196 
Proceedings of the Royal Society 
Table IY. 
Temperature of 
solution, ° C. 
13*5 
13*8 
14-0 
14-2 
14-9 
15*0 
151 
15-2 
Duration of 
action . min. 
16-5 
33 
49-5 
66 
99 
132 
165 
198 
Permanganate 
used, . c.c. 
16-35 
15-2 
14-25 
13-35 
11-5 
10-4 
9-35 
8-5 
Per cent, chlorate 
used, 
7-10 
13-64 
19-03 
24T5 
34-66 
40-91 
46-88 
51-70 
It will be seen that during this series of observations the tempera- 
ture rose from 13*5° C. to 15 '2° C., in consequence the decomposi- 
tion has gone on during the short intervals more slowly, and during 
the long intervals more quickly than it would have done at a mean 
constant temperature. 
In Table Y. are given the results of observations on the action of 
nitrate and perchlorate solutions at higher temperatures. The com- 
position of the solutions was as before, 10 c.c. ferrous sulphate (c), 
20 c.c. H 0 S0 4 , 30 c.c. water, and 10 c.c. of perchlorate or nitrate of 
potash. They were heated for five or six minutes to two inter- 
mediate temperatures, and also boiled for a like time. In three 
blank experiments made during the series 17*55, 17*50, and 17*55 c.c. 
permanganate were used. 
Table Y. 
Oxidising agent. 
Perchlorate. 
Nitrate. 
Temperature, . ° C . 
46 
81 
boiling 
56 
84 
boiling 
Duration in minutes, . 
5 
5 
6 
5 
5 
5 
Permanganate used, c.c. 
17-5 
17-6 
17-55 
17-45 
17-6 
17*55 
From these results it will be seen, and in the case of nitrate at 
least with surprise, that even boiling for five minutes has had no 
effect in bringing about a reaction between the oxidising agent and 
the ferrous salt. In the case of chlorate it is otherwise. In the 
following three experiments the chlorate was allowed to act for five 
minutes. In a blank experiment 17*6 c.c. permanganate were used. 
