Part 2 / Book 6 — Book VI (continued 9)

Robert Sabine remarks (“The Electric Telegraph,” 8vo., 1867, p. 22; “History of the Electric Telegraph,” in Weale’s Rudimentary Treatises, 1869, pp. 23, 24; “History and Progress of the Electric Telegraph,” 3rd ed., 1872, p. 23):

“The discovery of the power of a galvanic current to deflect a magnetic needle, as well as to polarize an unmagnetized one, were known to, and described as early as 1804, by Prof. Izarn.... The paragraph which especially refers to this subject is headed ‘Appareil pour reconnaitre l’action du galvanisme, sur la polarité d’une aiguille aimantée.’ After explaining the way to prepare the apparatus, which consists simply in putting a freely suspended magnetic needle parallel and close to a straight metallic conductor through which a galvanic current is circulating, he described the effects in the following words: ‘According to the observations of Romagnosi, a physicist of Trent, a magnetized needle which is submitted to a galvanic current undergoes (éprouve) a declination; and according to those of J. Mojon, a learned chemist of Genoa, unmagnetized needles acquire by this means a sort of magnetic polarity.’ To Romagnosi, physicist of Trent, therefore, and not, as is generally believed, to Oersted, physicist at Copenhagen (who observed, in 1820, the phenomenon of the deflection of a magnet needle by a voltaic current), is due the credit of having made this important discovery.”

On the other hand, Gilb. Govi, who gives in his afore-named work a good illustration of Romagnosi’s experiment, explains that it resembles in no way the experiment of Oersted, there being no magnetic action of the column on the magnetic needle, which latter is in fact repelled by the mere electricity of the pile. Ronalds states that Romagnosi’s experiment, much like that made by Schweigger (A. F. Gehlen’s Journal für die Chimie und Physik, 1808, pp. 206–208), was a modification if not a repetition of the one which Thomas Milner performed with static electricity (T. Milner’s “Experiments and Observations in Electricity,” London, 1783, p. 35), wherein a magnetic needle forms the electrometer since improved upon by J. C. A. Peltier.

To the ordinary mind, a conclusive proof that Romagnosi had no part in the discovery of electro-magnetism would seem to be, as Fahie rightly observes, the fact that he himself never claimed any, although he lived until 1835, fifteen years after the announcement made by the Danish philosopher. Fahie calls attention, for some experiments in the same line, to J. B. Van Mons’ Journal de Chimie, Bruxelles, January 1803, p. 52, and to Nicholson’s Journal of Nat. Phil., Vol. VII. p. 304, as well as to the 1746 and 1763 Phil. Trans. for investigations made by B. Robins and Ebenezer Kinnersley, and he likewise alludes to others recorded in the Amer. Polytechnic Review for 1831, and in the Quarterly Journal of Science and the Arts for 1826, to all of which, he says, as little real attention should be given as can properly be attached to the observations of Aldini and of Izarn previously referred to.

References.—“Notizia di G. D. Romagnosi, stesa da Cesare Cantù,” Milan, 1835; “Nuova Scelta d’ Opuscoli,” Vol. I. p. 201; Gazetta di Roveredo for 1802, No. 65; “Atti della Reale Accad. delle Scienze di Torino,” Vol. IV, April 7, 1869; J. C. Poggendorff, Vol. II. pp. 681, 682; S. I. Prime’s “Life of Morse,” 1875, p. 264; Phil. Mag., Vol. LVIII. p. 43; Journal Soc. of Arts, April 23, 1858, p. 356, and July 29, 1859, pp. 605, 606; Bibl. Ital., Vol. XCVIII. p. 60; Gilbert, Annalen, 1821, Vol. LXVIII. p. 208; Larousse, “Dict. Univ.,” Vol. XIII. p. 1318; “Biographie Générale,” Vol. XLII. pp. 574, 575, the last named remarking that the discovery alluded to in the works of Aldini and Izarn passed unnoticed till Oersted caused its value to be fully appreciated.

A.D. 1802.—Parrot (George Friedrich), Russian physician and professor at Dorpat, is, of all the European savants, the one who developed most extensively the chemical theory of the voltaic pile. The superior manner in which all his observations were carried on have led many to consider him justly entitled to the credit of being the founder of the theory (Figuier, “Exposition et Histoire,” etc., Paris, 1857, Vol. IV. chapitre viii. pp. 426–429).

He commenced his experiments in 1801, and first recorded them in a memoir which was crowned the same year by the Batavi Scientific Society of Haarlem. His other papers on the same subject followed in rapid succession, mainly through L. W. Gilbert’s Annalen der Physik, under such heads as: “Sketch of a New Theory of Galvanic Electricity, and Concerning the Decomposition of Water,” etc. (“Combination of Induction and Chemical Action,” Gilb., Vol. XII. p. 49, Seypfer, p. 200), “How to Measure Electricity,” “Relative to the Electrometer,” “The Effects of the Condenser,” and “The Theory of Volta Concerning Galvanic Electricity,” all of which appeared in Vol. LXI. of the Annalen. These papers were alluded to in his letter to the editors of the Annales de Chimie et de Physique (An. Ch. et Phys., Vol. XLII. p. 45), and were afterward greatly amplified in his “Treatise on Natural Philosophy.”

Parrot started with the determination to demolish completely the theories of Volta and to thoroughly instruct him anew (instruire de toutes pièces le procès du physicien de Pavie), and it must be admitted that the many important facts enounced by Parrot were such as would have ordinarily created a disturbing influence, but they became known after Volta’s views had been thoroughly espoused by many German and French scientists and consequently attracted comparatively little attention.

At p. 466, Vol. II of Dr. Thomas Young’s “Course of Lectures,” London, 1807, reference is made to a paper in Gilbert’s Annalen der Physik (X. p. 11, also XIII. p. 244), concerning Parrot’s theory of evaporation, with mention of the fact that the same paper contains a proposal for inoculating the clouds with thunder and lightning, by projecting bombs to a sufficient height.

Parrot also devised a scheme for telegraphing, which is described in the Mem. Acad. Petropol., ser. vi. Vol. I for 1838, and is alluded to in the Report on Telegraphs for the United States, made at request of the Hon. Levi Woodbury, Secretary of the Treasury, by the Committee on Science and the Arts of the Franklin Institute. The proposed telegraph, as worded in the Report, “consists of a single arm or indicator, which should be about nine feet long and one foot wide, with a cross-piece at one end, about three feet long and one wide; the whole being movable about an axis at its centre.... The movements may be communicated with ease and certainty, either by an endless chain passing over a wheel on the axis, and a wheel in the building; or by a cog-wheel on the axis, and an endless screw on a vertical bar. For night signals, three lamps are used, one swinging beyond the end of the arm, the other two beyond the ends of the cross-piece.”

References.—Gilbert’s Annalen, Vols. XXI for 1805, LV for 1817, LX for 1819; J. H. Voigt’s Magazin, Vol. IV; Grindel’s “Russ. Jahrb. f. Chem. u. Pharm.,” XI, 1810; L. Turnbull, “Elec. Mag. Tel.,” p. 19; “Naturwiss. Abhandl. aus Dorpat.,” I, 1823; “Roy. Soc. Cat. of Sc. Papers,” Vol. IV. pp. 765–767; Annales de Chimie, Vol. XLII, 1829, pp. 42–45, and Vol. XLVI, 1831, p. 361; “Mém. sixième série Sc. Mathém.,” first part of Vols. III and V; “Pander’s Beitr. z. Naturk, I.”

A.D. 1802–1806.—Berzelius (Baron Jöns Jacob Freiherr von), M.D., one of the greatest of modern chemists, native of East Gothland, Sweden, publishes his “De Electricitatis ...” or “Physical Researches on the Effect of Galvanism upon Organized Bodies,” which established his reputation as an experimental philosopher and procured for him the appointment of Assistant Professor of Medicine, Botany and Chemical Pharmacy at Stockholm. Of the very great number of scientific papers which he communicated to learned Societies, that entitled “An Essay on the Division of Salts through Galvanism” deserves especial mention, for in it, he lays down the electro-chemical theory, the honour of being the original propounder of which is by many claimed for Sir Humphry Davy.

In conjunction with Gottlieb Gahn, with W. Hisinger, of Elfstorps Bruk, and with the Swedish physician, Magnus Martin de Pontin, Berzelius made many very extensive observations and published numerous treatises, the most important of which are embraced in the papers named at foot (Sir Humphry Davy, “Bakerian Lectures,” London, 1840, more particularly at pp. 13, 20, 109, 111, 122–123).

As has been before observed, the brilliant investigations of Berzelius and Hisinger, together with those of Nicholson and Carlisle, of Dr. William Henry and of Sir Humphry Davy, actually created a new epoch in the history of chemistry. Prof. Wm. B. Rogers better expressed the fact in his address of Jan. 16, 1879, when saying that “through the labours mainly of Berzelius and of Davy, the great generalization of electro-positive and electro-negative substances was established, and with it the fruitful theory of the electro-chemical exposition of compound bodies.” Such of the experiments of Berzelius as were repeated by Sir Humphry Davy before the English Royal Institution, are embodied in Davy’s paper (partly alluded to above in “Bakerian Lectures”) which was read before the Royal Society, June 30, 1808. According to J. F. W. Herschel, Berzelius and Hisinger ascertained it as a general law, that in all of the chemical decompositions which they effected, the acids and oxygen become transferred to, and accumulated around, the positive pole, and hydrogen, alkaline earths and metals around the negative pole of a voltaic circuit; being transferred in an invisible, and, as it were, a latent or torpid state, by the action of the electric current, through considerable spaces, and even through large quantities of water or other liquid, again to reappear with all their properties at their appropriate resting-places.

Berzelius discovered selenium while examining certain substances found in the acid manufactured at Gripsholm, Sweden. He includes selenium among the metals; but as it is a nonconductor of electricity, also a most imperfect conductor of heat, and as, in other respects, it bears much analogy to sulphur, it is generally placed among the non-metallic combustibles (Brande, “Manual of Chemistry,” London, 1848, Vol. I. p. 435; Berzelius, “Lehrbuch der Chemie,” “Traité,” etc., Paris, 1846, Vol. II. p. 184; “Annales de Chimie et de Physique,” Vol. IX. p. 160; “Annals of Philosophy,” Vol. XIII. p. 401 and Vol. VIII, N.S. p. 104). The important rôle which the high electrical resistance of selenium has in its early days been made to play by Mr. Willoughby Smith, Dr. Werner Siemens and others, is alluded to at pp. 791–794 of Vol. IV supplement to “Ure’s Dict. of Arts,” etc., London, 1878.

