12 THE ROYAL SOCIETY OF CANADA 

TAB GEE 
Activity on the Activity on the 
Pressure. Cathode. Anode. 


~ 
= 
=) 
= 
=) 
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= 
~I 
_ 
_ 
.5 : 33 
1-0 14-5 14-0 
2-0 18-5 17-0 
7-5 37-5 29-0 
12-0 49-0 33-0 
25:0 ‘ 62-5 28-5 
42-0 82-3 17:7 
72-0 “ 92-0 10-0 
92-0 91-0 7-5 
120-0 “ 76-0 5:5 
135-0 “ 73-0 5-0 
162-0 68-0 4-0 
192-0 66-5 3-0 
320-0 “ 43-0 1-15 
500-0 “ 31-0 -70 
750: 0) 7“ 20-5 -45 
From these curves it will be seen that a maximum deposit was 
obtained on the negative plate at the point under observation at a 
pressure of approximately 80 mm., while the maximum deposit on 
the positive plate was not obtained until a pressure of 16 mm. was 
reached. 
When these experiments were repeated with carbon dioxide and 
with hydrogen in place of air, it was found that the maximum deposit 
at the same point on the negative plate was obtained with a pressure 
of 60 mm. in carbon dioxide, and with a pressure of 250 mm. in hydrogen. 
Further, in some additional observations made by Kennedy since 
the publication of the paper referred.to above, it was found on measur- 
ing the deposit on the negative plate at different points at various 
distances from the salt, that a simple law existed connecting the pres- 
sure corresponding to the maximum deposit obtained at a given obser- 
vation point with the distance of that point from the salt. According 
to this law, if x, represents the distance from the salt of the point at 
which the deposit was investigated and p, the pressure which gave a 
maximum deposit at that point, then p, was found to vary inversely 
with x, or 
Pi X, = à constant. 

* Trans. B.A.A.S., 1910, p. 543. 
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