A second experiment similarly conducted gave a concordant result. 
Hence, it appears that 
a. normal cinnamic acid can yield a- as well as d-truxillie acid, 
bh. the formation of g-truxillie acid takes place not primarily but 
secondarily over the normal acid, 
c. B-truxillie acid is not formed by the union of 1 molecule of 
normal and one molecule of allocinnamic acid as was supposed 
formerly. ». 
It was still required to ascertain the reason why the modus 
operandi applied by Rurer did not give g-truxillie acid. 
According to this method the powdered cinnamic acid is spread 
out in a thin layer on a sheet of paper and placed in a photogra- 
phic frame. 
From the results of the following experiment it will be seen that 
the finely divided state of the cinnamic acid obstructs the for- 
mation of 3-truxillie acid. 
On sheets of paper were plotted surfaces of equal size. These 
sheets were placed on enfleurage frames and on each marked space 
were spread out 1 gram of cinnamic acid powdered or crystallised. 
After about an hour’s exposure to light, both the powders and the 
crystals were treated as stated in the following survey. In all, the 
exposure occupied 5 hours. 
With Without 
glass covering glass covering 
a B a p 
Powdered 0.364 nihil 0.650 nihil 
i mixing 0.260 ne 0.705 i 
Crystallised in porcelain dish and 
removed by scraping 0.120 0.044 0.321 0.150 
Same, after being recrystallised in 
the same manner each hour 0.061 0.088 0.221 0.176 
The glass used as covering and derived from photographic plates 
was not of uniform quality, hence the results obtained with glass 
covering are not mutuaily comparable. 
The powdered cinnamic acid, both with and without glass covering, 
has always yielded e-truxillie acid only. From the crystals @- and p- 
truxillie acid have formed in both cases. 
I hope, shortly, to revert to this remarkable transformation. 