For full accounts of Berzelius’ numerous contributions to science, attention is called to the following:

References.—“Royal Society Catal. of Sc. Papers,” Vol. I. pp. 330–341; “Gedächtnissrede auf Berzelius ...” Berlin, 1851; G. Forchammer, “J. J. Berzelius,” 1849; Poggendorff, Vol. I. pp. 172–175; “Afhandl. i Fisik. ...”; Jos. Thomas, “Dict. of Biography,” 1870, Vol. I. p. 341; “Report Smiths. Inst.” for 1862, p. 380; “Vetensk. Acad. Handl.”; “La Grande Encyclopédie,” Vol. VI. p. 478. See likewise, “Journal Frankl. Inst.,” 3rd Ser., Vol. XVI. pp. 343–348; Faraday’s “Experim. Researches,” Arts., 746, 870, 960, and Vol. II. pp. 226–228; Gahn at p. 226 of Becquerel’s “Eléments d’El. Ch.,” Paris, 1843; “Annalen der Physik,” Vol. XXVII. pp. 270, 311, 316, and Vol. XXXVI. p. 260; Gehlen’s “Journal für die Chem. und Phys.,” Vol. I. p. 115 and Vol. III. p. 177; John Black, “An Attempt ... Electro-Chem. Theory,” London, 1814; Gmelin’s “Chemistry,” Vol. I. pp. 400, 457–458, 461–462; “Encycl. Metrop.” (Galvanism), Vol. IV. pp. 221–222; “Sc. Am. Suppl.,” No. 284, p. 4523, for report of Helmholtz’s Faraday Lecture of April 5, 1881, taken from the “Chemical News”; Sturgeon’s “Annals,” Vol. VII. pp. 300–303; Vol. VIII. p. 80; Whewell, “History of the Inductive Sciences,” 1859, Vol. II. pp. 304, 347–348; Thos. Thomson, “An Outline of the Sciences ...” London, 1830, Chap. XIV. p. 532; Berzelius and Wöhler on Volcanoes, in Poggendorff’s “Annalen,” Bd. I. s. 221, and Bd. XI. s. 146; “Journal des Savants” for June 1892, pp. 375–385; J. Berzelius and F. Wöhler, Leipzig, 1901; “Svenskt Biografiskt Handlexikon,” Herm. Hofberg, Stockholm, pp. 88–89; “Bibl. Britan.,” Vol. LI, 1812, pp. 174–183 (“Nicholson’s Journal,” July 1812) for John Gough’s remarks on the hygrometer of Berzelius (Phil. Mag., Vol. XXXIII. p. 177); “Annales de Chimie,” Vol. LI. pp. 167, 171; Vol. LXXXVI for 1813, p. 146; Vol. LXXXVII. pp. 286, etc.; also Vol. LXXIII. pp. 198, 200–201, the last named giving an account of the ammoniacal amalgam which Berzelius and Pontin were the first to explain.

A.D. 1802.—Thompson (Sir Benjamin), Count Rumford, an eminent scientist, native of Woburn in Massachusetts, Knt., F.R.S., one of the founders of the English Royal Institution, publishes his “Philosophical Memoirs ... being a collection of ... Experimental Investigations ... of Natural Philosophy.”

Though more properly identified with important observations and researches on heat, the question of the nature of which, Dr. Edward L. Youmans says, he was the first to take out of the domain of metaphysics, where it had stood since the days of Aristotle, he has given accounts of some highly important experiments regarding the relative intensities and the chemical properties of light, heat and electricity, which can be seen at pp. 273, etc., Vol. LXXVI. part ii. of the Phil. Trans. for 1786. Heat spreads in every direction, whilst the electrical fluid may be arrested in its progress by certain bodies, which have on that account been called non-conductors, but he shows that the Torricellian vacuum affords, on the contrary, a ready passage to the electrical fluid while being a bad conductor of heat.

At p. 30 of George E. Ellis’ “Memoir of Sir Benjamin Thompson,” published in Boston (no date), is reproduced Rumford’s “Account of what expense I have been at toward getting an electrical machine” during 1771, and at pp. 481–488, Vol. I, also pp. 350, 351, Vol. III of the “Complete Works of Count Rumford,” published by the American Academy of Sciences, allusion is made to the galvanic influence in the construction of utensils.

References.—Sir W. Thomson, “Mathematical and Physical Papers,” London, 1890, Vol. III. pp. 123, 124; Phil. Mag., Vol. IX for 1801, p. 315; Silliman’s American Journal of Science, Vol. XXXIII. p. 21; “Biog. Universelle,” Tome XXXVII. p. 81; “Journal des Savants,” for Dec. 1881 and Jan. 1882; “Bibl. Britan.,” Vol. LVI., 1814, pp. 398–401 (necrology).

A.D. 1802.—Pepys (William Haseldine, Sr.), son of an English manufacturer of surgical instruments, who became F.R.S. and was one of the founders of the Askesian Society, as well as of both the London Institution and of the London Geological Society, constructs, during the month of February 1802, the strongest pile hitherto known. It consists of sixty pairs of zinc and copper plates, each six feet square, held in two large troughs filled with thirty-two pounds of water containing two pounds of azotic, or nitric, acid.

It is said that with this battery he succeeded in melting iron wires ranging in diameter from one two-hundredth to one-tenth of an inch, the combustion developing an extremely bright light, while platinum wires, one thirty-second of an inch in diameter, turned to white heat and melted in globules at the point of contact. Charcoal was permanently ignited a length of nearly two inches and the galvanic action was strong enough to light it after passing through a circuit of sixteen persons holding one another by the hand. Gold leaf displayed a bright white light, accompanied with smoke; silver leaf gave an intense green light without sparks, but with still more smoke; while sheets of lead burned actively, with accompaniment of very red sparks mixed with the flame (Figuier, “Exposition,” etc., Paris, 1857, Vol. IV. p. 347).

Later on, another battery was constructed by him for the London Institution. This consisted of 400 pairs of plates five inches square, and of 40 pairs one foot square. With it, Davy ignited cotton, sulphur, resin, oil and ether, melted a platinum wire, burned several inches of an iron wire one three-hundredth of an inch in diameter, and boiled easily such liquids as oil and water, even decomposing and transforming them into gases. It was during the year 1808 that Pepys finished the enormous battery of 2000 double plates already alluded to under the Cruikshanks (A.D. 1800) and the Davy (A.D. 1801) articles, and which is to be found described at p. 110 of the “Elements of Chemical Philosophy.”

One year before that (1807) Pepys constructed a new form of eudiometer, of which a description was given before the Royal Society on the 4th of June, as shown at p. 270 Vol. I of the “Abstracts of Papers,” etc., of that Institution, as well as in the 1807 volume of the Philosophical Transactions.

Of the many ingenious experiments by which Pepys distinguished himself, scarcely none attracted more attention than those which are referred to in the last-named Transactions for 1866, pp. 339–439. It is only since 1815, when he employed the electric current to heat iron wire and diamond dust together, whereby he obtained steel, that the direct carburization of iron by the diamond has been clearly established. Prior to this date, during 1798, Clouet had melted a little crucible of iron weighing 57·8 grammes containing a diamond weighing 0·907 gramme, and produced a fused mass of steel. Guyton de Morveau reported upon Clouet’s experiment in the Annales de Chimie for 1799 (Vol. XXXI. p. 328) and his investigations were repeated by many scientists, notably by Margueritte, as recently as 1865. The latter’s observations, which were communicated to the Annales de Chimie et de Physique (Tome VI), showed that, although carburization can be effected by simple contact of carbon and iron in a gaseous atmosphere, it is nevertheless true that in the ordinary process of cementation the carbonic oxide gas plays an important part, which had until then been overlooked (Translation of Prof. W. C. Roberts-Austen, F.R.S. For Mr. Children’s investigations in the same line, see the Phil. Trans. for 1815, p. 370, also A.D. 1809).

Sir Humphry Davy employed in his experiments on the decomposition and composition of the fixed alkalies two mercurial gasometers of Pepys’ design, described in No. 14 of the Phil. Trans. for 1807, in conjunction with the same apparatus used by Messrs. Allen and Pepys for the combustion of the diamond (“Bakerian Lectures,” London, 1840, pp. 84 and 93).

During the year 1822 Pepys constructed for electro-magnetic experiments a very large spiral galvanic battery, which was put together for the London Institution on the plan of the one first built by Dr. Robert Hare, Professor of Chemistry in the University of Pennsylvania. Pepys called it a calorimotor, by reason of its remarkable power of producing heat, and it is well illustrated in the 8th Edit. “Encyclopædia Britannica” article on “Voltaic Electricity.” It consisted only of two metallic sheets, copper and zinc, fifty to sixty feet long by two feet wide, coiled around a cylinder of wood and prevented from coming together by three ropes of horse-hair, the whole being suspended over a tub of acid so that, by a pulley or otherwise, it could be immersed or taken up. As stated in Vol. V of the Trans. of the Amer. Phil. Soc., this battery required nearly fifty-five gallons of fluid, and the solution used contained about one-fortieth of strong nitrous acid.

When, as Noad observes, it is stated that a piece of platinum wire may be heated to redness by a pair of plates only four inches long and two broad, the calorific power of such an arrangement as the above may be imagined to have been immense. The energy of the simple circle depends on the size of the plates, the intensity of the chemical action on the oxidizable metal, the rapidity of its oxidation, and the speedy removal of the oxide. Pouillet is said to have constructed one of these batteries with twelve couples for the Paris Faculté des Sciences, and found it very powerful in producing large quantities of electricity with low tension. The best liquid for this battery was water with one-fortieth in volume of sulphuric acid and one-sixtieth of nitric acid. With the above-described battery of Mr. Pepys, Sir Humphry Davy performed a remarkable experiment which is to be found described in the Phil. Trans. for 1823. A similar apparatus was produced independently, at about the same time, by Dr. Seebeck, of Berlin.

Another of Pepys’ inventions is the substitution, for the tinfoil coatings within the glass of Bennet’s electroscope, of two plates, forming an acute angle, which, by means of a regulating screw, can be adjusted to any required distance from the gold leaves. The angular part is secured to the bottom; the open part perpendicularly upward. By this mode of approximating the coatings to the gold leaves, the resistance being diminished, a weaker intensity of electricity suffices for their disturbance.

References.—Quarterly Journal of Science, Vol. I for 1816; Phil. Mag., Vol. XXI. p. 241; XLI. p. 15; Becquerel, Vol. I. p. 34. Mr. William H. Pepys, Jr., published descriptions of the newly invented galvanometer and of the large galvanic apparatus in the Phil. Mag., Vol. X., June 1801, p. 38, and Vol. XV for 1803, p. 94; “Cat. Sc. Papers Roy. Soc.,” Vol. II. p. 192; “Bibl. Britan.,” Vol. XVIII, 1801, p. 343, and Vol. XXII, 1803, p. 297.

A.D. 1803.—Geoffroy Saint-Hilaire (Etienne), a very eminent French naturalist, once the pupil of Haüy, whose life he was the means of saving during the massacre of September 1792, is the first to give a thoroughly complete description of the electrical organs and functions of the raia torpedo, of the gymnotus electricus, of the silurus electricus, and of other similar species of fishes. His work on the subject, entitled “Sur l’anatomie comparée,” etc., is alluded to in Vol. I. An. xi. No. 5 of the “Annales du Museum,” whence it is translated for the fifteenth volume of the Phil. Mag.

His analyzation of the fluid in the cells of the torpedo showed it to consist of albumen and gelatine; and he discovered some organs analogous to those of the torpedo in different species of the same genus raia, which, strange to say, do not appear possessed of any electrical power.

