William Robert Grove to Faraday   22 October 1842

London Institution | Saturday Oct 22 | 1842

My dear Sir

I have just completed a curious voltaic pile which I think you would like to see, it is composed of alternate tubes of oxygen & hydrogen through each of which passes platina foil so as to dip into separate vessels of water acidulated with sulphuric acid the liquid just touching the extremities of the foil as in the rough figure below.

The platina is platinized so as to expose by capillary attraction a greater surface of liquid to the gas, with 60 of these alternations I get an unpleasant shock & decompose not only iodide of potassium but water so plainly that a continuous stream of fine bubbles ascends from each electrode. Thus water is decomposed by its composition - no oxidable metal is employed. I have reversed the tubes & tried all the counter expts but the phenomena are too marked I think to render any mistakes possible[.] Mr Gassiot was with me today & saw the Expts[.] Can you spare me an hour next week on Tuesday if it suits you or any day except Wednesday at any hour from 11 to 3 - at the Laboratory of the London Institution[.] I cannot but regard the experiment as an important one both as to the chemical & other theories of the pile & as to the catalytic effect of the combination of the gases by platina¹[.]

I remain my dear Sir | yours very sincerely | W.R. Grove

M. Faraday Esq | &c &c &c