PRODUCED IN GASES BY EONTGEX RAYS. 
225 
for the positive ions, ‘825 centim. per second, for a pressure of 70 centims. and a 
temperature of about 17° C. 
A summary of the results obtained for dry carbonic acid is given in Table XVI. 
Table XVI.—Dry Carbonic Acid. Summary of Results. 
Reference 
X. 
U. 
A. 
T. 
Tempera- 
Gas 
Ionic Velocity. 
number. 
ture. 
pressure. 
Negative. 
Positive. 
1 
6-07 
8-61 
- 9-15 
•71 
°C. 
17-5 
75-4 
•787 
2 
fi-07 
8-63 
+ 9-59 
•71 
17-5 
75-4 
— 
•752 
3 
6-07 
16-7 
+ 19-07 
•36 
17-5 
75-8 
— 
•737 
4 
6-07 
17-1 
- 18-05 
•36 
17-5 
75-8 
•796 
— 
5 
3-08 
17-3 
-36-2 
•18 
18-3 
75-8 
•793 
— 
6 
3-08 
17-3 
+ 38-4 
•18 
18-3 
75-8 
— 
•747 
7 
3-08 
8-25 
+18-96 
•37 
17-2 
75-7 
— 
•725 
8 
3-08 
8-53 
- 18-18 
•36 
17-2 
75-7 
•781 
— 
9 
6-01 
8-63 
- 9-53 
•70 
17-3 
75-7 
•770 
— 
10 
6-01 
8-53 
+ 9-64 
•71 
17-3 
75-7 
— 
•753 
11 
6-01 
12-8 
+ 14-76 
•47 
17-5 
75-9 
— 
■738 
12 
6-01 
12-85 
- 14-04 
•47 
17-5 
75-9 
•777 
— 
The results are represented in fig. 15. 
The velocities appear to vary but little with T. 
The values for the positive velocity being comparatively large for the highest value 
of T, make it difficult to draw the line through the positive points, and the inclination 
of the one through the negative points has been used as a guide for drawing the one 
shown. The value thus found, when corrected, gives the velocity in dry carbonic acid 
for the negative ions as ‘81 centim. per second, and for the positive ions as ’76 centim. 
per second for a pressure of 76 centims. and a temperature of 17'5° C. 
Fig. 15. 
2 u 
YOL. CXCV.—A. 
