On the results of a series of experiments on the decomposition of water by the galvanic battery : with a view to obtain a constant and brilliant lime light / by N.J. Callan.

  • Callan, N. J. (Nicholas Joseph), 1799-1864.
Date:
1854
Catalogue details

Licence: Public Domain Mark

Credit: On the results of a series of experiments on the decomposition of water by the galvanic battery : with a view to obtain a constant and brilliant lime light / by N.J. Callan. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    18/24 (page 18)
    appears, that, for want of sufficient intensity, a sensible portion ot the electric current produced by 3 cast-iron cells passes through a solution of carbonate of soda without producing decomposition; and therefore in decomposing water, 3 cells cannot be used with advantage. On one occasion the current was sent from 3, 4 and 6 cells, through a solution of sulphate of soda mixed with some carbonate of soda. The quantity of the mixed gases was very nearly in proportion to the number of cells and to the sines of the angle of deviation shown by the sine galvanometer. The sine of deviation appeared to be a little less, in proportion to the quan- tity of the gases produced, with 4 than with 3 or 6 cells. In this case, the sulphate of soda, as well as the water, was decom- posed ; for when the flame of the gases was thrown on lime, the bright white light produced by the oxyhydrogen flame was sur- rounded by another dim light of a purple hue. With the solu- tion of carbonate of soda alone, the quantity of the gases pro- duced by 4, 5, or 6 cells appeared proportional to the number of cells and to the sines of deviation. Hence, cast-iron batteries of 4, 5, or 6 cells will be equally effective in producing decom- position. But a battery of 4 cells will work as long and a half with a given charge as one of 6 cells, and as long and a quarter as one of 5 ; because in these batteries the quantity of electricity constantly flowing through each cell is proportional to the num- ber of cells. Hence in preparing a battery for decomposing water, all the cells should be arranged in rows of 4 each. Four cells produced more than half the quantity of the gases produced by 12 cells of the same size. A battery of 60 cells, arranged in one series, after having worked for some time, produced in one minute very little more than 4 cells of the same size. I have not yet tried the decomposing power of a battery of a larger nunffier acting in one series; but I shall have occasion, in the month of February, to show to my class a battery of about 250 cells; and I will then measure the quantity of the gases produced in one minute when all act in one series. Eight cells, arranged in two rows of four each, so that the two end zinc plates were connected as one, and the two iron cells also acted as one, produced considerably more of the mixed gases in two minutes than was produced by 12 cells of the same size acting in one series. The quantities of the gases produced by the 8 and the 12 cells were in the ratio of 11£ to 9. But with the 12 cells, the sine of deviation shown by the sine galvanometer appeared to be greater in proportion to the quantity of the gases produced than when the battery of 8 cells in two rows was employed. Hence it would appear, that when the intensity of the current is much greater than that of 4 or 6 cells of the cast-iron battery, the ratio of the quantity of water decomposed to the quantity of electricity passing through it is diminished; and consequently