196 
IOWA ACADEMY OF SCIENCES. 
The Daniell cell, owing to its simple construction and low 
cost, is generally used for student purposes. All teachers 
of physics will agree with me, however, that the Daniell 
cell in the student’s hands is the source of many exasper- 
ating accidents. The cell as usually mounted with porous 
jar practically destroys itself when accidently left on open 
circuit for a period of time. To prevent this the cell must 
be dismounted and again be reassembled at each new use. 
The zincs must be repeatedly amalgamated. The electro- 
lytes in this process of dismounting and reassembling are 
spilled upon the laboratory tables. The glass jars are fre- 
quently broken producing chaos indescribable. 
In order to avoid the great cost of the Lalande type of 
cells and also the exasperating incidents arising from the 
use of the Daniell, I undertook some two years ago to 
devise a cell cheap in cost and efficient in action. The 
result is the following cell sketched 
below and constructed as follows: 
The cell belongs to the Lalande class. 
It consists of a sheet steel container 
with double lapped seams. The seams 
are sealed by boiling into them a 
cement whose principal ingredients 
are old rubber and paraffine. This 
cement serves as a solder and pre- 
vents any leakage of the cell. The 
sides of the cell are either corrugated 
or plain and the interior is lined with 
a coil of netted elastic steel like 
ordinary window screen. Into the corrugations and 
the netted lining is firmly pressed the powdered copper 
oxide. To prevent the copper oxide from falling out its 
surface is lined with a piece of heavy muslin kept in its 
place by a piece of elastic steel netting. The bottom of 
the cell is finally covered with a thick layer of cement 
which prevents the copper oxide from leaking out from 
under the bottom of the lining. The sheet steel container 
with its netted linings and copper oxide constitute the 
positive pole electrode. The electrolyte is a thirty to forty 
t 
