William Robert Grove to Faraday   2 May 1843

My dear Faraday

The manganese battery is a mares nest, as far at least as any practical application goes, its intensity is very great so that 1 or 2 cells with very small electrodes beat the nitric acid but with a greater number of cells on large electrodes the supply of chlorine is quite unequal to the demand ergo it is not constant & lamentably inferior to the nitric acid[.] I write to relieve you because I know you do not like secrets[.] You need not mention it for the present as I may possibly send a note of it to the Phil Mag.¹ but as the secret is (like secrets in general) of no great value if I should hear of its being published it will occasion me no annoyance[.]

Although I thought very differently on the commercial question after having slept on it I am not sorry it is quite out of the question as my mind will be free to attack the much more interesting point of interrupted currents²; with compliments to Mrs Faraday I remain

In haste yours very truly | W.R. Grove

4 Hare Court Temple | May 2 1843

M. Faraday Esq