William Robert Grove to Faraday   4 September 1846

Sept 4, 1846.

My dear Faraday

I gave my paper¹ into the hands of the RS offices yesterday & as it will shortly be no secret I should like to be the first to mention it to you although I dare say you will think I make more of the point than it deserves[.] It is simply this I can decompose water by heat liberating both its constituent gases in a mixed state. There are other points of minor interest in the paper the Title of which is 'On voltaic Ignition & the decomposition of water by heat'.

I find that whenever water or steam is exposed to ignited platinum at a temperature not far short of its fusing point the water is decomposed. I part got it by voltaic ignition of a conjunctive wire but though the phenomena was very clear to me I thought others would attribute it to Electricity & so I went on & after some labour I can now get it with ordinary heat in a very distinct manner - a simple way of doing it is to fuse a globule of platinum on the end of a wire either of the battery or oxyhydrogen blow pipe & plunge it into simmering water under a collection tube, we get point decomposition there, the spheroidal or balanced state there ebullition[.] The spheroidal obtaining to be intermediate or a state analogous to polar tension. I can by other expt get the effect continuously[.] The point such as it is I believe I can prove of its importance I am not the proper judge & perhaps estimate it in proportion to the labour it has cost me as I have sacrificed my vacation to it. Kind remembrances to Mrs Faraday

Yours very sincerely | W.R. Grove