Christian Friedrich Schoenbein to Faraday   18 December 1852

My dear Faraday

I had already given up the hope of my paper¹ having reached you, when I was most agreeably undeceived by your kind letter from Brighton². I am really curious to know what you will think about my notions on the relations of the different conditions of oxigen to the voltaic, magnetic and optical properties of that body. The conviction of their being correct has by no means been shaken by my recent experimental results of which you shall hear before long. But however they may turn out I trust they will at any rate draw the attention of philosophers to a most important set of phenomena.

I am not acquainted with the experiments of Stokes³ but from what you say about them I am inclined to believe that they are closely connected with my subject. I am just now working upon the optical action of nitrous gas (NO⁴) upon the solutions of the protosalts of iron, which, as you are well aware, is so very striking. As I entertain the notion that the deep coloring of those solutions produced by NO⁵ is due to a change of the condition of the oxigen being contained in the base of the ironsalt i.e. to the transformation of the inactive state of that oxigen into the active one, I suspect that the paramagnetic force of the black liquid is smaller than the sum of the paramagnetic forces of its constituent parts. You know that by uniting two equiv of inactive i.e. paramagnetic oxigen to one equiv of paramagnetic deutoxide of Nitrogen a diamagnetic compound is produced and you are likewise aware, that the two eq. of oxigen united to NO⁶ exist in hyponitric acid in the ozonic or excited condition. Again by associating 2 equiv. of the highly paramagnetic protoxide of iron to one equiv. of paramagnetic oxigen a compound is obtained being, according to your own experiments, magnetically indifferent. I have shown in my paper that Fe⁷O⁸ is = 2FeO + <oring>O that is to say that the third equiv. of the peroxide of Iron exists in the exalted condition. From these facts I infer that in the first case the diamagnetism of 2 equiv. of ozonic Oxigen is stronger than the paramagnetism of the two equiv. of inactive oxigen contained in NO⁹; and that in the latter case the diamagnetism of one equiv. of ozonic Oxigen neutralizes the paramagnetism of 2 equiv. of protoxide of Iron. Now I conjecture that by uniting the two paramagnetic compounds: a proto iron salt to NO¹⁰ either a diamagnetic or a less paramagnetic fluid will be obtained. I should consider it as a great favor, if you would settle that point by experiment.

I trust the bracing air of Brighton will refresh your body and mind so much as to enable you not only to resume your Lectures, but what is more important your scientific labors. We cannot spare you, our present age being so woefully deficient of original thinkers and experimental Philosophers. There are indeed but a very few to whom I might say: You are the salt of the Earth, but if the salt have lost his savour, wherewith shall it be salted?¹¹ Permit me to tell you that I count you amongst those few.

Mrs. Schoenbein and the Children are well. My eldest daughter is now rather a big child i.e. a grown up Lady. They charge me with their best compliments to you and Mrs. Faraday, to whom you will reme<<m>>ber me in particular and in the most friendly mann<<er.>> Excuse my badly written letter, which I was obliged to scribble down in a great hurry and believe me, my dear Faraday

Your’s | most truly | C.F. Schoenbein

Bâle Dec. 18th 1852.

Address: Doctor Michael Faraday | &c &c &c | Royal Institution London

Postmark: Melksham¹², 27 December 1852