Faraday to William Henry Blaauw   5 April 1837¹

R Institution | 5 April 1837

Sir

When I returned to town Mr Fincher² put into my hands your letter & the bottles referred to, but very close engagement prevented me from examining them before, & Mr Brande had as little time as myself[.]

I enclose such a report as is useful and as I think you wish for[;] such a report indeed as I should want for my own use. As to expence it always gives me great pleasure to meet the wishes of the Members of the Royal Institution when the necessary occupations of my position in it & my health will allow me[.] Expence there is none.

I am Sir | Your Very Obedient Servant | M. Faraday

W.H. Blaauw Esq | &c &c &c

Royal Institution | 5 April 1837.

Waters.

House Pump<r>

This is a very good water. It contains some sulphate of lime and also muriate of Soda[.] The quantities are moderate & though the water is not very soft it is a good average specimen. It will not become much if any softer by boiling[.]

Cottage Well

This is a softer water than the last. It contains less sulphate of lime though some is present. The muriate is about the same as in the first water. Boiling will effect little or no change here, but the water is excellent as it is.

Bog Water

This water is very like the former in its contents except that when recent it contains a portion of carbonate of protoxide of iron & so becomes a chalybeate. Boiling or even standing with exposure to air will throw down this iron & then the clear water is even softer than either of the former. Such chalybeates as this are very numerous[.] Abundance existed formerly at the Spa fields & do now exist I think at Hampstead[.]

Field Spring Water

This is of the same nature as the last but contains more iron when in its fresh and natural state. All the iron is however separated by boiling or standing exposed to air³[.]

M. Faraday