My dear Sir!
I thank you for your very kind letter of the 14th of February.1 Prof. Faraday informed my self that my last letter2 did not reach you in town. To answer old letters is not at all amusing, therefore I thank you the more.
I am very glad to see that, with infatigable zeal, you continue your researches about glaciers3 and that finally you succeeded to reduce all principal phenomena to their physical causes.4
I am working always on electric discharges through rarefied gases. Lately I finished that part of these researches which regards the action of the Magnet on such currents. Two months ago, after having sent my paper to Poggendorff,5 I gave in a letter to Prof. Faraday6 a short account of some of the most striking new phenomena[.]
In the general case the positive light, if acted upon by the magnet, moves in spirals towards the negative wire where heat or chemical action are produced. In all cases the law of these spirals and their modifications easily derives from the well known magnetic action on an electric particle moving towards the negative wire. Properly speaking, the negative light, exhibiting the magnetic surfaces, has nothing to do with the current itself; I think it a secondary phenomenon.
I have before me some papers of mine, but I should not like to send them over to my English friends, but joined to the best and longer paper provided now.7
Recently all my attention is absorbed by the splendid phenomena of electric gas spectra.8 Generally in the case of such spectra all the light is concentrated into a certain number of bright luminous lines, of an absolutely constant refrangibility.9 These lines will in most cases replace with great advantage Fraunhofers dark lines;10 in my experimental researches I continually made use of the three beautifull lines of hydrogen gas. —I procured an excellent instrument in order to measure the positions of the questioned lines with greatest accuracy. I examined already a certain number of gas spectra—where principally, I meet with chemical questions.
Nearly every week I get new wonderfull appearances, not unworthy to be schown in Roy. Institution. So I sit lately in examining the vapour of the chlorides of tin and titane. The discharge through the vapour of the feros chloride in an larger tube is of a deep blue colour, which, when the discharge enters a very narrow tube, becomes a bright one of gold. The Magnet, when acting upon the larger tube provokes beautifull golden lightnings within the blue gas.
I was happy to know that Prof. Faraday continues very well. Pray present to him my compliments.
Most truly | Yours | Plücker | Bonn 7/3 59
RI MS JT/1/P/128
your very kind letter of the 14th of February: Tyndall sent Plücker a letter dated 13 February 1859 (see Vol. 6, letter 1589).
my last letter: letter missing (see also Volume 6, letter 1589, n. 1).
you continue your researches about glaciers: Tyndall had been researching the nature and behaviour of glaciers since the mid-1850s. In 1859 Tyndall was working on his book The Glaciers of the Alps (see n. 4).
finally you succeeded to reduce all principal phenomena to their physical causes: Likely refers to Tyndall’s proposed theory of glacial motion. Tyndall believed that glaciers moved by perpetually fracturing and relegating, and he elaborated on this theory in his book The Glaciers of the Alps: Being a Narrative of Excursions and Ascents, an Account of the Origin and Phenomena of Glaciers and an Exposition of the Physical Principles to which They are Related (London: John Murray, 1860). It was published on July 6, 1860.
I am working always … having sent my paper to Poggendorff: likely refers to J. Plücker, ‘Ueber die Constitution der elektrischen Spectra der verschiedenen Gase and Dämpfe’, Poggend. Annal., 107 (1859), pp. 497–539.
I gave in a letter to Prof. Faraday: Plücker wrote to Faraday on 3 July 1859, where he elaborated on his experiments using Ruhmkorff’s Apparatus (letter 3612, Faraday Correspondence, Vol. 5, 1855–1860, pp. 530–1).
I have before me some papers of mine … joined to the best and longer paper provided now: the enclosed paper is missing, but may refer to J. Plücker, ‘Abstract of a Series of Papers and Notes Concerning the Electric Discharge through Rarefied Gases and Vapours’, Proc. Roy. Soc., 10 (1860), pp. 256–69, which was read to the society on 19 January 1860.
the splendid phenomena of electric gas spectra: the light produced by a gas-charge lamp.
refrangibility: refers to the ability of light to be refracted (OED).
Fraunhofers dark lines: the dark lines in the solar spectrum, caused by substances in the solar atmosphere absorbing radiation in specific parts of the continuous solar spectrum. They were noticed by Wollaston, investigated by Joseph Fraunhofer (1787–1826) and named after him (OED).
Please cite as “Tyndall1595,” in Ɛpsilon: The John Tyndall Collection accessed on