ELECTRIC DISCHARGE WITH THE CHLORIDE OF SILVER BATTERY. 
175 
cylindrical nebulosity of about a \ incli in diameter, and a glow filled up 
the end of the tube. 
Fig. 44. 
TUBE 129. 
31 
18. — Pressure 0'4 m.m., 526 M, 1200 cells. Strata produced resembling the 
four on the right of 58, fig. 46 ; the convex part being blue and the 
concave part pink ; the last stratum, nearest to the negative, had two 
points ; the negative ring was enveloped in a cylindrical nebulosity, pink 
close to the terminal, the strata reached within 5 inches of the negative 
terminal. There was seen in the rotating mirror a rapid flow towards the 
positive. 
19. — Pressure 0‘2 m.m., 263 M, 1200 cells, 100,000 ohms resistance. 16 per- 
fectly steady grey strata like 14, fig. 43, a blue fine on the convex face and 
pink on the concave, the negative discharge like that in the same figure. 
With 900,000 ohms resistance the number of the strata changed to 14. 
20. — Pressure 0'2 m.m., 263 M, 1200 rod cells. 39 strata were produced as in 
14, fig.- 43, when 400,000 ohms resistance was in circuit, the convex side 
being blue and the broader concave side reddish, they extended to within 
5 inches of the negative. With 50,000 ohms resistance, (C.) 0'005830 W, 
there were 34 strata. The luminosity at the negative is correctly shown in 
the diagram ; no flow of strata could be detected by the rotating mirror, 
the image remaining steady. 
21. — Pressure about 01 m.m., 132 M, 1200 cells, 500,000 ohms resistance. 
21 strata as 14, fig. 43, very blue on the convex face, pink on the concave, 
the glow on the terminals pink. Observed with the rotating mirror the 
strata were steady, but from time to time secondary strata formed as 18, 
fig. 43, which were seen to flow towards negative. 
22. — The vacuum carried further by running -g-rd of a cistern-full of mercury 
through the pump; 1200 cells. 21 very blue strata, like a. fig. 43; with 
100,000 ohms, still 21 strata; with 500,000 ohms, 22 strata; with 900,000 
ohms the strata became like spheroids, being bounded on both sides by 
a convex face. 
23. — The exhaustion was carried further, but the pressure was not measurable 
with our then means, the gauge appearing to stand higher than the 
barometer. The current of 1200 rod cells, (C.) 0‘ 00763 W, did not pass 
very readily, and the strata were unsteady ; the introduction of 50,000 ohms 
resistance, (C.) 0 ’005830 W, rendered them steady ; they were 19 in number, 
