Chapter XXII: Book I: chap. i. Therein, he says that Baptista Porta, who has made the (7)

REFERENCES.--Jallabert (A.D. 1749); Lovett (A.D. 1756);
Bertholon (A.D. 1780–1781); Mauduyt (A.D. 1781); Van Swinden,
“Recueil,” etc., La Haye, 1784, Vol. II. pp. 122–129 for the
experiments of Sauvages, De La Croix, Joseph Elder von Herbert,
H. Boissier and others; Thomas Fowler, “Med. Soc. of London,”
Vol. III; M. Tentzel, “Collection Académique,” Tome XI; the
works of L’Abbé Sans, Paris, 1772–1778; M. de Cazèles Masar’s
“Mémoires et Recueils,” published 1780–1788, and reproduced in
Vols. II and III of the “Mémoires de Toulouse”; Jacques H. D.
Petetin, “Actes de la Soc. de Lyon,” p. 230; M. Partington,
_Jour. de Phys._, 1781, Vol. I; Dr. Andrew Duncan’s “Medical
Cases,” Edinburgh, 1784, pp. 135, 191, 235, 320; C. A. Gerhard,
“Mém. de Berlin,” 1772, p. 141; _Jour. de Phys._, 1783, Vol.
II; J. B. Bohadsch, “Dissertatio,” etc., Prague, 1751; _Phil.
Trans._ for 1752; Patrick Brydone, _Phil. Trans._ for 1757;
Geo Wilkinson, of Sunderland, “An account of good effects,”
etc., in _Medical Facts_, etc., 1792, Vol. III. p. 52; M.
Carmoy, “Observ. sur l’El. Med.,” Dijon, 1784; M. Cosnier, M.
Maloet, Jean Darcet, etc.; “Rapport,” etc., 1783; Le Comus,
“Dissertatio,” etc., 1761; Le Comus, “Osservazioni,” etc., 1776
(_Jour. de Phys._, 1775, Vols. V and VI; 1776, Vol. VII; 1778,
Vol. I; 1781, Vol. II); Ledru, “Sur le traitement,” etc., 1783;
Le Dr. Boudet, “De l’Elec. en Médecine,” conférence faite à
Vienne le 6 Octobre, 1883.

=A.D. 1769.=--Bancroft (Edward Nathaniel), a resident physician of Guiana, openly expresses the belief that the shock of the _torpedo_ is of an electrical nature. He alludes (“Natural History of Guiana”) also to the _gymnotus electricus_, which, he says, gives much stronger strokes than the _torpedo_; the shocks received from the larger animals being almost invariably fatal.

The discharge of the _gymnotus_ has been estimated to be equal to that of a battery of Leyden jars of three thousand five hundred square inches, fully charged. At a later date, the American physicians, Garden and Williamson, showed that as the fluid discharged by that fish affects the same parts that are affected by the electric fluid; as it excites sensations perfectly similar; as it kills and stuns animals in the same manner; as it is conveyed by the same bodies that carry the electric fluid and refuses to be conveyed by others that refuse to take the fluid, it must be the electric fluid itself, and the shock given by the eel must be the electric shock.

Humboldt, speaking of the results obtained by M. Samuel Fahlberg, of Sweden, says: “This philosopher has seen an electric spark, as Walsh and Ingen-housz had done before him at London, by placing the _gymnotus_ in the air and interrupting the conducting chain by two gold leaves pasted upon glass and a line distant from each other” (_Edinburgh Journal_, Vol. II. p. 249). Faraday, who gives this extract at paragraph 358 of his “Experimental Researches” says he could not, however, find any record of such an observation by either Walsh or Ingen-housz and does not know where to refer to that by Fahlberg. (See the note accompanying afore-named extract.)

REFERENCES.--_Annales de Chimie et de Physique_, Vol. XI; _Phil.
Trans._ for 1775, pp. 94, 102 (letter of Alexander Garden,
M.D.), 105, 395; “Acad. Berlin,” 1770, 1786; fifteenth series
Faraday’s “Exper. Researches,” read December 6, 1838; Wheldon’s
“Catalogue,” No. 74, 1870; Sir David Brewster’s “Edin. Jour.
of Science,” 1826, Vol. I. p. 96, for the observations of
Dr. Robert Knox; G. W. Schilling: at Ingen-housz, “Nouvelles
Expériences,” p. 340, as well as at note, p. 439, Vol. I. of Van
Swinden’s “Recueil,” etc., La Haye, 1784; also G. Schilling’s
“Diatribe de morbo in Europâ penè ignoto,” 1770; article
“Physiology” in the “Encycl. Brit.,” 1859, Vol. XVII. p. 671;
Aristotle (B.C. 341), Scribonius (A.D. 50), Richer (A.D. 1671),
Redi (A.D. 1678), Kaempfer (A.D. 1702), Adanson (A.D. 1751);
_Sc. Am. Suppl._, No. 24, p. 375 (for M. Rouget’s observations
on the _gymnotus_) and No. 457, p. 7300; M. Bajon, “Descrizione
di un pesce,” etc., Milano, 1775 (_Phil. Trans._, 1773, p. 481);
M. Vanderlot’s work on the Surinam eel, alluded to at p. 88 of
“Voyage Zoologique,” by Humboldt, who published in Paris, during
1806 and also during 1819 special works on the _gymnotus_ and
upon electrical fishes generally.

=A.D. 1769.=--Cuthbertson (John), English philosophical instrument maker, issues the first edition of his interesting work on electricity and galvanism.

He is the inventor of the _balance electrometer_, employed for regulating the amount of a charge to be sent through any substance, as well as of an electrical condenser and of an apparatus for oxidating metals, all of which are respectively described at pp. 593, 614 and 620, Vol. VIII. of the 1855 “Encycl. Brit.”

At the end of Part VI of his “Practical Electricity and Galvanism,” Cuthbertson gives the conclusions he reached from his numerous experiments with wire. These, as well as Mr. George Adams’ own observations (“Essay,” etc., 1799, p. 285), proved that the quantity of electricity necessary to disperse a given portion of wire will be the same, even though the charged surface be greatly varied; and that equal quantities of electricity in the form of a charge will cause equal lengths of the same steel wire to explode, whether the jar made use of be of greater or less capacity (_Nicholson’s Journal_, Vol. II. p. 217).

During his many experiments Cuthbertson made the very extraordinary discovery that a battery of fifteen jars and containing 17 square feet of coated glass, which, on a very dry day in March 1796 could only be made to ignite from 18 to 20 inches of iron wire of ¹⁄₁₅₀ part of an inch in diameter, took a charge which ignited 60 inches when he breathed into each jar through a glass tube (Noad, “Manual,” p. 122; also Cuthbertson, “Prac. Elec. and Magnetism,” 1807, pp. 187, 188).

