chemical change by measurement of the gases evolved. 593 
a theory which was proposed by Veley to explain his conclusion 
that the action was bimolecular. 
I wish here to acknowledge my indebtedness to Prof. Bredig, 
of Heidelberg, who, after this paper had been read before the 
Chemical Society, and an abstract published in Proc. C. S., 
1906, 280, was so good as to bring before my notice the fact 
that in an Inaugural Dissertation published in the University 
of Heidelberg in 1906, David M. Lichty had shown by a titration 
method that the decomposition of oxalic acid by sulphuric acid 
is a unimolecular reaction, and not bimolecular as found by Yeley. 
In that paper also it is pointed out that Veley measured, not the 
velocity of reaction, but chiefly the velocity of evolution of a gas 
from its supersaturated solution. 
Urea and Sodium Hypochlorite. 
A few experiments were made to determine whether the action 
between urea and sodium hypochlorite was also one which could 
be described by a simple law. The solution of sodium hypo- 
chlorite was made by passing chlorine gas through a solution 
of soda. 40 c.c. of this solution were allowed to react with 10 c.c. 
of a solution of urea '0169 gm. p. c.c., the hypochlorite being 
Volume of gas 
evolved, c.c. 
Time, 
minutes 
Volume of gas 
evolved, c.c. 
Time, 
minutes 
0 
O'OO 
40 
9-00 
0-6 
0-55 
50 
14-00 
1 
0-77 
55 
18-33 
2 
1-00 
60 
25-16 
4 
1-43 
61 
27-28 
10 
2-50 
62 
29-75 
15 
3-28 
63 
32-78 
20 
4-08 
67-6 
2 hours 
30 
6-11 
present in considerable excess, the mixture being made strongly 
alkaline by the addition of a solution of soda. In one out of three 
well agreeing experiments the observations given in the above 
table were taken — intermediate readings being omitted for brevity. 
It will be seen that the reaction takes some time to develop, 
but this induction period is much too great to be accounted for 
entirely by solution of the nitrogen first given off. 
