---- lady, explanation of, xxxiii, 394; xl, 386. ---- light, a mode of producing, viii, 380. ---- machine, form and arrangement of, _W. R. Johnson_, xxv, 66. ---- ----, plate, viii, 378. ---- ----, ----, _R. Hare_, vii, 108^f; xxxii, 272.^f ---- ----, communication of, with the earth not necessary, _R. Hare_, xxiv, 253. ---- pile, theory of, xix, 375. ---- shock from a cat, mode of receiving, viii, 391. ---- sound, xlix, 390. ---- spark, _W. R. Johnson_, xxv, 57. ---- ----, length of, as affected by the size of the balls, _W. R. Johnson_, xxv, 60. ---- ----, perforations by, in a quire of paper or card, _W. R. Johnson_, xxv, 64. ---- ----, ----, ibid, _C. G. Page_, xxxvi, 353. ---- ---- drawn from a heated stove, xl, 385, 386. ---- ----, remarks on the so-called positive and negative, _R. Hare_, xxxii, 275.^f ---- ----, _Wheatstone's_ experiment to determine whether there is a sensible duration to, xxviii, 60. ---- ----, from magnets, _J. Henry_, xxii, 403. ---- ----, ----, _J. P. Emmet_, xxiv, 78.^f ---- syringe, _C. G. Page_, xxvi, 110.^f ELECTRICITY. ----, animal, mode of receiving a shock from a cat, viii, 391. ----, ----, peculiar case in a woman, xxxiii, 394; xl, 386. ----, ----, of fish on the coast of Cape Cod, _D. H. Storer_, xliv, 213. ----, ----, _Matteucci_ on, xxi, 157. ----, ----, observations on, _Linari_ and _Matteucci_, xxxii, 198; xlix, 388. ----, atmospheric, water decomposed by, xx, 179; xxi, 368. ----, ----, observations on, _M. Matteucci_, xxx, 376. ----, blasting by means of, xvi, 372.^f ----, capillary attraction influenced by, _J. W. Draper_, xxvi, 399. ----, ----, ---- productive of, ix, 193. ----, conducting power of liquid gases, xxi, 374. ----, ----, ---- of the metals, xii, 199. ----, ----, ---- of steam, xxvii, 206. ----, ----, ---- of the solar rays, xvii, 391. ----, the conductibility of, by liquids, increased by adding water, xvii, 165. ----, by contact, _Karsten_, xxxi, 159. ----, decomposition of water by atmospheric and common, xxi, 368. ----, discharge, lateral, _J. Henry_, xxxiv, 16.^f ----, effects of, on vegetation, _M. Baric_, xxxi, 160. ----, fluids of, one or two, _R. Hare_, vii, 103.^f ----, ----, ibid, _C. G. Page_, xxxvi, 353. ----, generation of, by the electrical machine, _G. W. Rains_, xlix, 93.^f ----, evaporation in gilding, producing, v, 198. ----, induced currents of different orders produced by, _J. Henry_, xxxviii, 232.^f ----, influence of, on the process of beer making, xxxiv, 8. ----, ----, on capillary attraction, xxvi, 399. ----, ----, on odors, xv, 394. ----, ----, on phosphorescence, _T. J. Pearsall_, xxi, 378. ----, light acting on an iodized plate, producing, xlvii, 190. ----, machinery producing, _A. Smith_, xxxix, 134. ----, medical, _J. Hall_, iii, 166. ----, motion producing and motion produced by, _J. Locke_, xxxiv, 130. ----, needle deflected by, xii, 199.