In his great work on Egypt (Pl. XII, 2) Geoffroy gives the figure of a malapterus electricus (see Adanson, A.D. 1751) which is opened to show the viscera, but, by a singular inaccuracy, says Mr. James Wilson, the fish is represented as scaly, whereas there are no scales whatever upon this fish, and no fish known to possess electric powers has either scales or spines. The torpedo, the gymnotus and the malapterus have all naked skins. The tetraodon electricus (see Shaw at A.D. 1791) is also destitute of spines on the skin, although all its congeners have skins as bristly as those of a hedgehog.
Geoffroy Saint-Hilaire (Isidore), son of Etienne, was also a distinguished naturalist. He became Assistant Professor of Zoölogy to his father in 1829, likewise his assistant at the Faculté des Sciences in 1837, and, when Etienne became blind, during the year 1841, he succeeded to the Professorship of Zoölogy at the Museum of Natural History. He is the author of “The Life, Works and Theories (Vie, Travaux et Doctrine) of Etienne Geoffroy Saint-Hilaire,” Paris, 1847.
References.—Gilbert’s Annalen, XIV. p. 397; Bulletin Soc. Phil., No. 70; Geo. Wilson’s “Life of Cavendish,” London, 1851, p. 469, alluding to the later experiments on electrical fishes made by Faraday (1838), Dr. James Stark, of Edinburgh (1844), Prof. Goodsir (1845), and Dr. C. Robin (1846). Consult also, Journal de Physique, Vol. LVI. p. 242, and the complete list of Geoffroy’s works in Callisen’s “Medicinisches-Schriftsteller Lexicon”; “Memoir of M. Isidore G. Saint Hilaire,” by M. De Quatrefages, in “Report of Smithsonian Institution” for 1872, pp. 384–394; “Journal des Savants” for May-Aug., 1864; “Roy. Soc. Cat. of Sc. Papers,” Vol. II. pp. 824–832; Vol. VI. p. 669; Vol. VII. p. 757.
A.D. 1803.—Carpue (J. C. S.), English scientist, relates, in his “Introduction to Electricity and Galvanism,” published in London, some noteworthy experiments on the curative action of common electricity.
He repeated many of the investigations of Giovanni Aldini, and, in the presence of Dr. Pearson and other medical gentlemen, experimented upon the body of Michael Carney, immediately after his execution for murder. Carpue’s main object was to ascertain whether galvanism, applied at once to the nerves, could excite action in the internal parts, and especially in the respiratory organs. He first made an opening into the windpipe and, after introducing about three pints of oxygen into the lungs, he applied conductors to the phrenic nerve as well as to other parts of the body, the lungs being at the same time occasionally inflated, but no action could be excited in the diaphragm. The application of conductors to the inside of the nostrils and elsewhere, however, excited very considerable contractions in the right auricle more than three hours after death, the ventricles being, as in Aldini’s experiments, perfectly motionless.
References.—“Galvanic Experiments Made by Carpue on the Body of Michael Carney,” etc., London, 1804 (Phil. Mag., Vol. XVIII. p. 90); the “Encyclopedia Metropolitana,” article “Galvanism,” Vol. IV. pp. 105, 106, also the “Introduction,” etc., above named for descriptions of Mr. Cuthbertson’s plate electrical machine and of Mr. Read’s condenser.
A.D. 1803.—Hachette (Jean Nicholas Pierre), a protégé of Monge, who became professor at the Paris Ecole Polytechnique, where he had among his pupils Poisson, Arago and Fresnel, presents to the Institut National the dry pile which was the result of the many experiments he had carried on in conjunction with Charles Bernard Desormes, who was then known as a prominent French scientist and manufacturer of chemical products.
Their idea was to establish the development of electricity by simple contact, and they sought to obtain a substance which would satisfactorily replace the wet discs, and not be affected by the metals, as had been all the liquids hitherto employed (H. Boissier, “Mémoire,” etc., Paris, 1801). After numerous investigations they adopted a compound consisting of common starch and either salts, varnishes or gums, with which they made the necessary discs. These discs were dried and placed alternately between the copper and zinc couples, but were afterward found to be too easily affected by moisture to prove very effective (D. Tommasi, “Traité des Piles Electriques,” Paris, 1889, p. 529).
In the columns of the Annales de Chimie, named below, will be found detailed the numerous experiments with the galvanic pile carried on individually and collectively by Hachette, Desormes and other scientists; those of Hachette and Thénard upon the ignition of metallic wires claiming especial notice. Prof. John Farrar (“Elem. of Elec. Magn.,” etc., Cambridge, 1826, p. 167) calls attention to the latter and in the Phil. Mag. for 1821 will be found an account of the researches of the above-named scientists made during the year 1805, to establish more properly the analogy between galvanism and magnetism. Hachette and Desormes endeavoured to ascertain the direction which would be taken by a voltaic pile, whose poles were not joined, when freely suspended horizontally. Their pile, as Fahie gives it, was composed of 1480 thin plates of copper tinned with zinc, of the diameter of a five-franc piece, and was placed upon a boat floating on the water of a large vat; but it assumed no determinate direction, although a magnetized steel bar, of a weight nearly equal to that of the pile, and likewise placed upon the boat, would turn, after some oscillations, into the magnetic meridian.
References.—Annales de Chimie, Vol. XXXVII. pp. 284–321; XLIV. pp. 267–284; XLVII (Biot’s Observations), p. 13; XLIX. pp. 45–54, and XLV for 1808. See also, the Annales for 1834, as well as Vol. XLII. p. 125, for experiments of MM. Desormes and Clement on the fixed alkalies; Journal de Physique of Sept. 1820, for the paper of Hachette and Ampère on the electro-magnetic experiments of Oersted and Ampère; Annales de Chimie et de Physique, Vol. II for May 1816, pp. 76–79, and V. p. 191; Phil Mag., Vol. LVII. p. 43; L. W. Gilbert, Annalen der Physik, Vols. IX. pp. 18–39; XVII. pp. 414–427; Journal de l’Ecole Polytechnique, Vol. IV for 1802; XI. p. 284; Leithead, “Electricity,” p. 252; Bull. de la Soc. Philomathique, No. 83; P. Sue, aîné, “Hist. du Galv.,” Paris, An. X, 1802, Vol. II. pp. 160, 167, 188, 345 (Hachette et Thénard), and p. 371; Joseph Izarn, “Manuel du Galvanisme,” An. XII, 1804, s. 4. p. 179; Poggendorff, Vol. I. pp. 562, 985; Larousse, “Dict. Universel,” Vol. VI. p. 576; “Royal Society Catalogue of Scientific Papers,” Vol. III. pp. 106–109.