Faraday to Peter Henry Berthon   11 February 1859

Royal Institution | 11 Feby 1859.

Dear Sir

Since my return to town I have carefully analyzed the water from Hurst point which you sent me¹. It is very bad for culinary use and must be injurious to health. The history of it is this. Being rain water originally (as its state proves) it would if in an inland situation be collected by the roofs & be conducted by leaden gutters without any probable harm. But at Hurst point the wind drives sea spray on to the roofs & gutters & the salt in that spray acts upon the lead of the pipes &c & dissolves it[.] Such lead remains in solution as I find is the case in this instance. The salts which occur in the water are the salts derived from the spray[.]

I think cases like this have happened before in lesser degrees[.] They will occur in a greater or smaller degree whenever the spray of the sea may be caught by the roof - the water from which roofs being conducted by leaden gutters or pipes or collected in leaden tanks - The degree of poisoning will of course vary in different weathers as well as in different situations[.]

I am Dear Sir | most faithfully Yours | M. Faraday

P.H. Berthon Esqr | &c &c &c

4 pints of the water gave 0.4 of grain of dry sulphate of lead