Chemistry. — A. W. K. de Jone. “The Truzillic Acids’. (Communi- 
cated by Prof. van ROMBURGH.) 
(Communicated at the meeting of May 3, 1919). 
The separation of truailhe acids from cinnamic acid. Since 
mixtures of cinnamic acid and the truxillie acids are obtained by 
the action of light on the salts of the former, it was necessary to 
be in possession of a good method of separation. 
Although various attempts have been made to carry out the 
separation in the wet way, these have so far failed to yield 
quantitative results. This is partly due to the increased solubility of 
the truxillie acids in presence of other truxillie acids and especially 
of cinnamic acid; and partly to the smallness of the quantity of the 
truxillie acids compared with the cinnamic acid present. With petro- 
leum ether, for example, undoubtedly one of the best solvents for the pur- 
pose, no quantitative separation is obtained, since 6-cocaic acid and 
d-truxillie acid arevery appreciably soluble in proportion to the amount 
of cinnamic acid present. The same is true in a less degree of the 
other acids. 
The attempt was also made to effect the separation by means 
of the acid potassium salt, which is diffieultly soluble in alcohol. 
This, however, appeared to be impracticable, since some of the 
traxillie acids were also precipitated to some extent. 
For the present there remains only the sublimation method. This, 
however, with RrBer’s apparatus proceeds very slowly. For this 
reason the sublimation was carried out at ordinary pressure in a 
current of air at 130°. The substance was placed in a little boat, 
which in its turn was placed in a glass tube. The whole was heated in 
a sand bath at 130°. Sublimation was continued until the weight 
of the residue became constant. 
Separation of the trucillic acids from each other. The acids were 
dissolved in the calculated quantity of N/,, potassium hydroxide 
solution on beating. To the solution anhydrous calcium chloride 
was added, 1.5 grm. for each 10 c.c. of solution. After twenty- 
four hours the precipitate, which may contain the calcium salts of 
B-, d- and e-truxillie acid, was filtered off and washed with calcium 
chloride solution (1.5 grm. per 10 ¢.c.). The acids in the filtrate 
34 
Proceedings Royal Acad. Amsterdam. Vol XXII. 
