PHYSICS: K.-L. YEN 
95 
It may be proper to mention here that no sooner had the above conclu- 
sion been arrived at than it received corroboration from Wellisch's latest 
paper 18 in which it was reported that no trace could be found of Haines' ions 
B and C. 
Incidentally an interesting fact was revealed in the comparison between the 
two sets of curves. If was found that the amount of free negative electrons 
present in the gas was smaller when under high than when under low poten- 
tial. This would seem to suggest that the electrons — or some of them at 
least — did actually attach themselves to neutral molecules when a high poten- 
tial was applied and thus formed negative ions. This would not be at all 
TABLE 4 
Results Obtained for Nitrogen, July, 1917 
u4 
U- 
x+ 
X- 
p 
K+ 
K- 
R 
1. 60 cycles 
17.60 
22.96 
15.0 
11.5 
60 
1.39 
1.81 
1.30 
10.15 
26.0 
140 
1.87 
2.81 
3.88 
47.0 
33.5 
360 
1.33 
1.84 
1.38 
1.27 
1.65 
51.0 
40.0 
750 
1.26 
1.63 
1.30 
1.36 
1.84 
50.0 
38.0 
745 
1.33 
1.80 
1.35 
1.34 
1.82 
49.8 
38.0 
745 
1.31 
1.78 
1.36 
1.32 
1.79 
1.34 
2. 
14,758 cycles 
5000 volts 
1.31 
1.84 
17,670 
14,880 
750 
1.29 
1.82 
1.40 
1.31 
1.84 
17,670 
14,880 
745 
1.28 
1.80 
1.40 
1.31 
1.84 
17,670 
14,880 
742 
1.28 
1.80 
1.40 
2.76 
3.93 
13,910 
10,110 
360 
1.31 
1.86 
1.42 
2.76 
3.93 
13,910 
10,110 
345 
1.26 
1.78 
1.42 
1.28 
1.81 
1.41 
Mean of both frequencies 
1.30 
1.80 
1.38 
X - /P Max. = 29.0, Min. = 0.05. X + /P Max. = 40.0, Min. = 0.07. 
impossible since the tremendous velocity imparted to them by the high 
field would enable them to produce ions from neutral molecules by attach- 
ing themselves to the latter. It would be interesting to find out where, 
that is, at what potential — other conditions remaining the same — this sort 
of ionization actually would begin. 
c. Nitrogen. — Table 4 shows the results of the mobility measurements in 
nitrogen. The maximum potential gradient employed was 17,670 volt/cm. 
for the positive and 14,880 volt/cm. for the negative ions. The mobilities 
remained absolutely normal up to these limits and the law Up = constant 
was found to be applicable here as it was in the case of air and hydrogen. 
