217 
that a compound can only then be formed when the conditions are 
favourable for the formation of a 5-ring (and eventually of a 6-ring). 
A substance like mannitol might then unite readily with one or more 
mols. of borie acid, because the position of the hydroxyl groups would 
favour the formation of 5- or 6-rings. 
In the case of a hexatomie alcohol like mannitol, the conditions 
for the ring formation are, however, probably favourable, because 
to each carbon group is attached a hydroxyl group and because of 
the very great probability that two of these with the two carbon 
atoms attached thereto, are situated at the same side and in the same 
plane ; and this especially because it is a saturated non-cyclic substance. 
It occurred to me that a further study of the influence of these 
compounds on boric acid might become of more importance still, if 
the more simple alcohols were chosen for that purpose. 
Now, with the polyoxyderivatives of benzene the conditions are 
exceedingly simple. 
When in the benzene derivatives the six carbon atoms with the 
groups attached thereto, are situated in one plane, the orthodioxy- 
compounds only (eventually also the erthooxyacids have a configu- 
ration that offers the best chances for the formation of the said 
cyclic systems. 
In fact, the measurements carried out by myself and A. van 
Rossem (l.c) have shown that of the polyoxyderivatives of benzene 
only the orthocompounds exert a very great positive influence on the 
conductivity of boric acid. 
The specifie conductivity of */, mol. solution of this acid at 25° 
is increased : 
by '/, mol. pyrocatechol from 25.7 > 10-® to 553.2 X 10-6 
EE voy marae en Wd tk) OBD oe DD 
MR ETRA Ireen RE AO AE 
OLM A) EN VT de Wh ide DOL ORONO 
ee pase, IARI Ox EMO 
(measured by Mr. J. D. Rvys) 
on the other hand, the meta- and paraderivatives exerted an insigni- 
ficant negative influence. The spec. conductivity was lowered : 
by */, mol. resorcinol from 25.7 « 10-® to 25.0 ~ 10-6 
tues oo eavaneduinenie )< «an 7). R A0s8 
ae er opaorobimanol- . /. carver SIO: Og LORE 
Gallic acid and protocatechuic acid also suffer a considerably larger 
increase in conductivity by addition of boric acid than would agree 
with this acid’s own conductivity. 
> fs: » 1.2-dioxynaphtalene 
