Faraday to John Tyndall   19 November 1850

Royal Institution, | 19 Nov. 1850.

Dear Sir,

I do not know whether this letter will find you at Marburg, but though at the risk of missing you I cannot refrain from thanking you for your kindness in sending me the rhomboid of calcareous spar¹. I am not at present able to pursue that subject, for I am deeply engaged in terrestrial magnetism, but I hope some day to take up the point respecting the magnetic condition of associated particles. In the mean time I rejoice at every addition to the facts and to the reasoning connected with the subject. It is wonderful how much good results from different persons working at the same matter; each one gives views and ideas new to the rest. Where science is a republic, there it gains; and though I am no republican in other matters, I am in that.

With many thanks for your kindness, | I am, Sir, | Your very obliged servant, | M. Faraday

John Tyndall Esq, | &c. &c. &c.

Address: J.T. | Marburg | Hesse Cassel