REFERENCES.--Cuthbertson’s communication to the “Emporium of
Arts,” Vol. II. p. 193, regarding his experiments on John
Wingfield’s “New Method of Increasing the Charging Capacity
of Coated Electric Jars”; Cuthbertson’s “Electricity,” Parts
VIII, IX and XI; Cuthbertson’s letter addressed to _Nicholson’s
Journal_, Vol. II. p. 526, also _Phil. Mag._, Vol. II. p. 251.
for electrometers; “Bibl. Britan.,” Vol. XXXIX. 1808, p. 97;
Vol. XLVII. 1811, p. 233; Cuthbertson’s several works published
at Amsterdam and Leipzig, 1769–1797, and alluded to in _Phil.
Mag._, more particularly at Vols. XVIII. p. 358; XIX. p. 83;
XXIV. p. 170; XXXVI. p. 259, as well as at p. 313, Vol. XII.
of J. B. Van Mons’ _Journal de Chimie_; _Nicholson’s Journal_,
Vols. II. p. 525; VIII. pp. 97, 205, and the New Series, Vol.
II. p. 281; Gilbert’s _Annalen_, Vol. III. p. 1; “Bibl. Brit.
Sc. et Arts,” Genève, 1808, Vol. XXXIX. p. 118; Noad’s “Manual,”
p. 118; Van Marum (A.D. 1785); Harris, “Electricity,” p. 103,
and his “Frictional Electricity,” p. 76; C. H. Wilkinson,
“Elements of Galvanism,” etc., London, 1804, Vol. II. pp. 242,
266–268; _Phil. Trans._, 1782, for A. Brook’s electrometer,
which apparatus is described in the latter’s work published,
under the head of “Miscellaneous Experiments,” at Norwich,
1789, as well as in the “Electricity” article of the “Encycl.
Britannica.”

=A.D. 1769.=--St. Paul’s Cathedral, London, is first provided with lightning conductors. Dr. Tyndall, who mentions this fact (Notes of Lecture VI, March 11, 1875) likewise states that Wilson, who entertained a preference for blunt conductors as against the views of Franklin, Cavendish and Watson, so influenced King George III that the pointed conductors on Buckingham House were, during the year 1777, changed for others ending in round balls.

In 1772, St. Paul’s Cathedral was struck by lightning, which “heated to redness a portion of one of its conductors consisting of a bar of iron nearly four inches broad and about half an inch thick.” In 1764, the lightning had struck St. Bride’s Church, London, and “bent and broke asunder an iron bar two and a half inches broad and half an inch thick” (Sturgeon, “Sc. Researches,” Bury, 1850, p. 360; _Phil. Trans._ for 1764 and 1762).

The Rev. James Pilkington, Bishop of Durham, published in London a detailed account of the partial destruction of St. Paul’s Church by lightning, June 4, 1561, which is also to be found at pp. 53–55 of Strype’s “Life of Grindall,” published in London, 1710, and of which an abstract appears under the A.D. 1754 date.

REFERENCES.--Sturgeon’s _Annals_, Vol. X. pp. 127–131; also,
Biography of John Canton in “Encycl. Britannica”; Sir John
Pringle, at A.D. 1777; Hutton’s abridgments of the _Phil.
Trans._, Vol. XII. pp. 620–624.

=A.D. 1769.=--Mallet (Frederick) member of the Royal Society of Upsal and of the Stockholm Academy of Sciences, acting upon the observations of Anders Celsius (at A.D. 1740), is the first to make an attempt to determine the intensity of magnetism simultaneously at distant points. He ascertains that the number of oscillations in equal times at Ponoi, China (latitude, 67 degrees 4 minutes north; longitude, 41 degrees east) are the same as at St. Petersburg, Russia (59 degrees 56 minutes north latitude; 30 degrees 19 minutes east longitude).

REFERENCES.--Walker, “Magnetism,” Chap. VI; “Novi Commen. Acad.
Sc. Petropol.,” Vol. XIV for 1769, part ii. p. 33; Le Monnier,
“Lois du Magnétisme,” etc., 1776, p. 50; “Biog. Univ.,” Vol.
XXVI. p. 258.

=A.D. 1770.=--The well-known work of Jas. Ferguson, F.R.S., which first appeared under the title of “Introduction or Lectures on Electricity,” now becomes still more popular under the head of “Lectures on Select Subjects,” etc. (Consult likewise his “Lectures on Electricity,” corrected by C. F. Partington, with appendix, London, 1825.)

In his first lecture he says that the most remarkable properties of the loadstone are: (1) it attracts iron and steel only; (2) it constantly turns one of its sides to the north and the other to the south, when suspended to a thread that does not twist; (3) it communicates all its properties to a piece of steel when rubbed upon it without losing any itself. He cites the experiments of Dr. Helsham, according to whom, says he, the attraction of the loadstone decreases as the square of the distance increases. He also treats of electrical attraction generally, and reports in the sixth lecture having “heard that lightning, striking upon the mariner’s compass, will sometimes turn it round and often make it stand the contrary way, or with the north pole towards the south.”

=A.D. 1770.=--Hell--Hehl--Heyl--Höll (Maximilian), Hungarian scientist (1720–1792), member of the Order of Jesuits and Professor of Astronomy at Vienna, who had great faith in the influence of the loadstone, invented a singular arrangement of steel plates to which he afterward attributed the cure “with extraordinary success” of many diseases, as well as of a severe attack of rheumatism from which he himself had long suffered.

He communicated his discovery to Friedrich Anton Mesmer, who was so strongly impressed by Hell’s observations that he immediately procured every conceivable description of magnet, with which he made many experiments that led to his introduction of animal magnetism, or rather _mesmerism_.

He is the author of many works, the most important being “Elementa Algebræ Joannis Crivelii magis illustrata et novis demonstrationibus et problematibus aucta,” Vienna, 1745; “Observ. Astronomicæ,” 1768, and “Auroræ Boreales Theoria nova,” 1776.

REFERENCES.--Beckmann, Bohn, 1846, Vol. I. p. 44; _Practical
Mechanic_, Glasgow, 1843, Vol. II. p. 71; Van Swinden,
“Recueil,” etc., La Haye, 1784, Vol. II. pp. 303, 304, etc.;
J. Lamont, “Handbuch,” etc., p. 436; M. V. Burq, “Métallo
thérapie,” Paris, 1853; “Biog. Générale,” Vol. XXIII. pp.
836–839; Schlichtegroll, “Nekrol.,” 1792, Vol. I. pp. 282–303;
“Journal des Sçavans,” for July 1771, p. 499; Meusel, “Gelehrtes
Teutschl”; Jer. de la Lande, “Bibliogr. Astronomique,” Paris,
1803, pp. 721–722.

