John Frederick William Herschel to Faraday   15 February 1828

Dear Sir[,] This is a note I recd this morning from Dr Wollaston. I hope, the first opportunity - you will see the possibility of making the experiments suggested - Yours truly J.F.W. Herschel.

Pray preserve this.

Dorset Street | Manch[ester] Square | Tuesday 12 Feby

My dear Sir

I must own that I am not sufficiently acquainted with the proceedings of the Sub-committee for the Improvement of Glass, to warrant my attempting to reply so definitely to your note as you seem to wish, as I cannot in direct terms specify the exact proportions or even the exact ingredients that would be proper for any one experiment.

But I may nevertheless answer very explicitly as to the special object of the experiment, which I have suggested.

If as the result of your inquiries the best proportion of any ingredients for making glass with Potash (p) be a, + b + c &c + (p) I would in one pot place exactly that mixture & in another pot at the same time & in the same furnace for the same time I would put beside it a + b + c &c + (s) an equivalent quantity of soda in order to learn as exactly as possible the relative merits of the two alkalis for making Flint Glass.

As it is not my wish to intrude unnecessarily upon the proceedings of the Sub-Committee & as I conceive that the above explanation cannot fail to make my object intellig<<ible>> I see no reason for further interference on the part of | Yours ever | Dear Sir | very truly | W.H. Wollaston

Address: M. Faraday Esq | Royal Institution | Albemarle Street | London

Postmark: 15 February 1828