OF GASES AT HIGH EXHAUSTIONS. 
423 
Table VI. (continued).—Log. dec. of hydrogen gas at pressures between 1000 M and 
0’16 M. Temp. 15° C. 
Pressure. 
Log. 
Repulsive force 
Mean free 
ot molecul 
Millimi 
M. 
decrement. 
of radiation. 
lOOO'O ( = 0'76 m.m.) 
0-0498 
10 
o-io 
921'0 
0-0498 
1-0 
Oil 
526-0 
0-0497 
3-0 
0-19 
421-0 
0-0496 
4-0 
0-24 
330-0 
0-0495 
5-0 
0-30 
314-0 
0-0493 
8-0 
0-32 
234-0 
0-0488 
11-0 
0-43 
205-0 
0-0486 
14-0 
0-49 
179-0 
0"0486 
18-0 
0-56 
168-0 
0-0485 
19-0 
0-59 
155-0 
0-0484 
25-0 
0-65 
147-0 
0-0482 
28-0 
0-68 
135-0 
0-0479 
31-0 
0-74 
122-0 
0-0475 
37-0 
0-82 
110-0 
0-0472 
40-0 
0-91 
95-0 
0"0466 
44-0 
11 
79-0 
0-0457 
52-0 
1-3 
65"0 
0-0446 
60-0 
1-5 
59-0 
0-0441 
64-0 
1-7 
54-0 
0-0435 
66-0 
1-8 
48-0 
0-0430 
68-0 
21 
45-0 
0-0422 
69-0 
2-2 
41-0 
0-0417 
70-0 
2-4 
37-0 
0-0408 
69-0 
2-7 
33-0 
0-0394 
69-0 
3-0 
29-0 
0-0384 
67-0 
3-4 
26-5 
0-0373 
66-0 
3-8 
22-0 
0-0358 
60-0 
4-5 
20-0 
0-0351 
58-0 
5-0 
16-0 
0-0333 
52-0 
6-3 
14-5 
0-0324 
49-0 
6-9 
12-0 
0-0304 
45-0 
8-0 
8-0 
0-0270 
37-0 
12-5 
6-5 
0-0253 
31-0 
15-4 
5-0 
0-0232 
29-0 
20-0 
4-0 
0-0214 
26-0 
25-0 
2-6 
0-0191 
15-0 
38-5 
1-8 
0-0172 
10-0 
55-5 
1-5 
0-0169 
9-0 
66-7 
1-0 
0-0157 
7-0 
100-0 
0-37 
0-0130 
3-0 
270-0 
0-16 
0-0118 
2-0 
625-0 
* For convenience I have taken the mean free path of the molecules of hydrogen the same as that of 
air, viz.: O'OOOl millim., at a pressure of 760 millims, and at 0° C. The actual figures, according to the 
most recent determinations, are—for air, 0’000095 millim.; and for hydrogen, 0'0000104 millim. The 
difference between these figures and O'OOOl is too small to show itself on the diagrams. 
