96 
MESSRS. W. DE LA RUE AND H. W. MULLER ON THE 
a current of 0'05353 W, and produced thin strata near the positive, the negative being 
completely covered with a purple glow, fig. 18. 
Distance 6'4 inches, pressure 2'6 nun., 1316 M, 1200 cells, the zinc rods of which 
had been recently scraped to remove the oxychloride of zinc, gave a current of 
0'17230 W, and produced a discharge one and a half inches wide, nearly reaching 
the negative, which was covered with a purple light, surrounding the top and bottom 
surfaces to a depth of three-eighths of an inch. 
Distance. 
Pressure. 
Depression. 
Katio of 
increased to 
normal pressure. 
Current. 
inches. 
M. 
m.m. 
W. ' ratios. 
046 
1,001,317 
Rone 
, , 
0-02371 1-71 
0-32 
358,027 
Rone 
. , 
0-02456 1-77 
0-48 
238,553 
0-25 
1-0002 
0-02209 1-59 
0-64 
197,111 
1-00 
1-007 
0-02131 1-54 
0-80 
184,211 
3-5 
1-025 
0-02209 1-59 
0-96 
155,131 
2"5 
1-021 
0-02249 1-62 
142 
155,789 
2-0 
1-016 
0-02209 1-59 
1-28 
155,789 
3'0 
1-025 
0-02470 1-56 
1-44 
155,789 
3-0 
1-025 
0-02170 1-56 
1-60 
155,789 
3-0 
1025 
0-02056 L48 
176 
146,448 
4-0 
1-036 
0-01948 1-40 
3-20 
98,158 
8'0 
1407 
0-01840 1-32 
6'40 
63,947 
9-0 
1493 
001390 100 
6 - 40 
35,395 
10-0 
1-372 
0-01840 1-32 
640 
18,026 
3-0 
1-219 
0-02056 1-48 
640 
7237 
Rone 
Rot taken 
Th e arc in hydrogen between two spherical surfaces, 3 inches radius, and 1 '5 inch diameter, 
at various distances and pressures, chiefly with 10,960 cells. Temp. 13°'3C. 
Distance 0'225 inch (the current would not pass at 0'23 inch), pressure 762'8 m.m., 
1,003,685 M, current 0'02456 W, no depression apparent on making connexion with 
the battery. The central spindle did not quite reach the negative terminal. A, 
fig. 84 ; C and F lines visible with the spectroscope. 
Distance X 2 = 0'45 inch, pressure 339 m.m., 446,053 M, current 0'02371 W, 
depression O'l m.m., total pressure 339T m.m., ratio of increased pressure 1'0002. 
The central spindle did not quite reach the negative terminal. The arc appeared to 
be crossed by very close lines ; at the positive, winged appendages were formed 
B, fig. 84. 
Distance X 3 = 0'675 inch, pressure 256 m.m., 336,842 M, current 0'02456 W, 
depression 0'5 m.m., total pressure 256'5 m.m., ratio of increased pressure 1'002. 
The arc at first formed in the centre as on the left of C, fig. 84, then moved towards 
the periphery, as on the right of the same figure. Winged appendages were formed 
as represented. 
Distance X 4 = 0'90 inch, pressure 255 m.m., 335,526 M, current 0 02544 W, 
