ELECTRIC DISCHARGES IN GASES AT LOW PRESSURES. 
415 
Table IV.—Hydrogen. 
Spark length 
= 1 millim. 
Spark length 
= 2 millims. 
Sf)ark length 
= 3 millims. 
Spark length 
= 5 millims. 
Spark length 
= 10 millims. 
1 
Product 
' of 
pressure 
and spark 
length. 
Spark 
potential 
in 
volts. 
Product 
of 
pressure 
and spark 
length. 
Spark 
jjotential 
in 
volts. 
Product 
of 
pressure 
and spark 
length. 
Sj^ark 
potential 
in 
volts. 
1 
' Product 
of 
pressure 
and spark 
length. 
1 
Spark 
potential 
in 
volts. 
Product 
of 
pressure 
and spark 
length. 
Spark 
potential 
in 
volts. 
: 21-7 
328 
46 
435 
40-8 
415 
68 
469 
75-3 
526 
16-2 
300 
29-6 
360 
25-6 
356 
46-7 
415 
43-7 
427 
11-9 
281 
22-0 
323 
16-2 
301 
30 •! 
350 
25-5 
3.35 
10-3 
278 
16-1 
299 
13-9 
286 
19-0 
300 
17-7 
299 
8-94 
287 
13-9 
285 
12-0 
278 
16-4 
287 
14-6 
283 
7-74 
306 
11-8 
279 
10-3 
282 
14-0 
281 
12-2 
287 
6-52 
335 
10-0 
284 
8-79 
292 
12-0 
282 
10-1 
295 
5-57 
374 
8-60 
293 
7-56 
310 
10-2 
285 
8-46 
313 
4-73 
487 
7-44 
305 
6-45 
356 
8-80 
293 
7-00 
343 
4-11 
649 
6 ■ 46 
333 
5-55 
440 
7-55 
305 
5-75 
426 
3-54 
905 
5-54 
399 
4-77 
564 
6-30 
345 
4-70 
595 
3-04 
1275 
4-72 
523 
4-05 
780 
5-45 
410 
3-90 
850 
2-60 
1781 
4-06 
727 
3-48 
1054 
4-Of 
539 
3-30 
1142 
— 
3-46 
1010 
3-00 
1382 
4-04 
706 
2-76 ' 
1477 
— 
— 
2-96 
1380 
2-58 
1789 
3-50 
975 
2-64 ' 
1710 
— 
— 
2-66 
1746 
— 
— 
3-00 
1373 1 
— 
— 
— 
— 
1 
2-58 
1775 1 
1 
— 
— 
V - Hydrogen 
To indicate further that the law i.s applicable at all points, a table of products, 
similar to that recorded for air, was calculated, and is given in Table IV. A single 
curve, fig. 5, represents these five sets of readings, and again the close grouping of 
the different results about this common curve shows that the law is equally applicable 
above and below the critical pressure to all spark potentials. 
It is evident, then, that with hydrogen, just as with air, Paschen’s law is rigidly 
applicable over the whole range of pressures. 
