[1] Helmholtz. _Die Lehre von dem Tonempfindungen._ (English Translation by Alexander J. Ellis, _Theory of Tone_.)
[2] _C. G. Page._ “The Production of Galvanic Music.” Silliman’s Journ. 1837, xxxii. p. 396; Silliman’s Journ. July, 1837, p. 354; Silliman’s Journ. 1838, xxxiii. p. 118; Bibl. Univ. (new series), 1839, ii. p. 398.
[3] _J. P. Marrian._ Phil. Mag. xxv. p. 382; Inst. 1845, p. 20; Arch. de l’Électr. v. p. 195.
[4] _W. Beatson._ Arch. de l’Électr. v. p. 197; Arch. de Sc. Phys. et Nat. (2d series), ii. p. 113.
[5] _Gassiot._ See “Treatise on Electricity,” by De la Rive, i. p. 300.
[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.
[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.