Faraday to Isambard Kingdom Brunel   19 October 1837

R Institution | 19 Octr. 1837

My dear Sir

Your sediment is very well washed. There is some mercurial i.e. calomel & insoluble carbonate of corr sul & vegetable matter; but the great mass of the substance is sand & little pebbles and with them is much loose wood chips fibres &c[.] How so much dirt gets into your tanks I do not know.

Ever Truly Yours | M. Faraday

I.K. Brunell Esq | &c &c &c