EMISSION VELOCITIES OF PHOTO-ELECTRONS. 
217 
Table III. — Cadmium. 
M 
AVave-length. 
Velocities (in volts). 
Mean velocities. 
A 2537 
•869 
•869 
•869 
-869 
A 2257 
1-399 
1-389 
1-389 
1 - 392 
A 1849 
2-459 
2-459 
2-448 
2-455 
AA^ave-length. 
Frequency, 
n. 
Experimental 
velocities. 
o 
1 
II 
VV = k'n - c. 
A 1849 
1623 X 1012 
2 - 455 volts 
[2•455] 
[2 • 455] 
A 2257 
1329 
1-392 
1 • 396 
1-309 
A 2537 
1182 
•869 
[-869] 
[-869] 
A 2967 
1010 
•159 
•249 
•468 
A3126 
960 
•042 
•070 
-.373 
A 3340 
898 
No effect. 
(-•15) 
•274 
Vo = 3;384 volts; 7 = 3^597 x IQ-iL 
From these two experiments with oxygen one may conclude that the effect of 
contact with oxygen is to move the line V = Joi — Yq parallel to Itself, the A^alue of Vg 
being increased. 
The results of a third experiment with cadmium are given in Table IV. 
Table IV. — Cadmium. 
Wave-length. 
Velocities (in volts). 
Mean velocities. 
A 2537 
•716 
•716 
•720 
•720 
•718 
A 2257 
1-256 
1-282 
1-267 
1-282 
1-270 
A 1849 
2-380 
2 • 395 
2 • 385 
2-387 
AVave-length. 
A 1849 
A 2257 
A 2537 
A 2967 
A 3126 
Frequency, 
n. 
1623 X KV^ 
1329 
1182 
1010 
960 
Experimental 
velocities. 
V = kn - Vo 
2 • 387 volts 
1-270 
•718 
0 
No effect. 
[2-387] 
1 • 275 
[-718] 
•068 
(-• 12 ) 
VV = k'n - ( 
[2-387] 
1-185 
[■ 718 ] 
•334 
•253 
VOL. OCXII.—-A. 
Vo = 3-754 volts; k = 3-784 x 10-V 
2 F 
