C. E. Fritts—New Form of Selenium Cell. 467 
for inspection and trial by the members of the association, was 
then described. ' 
As the result of some thousands of tests and measurements. 
made by me, I have reached the following new conclusions : 
Ast. The electrical resistance of a cell changes enormously 
with different battery powers. There does not appear to be any 
invariable law governing this change, but each cell seems to 
have its individual character in this respect. In most cases the 
Tent increases, One cell cited measured, with one Leclanché 
element, 14,000 ohms; with 5 elements, 9,900 ohms; with 10 
elements, 7,600 ohms; with 23 elements, 4,600 ohms. Another - 
measured, with 23 elements, 3,600 ohms; with 10 elements, 
8,000 ohms; with 5 elements, 10,000 ohms. In other cases, ° 
but less frequently, the resistance increases as the battery power 
increases. ‘These changes may be produced in either direction, 
and as often as desired.* 
2d. I have discovered that simply reversing the direction of 
the current through a cell can make its resistance, in some 
cases, as much as ten or fifteen times as high as before, even 
though that increase should amount to millions of ohms. 
Some instances the change may be even greater, in others not 
so much, but it is seldom less than twice as much, or as two to 
one. When the original direction of the current is restored, 
the resistance also returns, and these effects can be repeated 
any number of times. The cell is sensitive to light in both 
cases, but is generally more sensitive when the current enters 
thé selenium at the same surface which the light is acting upon. 
Instances of such changes were given, and several hypothe- 
Ses were considered, but none were thought to satisfactorily 
account for this phenomenon.t+ 
forty-four times as much in the dark as in the sunlight? [also wish to record 
cell whose resistance becomes greater 
in the light and less in the dark,—being, so fur as I know, the first instance of 
rare ins a oes on up to a certain battery 
power, and any further increase of intensity in the current causes a fall in the 
resistance,—so that a change from that battery power in either direction would 
produce the same change in the resistance of the cell. 
+ The foregoing changes are not always in the same direction. That is to say, 
if the cell has a certain resistance, with the positive pole of the battery connected 
to a certain electrode of the cell, the resistance will i in ed by 
connecting the negative pole of the battery to that electrode, an t ses it 
I be I have b ere reversing the direction of the 
curren no change in the resistance of t And, ll more 
Singular, I have had two cells which reversed their action while experi- 
mented with,—so that the electrode which offered the highest resistance to the 
positi ve current at first, afterwards offe e lower resistance to it, ange 
having e in the connections or conditions. e selenium or the cell 
Seemed to have been jm some way permanently affected by the action of the cur- 
rent flowing through it. The cause of this change has not been ascertained. 