The electrical organs of the silurus electricus he found to be much less complicated than those of other electrical fishes. They lie immediately below the skin and stretch all around the body of the animal. Their substance, he says, is a reticulated mass, the meshes of which are plainly visible, and these cells are filled, like those of other electrical fishes, with an albuminous gelatinous matter. The nerves distributed over the electrical organs proceed from the brain, and the two nerves of the eighth pair have a direction and nature peculiar to this species. (Consult C. Matteucci, “Traité des Phénomènes ...” Paris, 1844, Chaps. VI and VII. pp. 301–327.)

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.

A.D. 1803.—Biot (Jean Baptiste), who, in 1800, at the age of twenty-six, was made Professor of Natural Philosophy at the “Collège de France,” and afterward ranked among the first astronomers and mathematicians, gives an account of his journey to Aigle, in the Department of l’Orne, whither he was sent by the Government to examine and report upon a very extraordinary shower of meteorites. The facts obtained by him were communicated to the Institute on the 29th Messidor, An. XI, and also appeared at the time in the Paris Journal des Débats (Phil. Mag., Vol. XVI. p. 299).

On the 23rd of August of the year following (1804) Biot accompanied Gay-Lussac in the latter’s first memorable balloon ascent. This aeronautic voyage, sanctioned by the French Government mainly through the efforts of Berthollet and Laplace, was the first of the kind undertaken solely for a scientific object.

Besides numerous barometers and electrometers, Biot and Gay-Lussac carried with them two compasses, a dipping needle and other instruments. For the examination of the electricity of different strata of the atmosphere, they had several metallic wires from 60 to 300 feet in length, also a small electrophorus feebly charged, while for galvanic experiments they added some discs of copper and zinc, together with a supply of frogs, insects and birds. An account of the exceedingly important results obtained by those scientists at different elevations, of which the highest reached exceeded four miles, was read before the National Institute, Aug. 27, 1804. It was also published in London during the latter year, and alluded to at p. 371, Vol. XIX of the Philosophical Magazine. Mary Somerville remarks (“Connection of the Physical Sciences,” 1846, p. 334) that according to the observations of Biot and Gay-Lussac, the magnetic action is not confined to the surface of the earth, but extends into space. The moon has become highly magnetic by induction, in consequence of her proximity to the earth, and because her greatest diameter always points toward it. Her influence on terrestrial magnetism is now ascertained; the magnetism of the hemisphere that is turned toward the earth attracts the pole of our needles that is turned toward the south and increases the magnetism of our hemisphere; and as the magnetic, like the gravitating force, extends through space, the induction of the sun, moon and planets must occasion perpetual variations in the intensity of terrestrial magnetism, by the continual changes in their relative positions.

In 1805 Biot published an investigation of the laws which should govern the dip and intensity, in the hypothesis of a magnet situated at the centre of the earth, having its poles infinitely close to each other and directed to opposite points on the surface of the globe and, as justly adds Major Edward Sabine (Report Seventh Meeting Brit. Asso.), it is a well-known consequence of this hypothesis that the lines of equal dip and equal intensity on the earth’s surface should everywhere be parallel to each other. The phenomena of electricity had been brought within the pale of mixed mathematics by C. A. Coulomb (A.D. 1785), whose considerations mainly attached to the distribution of electricity upon the surface of spheres, and his investigations were at once diligently pursued by the French scientists, Biot, Laplace and Poisson. Laplace, who undertook to investigate the distribution of electricity upon the surface of ellipsoids of revolution, showed that the thickness of the coating of the fluid at the pole was to its thickness at the equator as the equatorial is to the polar diameter, or, what is the same thing, that the repulsive force of the fluid, or its tension at the pole, is to that at the equator as the polar is to the equatorial axis. Biot extended this investigation to all spheroids differing little from a sphere, whatever may be the irregularity of their figure, and his solution of the problem will be found in No. 51 of the Bulletin des Sciences. He also determined, analytically, that the losses of electricity form a geometrical progression when the two surfaces of a jar or plate of coated glass are discharged by successive contacts, and he found that the same law regulated the discharge when a series of jars or plates are placed in communication with each other (Whewell, “History of the Inductive Sciences,” Vol. II. pp. 208, 223; Noad’s “Manual,” p. 15; Eighth “Britannica,” Vol. VIII. p. 531. For Biot’s experiments, touching upon electrical attraction and demonstrating practically the distribution of electricity upon the surface of a conductor, see the last-named volume of the “Britannica,” pp. 552, 556, and Noad, p. 56).

In conjunction with Frederick Cuvier, Mr. Biot investigated the connection of chemical charge with the production of electricity. Like Mr. W. H. Pepys, they examined the effect produced by the pile on the atmosphere in which it is located. Mr. Pepys placed the pile in an atmosphere of oxygen, and found that in the course of a night 200 cubic inches of the gas had been absorbed, but that in an atmosphere of azote the pile ceased to act. Biot and Cuvier likewise observed the quantity of oxygen absorbed, and inferred from their experiments that “although, strictly speaking, the evolution of electricity in the pile was produced by oxidation, the share which this had in producing the effects of the instrument bore no comparison with that which was due to the contact of the metals, the extremity of the series being in communication with the ground.” Their investigation was attended by the discovery that as long as any oxygen remained to be absorbed, the chemical and physiological effects of the apparatus still continued, but with decreasing intensity; so that if the conducting wires attached to the two poles are made to return from under the receiver in tubes of glass they may be used to decompose water and communicate shocks to the organs. All these effects, however, cease when the surrounding oxygen is exhausted (Annales de Chimie, Vol. XXXIX. p. 242; Soc. Philomathique, An. IX. p. 40; Sue, “Histoire du Galv.,” Vol. II. p. 161).

In the second volume of Biot’s “Traité de Physique” will be found recorded his many observations on the nature and origin of the electric light, extracts from which are given by Sir David Brewster in the electricity article of the “Britannica.” Biot remarks that the light which is observed during an electric explosion was for a long time considered by philosophers as a modification of the electric principle itself, which they supposed to be the quality of becoming luminous at a certain degree of accumulation (John Farrar, “Elem. of Elec., Mag. and El. Mag.,” 1826, p. 118). Brewster adds that this eminent French writer, however, considered the opinion as erroneous, and he has devoted a whole chapter to prove that electricity has the same origin as the light disengaged from air by mechanical pressure, “and that it is purely the effect of the compression produced on the air by the explosion of electricity.” In order to establish this theory, Mr. Biot has stated, on the authority of several experiments, “that the intensity of electric light depends always on the ratio which exists between the quantity of electricity transmitted and the resistance of the medium”; and he has shown, by an experiment with Kinnersley’s thermometer, “that at each spark the air of the cylinder, driven by the repulsive force, presses on the surface of mercury, which rises suddenly in the small tube, and falls back again immediately after the explosion.” He adds:

“This indication proves the separation produced between the particles of the mass of air where the electricity passes; and from what we know of its extreme velocity it is certain that the particles exposed immediately to its shock ought in the first moment to sustain individually all the effect of the compression. They ought, then, from this cause alone to disengage light, as when they are subjected to any other mechanical pressure. Thus one part at least of the electric light is necessarily due to this cause; and this being the case, there is no experiment which can lead us to conjecture that it is not all due to this cause.”

References.—“Encycl. Brit.,” 1857, Vol. XIV. pp. 7, 63, and Journal de Physique, Vol. LIX. p. 450. For Mr. Biot’s observations on the magnetism of metals and minerals, and on the distribution of magnetism in artificial magnets, as well as for his improvement upon Coulomb’s method of constructing the latter, see the last-named volume of the “Britannica,” pp. 23, 26, 71, and Noad’s “Manual of Electricity,” London, 1859, pp. 528, 535, while, for Biot’s very ingenious theory relative to the aurora, see Lardner and Walker’s “Manual of Elec. Mag. and Meteor.,” London, 1844, Vol. II. p. 235, and Noad, pp. 232, 233. The observations concerning the laws regulating the intensity of electro-magnetic phenomena, made by MM. Biot and Savary, are alluded to by Noad at pp. 644, 645, in the “Encycl. Metropol.” (Elec. Magn.), Vol. IV. p. 427; and Whewell’s “History of the Inductive Sciences,” 1859, Vol. II. pp. 245–249; “Scientific papers of the Royal Society,” Vol. I. pp. 374–386; Biot’s “Traité de Phys. Exp. et Math.,” Vol. II. p. 457; Journal de Physique, Vol. LIX. pp. 315, 318; Wilkinson’s “Elem. of Galv.,” Vol. II. pp. 38, 123, 154, 361, Chap. XVI; Humboldt’s “Cosmos,” treating of Aerolites, of the Zodiacal Light and of the figure of the earth; Noad, “Manual,” p. 530; Eighth “Ency. Brit.,” Vol. VIII. p. 580; Sir H. Davy, “Bakerian Lectures,” London, 1840, p. 3, alluding to Biot and Thénard in No. 40 of the Moniteur for 1806; “Encycl. Metropol.,” Vol. IV. (Electro-Magn.), p. 7; Harris “Rudim. Magn.,” Part III, London, 1852, pp. 116, 117; Gautherot at A.D. 1801; Figuier, “Exposition,” etc., Paris, 1857, Vol. iv. p. 429; “Lib. of Useful Knowl.” (Electricity), p. 64 and (Magnetism), p. 89; “Soc. Philomath.,” An. IX. p. 45; An. XI. pp. 120, 129; Becquerel’s “Traité,” 1856, Vol. III. p. 11; Phil. Mag., Vols. XVI. p. 224; XXI. p. 362; “Mém. de l’Institut” for 1802, Vol. V; “Annales des Mines” for 1820, relative to the experiments on electro-magnetism made by Oersted, Arago, Ampère and Biot; Phil. Mag., Vol. XXII. pp. 248, 249, for the magnetical observations made by Biot and Arago; Comptes Rendus for 1839, I Sem., VIII, No. 7, p. 233, for the observations of Biot and Becquerel on the nature of the radiation emanating from the electric spark; “Chemical News,” London, 1868, Vol. XVI for John Tyndall’s lecture on some experiments of Faraday, Biot and Savary; “Atti dell’ Accad. dei Nuovi Lincei, Ann.,” XV. Sess., IV. del 2 Marzo 1862, for the biography of J. B. Biot, who died Feb. 2, 1862, within two months of the completion of his eighty-eighth year. “Journal des Savants” for June and July 1820, April 1821, and for Feb.-Mar.-April 1846.

J. B. Biot’s son, Edward Constant Biot (1803–1850), is the author of the extended catalogue of shooting stars and other meteors observed in China during twenty-four centuries, which was presented to the French Academy during 1841, and a supplement to which was published at Paris in 1848 (Acad. des Sciences, Savants Etrangers, Tome X).

A.D. 1803–1805.—Acting upon the discovery of Gautherot, the Bavarian philosopher Johann Wilhelm Ritter (1776–1810) is the first to construct an electrical accumulator.

Ritter’s “ardency of research and originality of invention” had, as far back as 1796, shown itself in the numerous very able scientific papers relating to Electricity, Galvanism and Magnetism which he had communicated mainly through L. W. Gilbert’s Annalen der Physik, J. H. Voigt’s Mag. für Naturkunde and A. F. Gehlen’s Journal für die Chemie, all which obtained recognition in several foreign publications. These papers secured for him membership in the Munich Academy during the year 1805.

