Charles Wheatstone to Faraday   17 January 1846

20 Conduit St | Jany 17th 1846

Dear Faraday

The repulsion of Bismuth by the magnet was first observed by Brugmans¹, a Dutch philosopher whose work was published in Latin in 1778². Le Baillif's experiments were announced in the 7th vol of Ferussac's³ Bulletin des Sciences Mathematiques et Physiques at page 371⁴, and given in detail in the 8th vol. page 87⁵; he proved that a magnetic needle was repelled both by Bismuth and Antimony. Saigey's⁶ experiments on the mutual repulsion of bodies, of which he considered the former cases to be individual instances, were announced in the 8th vol of the same work p. 258 [sic]⁷, and given in full detail in the 9th vol pp 89, 167 and 239⁸. There is also a paper by Seebeck⁹ "on the magnetic polarization of different metals, alloys and oxides between the poles of magnetic bars"¹⁰ to which it may be worth while to refer. It is worthy of remark that Becquerel's¹¹, Le Baillif's, Seebeck's and Saigey's experiments were all made about the same time. All together they have done very little towards anticipating the great general principle which [you] have just discovered and demonstrated¹².

In reference to the experiment I suggested yesterday of submitting to your repelling forces spheres of liquids suspended in another liquid of the same specific gravity, I may mention that when I first read Plateau's interesting memoir¹³ it occurred to me that by employing his method a number of instructive electrical experiments might be made.

By floating spheres of a conducting in a non conducting liquid, and charging the former with either electricity, they would be attracted and repelled by excited electrics, and the alterations in their equilibrium shown by their changes of form. The spheres might also be similarly or dissimilarly charged and their mutual actions observed. But what, perhaps, would be a more interesting experiment would be to examine the effects which one of these conducting spheres would exhibit when forming part of a voltaic circuit; to avoid the production of hydrogen gas the negative wire should be coated with per-oxide of lead; the sphere would probably change its form immediately the current is completed, and it would be certainly be [sic] attracted or repelled by a magnet or another similar sphere forming part of the same or a different circuit; rotations would also by certain arrangements be produced. I noted down at the time these and other experiments I proposed, and have several times since thought of setting about them, but other occupations have always interfered, and I have also been somewhat deterred by the consideration that for such experiments to succeed a delicacy and dexterity of manipulation equal to your own would be required.

Yours very Truly | C. Wheatstone