90 The Rev. Dr. Callan's Eoeperiments on the 



meter, than it was when 4 or 5 cells were employed. Hence it 

 appears, that, for want of sufficient intensity, a sensible portion 

 of 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 efi"ective 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 moi-e than 4 cells of the same size. I have 

 not yet tried the decomposing power of a battery of a larger 

 number acting in one series j 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 Mheu 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 

 18 cells were in the ratio of \\l 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 roMs 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. 



