On voltaic combinations. In a letter to Michael Faraday, Esq., D. C. L., F. R. S., &c

The author, after expressing his obligations to Mr. Faraday for the important light which his late researches in electricity have thrown on chemical science, proceeds to state that in pursuing the train of inquiry which has thus been opened, he has obtained further confirmations of the truth of that great principle discovered and established by Mr. Faraday, namely, the definite chemical action of electricity; and has thence been led to the construction of a voltaic arrangement which furnishes a constant current of electricity for any required length of time. For the purpose of ascertaining the influence exerted by the different parts of the voltaic battery in their various forms of combination, he contrived an apparatus, which he designates by the name of thedissected battery , and which consists of ten cylindrical glass cells, capable of holding the fluid electrolytes, in which two plates of metal are immersed; each plate communicating below, by means of a separate wire, which is made to perforate a glass stopper closing the bottom of the cell, with a small quantity of mercury, contained in a separate cup underneath the stopper, and with which electric communications may be made at pleasure through other wires passing out of the vessel on each side. The active elements of the circuit, which were adopted as standards of comparison, were, for the metals, plates of platinum and amalgamated zinc three inches in length by one in breadth; and for the electrolyte, water acidulated with sulphuric acid, in theproportion of 100 parts by volume of the former to 2.25 of the latter; this degree of dilution (giving a specific gravity of 1.0275,) being adopted, in order to connect the author’s experiments with those of Mr. Faraday.