511 
The residue consists of «-truxillie acid. On cooling the filtrate 
yields y-truxillie acid which, if necessary, may be recrystallised 
from boiling water. 
In order to test the effectiveness of the method of separation a 
mixture of the six truxillie acids was subjected to the treatment 
above described with the following result. 
i | ; | | Melting point 
Quantity used |Ouantty found) ating point | AER Feet 
water. 
g-truxillic acid 0.119 0.086 270° — 
ER 0.100 0.096 2029 204° = 
y - = 0.134 0.099 200° — 215° 220° — 226° 
P 5 5 0.106 0.132 gummy 1729 — 1749 
€ - - 0.078 0.079 208° — 220° 230° 
B-cocaic , 0.106 0.120 165° — 175° 189° — 190° 
Total. . 0.643 0.612 | . 
For the sum of the «- and the y-acid 0.224 grm. was found. 
The method is therefore sufficient for the detection of the truxillic 
acids in presence of each other. If there are only two truxillic acids 
in the mixture an almost quantitative separation may be effected. 
From the above separation several properties of the truxillie acids 
may be noted. The following may be added. 
p-cocaic acid‘) forms with cinnamic acid a well crystallised double 
avid with equal proportions of the components. This is obtained by 
boiling a petroleum ether solution of einnamic acid, saturated at the 
ordinary temperature, with a little g-cocaic acid until the latter is 
dissolved (0.1 grm g-cocaie acid in 500 c¢.c.). On cooling the double 
acid separates out, frequently only after several days, in long needles, 
which melt at 139°. The filtrate gives a fresh quantity of double 
acid whenever 0.1 grm. of each of the acids is dissolved in it by 
boiling. The composition is determined by sublimation at 130°— 140°. 
The solubility of y-truxillie acid in chloroform is increased in a 
remarkable degree by the presence of 8-cocaic acid. 
The ammonium salts of the truxillic acids slowly lose their ammonia 
when their aqueous solutions are evaporated on a water bath and 
are transformed into the free acids. The ammonium salt of cinnamic 
acid also possesses this property. 
') The acid (m.p. 190°) formerly separated from the acids derived from the 
coca alkaloids appears to be (-cocaic acid. 
34* 
