ACTION OF LIGHT ON SELENIUM. 
d-2b 
Time in minutes. 
Direction of current. 
Eesistance in 
megohms. 
Number of cells. 
0 
+ 
4-15 1 
1 
4 
— 
3-40 | 
Q 
2 
+ 
4-15 | 
At 
2 
— 
3-40 J 
1 
7 
_ 
3-34 1 
I 
2 
+ 
4-03 
A 
2 
— 
3-34 
f 
1 
+ 
4-03 
1 
5 
+ 
3-99 ' 
| 
4 
— 
3-29 
6 
4 
+ 
3-98 
f 
3 
- 
3-29 J 
1 
8 
_ 
3*27 1 
| 
3 
+ 
3-94 | 
g 
4 
— 
3-27 | 
4 
+ 
3-94 J 
1 
7 
+ 
3-90 1 
5 
— 
3-24 
i ft 
5 
+ 
3-89 
1U 
6 
— 
3-24 J 
1 
6 
_ 
3*22 1 
4 
+ 
3-87 | 
[ 
1 o 
2 
— 
3*22 1 
X At 
1 
+ 
3-87 J 
A set of observations made with tube No. 10, the temperature being kept constant, 
while the battery-power was varied, gave the following results : — 
Interval in minutes. 
Direction of current. 
Eesistance in 
megohms. 
Number of cells. 
0 
+ 
5‘65 1 
1 
- 
6-05 J 
6 
_ 
5-87 1 
4 
2 
+ 
5-25 J 
l h 9 
7 
+ 
5-07 1 
5-40 J 
10 
2 h 0 
— 
4-92 1 
18 
4 
+ 
4-43 J 
4 
+ 
4*41 1 
20 
2 
— 
4-77 J 