=A.D. 1771.=--Morveau (Baron Louis, Bernard Guyton de), a very prominent French chemist and scientist, publishes at Dijon his “Reflexions sur la boussole à double aiguille,” and, later on, communicates to the _Annales de Chimie_, Vol. LXI. p. 70, and Vol. LXIII. p. 113, very valuable papers treating on the influence of galvanic electricity upon minerals, which are read before the French Institute.

REFERENCES.--Thomson, “Hist. of Chemistry,” Vol. II. 1831;
the translation of Morveau’s letter to Guénaud de Montbéliard
in _Scelta d’ Opuscoli_, Vol. XXXIII. p. 60; Berthollet,
“Discours,” etc., 1816; “Biog. Univ.,” Tome XVIII. pp. 296–298;
“Journal des Savants” for Jan. 1860; “Roy. Soc. Cat. of Sc.
Papers,” Vol. III. pp. 99–102; Vol. VI. pp. 679–680; “Biog.
Univ. et Portative,” etc., 1834, Vol. III. p. 701; _Annales
de Chimie_, Vol. LXI. pp. 70–82; Sir Humphry Davy, “Bakerian
Lectures,” London, 1840, p. 51.

=A.D. 1771.=--In a very interesting article published by the _Gazette_ at Salem (Mass.), August 9, 1889, on the occasion of the formal opening of the new station of the Electric Lighting Company, the connection of that city with the progress of electricity was traced in the following manner:

“In 1771 Col. David Mason, a prominent figure among the patriots at Leslie’s Retreat, gave a course of lectures on ‘Electricity’ at his house near North Bridge. The Rev. John Prince, LL.D., minister of the First Church from 1779 to 1836, was especially interested in electricity, and is said to have made the first electrical machine in Salem, if not in the country. Col. Francis Peabody, assisted by Jonathan Webb, the apothecary, was much interested in the subject, and, in 1829, gave a series of lectures, illustrated with a machine made by himself, which had a glass plate wheel imported from Germany at a reported cost of $1500.

“Dr. Charles Grafton Page, another native of Salem, invented the first electric motor in which solenoids were used, and as early as 1850 constructed a motor which developed over 10 h.p. The next year he made a trial trip with his electro-magnetic locomotive over the Baltimore and Washington Railroad. Prof. Moses Gerrish Farmer lived in Pearl Street between the years 1850 and 1870, and, as far back as 1859, illuminated the house with divided electric lights--_probably the first time that any house in the world was lighted by electricity_. In 1847 Prof. Farmer had constructed and exhibited in public an electro-magnetic locomotive drawing a car holding two passengers, on a track one foot and a half wide.

“Many of Prof. Alexander Graham Bell’s early experiments were conducted in Salem, and the first lecture on the telephone in this country, if not in the world, was delivered by him before the Essex Institute in Lyceum Hall, February 12, 1877. The late Prof. Osbun, teacher of chemistry and physics at the Normal School in Salem, was also an electrical expert. He exhibited the first arc lights in Salem, and was the inventor of the storage battery system from which lights were exhibited.”

The advertisement of March 7, 1765, previously alluded to herein at Kinnersley, A.D. 1761, is as follows:

“A COURSE OF EXPERIMENTS ON THE

newly discovered _Electrical Fire_, to be accompanied with methodical LECTURES on the Nature and Properties of that wonderful Element will be exhibited by DAVID MASON, at his House opposite Mr. _Thomas Jackson_; Distiller, near Sudbury-Street.--To consist of two Lectures, at one Pistareen each Lecture.--The first Lectures to be on Monday and Thursday, and the Second on Tuesday and Friday Evenings every week, Weather permitting.

“OF ELECTRICITY IN GENERAL

“That the Electric Fire is a real Element,--That our Bodies at all Times contain enough of it to set an House on Fire,--That this Fire will live in Water,--A Representation of the seven Planets, shewing a probable Cause of their keeping their due Distances from each other, and the Sun in the Centre,--The Salute repulsed by the Ladies’ Fire, or Fire darting from a Lady’s Lips, so that she may defy any Person to salute her,--A Battery of Eleven Guns discharged by the Electric Spark, after it has passed through eight Feet of Water,--Several Experiments shewing that the Electric Fire and Lightning are the same, and that Points will draw off the Fire so as to prevent the Stroke,--With a number of other entertaining Experiments, too many to be inserted in an Advertisement.

“TICKETS to be had either at his House above or at his Shop in Queen-Street.”

Another advertisement, which appeared in the Salem _Gazette_ of Tuesday, January 1, 1771, is thus worded: “To-morrow evening (if the Air be dry) will be exhibited A Course of Experiments in that instructive and entertaining branch of Natural Philosophy called Electricity; to be accompanied with Methodical Lectures on the nature and properties of the wonderful element; by David Mason, at his dwelling-house near the North-Bridge. The course to consist of two lectures, at a pistareen each lecture.”

=A.D. 1771.=--Milly (Nicolas Christiern de Thy, Comte de) French chemist, constructs compass needles of an alloy of gold and ferruginous sand. These needles answered well their purpose, as did also the brass needle owned by Christian Huyghens (alluded to at A.D. 1706), a fact which received the confirmation of Messrs. Du Lacque, Le Chevalier d’Angos and M. Arderon, while the latter further ascertained that he could impart a feeble though distinct magnetic force to a brass bar either by striking it or by means of the “double touch.”

REFERENCES.--The Comte de Milly’s “Mémoire sur la réduction des
chaux métalliques par le feu electrique,” read before the Paris
Academy May 20, 1774, brought about many controversial articles,
notably from Sigaud de la Fond, Felice Fontana, Jean M. Cadet,
Jean Darcet, G. F. Rouelle and Le Dru le Comus; “Biog. Univ.,”
Vol. XXVIII. p. 312; _Journal de Physique_, Tome XIII. p. 393;
_Philosophical Transactions_, Vol. L. p. 774; Duhamel, “Hist.
Acad. Reg. Paris,” p. 184; _Journal des Sçavans_, Paris edition
of December 1772, and Amsterdam edition of January 1773.

=A.D. 1772.=--Mesmer (Friedrich Anton), an Austrian physician, who, upon taking his diploma at Vienna in 1766, had published a thesis “On the Influence of the Planets upon the Human Body,” begins his investigations as to the power of the magnet with the steel plates of Father Hell. The results proved so favourable that Hell was induced to publish an account of them, but he incurred the displeasure of his friend by attributing the cures merely to the _form_ of the plates.

Mesmer subsequently arrived at the conclusion that the magnet was incapable, by itself, of so acting upon the nerves as to produce the results obtained and that another principle was necessarily involved; he did not, however, give an explanation of it, and managed to keep his process a secret for quite a while. He had observed that nearly all substances can be magnetized by the touch, and in due time he announced his abandonment of the use of the magnet and of electricity in his production of what became known as _mesmerism_.

