1896-97.] Experiments on Electric Properties of Uranium. 417 
The following are some of the results obtained : — 
O 
[Sensibility of electrometer 140 sc. divs. per volt.] 
February 5, 1897. Zinc charged negatively to 285 scale divisions from the 
metallic zero. 
Reading from metallic zero with Rontgen lamp acting : — 
Time. 
-276 
- 265 
- 255 
- 243 
-227 
-214 
-184 
scale divisions 
after 1 min. 
3 3 
3 3 
3 3 
3 3 
3 3 
3 3 
J 3 
2 
3 3 
33 
3 3 
4 
5 
3 3 
6 
3 3 
8 
3 3 
3 3 
3 3 
3 3 
3 3 
3 3 
Discharge still continued. 
The zinc was then discharged by metallic connection. The 
readings, with the Rontgen light shining, and the two pairs of 
electrometer quadrants again disconnected, were : — 
- 4 sc. divs. from metallic zero after 4 
J> >: j) U 
-41 
3 3 
-53-5 
3 3 
3 3 
3 3 
3 3 
3 3 
24 
min. 
3 3 
-61 
-67 
-70*5 
-7D0 
3 3 
3 3 
3 3 
3 3 
33 
3 3 
41 
3 3 ^2 3 3 
Kl 
33 ^2 33 
3 3 U 2 J3 
» J I 5 J 
The difference between the rays-zero and the metallic zero is thus 
found to be -71 sc. divs., or -0*5 of a volt. Immediately after 
this experiment, we removed the lead window and allowed the 
Rontgen light to shine on both metals, still 7 cms. apart. We 
then found the difference of zeros to be - 89 sc. divs., or - 0'64 of 
a volt ; but instead of seven minutes, scarcely a quarter of a minute 
was taken to reach the rays-zero after the metallic connection was 
broken. These results are substantially in accordance with Erskine 
Murray’s §§ 9 of his paper already referred to.] 
Art. V. — Experiments on Electric Properties of Uranium. 
(Read April 4, 1897.) 
§ 25. Potential differences of uranium-conductance-zero from 
metallic zero for different metals in air. 