From Prof. H. W. Dove’s discourse before the Society for Scientific Lectures, of Berlin, the following is extracted:

“As the (then considered) essential portions of a galvanic circuit were two metals and a fluid, innumerable combinations were possible, from which the most suitable had to be chosen. This gigantic task was undertaken by Ritter, an inhabitant of a village near Leignitz, who almost sacrificed his senses to the investigation. He discovered the peculiar pile which bears his name, and opened that wonderful circle of actions and reactions which, through the subsequent discoveries of Oersted, Faraday, Seebeck and Peltier, drew with ever-tightening band the isolated forces of nature into an organic whole. But he died early, as Günther did before him, exhausted by restless labour, sorrow and disordered living.”

Ritter’s charging or secondary pile consists of but one metal, the discs of which are separated by circular pieces of cloth, flannel or cardboard, moistened in a liquid which cannot chemically affect the metal. When the extremities are put in communication with the poles of an ordinary voltaic pile it becomes electrified and can be substituted for the latter; and it will retain the charge, so that for a time there can be obtained from it sparks, shocks, as well as the decomposition of water.

The writer of the article at p. 268 of the April 1802 Monthly Magazine, making reference to an artificial magnet discovered at Vienna (Bakewell, “Elec. Science,” p. 40), no doubt alludes to the above-named charging or secondary pile, in the construction of which Ritter made many modifications. At first he arranged 32 copper and card discs in three series, two of which series contained 16 copper discs while the intermediate series consisted of 32 card discs. He then placed them so that the discs alternated, employing but 31 discs of copper, and he also used 64 as well as 128 copper discs alternating with similar ones of cardboard. In each case he compared the chemical action through the decomposition of water as well as the physiological effect or shock and the physical property or electrical tension. The results obtained are given in his many papers alluded to below.

Independently of the English scientists he discovered the property possessed by the voltaic pile of decomposing water as well as saline compounds, and of collecting oxygen and acids at the positive pole while hydrogen and the bases collect at the negative pole. He conceived that he had procured oxygen from water without hydrogen, by making sulphuric acid the medium of the communication at the negative surface, but, as Davy says, in this case sulphur is deposited, while the oxygen from the acid and the hydrogen from the water are respectively repelled, and the new combination produced.

A correspondent in Alex. Tilloch’s Philosophical Magazine (Vol. XXIII for 1805–1806, pp. 51–54—Extracts from a letter of M. Christ. Bernoulli abridged from Van Mons’ Journal, Vol. VI) thus alludes to some of Ritter’s experiments communicated in May 1805 to the Munich Royal Society:

“I have seen him galvanize a louis d’or. He places it between two pieces of pasteboard thoroughly wetted, and keeps it six or eight minutes in the circuit of the pile. Thus it becomes charged, though not immediately in contact with the conducting wires. If applied to the recently bared crural nerves of a frog the usual contractions ensue. I put a louis d’or thus galvanized into my pocket, and Ritter told me, some minutes after, that I might discover it from the rest by trying them in succession upon the frog. I made the trial, and actually distinguished, among several others, one in which only the exciting quality was evident. The charge is retained in proportion to the time that the coin has been in the circuit of the pile. Thus, of three different coins, which Ritter charged in my presence, none lost its charge under five minutes. A metal thus retaining the galvanic charge, though touched by the hand and other metals, shows that this communication of galvanic virtue has more affinity with magnetism than with electricity, and assigns to the galvanic fluid an intermediate rank between the two. Ritter can, in the way I have just described, charge at once any number of pieces. It is only necessary that the two extreme pieces of the number communicate with the pile through the intervention of wet pasteboards. It is with metallic discs charged in this manner and placed upon one another, with pieces of wet pasteboard alternately interposed, that he constructs his charging pile, which ought, in remembrance of its inventor, to be called the Ritterian pile. The construction of this pile shows that each metal galvanized in this way acquires polarity, as the needle does when touched with a magnet.”

The same correspondent alludes to experiments made with Ritter’s battery of 100 pairs of metallic plates, the latter having their edges turned up so as “to prevent the liquid pressed out from flowing away” (Phil. Mag., Vol. XXIII. p. 51), but he says he was unable to see either Ritter’s great battery of 2000 pieces, or the one of 50 pieces, each 36 inches square, the action of which is said to have continued very perceptibly for a fortnight. He writes as follows:

“After showing me his experiments on the different contractibility of various muscles (“Beiträge zur nähern Kenntniss,” etc., Jena, 1802, B. II) Ritter made me observe that the piece of gold galvanized by communication with the pile exerts at once the action of two metals, or of one voltaic couple, and that the face which in the voltaic circuit was next the negative pole became positive, and the face toward the positive pole negative. Having discovered a way to galvanize metals, as iron is rendered magnetic, and having found that the galvanized metals always exhibit two poles as the magnetized needle does, Ritter suspended a galvanized gold needle on a pivot, and perceived that it had a certain dip and variation, or deflection, and that the angle of deviation was always the same in all his experiments. It differed, however, from that of the magnetic needle, and it was the positive pole that always dipped.”

It can truly be said that the nearest approach to a solution of the question as to the analogy between electric and magnetic forces, which had remained unsettled since the time of Van Swinden (see A.D. 1784), was given by Ritter, who announced “that a needle composed of silver and zinc arranged itself in the magnetic meridian and was slightly attracted and repelled by the poles of a magnet; that by placing a gold coin in the voltaic circuit, he had succeeded in giving to it positive and negative electric poles; that the polarity so communicated was retained by the gold after it had been in contact with other metals, and appeared therefore to partake of the nature of magnetism; that a gold needle under similar circumstances acquired still more decided magnetic properties; that a metallic wire, after being exposed to the voltaic current, took a direction N.E. and S.W.” Dr. Roget gives these same extracts in his article on “Electro-Magnetism,” and justly remarks that Ritter’s speculations were of too crude a nature to throw any distinct light on the true connection between magnetism and electricity, nor was much notice taken of Ritter’s announcements, owing to the vague manner in which they were made. No satisfactory results were in fact obtained until Oersted (at A.D. 1820) made his famous discovery which forms the basis of the science of electro-magnetism.

References.—The “Encyclopædia Britannica” article relating to the influence of magnetism on chemical action, for an account of Ritter’s other experiments; also Faraday’s “Experimental Researches,” No. 1033; Ritter’s “Physisch. Chem. Abhand.,” etc., 3 vols., Leipzig, 1806; Poggendorff, Vol. II. p. 652; Tyndall’s notes on Electric Polarization; Donovan’s “Essay on the Origin, Progress and Present State of Galvanism,” Dublin, 1816; “Société Philomathique,” An. IV. p. 181; An. IX. p. 39; An. XI. pp. 128, 197; An. XII. p. 145; Bull. Soc. Phil., Nos. 53, 76, 79; Nuova Scelta d’Opus., Vol. I. pp. 201, 334; Bibl. Brit., XXXI; “Reichsanzeiger,” 1802, Bd. I, No. 66, and Bd. II, No. 194; also F. L. Augustin’s “Versuch einer geschichte ...” 1803, p. 75; Gilbert’s Annalen, II, VI, VII, VIII, IX, XIII, XV, XVI; Voigt’s Magazin, Vol. II. p. 356; Gehlen’s Journal, Vol. III for 1804, and Vol. VI for 1806; “Denkschr. d. Münch.,” 1808 and 1814; Phil. Mag., Vol. XXIII. chap. ix. pp. 54, 55 (for experiments from Van Mons’ Journal, No. 17), Vols. XXIV. p. 186; XXV. p. 368; LVIII. p. 43; L. F. F. Crell, “Chemische Annalen” for 1801; Nicholson’s Journal, Vols. IV. p. 511; VI. p. 223; VII. p. 288, VIII. pp. 176, 184; “Gottling’s Almanach” for 1801; Leithead, “Electricity,” p. 255; “Encycl. Metropolitana,” article “Galvanism,” Vol. IV. p. 206; “Biographie Générale,” Vol. XLII. p. 322; Larousse, “Dict. Universel,” Vol. XIII. p. 1234; Pierre Sue, aîné, “Histoire du Galvanisme,” Paris, An. X, 1802, Vol. I. pp. 226, 266; Vol. II. pp. 112–119, 156; Joseph Izarn, “Manuel du Galvanisme,” Paris, An. XII, 1804, pp. 84–87, 249, 255–261; Brugnatelli, “Notizie ... nell’ anno 1804,” Pavia, 1805, p. 16, also his Annali di chimica, Vol. XXII. p. 1; Journal de Physique, Vol. LVII. pp. 345, 406; Annales de Chimie, Vols. XLI. p. 208; LXIV. pp. 64–80; Jour. de Chim. de Van Mons, No. 14, p. 212, for the experiments of Van Marum and Oersted, made with Ritter’s apparatus; Sturgeon’s “Scientific Researches,” Bury, 1850, pp. 7, 8, and Prof. Millin’s “Magazin Encyclopédique”; “Allgemeine Deutsche Biographie,” Leipzig, 1875, Vol. XXVIII. pp. 675–678; “Bibl. Britan.,” Vol. XXXI. 1806, p. 97, Vol. XXV. 1807, pp. 364–386 (Lettre de M. le Dr. Thouvenel).

A.D. 1803.—Basse (Frédéric Henri), of Hamel, makes one of the earliest trials of the transmission of galvanism through water and soil, the results of which appear in his work, “Galvanische Versuche,” etc., published at Leipzig the year following.

Along the frozen water of the ditch or moat surrounding the town of Hamel he suspended, on fir posts, 500 feet of wire, at a height of six feet above the surface of the ice, then making two holes in the ice and dipping into them the ends of the wire, in the circuit of which were included a galvanic battery and a suitable electroscope, he found the current circulating freely. Similar experiments were made in the Weser; afterwards, with two wells, 21 feet deep and 200 feet apart; and, lastly, across a meadow 3000 to 4000 feet wide. Whenever the ground was dry it was only necessary to wet it in order to feel a shock sent through an insulated wire from the distant battery. Erman, of Berlin, in 1803, and Sömmering, of Munich, in 1811, performed like experiments, the one in the water of the Havel, near Potsdam, and the other along the river Isar.

Fahie, from whom we take the above, alludes to Gilbert’s Annalen der Physik, Vol. XIV. pp. 26 and 385, as well as to Hamel’s “Historical Account,” p. 17, of Cooke’s reprint, and adds that Fechner, of Leipzig, after referring to Basse’s and Erman’s experiments in his “Lehrbuch des Galvanismus,” p. 268, goes on to explain the conductibility of the earth in accordance with Ohm’s law. As he immediately after alludes to the proposals for electric telegraphs, he has sometimes been credited with the knowledge of the fact that the earth could be used to complete the circuit in such cases. This, however, is not so, as we learn from a letter which Fechner addressed to Prof. Zetzsche, on the 19th of February 1872.

References.—Zetzsche’s “Geschichte der Elektrischen Telegraphie,” p. 19. See Dr. Turnbull’s Lectures in the Journal of the Franklin Institute, Vol. XXI. pp. 273–274; “Scientific Papers of the Royal Society,” Vol. I. p. 203.

