Ɛpsilon

George Biddell Airy to Faraday   17 April 1848

Royal Observatory Greenwich | 1848 April 17

My dear Sir

I have several times read with infinite pleasure your beautiful experiments on the diamagnetism (I do not like that word) of flame and gases1, and only trouble you with one remark. You ascribe the gradual beginnings of the effect to certain supposed mechanical modifications in the effect on, and the means of receiving the effect by, the ponderable gases2. But, inasmuch as there is the same graduality of beginning of the effect on the circular polarization of light, where it is impossible that this explanation can find place, does it not appear to arise from something in some part of the magnetic arrangements which requires time for its development? And if so, is it not an important subject of examination per se?

I think it probable that this is not worth reading, and am certain that it is not worth answering; therefore I request that you will not waste any time upon it.

I am, my dear Sir, | Very truly yours | G.B. Airy

Michael Faraday Esq | &c &c &c


Endorsed by Faraday: Exp. Research 21703. the time in the heavy Glass &c. referred to in letter to Taylor E. Phil Jour Sept & Octr 18464.

Time in diamagnetism of flame Phil Mag Dec. 1847 p 4025

Time My letter6 to Gay Lussac7 - Vol 2 p 191, 1958

E Res Vol I. Index a dozen places9.

1
Faraday (1847).
2
Ibid.,402.
3
Faraday (1846b), ERE19, 2170.
4
Faraday (1846f). Faraday misnamed the journal, but it is this paper he had in mind since he cited it in his reply to Airy, letter 2073.
5
Faraday (1847), 402.
6
Faraday (1832c, 1840d).
7
Joseph Louis Gay-Lussac (1778-1850, DSB). French chemist and co-editor of Ann.Chim.
8
Faraday (1844b), 191, 195. These translate into Faraday (1840d), 358-9, 362. It should be noted that the translation into English of Faraday (1832c) in Faraday (1844b) is different from that in Faraday (1840d).
9
Faraday (1839b), 573.

Bibliography

FARADAY, Michael (1832c): “[Lettre] A M. Gay-Lussac”, Ann. Chim., 51: 404-34.

FARADAY, Michael (1839b): Experimental Researches in Electricity, London.

FARADAY, Michael (1840d): “On Magneto-electric Induction; in a Letter to M. Gay-Lussac”, Phil. Mag., 17: 281-9, 356-66.

FARADAY, Michael (1844b): Experimental Researches in Electricity, volume 2, London.

FARADAY, Michael (1846b): “Experimental Researches in Electricity. - Nineteenth Series. On the magnetization of light and the illumination of magnetic lines of force”, Phil. Trans., 136: 1-20.

FARADAY, Michael (1846f): “On the Magnetic Affection of Light, and on the Distinction between the Ferromagnetic and Diamagnetic Conditions of Matter”, Phil. Mag., 29: 153-6, 249-58.

Please cite as “Faraday2072,” in Ɛpsilon: The Michael Faraday Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/faraday/letters/Faraday2072