600 
ME. J. HOPKINSON ON THE 
one case are not quite accordant, possibly owing to variations of temperature, or to 
slight unremoved effects of previous chargings ; but the irregularities indicate no con- 
tinuous deviation from the law. In these and all the subsequent experiments the flasks 
were blown as thin as possible in the body, but with thick necks, the neck being thick 
that the capacity of any zone might be small. 
Flask of optical soft crown, No. 5. The electrometer reads 28^- for one Daniell’s 
element. The charging in each case lasted some hours, the discharge 30 seconds. The 
flask was then insulated and remained insulated ; the residual charge was read off from 
time to time. Column I. gives the time in minutes from insulation ; II., III., IV., V., 
the readings at those times, the exciting electromotive force being respectively that 
of 48, 48, 24, and 12 elements of the battery. 
I. 
n. 
III. 
IV. 
V. 
1 
90 
92 
46 
5 
218 
225 
103 
51 
15 
344 
160 
79 
30 
423 
197 
99 
60 
478 
462 
226 
114 
120 
492 
233 
120 
Flask of blue glass, No. 2. The reading of the electrometer for one element was 
69 divisions. The charge in each case lasted 10 minutes, the discharge 30 seconds; 
the flask was then insulated. Column I. gives the time from insulation in minutes ; 
II., III., IV., V., the potentials at those times when the batteries which had been 
employed were respectively of 48, 12, 3, and 1 Daniell’s elements. 
I. 
II. 
III. 
IV. 
V. 
1 
2 
414 
102 
26| 
9 
Maximum 
potential. 
472 
117| 
30| 
10 
H 
456 
114 
29 1 
10 
Ql 
* 2 
385 
96 
24f 
84 
4 2 
256 
65 
16| 
6 
9| 
120 
H 
3 
The agreement in this case, all the experiments being made on the same day, is 
fairly satisfactory. 