In 1779 he published his “Mémoire sur la découverte du magnétisme animal,” in which he says: “I had maintained that the heavenly spheres possessed a direct power on all of the constituent principles of animated bodies, particularly on the _nervous system_, by the agency of an all-penetrating fluid. I determined this action by the intension and the remission of the properties of matter and organized bodies, such as gravity, cohesion, elasticity, irritability and electricity. I supported this doctrine by various examples of periodical revolutions; and I named that property of the animal matter which renders it susceptible to the action of celestial and earthly bodies, _animal magnetism_. A further consideration of the subject led me to the conviction that there does exist in nature a universal principle, which, independently of ourselves, performs all that we vaguely attribute to nature or to art.”

The whole theory and practice of mesmerism was, however, openly rejected by one of Mesmer’s most capable pupils, Claude Louis Berthollet (A.D. 1803), a very distinguished French chemical philosopher, founder of the “Société Chimique d’Arcueil,” and who, in conjunction with Lavoisier (A.D. 1781), Guyton de Morveau (A.D. 1771), and Fourcroy (A.D. 1801), planned the new philosophical nomenclature which has since proved of such service to chemical science (“La Grande Encycl.,” Tome VI. p. 449; “Biog. Universelle,” Tome IV. pp. 141–149).

Mesmer gave all his manuscripts to Dr. Wolfart, of Berlin, who published in 1814, “Mesmerism ... as the general curative of mankind.” And it was one of Mesmer’s students, le Marquis de Puységur, who discovered magnetic somnambulism, an entirely new phenomenon in animal magnetism. (See the article “Somnambulism” in the “Encyl. Britannica,” as well as the numerous works therein quoted, relating to the above-named subjects, notably Mesmer’s own “Précis historique des faits relatifs au magnétisme animal, jusques en Avril 1781.”)

REFERENCES.--“Bulletin de l’Acad. de Méd.,” Paris, 1837, Tome I.
p. 343, etc., and Tome II. p. 370; Blavatsky, “Isis Unveiled,”
Vol. I. p. 172, etc.; “L’Académie des Sciences,” par Ernest
Maindron, Paris, 1888, pp. 57–63; Richard Harte, “Hypnotism and
the Doctors,” Vols. I and II, New York, 1903 (from Mesmer to
De Puységur, Dupotet, Deleuze, Charcot, etc.); Robert Blakey,
“History of the Philosophy of Mind,” London, 1850, Vol. IV.
pp. 570–582, 639–645; the report of Dr. Franklin and other
Commissioners ... against mesmerism, translated by Dr. William
Bache, London, 1785; J. C. Schäffer, “Abhandlung,” etc., and
“Kräfte,” etc. (1776), “Fernere,” etc. (1777), also “Journal
Encyclopédique” for March 1777; Van Swinden, “Recueil,” etc., La
Haye, 1784, Vol. II. pp. 373–446; C. H. Wilkinson, “Elements of
Galvanism,” etc., Chapter XVIII; Champignon, “Etudes Physiques,”
etc., Paris, 1843; “Archives du Magn. Animal,” published by M.
Le Baron d’Hénin de Cuvillers, Paris, 1820–1823; “Report on
Animal Magnetism” made by Charles Poyen Saint Sauveur, 1836;
Dupotet’s “Manuel,” etc., Paris, 1868; Hale’s “Franklin in
France,” 1888, Part II. chap. v. alluding to an interesting
manuscript of T. Auguste Thouret now in the collection of the
American Philosophical Society.

=A.D. 1772.=--Henley (William T.), F.R.S., invents the _quadrant electrometer_, an apparatus with which the quantity of electricity accumulated in a jar or battery can be measured through the amount of repulsion produced by the fluid upon a pith ball suspended from the centre of a graduated arc. It is generally attached to the prime conductor to measure the state of action of the electrical machine.

He is also the inventor of the _universal discharger_, for directing the charge of jars or batteries (Edw. Whitaker Gray--1748–1807--“Observations on manner glass is charged and discharged by the electric fluid” in Hutton’s abridgments, Vol. XVI. p. 407).

In the _Philosophical Transactions_ for 1774, Henley and Nairne give an account of many curious experiments proving the superiority of points over balls as conductors. The same is shown by William Swift in the _Phil. Trans._, Vol. LXVIII. p. 155. (For Wm. Swift consult, besides, the _Phil. Trans._, Vol. LXIX. p. 454, and Hutton’s abridgments, Vol. XIV. pp. 314, 571.) Henley also states that the vapour of water is a conductor of electricity; that when the flame of a candle is introduced into the circuit and a Leyden jar is discharged through it, the flame always inclines toward the negative side; and he proves that electricity cannot effect a passage through glass (_Phil. Trans._, Vol. LXVIII. p. 1049). He likewise makes a number of experiments to determine the relative conducting power of the different metals according to the quantity of a wire, each of a given size, melted by equal electrical shocks passed through them, and finds the metals to hold the order following as conductors: gold, brass, copper silvered, silver, iron. It was also shown by Nairne that copper conducts better than iron, in the _Phil. Trans._ for 1780, Vol. LXX. p. 334.

REFERENCES.--Harris, “Rud. Electricity,” 1853, p. 93, and
his “Frictional Electricity,” 1867, p. 23; “The Electrical
Researches of the Hon. Hy. Cavendish,” Cambridge, 1879, Nos.
559, 568, 569, 580; Thos. Young, “Nat. Phil.” _passim_; _Phil.
Trans._, Vol. LXIV. pp. 133, 389; Vol. LXVI. p. 513; Vol. LXVII.
pp. 1, 85; also Hutton’s abridgments, Vol. XIII. pp. 323 (new
electrometer), 512, 551, 659; Vol. XIV. pp. 90, 97, 130, 473;
_Transactions of the Humane Society_, Vol. I. p. 63; Ronayne and
Henley, “Account of Some Observations ...” London, 1772 (_Phil.
Trans._, p. 137).

=A.D. 1772.=--Cavendish (Henry), F.R.S., eldest son of Lord Charles Cavendish, and a prominent English scientist, sometime called “The Newton of Chemistry” (“the most severe and cautious of all philosophers”--Farrar, 284), commences investigating the phenomena of electricity, the results of which study were duly communicated to the _Philosophical Transactions_. His papers embrace twenty-seven mathematical propositions upon the action of the electric fluid, and contain the first distinct statement of the difference between common and animal electricity.

Cavendish made many very important experiments upon the relative conducting power of different substances. He found that a solution of one part of salt in one part of water conducts a hundred times better, and that a saturated solution of sea-salt conducts seven hundred and twenty times better than fresh water, also that electricity experiences as much resistance in passing through a column of water one inch long as it does in passing through an iron wire of the same diameter four hundred million inches long, whence he concludes that rain or distilled water conducts four hundred million times less than iron wire.

