Julius Plücker to Faraday   1 July 1857

Dear Sir!

Let me first thank you for the kind letter of the 23rd March¹ and the interesting paper², I received nearly at the same time. I learnd by the letter that you have sent my Memoir³ to Prof. Miller of Cambridge, the foreign Secretary. Since I got not the least notice about it, I fear therefore that I was ill informed with regard to the rules of the Royal Society, when I supposed, that papers, presented to the Society, (if approved) were published, in all cases announced in the proceedings. If the Memoir should get the honour to be printed, I would have found a friend, to eliminate the incorrectness of the language. My former views abandoned by myself since two years, being always reproduced in Journals (for instance by Mr Verdet⁴ in the “Annales de Chimie”⁵) I am interested to have my Memoir published, but, under the actual circumstances, I think myself not entitled to publish its contents.

I fear, Sir, to annoy you, when speaking again about the difference with Prof. Tyndall. Being desirous to have this difference settled, I think it best, not to enter into any detail. Allow me only a few words in answering your letter. I dont know what reason Prof. Tyndall has to believe that I charged him with wilful misstatement. I published no word against him, except the note p.6 of my paper⁶, and whatever should be my personnel feelings, I would not publish such a charge.- With regard to Mr de la Rive’s relation quoted by Prof. Tyndall⁷, the fact is this. After having showed to him all my experiments, he put to me, by letter, a great number of questions. These questions, difficult to be answered by yes and no, admitted partly a double meaning, you might refer them to the pure fact or to its theoretical explication: I fear to have induced him myself to some expressions contrary to my own real meaning.- The reason of the misstatement is to be sought in some strange circumstances, by which I got my paper of 1849 (of which I gave you an abstract January 1850⁸) published only 1852⁹ and therein that it was not translated neither into English nor French.

I worked not much this last time. I got only confirmed my theory of the magnetic induction of crystals in some new cases. Lately too I made a series of experiments in order to get an explication of the stratification of light, exhibited first by Ruhmkorff’s apparatus within certain rarified vapours, but equally obtained in every rarefied gaz and also by the electric spark or a series of them taken from a conductor, by retarding the decharge by means of less well conducting bodies¹⁰. I have the opportunity here to obtain tubes of glass, of different forms, filled with any gaz or vapour whatever at a measured tension, through which you may send the electric charge by means of platina wires. The various experiments are beautiful. You may easily observe the influence of tension and heat, the various spectra, sounds etc. But most beautifull is the effect, when the tubes are placed in the Electromagnet, in different ways, as well axially as equatorially. A tube 16-18 inches long showed many hundred blak intervals equally distant from each other; in other cases the blak intervals are larger and distant ¼ to 1/6 of an inch. The blak spaces are differently directed when put axially on the iron pieces of the Electromagnet. The current is under certain circumstances interrupted by the Electromagnetism. It is impossible to give by a sketch an idea of the most splendid phenomena. I join a very imperfect sketch of a more simple case. (I the tube and the sphere contains rarefied hydrogen gaz, II & III the sphere is put in the equatorial direction on the iron pieces and the polarity co<line>mutated) Whatever may be the variety of appearances the general phenomena of inflection of the luminous current by the Magnet is indicated by theory.

With all my heart | Yours, | Plucker

Bonn 1 / 7 57.

Endorsed by Faraday: 1 July 1857