844 
PEOFESSOE B. C. BEODIE ON THE OXIDATION AND 
The value of the solution of peroxide of hydrogen vras estimated, as before, \vith per- 
manganic acid. 
When the peroxide of hydrogen was taken in excess, a measured amount of the solu- 
tion was precipitated by a solution of hydrate of barium. To this a measured amount 
of the solution of hypochlorite was added by a pipette. After the decomposition, the 
excess of peroxide of barium was estimated by determination with permanganic acid, 
the solution being first diluted and rendered acid. 
When the hypochlorite was taken in excess, a measured amount of the solution was 
rendered strongly alkaline with baryta water, and the measured amount of the solution 
of peroxide of hydrogen added to this by means of a pipette. The excess of hypochlorite 
present after the decomposition was estimated by the iodine method. 
In the former case, putting 
s=the parts of permanganate required to effect the decomposition of 1 part of the 
peroxide of hydrogen employed, 
Sj = the parts of permanganate equivalent to 1 part of the solution of hypochlorite of 
barium employed, as calculated from the determination with iodine, 
m=the parts of the solution of peroxide decomposed, 
jWj = the parts of the solution of hypochlorite decomposed, 
^=the ratio of the amount of oxygen evolved from the peroxide of hydrogen to that 
evolved from the hypochlorite, 
ms 
X— 5 
m^s^ 
where, putting w=the parts of the solution of peroxide employed in the experiment, 
and ^;=the parts of permanganate required to decompose the excess of peroxide after 
the decomposition. 
and 
ms—ns—]). 
ns — p 
In the second case, where the hypochlorite was taken in excess, let 
s=the parts of the standard iodine solution equivalent to 1 part of the solution of 
peroxide of hydrogen ; 
Si=the parts of the same solution equivalent to 1 part of the solution of hypochlorite; 
?n=the parts of the solution of peroxide employed in the experiment; 
?/^J=the parts of the solution of hypochlorite decomposed; 
then, as before, 
ms 
x = — ? 
mjSi 
where, putting n^—ihe parts of hypochlorite employed in the experiment, and j)i = thc 
parts of the iodine solution equivalent to the excess of hypochlorite present, as deter- 
mined by experiment. 