He decomposed atmospheric air by means of the electric spark, and he successfully demonstrated the formation of nitric acid by exploding a combination of seven measures of oxygen with three of nitrogen. The latter he did on the 6th of December, 1787, with the assistance of Mr. George Gilpin, in presence of the English Royal Society. (For George Gilpin, consult “Bibl. Britan.,” Vol. XXXVI, 1807, p. 3; _Phil. Trans._ for 1806.)

He improved upon Priestley’s experiments after studying thoroughly the power of electricity as a chemical agent. In one of his experiments he fired as many as five hundred thousand measures of hydrogen with about two and a half times that quantity of atmospheric air, and having by this means obtained 135 grains of pure water, he was led to the conclusion which Mr. Watt had previously maintained, that water is composed of two gases, viz. oxygen and hydrogen.

He explains why no spark is given by the electrical fishes: the latter may contain sufficient electricity to give a shock without being able to make it traverse the space of air necessary for the production of a spark, as the distance through which the spark flies is inversely (or rather in a greater proportion) as the square root of the number of jars in operation.

For an account of his experiments anticipating Faraday’s discovery of the specific inductive capacity of various substances, see Chap. XI. pp. 69–142 of Gordon’s “Physical Treatise,” etc., London, 1883. See, likewise, J. Clerk Maxwell’s “Electrical Researches,” etc., Cambridge, 1879, pp. liii-lvi, as well as references therein made, more particularly at articles Nos. 355–366, 376; also the notes 27, 29 as per Index at pp. 450 and 453; _Phil. Trans._, Vol. CLXVII (1877), p. 599; Sparks’ edition of Franklin’s “Works,” Vol. V. p. 201.

REFERENCES.--Dr. G. Wilson’s “Life and Works of Hon. Henry
Cavendish,” London, 1851; Sturgeon’s _Annals_, Vol. VI. pp.
137, 173, etc.; Noad, “Manual,” etc., pp. 14, 161; Harris,
“Electricity,” pp. 136, 140; Harris, “Frictional Electricity,”
pp. 23 and 45; Whewell, “Hist. of the Ind. Sciences,” 1859, Vol.
II. pp. 203–206, 273–275, 278; C. R. Weld, “Hist. Roy. Soc.,”
for Lord Charles Cavendish, Vol. II. pp. 171, 176–185, 221; T.
E. Thorpe, “Essays in Historical Chemistry,” London, 1894, pp.
70, 110; Thomas Thomson, “Hist. Roy. Soc.,” London, 1812, pp.
456, 457, 471; Sir William Thomson’s “Works,” 1872, pp. 34,
235; _Phil. Trans._ for 1776, Vol. LXVI. p. 196; Thos. Young,
“Lectures,” 1807, Vol. I. pp. 658, 664, 751, and Vol. II. p. 418.

=A.D. 1773.=--Walsh (John), F.R.S., demonstrates the correctness of Dr. Bancroft’s opinion that the shock of the _torpedo_ is of an electrical nature, resembling the discharge from a Leyden jar. In the letter announcing the fact, which he addressed to Franklin, then in London, he says: “He, who predicted and showed that electricity wings the formidable bolt of the atmosphere, will hear with attention that in the deep it speeds a humbler bolt, silent and invisible; he, who analyzed the electric phial, will hear with pleasure that its laws prevail in _animated_ phials; he, who by reason became an electrician, will hear with reverence of an instructive electrician gifted at its birth with a wonderful apparatus, and with skill to use it.”

Mr. Walsh’s experiments were made off Leghorn, in company with Dr. Drummond, as stated in _Phil. Trans._, 1775, p. 1, and were confirmed by Johan Ingen-housz as well as by the Italian naturalist, Lazaro Spallanzani (at A.D. 1780). The last named found the _torpedo_ shocks strongest when it lay upon glass, and that when the animal was dying the shocks were not given at intervals, but resembled a continual battery of small shocks: three hundred and sixteen of them have been felt in seven minutes.

REFERENCES.--Leithead, “Electricity,” p. 135; Gray, “Elements
of Natural Philosophy,” 1850, p. 323; “Electrical Researches
of Lord Cavendish,” 1879, pp. xxxv, xxxvi and 395–437;
Fifth Dissertation of “Encycl. Britannica,” 8th ed. p. 738;
_Phil. Trans._ for 1773, 1774, 1775 and 1776; also Hutton’s
abridgments, Vol. XIII. p. 469; “Chambers’ Ency.,” 1868, Vol.
III. p. 821; “People’s Cyclopædia,” 1883, Vol. I. p. 628;
Kaempfer (A.D. 1702); _Sc. American Supplement_, No. 457,
pp. 7300, 7301, “Lettera dell’ Abate Spallanzani al Signore
Marchese Lucchesini,” Feb. 23, 1783, inserted in the _Gothaische
Gelehrte Zeitungen_ for 1783, p. 409. See also the experiments
of Dr. Ingram, of Kaempfer and of Borelli, described in Van
Swinden’s “Recueil,” etc., La Haye, 1784, Vol. II; Wilkinson’s
“Galvanism,” 1804, Vol. I. pp. 318, 324; G. W. Schilling,
“Diatribe de morbo,” etc., 1770, and Friedrich von Hahn in the
preface to Schilling’s “De Lepra,” etc., 1778, as well as at pp.
436–442, Vol. I and at note, p. 160, Vol. II of Van Swinden’s
“Recueil,” already noted; J. B. Leroy and M. Saignette “Sur.
l’élect. de la Torpille,” etc. (_Jour. de Phys._, 1774, Vol. IV
and for 1776, Vol. VIII); “Annales du Musée d’Hist. Nat.,” p.
392; R. A. F. De Réaumur, “Mém. de l’acad. des Sc. de Paris” for
1714; C. Alibert, “Eloges,” etc., Paris, 1806.

=A.D. 1773.=--Odier (Louis), a well-known Swiss physician, thus addresses a lady upon the subject of an electric telegraph: “I shall amuse you, perhaps, in telling you that I have in my head certain experiments, by which to enter into conversation with the Emperor of Mogol or of China, the English, the French, or any other people of Europe, in a way that, without inconveniencing yourself, you may intercommunicate all that you wish, at a distance of four or five thousand leagues in less than half an hour! Will that suffice you for glory? There is nothing more real. Whatever be the course of those experiments, they must necessarily lead to some grand discovery; but I have not the courage to undertake them this winter. What gave me the idea was a word which I heard spoken casually the other day, at Sir John Pringle’s table, where I had the pleasure of dining with Franklin, Priestley and other great geniuses.”

