1 78 
DR. S. CHAPMAN ON THE KINETIC THEORY OF A COMPOSITE 
The following table contains the results of the Halle experiments on I ) 12 , as given 
in Jackmann’s summary. Additional columns give the values of (a) ——, calculated 
1 — e 0 
from (13'28) on the hypothesis that the molecules are rigid elastic spheres* : (6) 
V'/V— cf. (13'01)—estimated from the value of 
l-< 
in accordance with § 9 (a) and 
§13 (e): and (c) of D 12 , obtained by multiplying the values of V'/V by such a factor 
as to make the mean of the resulting values of D 13 equal to the mean of the 
corresponding set of observed values. This is all that is here necessary, since we are 
concerned now only with the variations of D 12 , and not with its absolute values. 
Table V.—Variation of D 12 with v 1 : v 2 . 
Gases. 
Authority. 
A 
n 
v \ + i'2 
Argon-helium. 
Schmidt! and Lonius, 
mi Ini 2 = 10 . 
f 0-273 
0-315 
J 0-3771 
j 0-500f 
0-677 
L 0-763 
Oxygen-hydrogen. 
Deutsch! and Jackmann, 
mi / m 2 =16. 
j 
t 
0-25f 
0-25 
0" 5f 
0-5 
0-75f 
Carbon dioxide-hydrogen. 
DEUTSCH, 
mi/m 2 = 22. 
0-25 
0-5 
0-75 
Nitrogen-hydrogen. 
Jackmann, 
vii jin 2 = 14. 
1 0-235 
r 0-5 
Oxygen-nitrogen. 
Jackmann, 
ri\Wo = 8/7. 
0-467 
0-5 
1 
V' 
1 ~ e o" 
V. 
1 • 035 
1-040 
1-044 
1-050 
1-058 
1-062 
1-050 
1-056 
1-063 
1-073 
1-087 
1-094 
1-035 1-050 
1 • 050 
1-073 
1-064 
1-097 
1-029 
1 • 059 
1-070 
1-040 
1-089 
1-108 
1-030 
1 • 042 
1 • 050 
1-073 
1-012 1-013 
1-013 1-014 
d 12 . 
Observed. 
Calculated. 
0-244 
0-248 
0-250 
0-250 
0-2501 
0-251 
0-254f 
0-254 
0-256 ' 
0-257 
0-263 
0-259 
0 • 2761 
0-276 
j 0-276 
0-280f 
0-273 
| 0-282 
0-2891 
0-289 
0-214 
0-212 
0-218 
0-222 
0-228 
0-226 
0-268 
0-263 
0-266 
0-271 
0-0733 
0-0731 
0-0730 
0-0732 
* The values of the molecular radii used in the calculation of e 0 were taken from the table on p. 476 of 
my first paper (‘ Phil Trans.,’ A, vol. 211, 1912); cf . the column there headed “elastic sphere theory.” 
