The Papers of Joseph Henry


Prof Henry
Dear Sir On reading your paper in the Jan number of Sillimans Journal I was particularly interested with the views you express in the last paragraph of page 27 in regard to the nature of common electric discharges as that of the Leyden jar.[2] I have entertained the same idea myself for a year or two without supposing it had ever occurred to anyone else. It was first suggested to me in reading Faraday's experiments and observations on the peculiar decomposing action of electric discharges[3] and I soon saw that it was no more than a reasonable inference from the known law of induction of currents for such is the comparatively small quantity and high intensity of a charge that up to the maximum rapidity of current in discharge we may reasonably believe that the resistance to conduction in a good conductor is very small compared with the force of induction which like inertia in a ponderable body opposes either[A] increase or diminution of motion. If so we could not avoid the conclusion that the current once generated for instance in the discharge of a jar would rush on after an equilibrium was attained until it charged the inner coating nearly as highly positive as it was before negative when of course it would return and I have thought the vibrations might even amount to hundreds or thousands all in the time of a single shock or spark the penetrated interval of air offering it is probable during the time but small resistance. The number of vibrations would of course depend on the difference between the force of induction and the resistance to conduction just as the number of vibrations a pendulum will make before coming to a state of rest depends on the difference between the force of its inertia and the resistance of the air. In the case of a very long discharging wire in which it is thought that time is required for the spark to pass the length of the wire time if my impression is correct which is a considerable part at least of the duration of the spark we must perhaps modify the above view by supposing as you would have done a succession of waves along the wire. I would not however speak with confidence on that point because I have not read fully Wheatstone's experiments.[4]
I was waiting for a favorable opportunity to make some experiments with the design of publishing my views on the above subject[5] if they appeared to be sustained hoping to subject the phenomena of decomposition by common electricity to the laws of decomposition by voltaic electricity but from the tenor of the paragraph referred to I suppose you have before published similar views though I do not recollect to have met with them. My object then in troubling you with this communication is to inquire where I may find them. There is nothing at this time I should read with higher interest.

Very respectfully Yours

J. H. Lane
Please address J. H. Lane Castleton Vt.
Henry Papers, Smithsonian Archives. Enclosed in Doc. 18. Reply: Doc. 42.
    [1] A schoolteacher and graduate of Yale (1846), Lane (1819–1880) received an appointment with the Coast Survey in 1847. He was later employed by the Patent Office (1848–1857) and the Office of Weights and Measures (1869–1880). In 1848, Henry described two of Lane's publications "on physico mathematical subjects" as exhibiting "much originality of thought, fertility of invention and a profound knowledge of the subject." Henry concluded "that with a suitable opportunity of developing his talents Mr Lane would become one of the first in the line of original physical research in our country." Henry to A. M. Clayton, June 1, 1848, Box 1, Scientific and Personal Papers of Jonathan Homer Lane, 1836–78, Records of the Bureau of Standards, RG 167, National Archives; DSB.
    [2] "On the Induction of Atmospheric Electricity on the Wires of the Electrical Telegraph," Silliman's Journal, 1847, 2d ser. 3:25–32. Lane's specific reference was to Henry's theory of the oscillatory discharge of a Leyden jar.
    [3] Presumably a reference to Michael Faraday's Experimental Researches in Electricity, Twelfth Series, "On Induction (continued)," Phil. Trans., 1838, pp. 83–123, containing Faraday's theory of electrical discharge.
    [4] Charles Wheatstone, professor of experimental physics at King's College, London, had measured the velocity of electricity in a long wire: "An Account of Some Experiments to Measure the Velocity of Electricity and the Duration of Electric Light," Phil. Trans., 1834, pp. 583–591. Henry had worried repeatedly about this experiment while developing his theoretical ideas about electricity. Henry Papers, 2:290–292, 491–493; 5:14–15, 406, 411; 6:172–173.
    [5] Lane summarized many of his thoughts on electricity in "On the Law of the Induction of an Electric Current upon Itself When Developed in a Straight Prismatic Conductor, and of Discharges of Machine Electricity through Straight Wires," Silliman's Journal, 1851, 2d ser. 11:17–35.
    [A] Altered from eather