Lead Works Sheffield | Dec 14th 1855
My dear Sir
I beg to hand you 4 castings of our refined lead which I hope is sufficiently pure to answer your purposes.2 My last analysis gave in 100 parts
Copper 000.0028
Iron 000.0042
Silver 000.0022
I cast them by pouring into a heated mould – continuing to pour until the metal solidified at the top in order to ensure as much as possible uniform density. I enclose also one waster3 which I have immersed in dilute nitric acid for 24 hrs – as it shows very prettily the crystalline structure of the metal & may afford you clearer insight of the nature of the objects you are experimenting upon.
If you think a nearer approach to absolute purity is necessary for your investigations I shall be happy at some time to furnish you with a bar or two, which I might prepare at my leisure.
Yours very truly | William Baker
John Tyndall Esq.
RI MS JT/1/B/9
Baker: William Baker (born in London in 1830; Ancestry) was a professional chemist and manager of the White Lead Mill on the River Sheaf. The works had opened in 1759 to manufacture pigments for paint and pottery glazes (1861 Census).
answer your purposes: This possibly had reference to the Pelletier–Seebeck effect which Gustav Magnus had investigated with different metals in 1852. In his ‘Reports on the Progress of the Physical Sciences’ in January 1852, Tyndall had abstracted Magnus’s paper ‘On Thermo-Electric Currents’, Phil. Mag., 3 (1852), pp. 81-90. In a table summarising Magnus’s results on p. 87, Tyndall noted that the results with lead were ‘uncertain’. Perhaps this led him to seek purer samples?
waster: an imperfect specimen.
Please cite as “Tyndall1165,” in Ɛpsilon: The John Tyndall Collection accessed on