A Physical Treatise on Eletricity and Magnetism Volume 2 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1880 Excerpt: ...Polarization. We have hitherto supposed the currents to be strong enough to decompose the liquids employed. When, however, only one Daniell's cell is used, decomposition does not take place; but a state of " polarization" or strain is set up which very closely resembles that set up in a charged Ley den jar. In fact, electrolytic polarization may be compared to the ordinary charging of a Leyden jar, and decomposition to the case where the charge of the jar is strong enough to perforate the glass. Messrs. Ayrton and Perry t have measured the rate of charging of a voltameter, and the rate of the return of the charge, and they have found a very close resemblance between the electrolytic curves and those obtained for the charging and discharging of a Leyden jar. They have also foundj that both the electrolysis and the Leyden jar curves are precisely similar to those expressing the deflection of a beam by weights, and its return when the weights are removed, and that the same form of mathematical (differential) equation will express all three phenomena. Measurement Of Deflections. The rapidly changing currents and potentials were measured by means of a reflecting galvanometer and electrometer whose light-spots were thrown on to a large rapidly revolving barrel covered with white paper. The limits of swing were noted by making rapid dots with a pencil at the extreme positions of the light-spot. By this means two curves were obtained (fig. 214, 1, 3, b, 7, and 2, 4, 6.) It is clear that the curve A, B, ... E, expressing the mean value of the current or potential, must lie somewhere between these curves. The authors show mathematically that each point on the Miller's " Chemistry," vol. i. pp. 541--548. t Journal of Soc. of Telegraph Engineers, 187...