43 
According to the experiments of Professor Daniel, 11.26 
grains of zinc, electrolitically dissolved, should give 25 cubic 
inches of mixed gases; and I found this proportion more 
practically accurate than the one I deduced from the gene- 
rally accepted tables of equivalents. Therefore 27.024 grains 
borne by the galvanometer, if correct, should equal one cubic 
inch of mixed gases per minute, and on these data I obtained 
the following results; in the first instance using a nitric 
acid battery, of which each cell balanced about 132 grains, 
being put in circuit with both voltameter and galvanometer: 
Cubic Inches Cubic Inches 
No. of Cells. Grains. per Minute. by Calculation. 
4 Balanced ... 84 3.1 3.11 
3 Ditto ... 62 2.3 2.29 
2 Ditto ... 30 1.07 1.1 
A series of much smaller cells being used, of which each 
cell with the galvanometer alone balanced 36 grains : 
No. of Cubic Inches Cubic Inches by 
No. of Cells. Grains. Minutes. Observed. Calculation. 
4 Balanced.. 23 3 2.4 2.55 
3 Ditto 19 3 2.08 2.1 
2 Ditto 9 5 1.62 1.66 
Although the discrepancy of the observed calculated 
quantities is not considerable, I am of opinion that it 
arises more from the difficulty of reading very small quan- 
tities in the collecting tube of the voltameter, rather than 
from errors of the galvanometer, and that the current was 
in no experiment quite uniform, the collection of gas on 
the electrodes of the voltameter sensibly diminishing the 
quantity of current indicated by the galvanometer. I there- 
fore arrive at the conclusion, that my form of galvanometer 
will give much more accurate indications than can be obtained 
from a voltameter, in addition to the advantage of giving its 
results more immediately, and interposing less additional 
resistance in the circuit. 
