Electricity from a Nernst Filament. 
TaBLeE IX. 
Filament IV. April 22nd. 
: y rrenit. 
| Pressure. Potential. ‘Temperature. sal aah amp. 
| ae volts. 3 OM | 
| 9008 — 200 1327 261 
+200 150 S| 600 
0-009 ony | | Bye | 732 
+200 1372 1008 
a —200 1395 1088 
+200 1390 1098 
0-012 2700," 1415 1494 
| 45509) ) 1415 1212 
0-010 —200 1450 2480 
+200 1450 12 | 1304 
| 00097 —200 1475 | 3680 
+200 1475 1560 
| 0:0097 200 1515 6840 
| +200 1510 2016 
pee Oot 200 1540 11760 
+200 1545 2592 
ile — 200 1585 44000 
+200 1585 2800 
291 
temperature tried (1585° C.) the negative leak was nearly 
16 times the positive. 
It will be noticed that there is a considerable difference 
between the shapes of the curves A and C. 
This is explained in the next section, as the said difference 
is a direct consequence of the effect described in that section, 
namely, the variation of the leak with the time. 
(6) Variation of the Leak with the Time. 
When a new filament is set up and made to glow at atmo- 
spheric pressure without being charged to any definite 
potential, it will at first discharge positive electricity. This 
positive leak diminishes, however, rapidly with the time, and 
soon vanishes. The leak with no potential now becomes 
negative, and remains so at all pressures. This is well shown 
by the jist observations made with filarfent III. The 
observations, which were taken on March 25, are given in 
Table X. 
