Page:Lifelettersoffaradayjonesvol1.djvu/38

1812.
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Æt. 20-1.

of magnesia—an effect which extremely surprised me; for I did not, could not, have any idea that the agent was competent to the purpose. A thought here struck me; I will tell you. I made the communication between the top and bottom of the pile and the solution with copper wire. Do you conceive that it was the copper that decomposed the earthy sulphate—that part, I mean, immersed in the solution? That a galvanic effect took place I am sure; for both wires became covered in a short time with bubbles of some gas, and a continued stream of very minute bubbles, appearing like small particles, ran through the solution from the negative wire. My proof that the sulphate was decomposed was, that in about two hours the clear solution became turbid: magnesia was suspended in it.

'Seeing the great effect of this small power, I procured from Knight some plate zinc, or sheet zinc I think they call it, about the thickness of pasteboard; from this I cut out discs, and also obtained some sheet copper, and procured discs of that metal. The discs were about 1 inch in diameter. These I piled up as a battery, interposing a solution of the muriate of soda by means of flannel discs of the same size. As yet I have only made one trial, and at that time had, I believe, about eighteen or twenty pairs of plates. With this power I have decomposed the sulphate of magnesia, the sulphate of copper, the acetate of lead, and I at first thought also water, but my conclusions in that respect were perhaps too hastily made.

'I inserted the wires into a portion of water that I took out of the cistern, and of course, in a short time, strong action commenced. A dense—I may really say