A.D. 1803.—Thillaye-Platel (Antoine), French savant, who was afterward appointed pharmacist in the Paris Hôtel-Dieu, gives out as the result of numerous investigations a great many useful precepts on the medical application of electricity and galvanism, which will be found in his thesis presented to the Paris Ecole de Médecine on the 15th Floréal, An. XI. These precepts, De la Rive says (“Treatise on Elect.,” translated by C. V. Walker, London, 1858, Vol. III. pp. 587, 588), are followed to this day and are extremely simple, requiring only the use of metallic brushes held by an insulated handle and put into communication with the conductor of the machine; and directing the application of electricity in its mildest form as well as its gradual increase to as much as the invalid is able to support, besides allowing of the concurrent employment of other means acting in the same direction, such as frictions, blisters, etc.

Antoine Thillaye-Platel’s uncle, Jean Baptiste Jacques Thillaye (1752–1822), French physician and Professor of Anatomy at Rouen and in Paris, published “Eléments de l’Elect. et du Galv.,” Paris, 1816–1817, ten years after the death of his nephew (Poggendorff, Vol. II. p. 1094; Larousse, “Dict. Univ.,” Vol. XV. p. 131).

De la Rive alludes to cures effected by several specialists and particularly to Father R. B. Fabre-Palaprat’s translation made in 1828 of La Beaume’s English work on the medical efficacy of electricity and galvanism, originally published in 1820–1826. The latter, he says, is preceded by a preface wherein the translator rivals the author on the wonderful effects of the electric fluid as a sovereign remedy for nearly all maladies.

References.—For M. Thillaye’s experiments with M. Butet on galvanic electricity, made at the Paris École de Médecine, see the Bulletin des Sciences de la Soc. Philom., No. 43, Vendémiaire An. IX, also Vol. IX. p. 231, of the “Recueil Périodique de la Soc. Libre de Médecine du Louvre.” Consult likewise, Poggendorff, Vol. II. p. 1094; “Royal Society Catalogue of Scientific Papers,” Vol. V. p. 954; De la Rive’s “Treatise,” Vol. III. pp. 587, 588; P. Sue, aîné, “Histoire du Galvanisme,” Vol. III. p. 14. Some of the other authors who have treated of the same subject are: F. Zwinger, 1697–1707; W. B. Nebel, 1719; Oppermanno, 1746; E. Sguario, 1746; G. C. Pivati, 1747–1750; G. Veratti, 1748–1750; O. de Villeneuve, 1748; L. Jallabert, 1748–1750; G. F. Bianchini, 1749; Mellarde, of Turin, 1749; Palma, 1749; F. Sauvages de la Croix, 1749–1760; J. B. Bohadsch, 1751; O. M. Pagani, 1751; S. T. Quellmaz, 1753; A. von Haller, 1753–1757; Linné (Linnæus), 1754; P. Paulsohn, 1754; E. F. Runeberg, 1757; P. Brydone, 1757; Lower, 1760; De Lassone, 1763; Wm. Watson, 1763; G. F. Hjotberg, 1765; J. G. Teske, 1765; P. A. Marrherr, 1766; Gardane, 1768–1778; J. G. Krunitz, 1769; R. Symes, 1771; Sigaud de la Fond, 1771; C. A. Gerhard, 1772; Abbé Sans, 1772–1778; J. Janin de Combe Blanche, 1773; J. B. Becket, 1773; Marrigues à Montfort L’Amaury, 1773; G. F. Gardini, 1774; J. G. Schaffer, 1776; Mauduyt, 1776–1786; De Thouri, 1777; A. A. Senft, 1778; Masars de Cazéles, 1780–1788; P. F. Nicolas, 1782; Bonnefoy, 1782; Niccolas, 1783; K. G. Kuhn, 1783, 1797; C. W. Hufeland, 1783; Cosnier, Maloet, Darcet, etc., 1783; J. P. Marat, 1784; G. Vivenzio, 1784; Carmoy, 1784–1785; G. Piccinelli, 1785; L. E. de Tressan, “Essai ...” 1786, p. 233, etc.; Krunitz-Kirtz, 1787; Porna and Arnaud, 1787; F. Lowndes, 1787–1791; J. H. D. Petetin, 1787, 1808; G. Pickel, 1788; Van Troostwijk and Krayenhoff, 1788; R. W. D. Thorp, 1790; G. Wilkinson, 1792; C. H. Pfaff, 1793; G. Klein, 1794; M. Imhof, 1796; C. H. Wilkinson, 1799; C. A. Struve, 1802; Maurice, 1810; J. Morgan, 1815; Le Blanc, 1819; P. A. Pascalis, 1819; J. Price, 1821; K. Sundelin, 1822; Girardin, 1823; Ch. Bew, 1824; Sarlandière, 1825; S. G. Marianini, 1833; F. Puccinotti, 1834; François Magendie, 1836, 1837; Gourdon, 1838; C. Matteucci, Piria, etc., 1838, 1858; Breton Frères, 1844; B. Mojon, Jr., 1845; J. E. Riadore, 1845; A. Restelli, 1846; Budge, 1846; F. Hollick, 1847; R. Froriep, 1850; C. V. Rauch, 1851; H. Valerius, 1852; Burci, 1852; Marie-Davy, 1852–1853; W. Gull, 1852; C. Beckensteiner, 1852–1870; F. Channing, 1852; F. F. Videt, 1853; R. M. Lawrance, 1853–1858; G. M. Cavalleri, 1854, 1857; Briand, 1854; M. Kierski, 1854; P. Zetzell, 1856; Ad. Becquerel, 1856–1860; E. Pfluger, 1856, 1858; Pulvermacher, 1856; P. C. Pinson, 1857; H. Ziemssen, 1857–1866; Philipeaux, 1857; J. Dropsy, 1857; M. Meyer, 1857–1869; Nivelet, 1860–1863; A. Tripier, 1861; J. Rosenthal, 1862; Desparquets, 1862; M. P. Poggioli (Mémoire lu à l’Institut, Oct. 31, 1853; “Annual of Scientific Disc.,” 1865, p. 327); G. Niamias, “Della elettr. ... medicina,” 1851 (“An. of Sci. Disc.,” 1865, p. 327); A. C. Garrat, 1866; H. Lobb, 1867; Aug. Beer, 1868; H. M. Collis (“An. of Sci. Dis.,” 1869, p. 175); Toutain, 1870; J. R. Reynolds, 1872; Onimus and Legros, 1872; as well as Jobert de Lamballe, Richter and Erdmon, T. Guitard, J. J. Hemmer, H. van Holsbeek, T. Percival, J. D. Reuss and Mr. Ware (in Kuhn, Hist. II. p. 183).

A.D. 1803.—Berthollet (Claude Louis de), very eminent French scientist, who was the first of the leading chemists to openly endorse the antiphlogistic doctrine propounded by Lavoisier (A.D. 1781), and who with Laplace founded the well-known scientific Société d’Arcueil, admits in his “Essai de Statique Chimique” the analogy existing between caloric and the electric fluid. He believes that the latter during the oxidation of metals does not give out much heat, but causes only a dilatation of bodies which separates their molecules, and he also believes that electricity aids metallic oxidation by lessening cohesion (Delaunay, “Manuel de l’Electricité,” p. 16).

When Berthollet and Charles passed heavy electrical charges through platinum wire, they observed that the latter acquired a temperature about equal to that of boiling water, and therefore not sufficient to fuse the wire. If the metal is one easily oxidized, the separation of the molecules causes them to unite with the oxygen of the air, and it is therefore the oxidation itself which produces the consequent high degree of heat.

References.—“Essai de Statique,” Vol. I. pp. 209 and 263. See also “Biographie Générale,” Vol. V. p. 716; Young’s “Lectures,” London, 1807, Vol. II. p. 423, and Nicholson’s Journal, Vol. VIII. p. 80; Larousse, “Dict. Univ.,” Vol. II. p. 617; “Sci. Papers of Roy. Soc.,” Vol. I. pp. 321–323; Sir H. Davy, “Bakerian Lectures,” London 1840, pp. 41, 94, regarding more particularly Berthollet’s elaborate experiments on the decomposition of ammonia by electricity alluded to in Mém. de l’Acad., 1782, p. 324, also Delaunay, “Manuel,” pp. 17, 150.

A.D. 1804.—Jacotot (Pierre), Professor of Astronomy at the Lyceum of Dijon, states, at p. 223, Vol. I of his “Eléments de Physique Expérimentale,” that Wlik, teacher of natural philosophy at Stockholm, invented the electrophorus during the year 1762. Jacotot, of course, refers to Johannes Carolus Wilcke (see A.D. 1757) who, during the month of August 1762, constructed a resinous apparatus to which he gave the name of perpetual electrophorus (Scripta Academiæ Suec., 1762). Books V, VI and VII of the same volume treat respectively of Electricity, Galvanism and Magnetism.

References.—With regard to the perpetual electrophorus, see L. S. Jacquet de Malzet “Lettre d’un Abbé de Vienne ...” Vienna, 1775, translated into German by “A. H.” (A. Hildebrand), Wien, 1776; also C. Cuyper’s “Exposé d’une méthode ...” La Haye, 1778; and, for other improvements, Marsiglio Landriani, Scelta d’Opuscoli, 12mo, XIX. p. 73; J. F. Klinkosch, Mém. de l’Acad. de Prague, III. p. 218. Consult J. C. Poggendorff, “Biog.-Litter. Hand. ...” Vol. I. pp. 1, 182, and Larousse, “Dictionnaire Universel,” Vol. IX. p. 868.

A.D. 1804.—Hatchett (Charles), F.R.S. and foreign member of the Paris Academy, communicates through a paper entitled “An Analysis of the Magnetical Pyrites ...” his conclusions that iron must be combined with a large portion of either carbon, phosphorus or sulphur in order to acquire the property of receiving permanent magnetic virtue, there being, however, a limit beyond which an excess of either of the above-named substances renders the compound wholly incapable of exhibiting the magnetic energy. In this connection, the interesting observations of Messrs. Seebeck, Chenevix and Dr. Matt. Young on anti-magnetic bodies, in Vol. XIV. p. 27, of the eighth “Encyclopædia Britannica,” will repay perusal.

Three years before, on the 26th of November 1801, Mr. Hatchett had communicated to the Royal Society an interesting paper on columbium, a new metallic substance found in an ore from the State of Massachusetts.

References.—“Abstracts of the papers ... of the Phil. Trans.,” Vol. I. p. 155; also the Phil. Trans. for 1804, p. 315; Phil. Mag., Vol. XXI. pp. 133 and 213; Poggendorff, Vol. I. p. 1031; “Cat. Sc. Papers Roy. Soc.,” Vol. I. p. 155.

A.D. 1804.—M. Dyckhoff publishes in Nicholson’s Journal, Vol. VII. pp. 303 and 305, “Experiments on the activity of a galvanic pile in which thin strata of air are substituted instead of the wet bodies.” His description of what has by many been called the first practical dry pile is as follows:

“I constructed a pile with discs of copper and zinc, and little bits of thin green glass about the size of a lentil, three of which I placed triangularly in the intervals that separated the metallic plates. Thus between each pair of metals I had a thin stratum of air instead of a wet substance. A pile of ten pairs tried by the condenser affected the electrometer as powerfully as a common (voltaic) pile of five pairs.”

It was in the year following, 1805, that Wilhelm Behrends, of Frankfort, constructed his dry pile consisting of eighty pairs of discs of copper, zinc and gilt paper (De la Rive, “Treatise on Electricity,” Vol. II. p. 852).

