SIR B. C. BRODIE OX THE ACTIOX OF ELECTRICITY OX GASES. 
471 
the gas is attended with a deposition of large quantities of sulphur. The experiment was 
conducted in all respects as the experiments with hyposulphite of soda last described, 
but the temperature was kept at 0° C. I have no record of the amount of polysulphide 
of barium contained in the solution ; but the proportion of the polysulphide of barium in 
the several experiments was greatly varied, the relative amounts of the polysulphide 
contained in the bulb being, assuming the amount in experiment 1 as the unit of com- 
parison, in experiments 2 and 3 twice that amount, in experiment 4 three times that 
amount, and in experiments 5 and 6 six times that amount. 
Experiments with Polysulphide of Barium. 
Experiment. 
I. 
T. 
II. 
V. 
III. 
v 
IV. 
V-V r 
V. 
v-v, 
v 1- 
T 
1 . 
12-60 
267-97 
254-73 
13-24 
1-05 
2. 
12-60 
267-34 
254-33 
13-01 
1-03 
3. 
11-94 
268-68 
255-79 
12-89 
1-08 
4. 
12-60 
267-7 
255-53 
12-17 
0-96 
5. 
12-60 
268-15 
254-33 
13-82 
1-09 
6. 
11-94 
268-41 
256-36 
12-05 
1-01 
Mean ... 1-04 
The following experiments were conducted in a manner precisely similar to the pre- 
ceding, but with a solution of polysulphide of sodium. The experiments were made 
at 0° C. In this case also the degree of concentration of the solution was very greatly 
varied, the amount of polysulphide of sodium employed being in experiment 11 six times 
that in experiments 2, 3, and 4, in experiments 8, 9, and 10 three times that in the same 
experiments, in experiments 5, 6, and 7 twice that in the same, and in experiment 1 
two thirds that in the same. In experiment 1 a slight trace of ozone escaped the action 
of the polysulphide. With a solution half the strength of that in experiments 2, 3, 4 
the ozone came distinctly through the solution when about half the gas had passed over. 
Experiments with Polysulphide of Sodium. 
Experiment. 
I. 
T. 
II. 
V. 
III. 
Y- 
IV. 
y-Y- 
V. 
v-Y 
T 
1 . 
11-41 
270-16 
256-86 
13-3 
1-16 
2. 
1 5-15 
272-84 
257-04 
15-80 
1-04 
3 . 
11-04 
270-65 
257-96 
12-69 
1-15 
4. 
13-24 
272-37 
257-15 
15-22 
1-15 
5 . 
11-41 
269-92 
257-82 
12-10 
1-06 
6 . 
10-2 
271-04 
258-4 
12-64 
1-24 
7 . 
10-2 
270-76 
259-03 
11-73 
1-15 
8. 
13-24 
273-57 
258*74 
14-83 
1-12 
9 . 
10-2 
271-04 
259-62 
11-42 
M 2 
10 . 
11-04 
270-65 
258-68 
11-97 
1-08 
11 . 
15-15 
272-66 
255-43 
17-23 
1-14 
Mean ... 1-13 
