[6] _De la Rive._ Treatise on Electricity, i. p. 300; Phil. Mag. xxxv. p. 422; Arch. de l’Électr. v. p. 200; Inst. 1846, p. 83; Comptes Rendus, xx. p. 1287; Comp. Rend. xxii. p. 432; Pogg. Ann. lxxvi. p. 637; Ann. de Chim. et de Phys. xxvi. p. 158. [7] _Matteucci._ Inst. 1845, p. 315; Arch, de l’Électr. v. 389. [8] _Guillemin._ Comp. Rend. xxii. p. 264; Inst. 1846, p. 30; Arch. d. Sc. Phys. (2d series), i. p. 191. [9] _G. Wertheim._ Comp. Rend. xxii. pp. 336, 544; Inst. 1846, pp. 65, 100; Pogg. Ann. lxviii. p. 140; Comp. Rend. xxvi. p. 505; Inst. 1848, p. 142; Ann. de Chim. et de Phys., xxiii. p. 302; Arch. d. Sc. Phys. et Nat. viii. p. 206; Pogg. Ann. lxxvii. p. 43; Berl. Ber. iv. p. 121. [10] _Elie Wartmann._ Comp. Rend. xxii. p. 544; Phil. Mag. (3d series), xxviii. p. 544; Arch. d. Sc. Phys. et Nat. (2d series), i. p. 419; Inst. 1846, p. 290; Monatscher. d. Berl. Akad. 1846, p. 111. [11] _Janniar._ Comp. Rend, xxiii. p. 319; Inst. 1846, p. 269; Arch. d. Sc. Phys. et Nat. (2d. series), ii. p. 394. [12] _J. P. Joule._ Phil. Mag. xxv. pp. 76, 225; Berl. Ber. iii. p. 489. [13] _Laborde._ Comp. Rend. l. p. 692; Cosmos, xvii. p. 514. [14] _Legat._ Brix. Z. S. ix. p. 125. [15] _Reis._ “Téléphonie.” Polytechnic Journ. clxviii. p. 185; Böttger’s Notizbl. 1863, No. 6. [16] _J. C. Poggendorff._ Pogg. Ann. xcviii. p. 192; Berliner Monatsber. 1856, p. 133; Cosmos, ix. p. 49; Berl. Ber. xii. p. 241; Pogg. Ann. lxxxvii. p. 139. [17] _Du Moncel._ Exposé, ii. p. 125; also, iii. p. 83. [18] _Delezenne._ “Sound produced by Magnetization,” Bibl. Univ. (new series), 1841, xvi. p. 406. [19] See London Journ. xxxii. p. 402; Polytechnic Journ. ex. p. 16; Cosmos, iv. p. 43; Glösener—Traité général, &c. p. 350; Dove.-Repert. vi. p. 58; Pogg. Ann. xliii. p. 411; Berl. Ber. i. p. 144; Arch. d. Sc. Phys. et Nat. xvi. p. 406; Kuhn’s Encyclopædia der Physik, pp. 1014-1021. [20] _Gore._ Proceedings of Royal Society, xii. p. 217. [21] _C. G. Page._ “Vibration of Trevelyan’s bars by the galvanic current.” Silliman’s Journal, 1850, ix. pp. 105-108. [22] _Sullivan._ “Currents of Electricity produced by the vibration of Metals,” Phil. Mag. 1845, p. 261; Arch. de l’Électr. x. p. 480. [23] The full description of this figure will be found in Mr. Alexander J. Ellis’s translation of Helmholtz’s work, “Theory of Tone.” [24] See _Researches in Telephony_.—Trans. of American Acad. of Arts and Sciences, vol. xii. p. 1. [25] _Elisha Gray._ Eng. Pat. Spec. No. 2646, Aug. 1874. USEFUL BOOKS ON TELEGRAPHY, &c. _Just published, Parts XIII. and XIV., in one vol._ _demy 8vo, sewed, 5s._ =Journal of the Society of Telegraph Engineers=, INCLUDING ORIGINAL COMMUNICATIONS ON TELEGRAPH AND ELECTRICAL SCIENCE. Edited by Major FRANK BOLTON and J. SIVEWRIGHT. _To be continued quarterly._