BY THE ACTION OF A RADIO-ACTIVE SUBSTANCE, ETC. 
267 
air in A in millims. of mercury ; V is the mean velocity in the tubing T x in centime, 
per second ; © is the temperature of the air during the experiment :— 
Table I.—Positive Ions in Dry Air. 
ni. 
n-2. 
Y. 
P. 
0 . 
88-2 
153 
344 
772 
19 
56T 
105-3 
387 
550 
13 
33-9 
73-9 
420 
400 
16 
14-8 
41-3 
410 
300 
13 
11-5 
34-5 
582 
200 
12 
Table II.—Negative Ions in Dry Air. 
n x . 
no. 
Y. 
P. 
0. 
63-4 
138-6 
344 
772 
19 
43-0 
93-8 
387 
550 
13 
24-8 
68-0 
420 
400 
16 
10-6 
39-9 
410 
300 
13 
7-6 
31-5 
582 
200 * 
12 
Table III.—Positive Ions in Moist Air. Table IY.—Negative Ions in Moist Air. 
«i- 
no. 
V. 
P. 
0. 
71-1 
135 
368 
772 
18 
210 
56-3 
430 
440 
11 
7-6 
27-1 
609 
200 
9-5 
n\. 
no_. 
V. 
P. 
0. 
81-3 
145-8 
368 
772 
18 
24-7 
58-5 
430 
400 
11 
9 - 5 
31-2 
609 
200 
9-5 
The connection between the ratio y (= 7q/?? 2 ) and the coefficient of diffusion can 
be shown graphically by means of a curve representing equation 2, Section I. The 
7-313 KZ . 
2a s V 
2 m 2 