REFERENCES.--Necrology of Prof. Odier in “Bibl. Britan.,” Vol.
IV. N. S., 1817, pp. 317–328; see also allusion to Odier at
Schwenter (A.D. 1600), and in the report of Bristol meeting of
the British Association, August 25, 1875; also Chambers’ “Papers
for the People,” 1851, _El. Com._, p. 6; Bertholon, “Elec. du
Corps Humain,” 1786, Vol. I. p. 357.

=A.D. 1773.=--Hunter (John), a native of Scotland, “by common consent of all his successors, the greatest man that ever practiced surgery,” gives at p. 481 of the _Phil. Trans._ for 1773 his observations on the anatomical structure of the _raia torpedo_.

The electricity of the animal, he found, is generated by organs on each side of the cranium and gills, somewhat resembling a galvanic pile, and consisting wholly of perpendicular columns reaching from the upper to the under surface of the body. Dr. Walsh gave him for examination a fish about eight inches long, two inches thick and twelve inches broad, and Hunter found in each electrical organ as many as 470 columns; but in a very large fish, four and a half feet long and weighing 73 pounds, he counted as many as 1182 in each organ.

He remarks that there is no part of any animal with which he is acquainted, however strong and constant its natural action, which has so great a proportion of nerves; and he concludes that, if it be probable these nerves are not necessary for the purposes of sensation or action, they are subservient to the formation, collection or management of the electric fluid.

REFERENCES.--_Phil. Trans._ for 1773, p. 461; for 1775, p. 465
(_gymnotus electricus_); for 1776, p. 196; the _Phil. Trans._,
Vol. LXIII. p. 481, (torpedo); Vol. LXV. p. 395 (gymnotus); and
Hutton’s abridgments, Vol. XIII. pp. 478, 666; also John Davy’s
account in _Phil. Trans._ for 1832, p. 259; “Am. Trans.,” Vol.
II. p. 166; _Nicholson’s Journal_, Vol. I. p. 355; _Journal de
Physique_, Vol. XLIX. p. 69; Becquerel et Brachet, _Comptes
Rendus_, III. p. 135; Carlo Matteucci, “Recherches,” Genève,
1837; Delle Chiage, on the organs of the torpedo; Geo. Adams,
“Essay on Electricity,” etc., 1785, p. 315; D. J. N. Lud. Roger,
“Specimen Physiologicum,” etc., Göttingæ, 1760; Dr. Buniva’s
experiments recorded in “Journal de Littér. Médicale,” Tome
II. p. 112; Leithead, “Electricity,” Chap. XII; _Scient. Am.
Suppl._, No. 457, pp. 7300–7302. See also the account of his
having been the first to observe the galvanic sensation of light
in the experiment on the eyes, published in “Opuscoli Scelti,”
Vol. XXII. p. 364.

=A.D. 1774.=--At p. 16 of the third volume of Dr. Wm. Hooper’s “Rational Recreations,” etc., there is given a fine illustration of the electrical machine made by Dr. Priestley, and mention is made of the fact that, since the publication of the latter’s “History and Present State of Electricity,” he contrived, to be placed on the top of his house, a windmill by which the machine could be occasionally turned.

Much of the remainder of the volume is given to all kinds of experiments in the line of electricity and magnetism.

=A.D. 1774.=--Lesage (Georges Louis, Jr.), a Frenchman living at Geneva, Switzerland, makes in that city the first real attempt to avail of frictional electricity for the transmission of signals between two distant points (see C. M., or Charles Morrison, at A.D. 1753). His apparatus consists of twenty-four metallic wires insulated from each other and communicating with separate electrometers formed of small balls of elder held by threads and each marked with different letters of the alphabet. Whenever the electric current was transmitted, the balls indicated the desired letter.

Lesage was not, however, satisfied with a telegraph upon so small a scale as to be utilized only in one building, and on the 22nd of June 1782 he addressed a letter to M. Pierre Prévost, at Geneva, on the subject of “a ready and swift method of correspondence between two distant places by means of electricity.” This, he says, had occurred to him thirty or thirty-five years before, and had been “then reduced to a simple system, far more practicable than the form with which the new inventor has endowed it.” He employed a subterranean tube of glazed earthenware, divided at every fathom’s length by partitions with twenty-four separate openings intended to hold apart that number of wires, the extremities of the wires being “arranged horizontally, like the keys of a harpsichord, each wire having suspended above it a letter of the alphabet, while immediately underneath, upon a table, are pieces of gold leaf, or other bodies that can be as easily attracted, and are at the same time easily visible.” Upon touching the end of any wire with an excited glass tube, its other extremity would cause the little gold leaf to play under a certain letter, which would form part of the intended message.

Georges Louis Lesage (sen.) wrote a work on “Meteors,” etc., published at Geneva in 1730, and alluded to in _Poggendorff_, Vol. I. p. 1433.

REFERENCES.--Abbé Moigno, “Traité,” etc., 2nd ed. Part II. chap.
i. p. 59; Ed. Highton, “The Electric Telegraph,” 1852, p. 38;
_Journal des Sçavans_, September 1782, p. 637; Pierre Prévost,
“Notice,” etc., 1805, pp. 176–177.

=A.D. 1774.=--Wales (William), English mathematician and the astronomer of Captain Cook during the expeditions of 1772, 1773 and 1774, is the first to make scientific observations relative to the local attraction of a ship upon mariners’ compasses. While on his way from England to the Cape and during his passage through the English Channel he found differences of as much as 19 degrees to 25 degrees in the azimuth compass.

REFERENCES.--Sturmy, at A.D. 1684; also Wales and Bayly’s
“Observations on Cook’s Voyages,” p. 49.

=A.D. 1775.=--Gallitzin (Dmitri Alexewitsch Fürst, Prince de), an able Russian diplomat and scientist, carries on at the Hague, between the 4th of June, 1775, and the commencement of the year 1778, a series of experiments upon atmospherical electricity, the results of which he communicates to the St. Petersburg Academy of Sciences in a Memoir entitled “Observations sur l’Electricité naturelle par le moyen d’un cerf-volant.” Therein he states that the presence of electricity was always noticeable whenever he raised his kite, whether in the night or in the daytime, as well as during hot, dry, or damp weather, and he ascertained that electricity is generally positive during calm weather and more frequently negative when the weather is stormy.

He also observed during an extensive course of experiments upon animals that hens’ eggs hatch sooner when they are electrified, thus confirming the previous observations of Koeslin and Senebier, and he gives an account of the effects of battery shocks upon various species. He cites the case of a hen which had sustained the shock of sixty-four jars and appeared dead, but which revived and lived thirty-two days; and he gives the report of the dissection made by M. Munichs, as well as the very curious observations upon it noted at the time by M. Camper.

