheric nuclei, but to nuclei 
in the liquid. 
Although for a permanent transformation into the +2°-acid a 
complete absence of 68°-acid nuclei is essential, it is, of course, to 
be understood that a single nucleus of this acid, remaining over 
on melting the acid, is not necessarily sufficient to cause an 
immediate transformation of the melt. This may only take place 
after the lapse of several hours. Moreover, the nuclei vary in size, 
and the effect produced by the smallest, which is probably built up 
of only two molecules of allocinnamiec acid, is presumably less 
effective and less rapid than that of nuclei consisting of several molecules. 
From the foregoing it appears that the arguments used by STOBBE 
and ScHONBURG in support of the chemical isomerism of the allocin- 
namie acids are fallacious, while the experimental results obtained 
admit of satisfactory explanation on the assumption of the trimorphism 
of these acids. 
hort summary of the results ained. 
Short y of tl lts obtained 
1. An experimental method was worked out and applied by which 
it is possible to avoid inoculation, to exclude atmospheric nuclei, and to 
bring about the complete dissociation of those nuclei present in the liquid. 
2. With this method it was shown that dilute solutions of the 
58°-acid and the 68°-acid give, after removal of the solvent by distil- 
lation at ordinary temperature, a residue which is transformed into 
the 42°-acid. 
3. When the concentration of the solutions of the 53°-acid and the 
68°-acid is great, as may occur with ether and benzene as solvents, these 
acids are not transformed into the 42°-acid at ordinary temperatures. 
4. The solutions may be transformed by cooling in ice and salt. 
In this way an aqueous solution containing no nuclei of the 58°- 
acid or the 68°-acid gives at —10° the 58°-acid and at —16° the 
58°-acid or the 68°-acid. 
5. In the solid state the acid forms appear to be unaltered after 
cooling for six days in ice and salt. 
6. The arguments of SroBBe and SCcHÖNBURG in support of the 
chemical isomerism of these acids are shown to be fallacious. All 
the results obtained are completely explicable on the assumption 
that the alloeinnamie acids are trimorphous. 
Buitenzorg, January 1919. 
