(73) 
III, from 0,0168 to 0,005 ; for the reactions in methylaleohol 
(II and IV) an increase at first occurs with increasing content of 
water, for [I there is a maximum at 70 °/, (0.032 to 0.0435) after 
which the numbers diminish to 0.004, for reaction IV the increase 
continues as far as the decomposition in 40°/, alcohol (0.00525. to 
0.0098) which was the extreme limit to which it was possible to 
go. The subjoined figure shows the change of the constants with 
the content of water. 
= 
oot 
oF 
B 
a 
Se 
Va 
nay 
It is thus evident that, as in the case of the reaction between 
o-dinitrobenzene and sodium alcoholate, the addition of water to 
ethylaleohol diminishes the velocity of the reaction, whilst with 
methylalevhol an increase first occurs which (reaction IT) is followed 
by a decrease. 
Attention may be drawn to some other conclusions. First, it 
appears that whilst for both iodides in methylaleohol there is a 
maximum for the mixture containing about 70 °/, of alcohol, the 
constants diminish regularly with methyliodide IT, whilst with 
ethyliodide (IV) they remain practically constant between 40°/, and 
70 °,. It is further seen that in the alcoho! in which the electro- 
lytic dissociation is the greater (methylaleohol) the velocity of 
6* 