The investigations of Maréchaux, De Luc, Zamboni and others in the same line will appear in due course.

References.—Young’s “Lectures,” London, 1807, Vol. II. p. 430, and Nicholson’s Journal, Vol. VII. pp. 303 and 305, Becquerel, Paris, 1851, p. 34; Sturgeon’s “Lectures on Galvanism,” p. 73; Sturgeon’s Annals of Electricity, Vol. VIII. pp. 378, etc.; Journal de Chimie de Van Mons, No. 11, p. 190, and also No. 12, p. 300, for Bouvier de Jodoigne’s experiments; “Catalogue Scientific Papers of the Royal Society,” Vol. II. p. 432; Gilbert, XIX. pp. 355–360, and Wilkinson’s denial of the effectiveness of Dyckhoff’s pile, in Nicholson’s Journal, Vol. VIII. p. 1.

A.D. 1804.—Gay-Lussac (Joseph Louis), one of the most prominent of modern scientists, who was for a time assistant to Berthollet, makes, in Paris, two ascents in a balloon, at heights varying between 12,000 and 23,623 feet, for the purpose of carrying out extensive observations upon terrestrial magnetism. The latter are recorded at length in the Journal de Physique, Vol. LIX, and are alluded to in the articles “Aeronautics” and “Meteorology” of the “Encycl. Brit.,” likewise at Biot, A.D. 1803, and in paragraphs 2961 and 2962 of Faraday’s “Experimental Researches in Electricity,” while at p. 193, Vol. XXI of the Phil. Mag. will be found the account of a very interesting aerial voyage made during January of the same year (1804) by M. Sacharof, of the St. Petersburg Academy of Sciences.

In conjunction with Louis Jacques Thénard (alluded to at Fourcroy, A.D. 1801), Gay-Lussac communicates to the Annales de Chimie for 1810 (Vol. LXXIII. p. 197, etc.), a paper relative to their “preparation of an ammoniacal amalgam through the agency of the voltaic pile” which had been read at the “Institut National” during the month of September 1809, and which is also alluded to at pp. 250, etc., of the Annales de Chimie, Vol. LXXVIII for 1811. Their united “physico-chemical researches on the voltaic pile ...” are reviewed at pp. 243, etc., of the last-named volume and are likewise alluded to at p. 36 of Vol. LXXIX for the same year. The largest of the many piles they employed in their several experiments consisted of 600 pairs with a square surface of 1800 feet (Figuier, “Exposition et Histoire ...” 1857, Vol. IV. pp. 387 and 433; Journal des Mines, Vol. XXX. pp. 5–56; Schweigger’s Journal, Vol. II. pp. 409–423).

At pp. 76, etc., of the second volume of the Annales de Chimie et de Physique for the month of May 1816, are to be found the observations of Gay-Lussac on dry voltaic piles, especially upon those of Desormes et Hachette, De Luc and Zamboni. He remarks that the last named does not appear to have so constructed his pile as to enable the oscillations of the needle to indicate an exact measure of time (Schweigger’s Journal für Chemie, Vol. XV. pp. 113, 130–132), but that the so-called electric clocks of M. Ramis, of Munich, and of M. Streizig, of Verona, readily pointed the hours, minutes and seconds (Schweigger’s Journal, Vol. XIII. p. 379; Ronalds’ “Catalogue” for notices of his own as well as of the clocks of Ramis and of Streizig).

The investigations of Gay-Lussac and Humboldt, relative to the magnetic intensity and dip or inclination, throughout France, Germany, Switzerland and Italy, will be found recorded in the first volume of Mém. d’Arcueil, 1807, while at p. 284, Vol. X, and at pp. 305–309 of the Annales de Chimie are observations of Gay-Lussac and Arago, and at p. 509 of the fourth volume of Figuier’s “Exposition et Histoire,” etc., Paris, 1857, appears an extended account of the special report upon lightning rods, which Gay-Lussac was authorized by the Natural Philosophy Division of the French Academy of Sciences to prepare during the year 1823, and the outcome of which appears in the Comptes Rendus des Séances ... Vol. XXXIX. p. 1142.

References.—Faraday’s “Experimental Researches,” 1839, Vol. I. p. 217, note, as well as paragraph No. 741 “Recherches Physicochimiques,” p. 12, and J. Farrar’s “Elem. of Elec. Mag.,” 1826, pp. 150–152; while for Gay-Lussac and Thénard’s repetition of Sir Humphry Davy’s experiments on the decomposition of the alkalies, see Phil. Mag., Vol. XXXII. p. 88; “Instruction sur les parat ...” for Gay-Lussac, Fresnel, Lefevre, Gineau and others, Paris, 1824, and for Gay-Lussac and Pouillet, Paris, 1855. Other reports on lightning rods not hitherto specially mentioned are: J. Langenbucher, 1783; Beyer, 1806–1809; P. Beltrami, 1823; Bourges, at Bordeaux, 1837; Boudin, 1855, and J. Bushee, Amer. Assoc., 1868. The observations of Thénard and Dulong are recorded at paragraphs 609, 612, 636, 637 of Faraday’s “Experimental Researches,” as well as at Vols. XXIII. p. 440; XXIV. pp. 380, 383 and 386 of the Annales de Chimie, and those of Thénard, Fourcroy, and Vauquelin will be found in the Mém. des Soc. Sav. et Lit., Vol. I. p. 204. See “Royal Society Catalogue of Sc. Papers,” Vol. II. pp. 800–807; Vol. V. pp. 944–948; Vol. VI. p. 666; Vol. VII. p. 748; Vol. VIII. p. 1072; “Discours de M. Becquerel ...” Inst. Nat. Acad. des Sciences; Phil. Mag., Vols. XX. p. 83; XXI. p. 220; Sci. Am. Supp., p. 11794; Edin. Magazine, Vol. V. p. 471; Annales de Chimie et Physique for 1818, Vol. VIII. pp. 68, 161, 163; the eighth “Britannica,” Vol. VIII. pp. 532, 539, 573 for Gay-Lussac’s additional experiments; the ninth “Britannica,” Vol. X. pp. 122, etc.; also Report Brit. Asso., London, 1838, pp. 7–8, for the magnetic observations of Gay-Lussac and Humboldt on the European Continent, likewise Sir Humphry Davy “Bakerian Lectures,” London, 1840, pp. 134–137; Humboldt, at A.D. 1799, and Cruikshanks, at A.D. 1800. For a description of the Volta eudiometer invented by Gay-Lussac, see Ann. de Ch. et Phys., Vol. IV. p. 188, also Dr. Hare in Silliman’s Journal, Vol. II. p. 312, and for the “Memoir of Louis Jacques Thénard,” by M. Flourens, see the “Report of the Smithsonian Institution” for 1862, pp. 372–383; “Journal des Savants” for Dec. 1850; Meyer’s “Konversations-Lexikon” Leipzig und Wien, 1894, Vol. VII. pp. 140–141; “Dict. Général de Biog. et d’Histoire,” Paris, 2nd ed., pp. 1218–1219.

A.D. 1805.—Mr. Joseph Davis submits to the London Society of Arts an improvement upon the telegraph of Lord George Murray (A.D. 1795), consisting of the addition of a seventh shutter, which, instead of being poised on a horizontal axis, is made to slide up and down in grooves in the centre of the framework; so that it may either range with the six shutters or, if not required at all, may descend into a space provided for it in the roof of the Observatory. By this simple device the power of the apparatus is quadrupled, it being made capable of indicating in all 252 changes.

The night signals are given by a coloured lamp mounted in the centre of the seventh or sliding shutter and by six white lights fastened to the outside of the frame, to produce, through their display or concealment by slides, the same signals as, under ordinary circumstances, are given by the opening and closing of the shutters.

A.D. 1805.—Grotthus—Grothuss—(Theodor—more properly Christian Johann Dietrich, Baron von) makes known his theory of electro-chemical decompositions, through the “Mémoire,” etc., published in 12mo at Rome, and of which an English translation appeared in London during 1806.

As Lardner and Fahie have it, Grotthus’ theory was the most plausible of the many proposed at this early period of experimental inquiry to explain chemical decomposition by the voltaic apparatus. The above-named “Mémoire ...” which appeared in the Phil. Mag. for 1806, Vol. XXV. pp. 330–334, is analyzed by both of these writers (Lardner, “Electricity, Mag. and Meteor.,” Vol. I. pp. 135–137, or “Popular Lectures,” 1851, Vol. I. pp. 348, 349; Fahie, “Hist. of Elec. Teleg.,” pp. 210, 211), but it may be briefly stated in the words of Sir David Brewster as follows:

“Grotthus (Annales de Chimie for 1806, Vol. LVIII. p. 61) regards the pile as an electric magnet with attracting and repelling poles, the one attracting hydrogen and repelling oxygen, and the other attracting oxygen and repelling hydrogen. The force exerted upon each molecule of the body is supposed to be inversely as its distance from the poles, and a succession of decompositions and recompositions is supposed to exist among the intervening molecules.”

In this connection it will be well to add here, by way of contrast, and again according to Sir David Brewster, the views held by other experimentalists of the same period. Sir Humphry Davy adopts the idea of attractions at the poles, diminishing to the middle or neutral points, and he thinks a succession of decompositions and recompositions probable. Messrs. Riffault and Chompré regard the negative current as collecting and carrying the acids on to the positive pole, and the positive current as doing the same, with the bases toward the negative pole. Biot attributes the effects to the opposite electrical states of the decomposing substances in the vicinity of the two poles. M. De la Rive considers the portions decomposed to be those contiguous to both poles, the current from the positive pole combining with the hydrogen or the bases which are there present, and leaving the oxygen or acids at liberty, but carrying the substances in union with it across to the negative pole, where it is separated from them, entering the conducting metal, and leaving on its surface the hydrogen or its bases. Faraday regards the poles as exercising no specific action, but merely as surfaces or doors by which the electricity enters into or passes out of the substance undergoing decomposition. He supposes that “the effects are due to a modification of the electric current and the chemical affinity of the particles through or by which that current is passing, giving them the power of acting more forcibly in one direction than in another, and consequently making them travel by a series of successive decompositions and recompositions in opposite directions, and finally causing their repulsion or exclusion at the boundaries of the body under decomposition in the direction of the current, and that, in larger or smaller quantities, according as the current is more or less powerful.”

In 1810 Grotthus published his “Uber d. elektricität ... wassers entwickelt,” one of his curious observations being the fact that when water is rapidly frozen in a Leyden jar, the outside coating, not being insulated, receives a weak electrical discharge, the inside being positive and the outside negative, and when the ice is rapidly thawed, the inside is negative and the outside positive.