REFERENCE.--Bertholon, “Elec. du Corps Humain,” 1786, Vol. I.
pp. 13–14, 66, and Vol. II. p. 48, etc.; “Anc. Mém. de l’acad.
Belge,” Vol. III. p. 3, showing preference for the pointed
form of electrical conductors; “Mercure de France,” 1774, p.
147; “Biog. Univ.,” Tome XV. p. 425; “Mém. de l’Acad. ... de
Bruxelles,” Vol. III. p. 14; _Journal de Physique_, Vols. XXI
and XXII for 1782 and 1783; “Opuscoli Scelti,” Vol. II. p. 305.

=A.D. 1775.=--Lorimer (Dr. John), “a gentleman of great knowledge on magnetics” (1732–1795), describes his combined dipping and variation needle for determining the dip at sea, which he calls _universal magnetic needle or observation compass_ in a letter to Sir John Pringle, Bart., copied in _Philosophical Transactions_, Vol. LXV. p. 79. This apparatus is also to be found described in Lorimer’s “Essay on Magnetism,” etc., 1795, as well as at p. 168 of Cavallo’s “Treatise on Magnetism” published in 1787; and, at p. 333 of the latter work, the Doctor endeavours to explain the causes of the variation of the magnetic needle.

REFERENCES.--For Lorimer, consult Hutton’s abridgments, Vol.
XIII. p. 593, and, for dipping needles, refer to the same volume
of Hutton, p. 613, wherein especial mention is made of those
of Thomas Hutchins. The dipping needle of Robert Were Fox is
described in the “Annals of Electricity,” as well as at p. 411,
Vol. II. of “Abstract of Papers of Roy. Soc.,” and the two
dipping needles of Edward Nairne are described in _Phil. Trans._
for 1772, p. 496. Capt. Henry Foster made a report on changes of
magnetic intensity ... in dipping and horizontal needles, to be
found in _Phil. Trans._ for 1828, p. 303 (“Abstracts Sc. Papers
... Roy. Soc.,” Vol. II. pp. 290–296, 344).

=A.D. 1775.=--Cavallo (Tiberius), a distinguished Italian natural philosopher, publishes in London “Extraordinary Electricity of the Atmosphere at Islington,” which volume was reprinted by Sturgeon, and contains his many experiments and important observations upon the line indicated by Franklin. This work was followed in 1777, 1782, 1787, 1795, 1802 by his “Complete Treatise on Electricity,” etc.; by his “Essay on the Theory and Practice of Medical Electricity” (London, 1780, 1781; Leipzig, 1782, 1785; Naples, 1784); and during 1787 was also published in London the first edition of his “Treatise on Magnetism,” a supplement to which appeared eight years later.

He had made many very remarkable observations during the year 1787 on the phenomena of electricity in glass tubes containing mercury, and he had particularly experimented with various substances floating upon mercury in order to test their magnetism.

Before the year 1795 he contrived what he called a _multiplier of electricity_, a good illustration of which is to be found, more particularly, opposite p. 270, Vol. II. of his “Elements,” etc., published at Philadelphia in 1825. It consisted of two brass plates insulated upon glass pillars, and of a third plate which could be insulated or uninsulated at will, and which, turning on a pivot, or rather a movable arm, could be made to successively convey electricity from one plate to the other until the desired quantity was accumulated. (For the _multiplier_, see Jean Damel Colladon in “Bibl. Britan.,” Vol. XXIX, N.S. for 1825, p. 316.)

Cavallo also invented a small electroscope and a _condenser of electricity_. The latter consisted of an insulated tin plate between the sides of a wooden frame lined with gilt paper, one edge of the plate being connected with the body containing the electricity, and the condensation making itself observable at the opposite edge by the electroscope.

In the fourth edition of his “Treatise on Electricity” (1795), which, like the previous editions, was freely translated into other languages, will be found at pp. 285–296 of the third volume mention of the possibility of transmitting intelligence by combinations of sparks and pauses. For his experiments he made use of brass wires 250 English feet in length, and his electric alarm was based upon either the explosion of a mixture of hydrogen and of oxygen, or of gunpowder, phosphorus, phosphuretted hydrogen, etc., fired by the Leyden phial (vide Bozolus at A.D. 1767). It is in Vol. I. p. 358 of the afore-named fourth edition that Cavallo explains the mode of action of the charged Leyden jar. His concluding words deserve reproduction: “Which shows that one side of a charged electric may contain a greater quantity of electricity than that which is sufficient to balance the contrary electricity of the opposite side. This redundant electricity should be carefully considered in performing experiments of a delicate nature.” The same is expressed in other words in the 1825 American edition of his “Natural Philosophy,” Chap. IV. Therein he asserts that glass is impervious to the electric fluid, saying: “If the additional electric fluid penetrates a certain way into the substance of the glass, it follows that a plate may be given so thin as to be permeable to the electric fluid, and, of course, incapable of a charge; yet glass balls blown exceedingly thin, viz. about the six-hundredth part of an inch thick, when coated, etc., were found capable of holding a charge.” (Consult Cavendish’s experiments which produced this remarkable discovery, in _Phil. Trans._, Vols. LXXV and LXXVIII.)

An electrical machine used by Cavallo in 1777 had a glass cylinder rotated by means of a cord passing around the neck and the wheel, also a cushion (amalgamated with two parts of mercury, one of tinfoil, some powdered chalk and grease) holding a silk flap and freely moving along a groove, and provided with a prime conductor resting on glass legs and with collecting points.

REFERENCES.--Sturgeon, “Lectures,” London, 1842, p. 12;
Young’s “Lectures,” London, 1807, Vol. I. pp. 682, 686, 694,
714; _Nicholson’s Journal_, 1797, Vol. I. p. 394; Du Moncel,
“Exposé,” Vol. III; Aikin’s “General Biography,” Vol. X; _Phil.
Transactions_, 1776, Vol. LXVI. p. 407; 1777, Vol. LXVII. pp.
48, 388; 1780, Vol. LXX. p. 15; 1786, p. 62; 1787, p. 6; 1788,
pp. 1 and 255, and 1793, p. 10 (Volta’s letters); likewise
Hutton’s abridgments, Vol. XVI. pp. 57, 170, 354, 449; Vol.
XIV. pp. 60, 129, 180, 608; see also “Encycl. Britannica,” art.
“Magnetism,” Chap. III. s. 1. for Cavallo’s “Observations on the
Magnetism of Metals,” etc.

=A.D. 1775.=--Bolten (Joach. Fred.), a German physician, is the author of “Nachricht von einem mit dem Künstlichen magneten gemachten Versuchein einer Nerven-Krankheit” (Hamburg, 1775), the title of which is here given in full, as the work is not usually found recorded in publications and is considered to be of excessive rarity.

