620 
MR. J. HOPKINSON ON THE 
h m 
Temperature — 5°, in a fresh freezing-mixture. 
Time 8 
48. 
Charged with 
7 elements. 
8 
49. 
463 to 432 in 
20 seconds. 
8 
50. 
464 to 438 
r> >5 
8 
53. 
465 to 447 
» J) 
B =_ 0 ' 14 1 at 
-5°. 
Log B=1T5 ) 
8 55. Charged with 48 elements. 
Temperature —3°. 
9 25. Discharged. 
9 26. 176 in 20 seconds. 
9 27. 108 „ „ 
9 28. 80 
9 30. 53 
+(1)-B=0-17 ) at _ 3 o. 
4(5)-B=0-050 J 
As in Mr. Perry’s experiments the results agree closely with the formula 
Log B=a-f- bdy 
where 6 is the temperature, and in this case a=l" 35. and 5=0 - 0415. The following 
Table gives the observed and calculated values : — 
Temp. 
B observed. 
B from formulas. 
391 
10 
9-8 
33f 
5-4 
5-4 
27i 
3-2 
3-0 
25f 
2-5 
2-6 
24i 
2-2 
2-2 
22f 
1-85 
1-9 
U 
0-45 
0-46 
-3 
0T7 
0-17 
-5 
0-14 
0-14 
The residual charge results do 
not show so great a degree of regularity, probably 
because the direct deduction of ^ 
as equal to ^ 
gives a greater error than the method 
used for obtaining B. This much is quite certain, that the value of \|/(] ) — B and \|/(5) — B 
is rapidly increasing up to 7°. It appears probable that at higher temperatures these do 
not increase so rapidly if at all ; 
but this is by 
no means certain, as although shorter 
