108 
PHYSICS: K.-L. YEN 
values may be considered the same. Therefore, the results of the present 
experiment are directly opposed to those obtained by Wellisch in 1909 1 in so 
far as the ratios of the negative to the positive mobilities are concerned. 
In table 10 there is comparison between the results obtained by Wellisch 
and those obtained by me. It may be of interest to note that in 191 2 2 
Wellisch himself reversed his results for C 2 H 6 0, C 5 Hi 2 , and SO2. 
table 1 
Sulphur Dioxide (S0 2 ) 
p 
u+ 
U- 
K+ 
K- 
R 
60 
5.327 
5.547 
0.421 
0.437 
1.04 
70 
4.523 
4.523 
0.416 
0.416 
1.00 
80 
4.935 
4.035 
0.423 
0.423 
1.00 
90 
3.329 
3.371 
0.394 
0.399 
1.01 
105 
2.833 
2.895 
0.398 
0.407 
1.02 
120 
2.669 
2.561 
0.421 
0.404 
0.96 
Mean 
0.412 
0.414 
1.00 
TABLE 2 
Ethyl Alcohol (C 2 H 6 0) 
p 
u+ 
u- 
K+ 
K- 
R 
15 
19.728 
19.024 
0.389 
0.378 
0.97 
20 
14.017 
14.017 
0.369 
0.369 
1.00 
25 
11.097 
11.097 
0.365 
0.365 
1.00 
30 
9.513 
9.864 
0.375 
0.388 
1.03 
40 
6.053 
7.008 
0.319 
0.367 
1.15 
Mean 
0.363 
0.373 
1.03 
P = pressure in mm. mercury. U + = Positive mobility. U — = Negative mobility. 
K + = Positive mobility reduced to 760 mm. mercury. K — = Negative mobility re- 
duced to 760 mm. mercury. R = K — /K +. 
TABLE 3 
Aldehyde (C 2 H 4 0) 
p 
u+ 
U- 
K+ 
K- 
R 
30 
7.885 
8.560 
0.311 
0.338 
1.09 
34 
7.885 
0.352 
38 
5.993 
0.300 
43 
5.256 
5.548 
0.297 
0.313 
1.07 
45 
5.166 
5.350 
0.306 
0.317 
1.05 
50 
4.832 
5.078 
0.318 
0.334 
1.05 
55 
4.280 
4.610 
0.310 
0.333 
1.07 
Mean 
0.307 
0.331 
1.07 
TABLE 4 
PENTANE (C5H12) 
p 
u+ 
U- 
K+ 
K- 
R 
3t) 1 
'8.812 
12.483 
0.347 
0.493 
1 
42 
40 
7.491 
8.812 
0.394 
0.462 
1 
18 
50 
5.993 
6.968 
0.397 
0.445 
1 
12 
50 
5.993 
6.968 
0.397 
0.445 
1 
12 
60 
4.832 
5.448 
0.382 
0.430 
1 
12 
66 
4.540 
4.994 
0.394 
0.434 
1 
10 
Mean 
0.385 
0.451 
1 
17 
TABLE 5 
Ethyl Chlordde (C 2 H 5 C1) 
p 
u+ 
U- 
K+ 
K- 
R 
30 
7.683 
7.885 
0.303 
0.311 
1.02 
40 
5.762 
5.993 
0.303 
0.317 
1.05 
40 
5.549 
5.762 
0.292 
0.303 
1.04 
50 
4.7S6 
5.078 
0.313 
0.334 
1.07 
50 
4.681 
4.833 
0.308 
0.318 
1.03 
Mean 
0.304 
0.317 
1.04 
TABLE 6 
Acetone (C 3 H 6 0) 
p 
u+ 
U- 
K+ 
K- 
R 
50 
3.699 
4.035 
0.243 
0.265 
1.09 
60 
2.959 
3.131 
0.235 
0.247 
1.05 
64 
2.833 
2.959 
0.239 
0.250 
1.07 
70 
2.513 
2.665 
0.229 
0.245 
1.07 
76 
2.336 
2.421 
0.234 
0.242 
1.03 
80 
2.219 
2.296 
0.234 
0.242 
1.03 
Mean 
0.236 
0.247 
1.04 
