dl 
in the Discharge through Gases at Low Pressures. 155 
As the tables show, the silver cathode had already begun to 
give the higher values in tube A before it was used in 
tube B. 
Tas_E I1J.—Disintegration in Tube B. 
| 
/ | | y(me. X 10m): | | y(ng. X 105-); 
oS 8 el ‘ PDE Vahl Vim Neetu dig 
Pathede| am, Es)|(Volts)| ) Cataode.'/ um. Hg) (Volts) i 
. | | Obs. Obs. - Cal. - Obs. Obs. —Cal. 
Platinum. Silver. 
B Peat abO! |, 1 As Oe S70F 1) TD —2 
B 1:10 400 io A 10 0-23 1120+ 168 +3 
B 0-48 600 ol AOS 0°15 SOD E25D +2 
B 0 29 960 | 70 — 1 A 9 Ota 1530); 296 —2 
D | 1200) F 104 a | , | | 
C Pee 1200 | 193 |) 4.14 | 
B Oil | 1540 156 — 4 Gold. 
D 0°05 | 1850 | 211 + 4 
C eye | 2210 | 252* =) | (0:20 1000 | 210 | +4 
D 0:03 | 2220 | 267 -- 93 0:19 1040 | 228 | —3 
C bak 2360 , 280* — 5 ts) 
G12 | 1270} 345 | 
The values of y are calculated from the equations :-— 
Platinum, y=0'153(V—495)=3A x0-00157(V —495) ; 
Silver,  /=0:324(V—610)=0-00200A(V—610) ; 
Gold, — y=0°527(V —610)=0-00267A(V—610). 
5. Disintegration in Hydrogen. 
Observations were also made in hydrogen. Two cathodes 
of each metal were used, one which had been before used in 
air and one fresh one. No difference in the behaviour of the 
two was observed. In order to be able to disintegrate more 
cathodes at one filling of the apparatus with hydrogen, a 
second tube of the form A was added. The hydrogen was 
produced electrolytically and freed from oxygen by passing 
it through an alkaline pyrogallol solution. 
Before each series of observations the whole apparatus was 
several times pumped out and partially filled with hydrogen. 
Notwithstanding this, it is hardly to be assumed that the 
tube contained only pure hydrogen, especially as it was not 
possible to heat the apparatus during the pumping. Small 
quantities of oxygen undoubtedly adhered to the walls and 
to the cathodes, and were set free when the discharge passed. 
At high potentials, when the cathode becomes heated, oxygen 
must be certainly given off, especially in the cases of the 
more easily oxidized metals. Nevertheless, the deposits of 
