116 
MESSRS. J. HOPKINSON AND E. WILSON ON THE 
by surrounding the beaker Avith a freezing mixture of ice and salt, the lower 
temperature being obtained by further cooling in carbonic acid snow. 
The same blue flask, which Avas the subject of the earlier experiments, was mounted 
as shown in flg. 1, and the residual charge observed for Anrious temperatures. This 
glass is composed of silica soda and lime; the colour is due to oxide of cobalt in small 
quantity. 
Out of a large number of experiments the data in Tables I. and 11. give the general 
character of the results. 
Table I. 
Time iu 
seconds. 
1.5° C. 
341 
54|. 
70. 
85. 
117. 
132. 
Remai’ks. 
10 
246 
9770 
7256 
Blue flask. 6th and 7th 
15 
.376 
1176 
2785 
5445 
, * 
November, 1894. Sen- 
20 
121 
265 
1030 
2586 
4100 
3590 
.3010 
sibility of galvanometer, - 
30 
87 
209 
892 
2070 
2980 
2150 
1735 
'378 X 10~®. Duration 
60 
46 
131 
683 
1.320 
1510 
950 
778 
of charge, 2 minutes. 
120 
224 
91 
483 
720 
688 
440 
350 
Charging volts, 1250 
300 
^4 
62 
256 
260 
210 
164 
107 
less than 
600 
• • 
123 
no 
• • 
86 
59 
Table II. 
Time in 
seconds. 
14" C. 
55. 
70. 
no. 
137. 
Remai’ks. 
10 
205 
11740 
12400 
Blue flask. 13th November, 1894. Sen- 
20 
99 
1230 
2850 
4790 
4340 
sibilitv of galvanometer, '407 X 10~®. 
60 
38 
837 
1560 
1212 
990 
Duration of charge, 2 minutes. Charging 
120 
17 
694 
878 
487 
366 
volts, 1250. ; 
300 
5 
308 
314 
134 
• • 
Table III. 
3rd .Tannai’j, 1895. 
4 January, 1895. 
Remarks. 
Time in 
seconds. 
8 °C. 
5 min. 
charge. 
117 
1 mill. 
im 
1 min. 
8 “ C. 
5 min. 
charge. 
122 
1 min. 
1221 
1 min. 
10 
75 
258 
70 
1100 
New window glass flask. Sensibility of 
20 
4o 
123 
148 
44 
, , 
664 
galvanometer, ’358 X 10~^. Resist- 
30 
30 
105 
109 
32 
400 
ance of flask, 8° C., 3340 x 10® ohms. 
60 
18 
80 
73 
19 
240 
240 
Charging volts, 1.500. 
ISO 
74 
56 
7| 
69 
68 
1 
