John Frederick William Herschel to Faraday   16 March 1827

Dear Sir,

Pellatt¹ has given notice of the pots being ready to fill on Monday. The mixture put into the pot No. 1 of the Last Expt was

and according to your analysis the glass turned out be have too much potash & you suggested it might be advantageously replaced with Lead. What do you therefore think of the following

as a change for the pot destined to ladled & reladled.

If approved, be so kind as to forward the order to make ready such a mixture, to Messrs Pellatt & Green for Monday without loss of time (per 2dy Post) or if you judge any alteration requisite, make it & there is no occasion to trouble yourself to write again to me about it as you are much the best judge.

Yours very truly | J.F.W. Herschel

Address: M. Faraday Esq | Royal Institution

Postmark: 16 March 1827