References.—Faraday’s “Experimental Researches,” articles 481, 485, 489, 492, 507, etc.; also Phil. Mag., Vols. XXIV. p. 183, and XXVIII. pp. 35 and 59; Joseph Izarn, “Manuel du Galvanisme,” pp. 280–284 for M. Riffault and N. M. Chompré; Whewell, “History of the Inductive Sciences,” Vol. II. p. 304; Noad, “Manual,” pp. 364, 365; William R. Grove, “On Grotthus’ Theory ...” London, 1845; J. S. C. Schweigger’s Journal, Vols. III, IV, IX, XXVIII and XXXI; A. F. Gehlen’s Journal for 1808; L. W. Gilbert’s Annalen der Physik, Vol. LXVII; Ostwald, “Elektrochemie,” 1896, pp. 309–316; A. N. Scherer’s Allgem. nördliche Annal. d. Chemie, Vol. IV; Annales de Chimie, Vol. LXIII; Phil. Mag., Vol. LIX. p. 67; J. C. Poggendorff, “Biog. Literarisches,” etc., Vol. I. pp. 959, 960; “Royal Society Catalogue of Scientific Papers,” Vol. III. pp. 29–31.

Grotthus’ theory was extended by Rudolf Clausius, and the latter’s theory in turn gave way to that of Svante Arrhénius. Clausius maintained that the exchanges were going on continuously, although no current was flowing; while the assumption of Arrhénius was that in every electrolyte, a certain number of molecules break up into ions and that all electrolytes contain some of these free ions. This is the much controverted dissociation theory (Dr. Henry S. Carhart’s Presidential Address).

The “Encycl. Amer.,” New York, 1903, Vol. II says that the establishment of the theory of electrolytic dissociation, which is due to the noted Swedish chemist, Svante Arrhénius, supplies a reasonable explanation of many chemical phenomena otherwise insoluble, and correlates various facts between which no connection was previously discovered. Two important publications by Arrhénius are “Sur la conductibilité galvanique des electrolytes” (1884), and a treatise in German on electro-chemistry (1902). (See “Le Moniteur Scientifique,” Avril 1904, pp. 241–243.)

Rudolf Clausius, German scientist (1822–1888), “one of the most celebrated mathematical physicists of the nineteenth century,” communicated in 1850 to the Berlin Academy of Sciences the paper wherein he announced the second law of thermo-dynamics, that “heat cannot of itself pass from a colder to a hotter body.” The honour of establishing the science of thermo-dynamics upon a scientific basis he thus shares with Rankine and Thomson (“Encycl. Amer.,” Vol. V. n. p.; “New Inter. Encycl.,” New York, 1902, Vol. IV. p. 711. For biography, consult Riecke, “Rudolf Clausius,” Göttingen, 1889; “Meyer’s Konversations-Lexikon,” Leipzig, 1894, Vol. IV. p. 213).

A.D. 1805.—Alexander Tilloch’s Philosophical Magazine, Vol. XXI. p. 279, has a letter addressed by W. Peel to the editor, under date Cambridge, April 23, 1805, relative to the “Production of Muriate of Soda by the Galvanic Decomposition of Water.” This is followed by a communication dated Pisa, May 9, 1805, from Dr. Francis G. Pacchiani, Professor of Philosophy at the Pisa University (Rees’ Encyclopedia, “Galvanism,” p. 15), to Lawrence Pignotti, Historiographer to the King, entitled “Formation of Muriatic Acid by Galvanism,” as well as by two letters, one from W. Peel, dated Cambridge, June 4, 1805, on “The Production of Muriates by the Galvanic Decomposition of Water,” and the other from Dr. Wm. Henry, dated Manchester, July 23, 1805, relative to the above-named processes and to the latter’s own experiments in the same direction.

References.—Phil. Mag., Vol. XXII. pp. 153, 179, 188; XXIII. p. 257; XXIV. p. 183; XXVII. p. 82; XXVIII. p. 306; Sir Humphry Davy’s allusion to above, as well as his earlier experiments communicated to Dr. Beddoes, Sir James Hall, Mr. Clayfield and others, in “Bakerian Lectures,” London, 1840, pp. 2, 3; Sylvester, at A.D. 1806, and Donovan, at A.D. 1812; Lardner’s “Lectures on Science and Art,” Vol. I. p. 350; Faraday’s “Experimental Researches,” No. 314; J. F. Macaire, Ann. Ch. et Phys., XVII. 1821; Marni “Sulla formazione ...”; G. B. Polcastro, “Giorn. Ital. Letter del Dal Rio,” X. p. 182, 1805; Cioni and Petrini, Phil. Mag., XXIV. 167, 1806; The Paris Galvani Society, Phil. Mag., XXIV. p. 172, and Ann. de Ch., Vol. LVI, 1806; A. B. Hortentz, Phil. Mag., Vol. XXIV. p. 91, 1806; Leop. de Buch, Phil. Mag., Vol. XXIV. p. 244, 1806; Veau Delaunay, Phil. Mag., XXVII. p. 260, 1807; G. Innocenti, Nuova Scelta d’ Opuscoli, II. p. 96, 1807; P. Alemanni, Phil. Mag., Vol. XXVII. p. 339, 1807; C. H. Pfaff, Phil. Mag., XXVII. p. 338, and XXIX. p. 19; Ann. de Chim., Vols. LX. p. 314; LXII. p. 23, 1807–8; Wm. Henry, Phil. Mag., Vols. XXII. p. 183; XL. p. 337, 1805–1812; F. G. Pacchiani, in Nuova Scelta d’ Opuscoli, I. p. 277; Brugnatelli, An. di Chimica, Vol. XXII. pp. 125, 134 and 144; Edin. Med. and Surg. Journal, of July 1, 1805; Phil. Mag., Vol. XXIV. p. 176, for his letter to Fabbroni. For Dr. Wm. Henry, consult “Bibl. Britan.,” Vol. XV, An. VIII. pp. 35, 293; Phil. Mag., Vols. VII for 1830, p. 228; XXII. p. 183; XXXII. p. 277, and XL. p. 337; Phil. Trans., Part II for 1808.

A.D. 1806.—On Oct. 16, Mr. Wm. Skrimshire, Jr., addresses from Wisbech a letter to Mr. Cuthbertson on the absorption of electric light by different bodies.

In this letter, which is given in full at pp. 281–283 of the fifteenth volume of Nicholson’s Journal, he says he was led to his experiments by the well-known fact that when the electric current is passed through a lump of sugar it makes the latter appear luminous. He tried many calcareous species, chalk, Kelton stone, the phosphate, nitrate, sulphates of lime, etc. etc., and he details some of the results obtained, the most interesting being that given by the sulphuret of lime, commonly called Canton’s phosphorus, which, he says, is, by the electric explosion, rendered the most luminous of all the substances tried.

A.D. 1806.—Heidmann (J. A.), physician at Vienna, publishes his “Theorie der Galvanischen Electricität ...” or “Theory of Galvanic Electricity deduced from Actual Experimentation” (London, 1807). This had been preceded by other important electrical reviews at Vienna during the years 1799, 1803 and 1804.

As stated by Guyton de Morveau, Heidmann has given us in the above the complete history of galvanic electricity—including the experiments and observations of Aldini, Arnim, Biot, Boeckman, Carminati, Cavallo, Creve, Davy, Fontana, Fowler, Gilbert, Haldane, Hallé, Helebrandt, Humboldt, Nicholson, Pepys, Pfaff, Reil, Reinhold, Ritter, Valli, Vassalli-Eandi, etc. etc.—together with the description of the construction and the relation of all parts of the galvanic pile, which is called by him a galvanic battery. Heidmann also gives an account of his many interesting experiments with frogs placed in different liquids as well as with the galvanic chain, and he reviews all the known phenomena presented by the voltaic pile.

References.—“Annales de Chimie,” Vol. LXI. p. 70; Phil. Mag., Vol. XXVIII. p. 97.

A.D. 1806.—Dr. Joseph Baronio of Milan constructs a galvanic pile composed exclusively of vegetable substances. He makes his discs, two inches in diameter, of beet roots (bietola rossa) and of walnut wood (legno di noce), the latter having been freed from all of its resinous substance by treatment in a solution of vinegar and cream of tartar. Through this pile, he produced convulsions in a frog by excitation with a leaf of cochlearia (spoon wort or scurvy-grass).

References.—“Annales de Chimie,” Vol. LVII. pp. 64–67; Vol. LXII. p. 212; Phil. Mag., Vol. XXIII. p. 283; “Nota di Brugnatelli sopra una pila di sostanze vegetabili,” Pavia, 1805 (“Am. di Chim. di Brugnatelli,” Vol. XXII. p. 301); Volta, in Giorn. Fis. Med., Vol. II. p. 122.

A.D. 1806.—Sylvester (Charles), the author of the articles on “Galvanism and Voltaism” in Rees’ “Encyclopædia,” announces that he obtains muriatic acid from pure water by passing through it the galvanic current. Mr. Wollaston, however, asserts this cannot be done unless the current traverses some vegetable or animal substance containing that acid.

His first paper on the subject appeared in Nicholson’s Journal, 1806, Vol. XIV. pp. 94–98; in Gehlen’s Journ. der Chemie, Vol. II for 1806, pp. 152–153, and in Gilbert’s Annalen der Physik, Vol. XXV. pp. 107–112, 454–457. The paper following is entitled “Repetition of the Experiment in which Acids and Alkalies are Produced in Pure Water by Galvanism (no animal or vegetable matter, nor oxidable metal being present).”

References.—Nicholson’s Journal, Vol. XV. pp. 50–52; Vol. XXIII. pp. 258–260; Gehlen’s Journal, Vol. II, 1806, pp. 155–158. For his other papers, consult Nicholson’s Journal, Vol. IX. p. 179; Vol. X. pp. 166–167; Vol. XIX. pp. 156–157; Vol. XXVI. pp. 72–75; Gilbert’s Annalen, Vol. XXIII. pp. 441–447; “Roy. Soc. Catal. of Sc. Papers,” Vol. V. pp. 900–901; Sturgeon’s Scientific Researches, Bury, 1850, p. 153; Sir Humphry Davy’s lecture “On some chemical agencies of electricity,” read Nov. 20, 1806; Annales de Chimie, Vol. LX. p. 314; Vol. LXI. pp. 330–331; “Bibl. Britan.,” Vol. XXXIII, 1806, p. 324.

A.D. 1806.—Maréchaux (Peter Ludwig), correspondent of the French Galvani Society at Wesel, is the first to construct an effective dry pile containing paper discs. He makes known through M. Riffault (Annales de Chimie, Vol. LVII for January 1806, p. 61), that water is not essential to the production of galvanic effects, and his experiments are repeated for the Chemical Society by M. Veau Delaunay, as shown in Journal de Physique, Messidor, An. XIV.

This “Maréchausian Pile,” or colonne pendule, as it was originally denominated, consists of pairs of oven-dried cardboard, pasteboard, or blotting-paper, and of copper discs all pierced in such manner as to be suspended by three silken cords which hold them fast in position. Sturgeon remarks (“Researches,” pp. 199 and 239) that in this dry column the electric pulsations are, in consequence of the very great number of interrupting papers, less frequent than in either the processes of Volta or in that of Seebeck, notwithstanding which the instrument produces slow pulsatory currents.

References.—W. Sturgeon’s “Annals of Electricity,” Vol. I. p. 256, note; Vol. VIII. pp. 379, 484; Phil. Mag., Vol. XXIV. p. 183; Poggendorff, Vol. II. p. 46; “Roy. Soc. Cat. of Sci. Papers,” Vol. IV. p. 236; Gilbert’s Annalen der Physik, Vols. X.-XXVII passim, also Vol. XV. p. 98 and Vol. XVI. p. 115 giving a description of the Maréchaux electro-micrometer (screw and silver leaf), likewise Vol. XXII, containing an account of the observations made by M. Paul Erman.

