IOWA ACADEMY OF SCIENCE 
167 
THE GOOGLER PRIMARY BATTERY. 
BY IIAERY RAY WOODROW. 
The cell furnished us by the Battery Company was of the two fluid type. 
The exciter was sulphuric acid and zinc and the depolarizer was principally 
nitric acid. It resembled very much the Groove and Bunsen cells but differed 
in the depolarizer, which contained ferric sulphate. The carbon was placed 
inside the porous cup surrounded by 450 c. c. of the depolarizer. Outside this 
was 2,000 c. c. of sulphuric acid and a round cylinder of zinc. The mercury 
served the purpose of keeping the zinc amalgamated and also in making con- 
tact with the external circuit. 
In the chemical analysis I found iron and a slight trace of zinc in the 
depolarizer but no metal in the exciting fluid. Both solutions were acid which 
proved to be nitric and a small amount of sulphuric in the depolarizer and 
only sulphuric in the exciting fluid. It was at once evident that the iron in 
the depolarizer was in the form of ferric sulphate which gave the solution its 
brown color. It is to be noted that this brown color turned to green as soon 
as the action began in the cell. The hydrogen reduced the ferric sulphate and 
then the nitric acid oxidized the ferrous sulphate. The object of this was to 
make the action milder and fewer nitrous fumes would escape. 
The quantitative analysis of nitric acid is best determined by titration and 
the sulphuric acid is determined very nicely by precipitating the sulphate with 
barium chloride and weighing the precipitate as barium sulphate. From this 
data the amount of sulphate (s) can be determined by the formula: 
s = abd ce (1) 
where (a) is the molecular weight of (s), (c) the molecular weight of the 
weighed precipitate, b the weight of the precipitate, (d) the total volume of the 
solution in the battery, and (e) the amount taken for determination. The sul- 
phate is not all in the form of sulphuric acid but some of it is combined with the 
iron and zinc. The iron was determined by precipitating it as ferric hydrate and 
weighing it as ferric oxide. The amount of iron is found by formula (1) by 
usng the values of a, b, and c which correspond to iron and ferric oxide. 
Formula (1) may be simplified by the use of the chemical factor (f) which is 
equal to a — c. 
log. (s) = log. (b) + log. (f) + log. (d) — log. (e) (2) 
The zinc was determined by precipitating it as a corbonate and weighing it 
as an oxide. After the amount of zinc and iron is known it is a simple matter 
to determine the amount of sulphate (k) combined with them by the use of the 
formula: 
k -= os g (3) 
where o is the molecular weight of sulphate, s the same as in formula (2) and 
g the atomic weight of the metal (s). 
