UNDER ^THE INFLUENCE OF CHEMICAL ACTION. 
1 O 
1 o 
IV. 0 .—Generator adjusted twice. Clieniical effect rose after first adjustment. 
After second it fell, then rose again. It was large most of the time. Chemical 
saturation current: maximum 700 divisions per minute with capacity 0 -04 mfd., 
minimum 7 divisions per minute with capacity 0-01 mfd. There was no detect¬ 
able photo-electric current with X = 4355 in this experiment. An effect equal 
to about 1 per cent, of the chemical emission should have been detected. Con¬ 
siderable gas pressure was present, and there may have been a small air leak 
into the apparatus. Six drops per minute. 
V. ©.—No adjustment of generator in this series. Chemical effect small but very 
steady, only varying between 26 -5 and 31 -5 divisions per minute with 0 -01 mfd. 
capacity: photo-electric X 4355 saturation, 300 divisions per minute with 
0 -01 mfd. 
VI. •.—No adjustment of generator. Chemical saturation current rose gradually 
from 18 to 268 divisions per minute with 0-01 mfd. and then fell to 120 per 
minute. Photo-electric 4355, saturation current 240 divisions per minute with 
0 -01 mfd. 
An examination of the foregoing remarks shows that the series of observations I. to 
V., which are comprised in fig. 4, embrace a wide variety of conditions. Thus the satura¬ 
tion chemical current is varied over the range from 700 divisions per minute with 0 -04 
mfd. or 8 -2 X 10~ 10 amperes to 7 divisions per minute with 0 -01 mfd., or 2 -05 X 10~ 12 
amperes. The photo-electric saturation currents under practically the same illumina¬ 
tion in each case varied between the limits 8 -8 X 10“ 11 amperes and something under 