A.D. 1807.—Young (Thomas), M.D., a very celebrated English scientist, “eminent alike in almost every department of human learning,” who was the associate of Davy at the Royal Institution, and who became the successor of Volta as Foreign Associate of the French Academy of Sciences, publishes his very elaborate “Course of Lectures on Natural Philosophy and the Mechanical Arts,” upon which he was assiduously engaged for five years, and a new edition of which was issued (with additional references and notes) by the Rev. P. Kelland, M.A., F.R.S., during the year 1845.

The above-named work comprises the sixty lectures which Dr. Young delivered during his connection with the Royal Institution and includes also his optical and other memoirs, as well as a very extended classified catalogue of publications in every leading department of science. His biographer in the “English Encyclopædia” remarks that Young’s lectures embody a complete system of natural and mechanical philosophy, drawn from original sources, and are distinguished not only by extent of learning and accuracy of statement, but by the beauty and originality of the theoretical principles. One of these is the principle of interferences in the undulatory theory of light. “This discovery alone,” says Sir John Herschel, “would have sufficed to have placed its author in the highest rank of scientific immortality, were even his other almost innumerable claims to such a distinction disregarded.” The first reception, however, of Dr. Young’s investigations of light was very unfavourable. The novel theory of undulation especially was attacked in the Edinburgh Review, and Dr. Young wrote a pamphlet in reply, of which it is said but one copy was sold, but it is now generally received in place of the molecular or emanatory theory.

His review and treatment of the field of electrical and magnetic phenomena, as may be imagined from the foregoing, is very extensive, and as no justice could be done it by making therefrom such extracts as would suitably come within the scope of the present “Bibliographical History,” only an extract from the lecture treating of “Aqueous and Igneous Meteors” will here be given.

Speaking of the aurora borealis, he says “that it is doubtful if its light may not be of an electrical nature. The phenomenon is certainly connected with the general cause of magnetism. The primitive beams of light are supposed to be at an elevation of at least 50 or 100 miles above the earth, and everywhere in a direction parallel to that of the dipping needle; but perhaps, although the substance is magnetical, the illumination, which renders it visible, may still be derived from the passage of electricity, at too great a distance to be discovered by any other test.... It is certainly in some measure a magnetical phenomenon; and if iron were the only substance capable of exhibiting magnetic effects, it would follow that some ferruginous particles must exist in the upper regions of the atmosphere. The light usually attending this magnetical meteor may possibly be derived from electricity, which may be the immediate cause of a change in the distribution of the magnetic fluid contained in the ferruginous vapours that are imagined to float in the air.”

The assumption of ferruginous particles or vapours, remarks Prof. Robert Jameson, of the Edinburgh University, seems, however, purely gratuitous and imaginary; and as iron is not the only substance or matter capable of exhibiting magnetic effects, light itself being susceptible of polarization, the above hypothesis is, therefore, untenable even on the ground upon which it has been rested by its author. But it is, nevertheless, certain that the cause of this luminous meteor is intimately connected with magnetism and electricity; or, rather, as the magnetic is variously modified and effected by the electric power, with the phenomena of electro-magnetism.

References.—Young’s Catalogue for “Aurora Borealis” and “Terrestrial Magnetism” (“Lectures,” London, 1807, Vol. II. pp. 440–443, 488–490), “Journal Roy. Inst.,” Vol. I; Dr. George Peacock’s “Life of Thomas Young”; also “Miscellaneous Works of T. Young,” London, 1855; “Memoirs of the Life of Thos. Young,” London, 1831; also Vol. XIII of John Leitch’s “Hieroglyphical Essays and Correspondence,” all of which contain every contribution made by the scientist to the Phil. Trans., as well as many other important articles communicated by him to other scientific publications of his time; “Eloge Historique de Dr. Thomas Young,” par M. Arago, in Mém. de l’Acad. Roy. des Sc., etc., Tome XIII. p. 57; Quarterly Review for April 1814; Tyndall, “Heat as a Mode of Motion,” 1873, pp. 267, 268; Annales de Chimie, Feb. 1815; Whewell, “History of the Inductive Sciences,” 1859, Vol. II. pp. 92, 96, 106, 111–118.

A.D. 1808.—Pasley (Charles William), F.R.S., D.C.L., K.C.B., who was at the time aide-de-camp to Sir John Moore, became Major-General in 1841 and Lieutenant-General in 1851, gives at pp. 205, 292, Vol. XXIX, and at p. 339, Vol. XXXV of Tilloch’s Philosophical Magazine, a description of the original and improved methods of constructing his “polygrammatic telegraph.”

The apparatus, as first devised by him between the years 1804 and 1807, consists of four posts, each bearing a pair of pivoted arms, which latter can be placed at different angles to indicate all desired numerals and letters. After he had seen the French semaphore during 1809 he improved his telegraph, employing but one post, upon which were three pairs of pivoted arms representing hundreds, tens and units.

In 1823 Pasley (then a Lieutenant-Colonel, Royal Engineers) issued a pamphlet entitled “Description of the Universal Telegraph for Day and Night Signals,” wherein he announces the abandonment of the polygrammatic principle. For day service he employs an upright post with two movable arms attached to the top on a pivot. Each arm is capable of assuming seven different positions, besides the quiescent position called the stop, in which the arms are turned down and concealed by the post. To prevent signals being seen in reverse, another arm, called an indicator, is added to one side of the post. For night signals he places a central lamp at the top of the post, as well as a lamp at the end of each arm, and suspends a fourth lamp, as an indicator, upon a light crane projecting horizontally beyond the range of both movable arms. Motion to the arms was communicated by means of an endless chain passing over two pulleys. Up to this time the semaphores employed by the Admiralty had been constructed without provision being made for the display of night signals.

Pasley was the first to apply the heating power of the galvanic battery to a useful practical purpose. While engaged on the River Thames he was written to by Mr. Palmer (Alfred Smee, “Electro-Metallurgy,” p. 297), who advised him to employ the galvanic battery instead of the long fuse then in common use, and as soon as he was made acquainted with the method of operating he at once adopted it and applied it effectively, during the year 1839, to the removal of the sunken hull of the “Royal George,” at Spithead.

References.—Sturgeon’s “Scientific Researches,” Bury, 1850, p. 174; Knight’s “Mech. Dict.,” Vol. I. p. 784; also “Documents relatifs à l’emploi de l’Electricité,” etc., Paris, 1841, taken from the United Service Journal and the “Militaire Spectateur Hollandais.” Consult likewise, “Trans. of the Society ... Arts,” Vol. XXXIX, London, 1821, for Peter Barlow, XL. pp. 76–100, and for Lieut. Nicolas Harris Nicolas, XL. p. 104; also Vol. XLII, London, 1824, for Mr. A. Westcott, pp. 165–166. A patented telegraph by James Boaz is alluded to in Vol. XII. pp. 84–87 of the Phil. Magazine.

Following close upon Pasley’s original telegraphic contrivance were several other methods of conveying intelligence at a distance, introduced at this period, worthy of mention here.

The Chevalier A. N. Edelcrantz, Swedish savant, sent to the London Society of Arts a model of his apparatus, which is to be found minutely described in Vol. XXVI. pp. 20, 184–189, of the Transactions of that institution. A description of his earlier contrivances for the same purpose had already been published at Stockholm in the year 1796, and after being translated into French had been noticed in William Nicholson’s Journal of Natural Philosophy for 1803. The one he finally adopted in 1808 consisted of ten boards placed in three vertical ranks, the central one having four boards and the side ranks three boards each. By this arrangement 1024 signals could be clearly shown, and it was possible, by observing the order in which the boards were exhibited, to make as many as 4,037,912 changes. He subsequently advised attaching lamps to the boards for night service. His system of working the boards, though very complicated, could be controlled by only one person, while the English method required several men to hold the shutters during heavy weather. As it was, his method is said to have been in constant use for fully twelve years prior to 1808 on both sides of the Baltic, and to have likewise served to transmit signals between Sweden and England.

Mr. Henry Ward, who had observed the difficulty with which the telegraph was worked at Blandford, in Dorsetshire, contrived the apparatus described in Vol. XXVI. pp. 20, 207–209 of the London Journal of the Society of Arts. The grooved wheels which are fixed upon the axis of the shutters to receive the ropes by which they are turned have the grooved portion of the rim formed in two segments, which are so attached to the periphery of the wheels by steel springs that they fly off and remain a little distance off when there is no strain upon the ropes, although so soon as a rope is pulled its pressure forces the segments into close contact with the solid rim of the wheel. In the segments are two notches, which, when the shutters are in either of their required positions, engage with a fixed catch so soon as the strain on the ropes is relaxed, and thus hold the shutters steady without any aid from the attendant. The pulling of a rope by drawing the segments close to the wheel releases the catch, and consequently enables the attendant to return any shutter to its original position.

Lieutenant-Colonel John Macdonald, F.R.S., who was already favourably known by two Reports on the Diurnal Variation of the Magnetic Needle observed at Fort Marlborough, Sumatra, and at St. Helena (Philosophical Transactions for 1796, p. 340, and for 1798, p. 397, also “Eighth Encycl. Brit.,” Vol. XIV. p. 54), publishes (1808–1817) two treatises upon his “Terrestrial Telegraph,” accompanied by an extensive “Telegraphic Dictionary.” His contrivance consists of thirteen boards or shutters arranged, like those of Edelcrantz, into three vertical ranks representing hundreds, tens and units. Twelve of the boards are capable of producing 4095 distinct combinations, and the thirteenth or auxiliary board, which is mounted over the centre of the apparatus, doubles that number. A flag or vane is added to the hundred side to distinguish it in whatever direction it may be viewed, and a ball sliding upon the staff which supports it affords the means of again doubling the number, so that, on the whole, 16,380 distinct signals can be obtained. He subsequently adopted a modification of the contrivance introduced by Pasley in 1809, and also described a sort of a “Symbolic Telegraph,” in which symbols like those of Dr. Hooke, but representing numerals instead of alphabetical characters, were dropped into open spaces denoting hundreds, tens and units. He further suggested a useful flag telegraph for the navy and devised several schemes for night telegraphs both for land and sea, one of which latter consists of three sets of four lights each, with an additional or director light to each set, affording the same extensive powers as his large board or shutter telegraph (Phil. Mag., Vols. LVII. pp. 88–93, and LVIII. pp. 99–103).

Major Charles Le Hardy communicates in 1808 to the London Society of Arts, Vol. XXVI. pp. 20, 180–183, a novel contrivance consisting of a large framework with nine radiating bars, representing the numerals from 1 to 9, and four sets of other bars intersecting them so as to form four concentric polygons, which latter express units, tens, hundreds and thousands; thousands being shown by the innermost polygon. Attached to the centre of the apparatus are four slender arms, carrying four square boards, the lengths of these arms being such that the board of one may, during the revolution of the arm, traverse the polygon which represents thousands, that of another the polygon representing hundreds, etc. By the addition of two other boards at the upper corners, one of which denotes 10,000 and the other 20,000, or, when displayed together, 30,000, the total range of the telegraph is from 1 to 39,999 (Philosophical Magazine, Vol. XXXIII. p. 343).