MR. DANIELL ON VOLTAIC COMBINATIONS. 
129 
receiver. When this cell is included in the circuit of double cells, the hydrogen is 
absorbed as before by the oxide of copper ; but the oxygen is evolved at the rate of 
84 cubic inches per hour. 
I shall conclude these observations with the result of an experiment which places 
the secondary action of the affinities of the disengaged gases in a striking point of 
view. The mixed gases collected in a voltameter in five minutes were found to 
amount to 1/ cubic inches ; the oxygen collected in an equal time, when the hydro- 
gen was absorbed, was 7 cubic inches; which are equivalent to 21 cubic inches of 
the mixed gases : and the hydrogen collected when the oxygen was absorbed (as is 
readily effected by reversing the connexions of the cell which I have just described) 
amounted to 16 cubic inches, equivalent to about 24 cubic inches of the mixed gases. 
Thus the removal of the hydrogen from the sphere of attraction allowed of an increase 
of action equal to 4 cubic inches, while the increase from the like removal of the 
oxygen was very nearly double ; a difference which is probably referable to the equi- 
valent combining volumes of the two gases. This observation opens a new field of 
inquiry of great interest, upon which, with your permission, I hope to have the plea- 
sure of addressing you at no very distant period. 
I remain, my dear Faraday, 
Yours very faithfully, 
J. F. Daniell. 
Kings College, 
Qth April , 1836. 
MDCCCXXXVI. 
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