1077 
The research which is being continued in different directions in 
order to confirm the result obtained has elucidated the catalytic action 
of AICI, thus far that it does not exert its action because it unites with 
one of the molecules, for the free AICI], was much more active than 
the combined portion. The view already expressed many times by 
one of us that-the catalytic action of aluminium chloride is based 
on an influence (called by him dislocation) which makes itself felt 
before the real compound is formed, has, therefore, been confirmed 
by this research. 
In harmony therewith it appeared that there was measured an 
additive reaction of the acid chloride with benzene, the first rendered 
active only in so far as it is united to AICI,,-the second rendered 
active by the total aluminium chloride present. 
We have also carried out some measurements with henzene deri- 
vatives in order to get some knowledge as to the influence of the 
substituting group on the reaction velocity; there it was shown that 
the reaction with toluene using N/,, acid chloride AICI, at 30° 
proceeded so rapidly that the conversion had already practically 
taken place after the mass had become homogeneous; a constant 
could only be approximated. We give here also the reaction constants 
for benzene, chlorobenzene, bromobenzene and nitrobenzene at 30° 
and for a MN/, concentration of the acidchloride-AlCl, . 
toluene for O1 n. | > 0.0064 
benzene ,, 02% 0.0021 
bromobenzene ,, 0.00102 
chlorobenzene ,, 0.00080 
nitrobenzene _,, 0.00000 | 
From this little survey we notice that in the reaction of FRIEDEL 
and Crarts, another succession of the velocity influences is observed 
than in the nitration where, according to the researches of HoLLEMAN 
and his students, it is exactly opposed to this in the case of the 
methyl group and the chlorine atom. It may, however, be pointed 
out that our succession is based on measurements whereas the 
succession of the nitration is deduced from a comparison of the 
dirigent power of the groups on the entering nitro-group which, 
perhaps, has no direct connection with the velocity of nitration. 
When carrying out the reaction of Frieper and Crarts it is 
desirable, according to this research, to have the catalyst in small 
excess when it forms an additional compound with one of the 
reacting molecules. 
Delft— Wageningen, December 1912. 
