1898-99.] Sulphuric Acid and Sulphates in Solution. 
495 
acid sulphate) the neutral salt must exert an accelerative effect on 
the catalysis, in the same manner and of the same magnitude as in 
the case of a monobasic acid. 
We must therefore correct the velocity constants obtained with 
solutions containing sulphuric acid and a neutral sulphate, for the 
accelerating influence of the latter. 
This influence has been measured in the case of cane sugar 
inversion by Sphor ( Zeit . physik. Ghem ., 1888, ii. 194), and by 
Arrhenius (loc. cit ., 1889, iv. 226). The latter has shown that the 
increase is nearly equal for all salts, or is at least of the same order 
of magnitude, and amounts to about 6*5 per cent, for an addition 
of OT equivalent neutral salt per litre. 
Trey (Jour, prakt. Chem ., 1886, xxxiv. 353), on the other 
hand, found in the catalysis of methylic acetate, an increase in the 
velocity of about 3 ’5 per cent, when the same quantity of neutral 
salt was added. 
As the influence of neutral salts on the velocity of catalysis of 
ethylic acetate had not been measured, I made special experiments 
with hydrochloric acid as the catalysing agent, to determine the 
influence of neutral chlorides in this reaction. These were carried 
out in the same manner as already described for sulphuric acid and 
sulphates, the increase in the velocity constant obtained with acid 
alone being determined for two concentrations of the neutral salt 
in each case. The details are given below, and are arranged as 
before. 
I. 
HC1 0*2 normal. 
t 
X 
E - x 
k 
1 t 
X 
E-x 
k 
235 
528 
446 
144*4 
120*5 
322 
638 
147*3 
261 
568 
406 
145*7 
130 
340 
620 
146*1 
270 
581 
393 
146*0 
166*3 
410 
550 
145*5 
280 
596 
378 
146*8 
175 
432 
528 
148*4 
290 
607 
367 
146*2 
185*3 
446 
514 
146*4 
300 
621 
353 
147*0 
195 
465 
495 
147*2 
315 
636 
338 
146*0 
205 
480 
480 
146*9 
oo 
974 
— 
146*3 
oo 
960 
— 
147*1 
A third experiment gave k equal to 147*3. The mean value of 
the velocity constant for 0*2 acid is therefore 146*9. 