Contrary to the accepted belief of many at the time, Bolten asserts that the application of magnetic plates for the cure of nervous and other affections is not only useless, but has, in many instances, been shown to greatly increase pain. This is proven by M. Fonseca in his _Journal_, which forms part of the above-named work; by Andry and Thouret (“Obs. et Rech sur ... l’Aimant ...” 8, pp. 599, 661), and by J. David Reuss (“Repertorium,” Vol. XII. p. 18), as well as by observations recorded in another very scarce work, translated into Dutch during 1775 by the celebrated physicist, J. R. Deimann, under the title of “Geneeskundige Proefneeming met den door Koast gemaakten Magneet, door den Heere T. C. Unzer.”

REFERENCES.--Magnetical cures by different processes are
treated of more particularly by Goclenius R., Jr., “Tract.
de Mag. Curatione ...” Marp., 1609; J. Robertus, “Curationis
Magneticæ ...” Luxemb., 1621, Coloniæ, 1622; Charlton, “A
Ternary of Paradoxes ...” London, 1650; G. Mascuelli, “De
Medicina Magnetica,” Franckfort, 1613, translated by W. Maxwell
(Maxvellus), 1679–1687; Tentzelius, “Medicina Diastatica
...” 1653; A. Van Leuwenhoeck (_Phil. Trans._, Vol. XIX for
1695–1697, as shown below); J. N. Tetens, “Schreiben ...
Magnetcuren,” Bützow and Wismar, 1775; Jacques de Harsu,
“Receuil des Effets ...” Geneva, 1783; W. Pigram, “Successful
Application ...” (_Phil. Mag._, Vol. XXXII. p. 154); Kloerich,
F. W., “Versuche ...” (“Götting. Anzeigen,” 1765), “Von dem
Medicin ...” Göttingen, 1766; M. Mouzin, “De l’emploi ...
Maladies,” Paris, 1843. See likewise A.D. 450, and Hell at A.D.
1770.

For Anthony Van Leuwenhoeck, consult the _Phil. Trans._ for
1695–1697, Vol. XIX. No. 227, p. 512; Vol. XXXII. p. 72; also
the abridgments of Reid and Gray, Vol. VI. p. 170, and of Eames
and Martyn, Vol. VI. part. ii. pp. 277–278.

=A.D. 1775.=--Volta (Alessandro), an Italian natural philosopher and Professor at the University of Pavia, who had already, in 1769, addressed to Beccaria a Latin dissertation, “De Vi Attractivâ ignis electrici,” etc., makes known his invention of the _electrophorus_, a sort of perpetual reservoir of electricity. This consists of two circular metallic plates having between them a round disc of resin, which is excited by being struck a number of times with either a silk kerchief or pieces of dry warm fur or flannel. During 1782 he discovered what he called an electrical condenser, wherein the disc of resin is replaced by a plate of marble or of varnished wood. With this he is reported (_Philosophical Transactions_, Vol. LXXII) to have ascertained the existence of negative electricity in the vapour of water, in the smoke of burning coals, and in the gas produced by a solution of iron in weak sulphuric acid. An account of the above named and of other discoveries, as well as of various experiments, appears in letters addressed by him to Prof. Don Bassiano Carminati, of the Pavia Medical University, April 3, 1792, and to Tiberius Cavallo, Sept. 13, and Oct. 25, 1792, as shown in the _Philosophical Transactions_ of the Royal Society, which institution gave him its gold Copley medal.

Volta’s crowning effort lies in the discovery of the development of electricity in metallic bodies and in the production of the justly famous pile which bears his name. The latter consisted of an equal number of zinc and copper discs separated by circular plates of cloth, paper or pasteboard soaked in salt-water or dilute acid, all being suitably connected to develop a large quantity of the electric fluid. Thus, says Dr. Dickerson in his address at Princeton College, Volta gave to the world that new manifestation of electricity called Galvanism. In that form this subtle agent is far more manageable than in the form of static electricity; and by the use of galvanic batteries a current of low tension, but of enormously greater power, can be maintained with little difficulty; whereas static electricity is like lightning, and readily leaps and escapes on the surfaces on which it is confined.

“It was Volta who removed our doubtful knowledge. Such knowledge is the early morning light of every advancing science, and is essential to its development; but the man who is engaged in dispelling that which is deceptive in it, and revealing more clearly that which is true, is as useful in his place and as necessary to the general progress of science as he who first broke through the intellectual darkness and opened a path into knowledge before unknown” (Faraday’s “Researches”).

The last mentioned discovery, though made in 1796, was first announced only on the 20th of March, 1800, in a letter written from Como to Sir Joseph Banks, by whom it was communicated to the Royal Society. It was publicly read June 26, 1800 (_Phil. Trans._ for 1800, Part II. p. 408).

At pp. 428–429 of “La Revue Scientifique,” Paris, April 8, 1905, will be found a review of J. Bosscha’s work entitled “La correspondance de A. Volta et de M. Van Marum,” published at Leyden. Bosscha calls especial attention to letters numbered XIII and XIV, dated respectively August 30 and October 11, 1792, wherein Volta describes his construction of the apparatus which, as already stated, was not made known until March 20, 1800. M. Bosscha’s work is also referred to in the “Journal des Savants” for August 1905.

Volta, at about the same period, constructed an electrical battery, which has been named _La Couronne de Tasses_ (the crown of cups), and which consisted of a number of cups arranged in a circle, each cup containing a saline liquid and supporting against its edges a strip of zinc and one of silver. As the upper part of each zinc strip was connected by a wire with a strip of silver in the adjoining cup, the silver strip of the first cup and the zinc strip of the last cup formed the poles of the battery. It is said that twenty such combinations decomposed water, and that thirty gave a distinct shock.

On the 16th, 18th and 20th of November 1800 (Brumaire an. IX), Volta, who had obtained permission of the Italian Government to go to Paris with his colleague Prof. Brugnatelli, delivered lectures and experimented before the French National Institute (Sue, “Histoire du Galvanisme,” Vol. II. p. 267). As a member of the latter body, Bonaparte, the First Consul, who had attended the second lecture and witnessed the electro-chemical decomposition of water, proposed that a gold medal be stuck to commemorate Volta’s discovery, and that a commission be formed to repeat all of Volta’s experiments upon a large scale. The commission embraced such prominent men as Laplace, Coulomb, Hallé, Monge, Fourcroy, Vauquelin, Pelletan, Charles, Brisson, Sabathier, Guyton De Morveau and Biot. Biot, the chairman of the commission, made a report December 11, 1800, which appears in Vol. V of the _Mémoires de l’Institut National de France_, as well as in the _Annales de Chimie_, Vol. XLI. p. 3. In addition to the gold medal, Volta received from Bonaparte the sum of six thousand francs and the cross of the Legion of Honour.

To Volta has been attributed the fact of having, as early as 1777, entertained the idea of an electric telegraph, although nothing more appears to be on record in relation to the matter. Fahie quotes a letter of Sir Francis Ronalds, alluding to an autograph manuscript, dated Como, April 15, 1777, and gives its translation by César Cantu, wherein Volta states that he does not doubt the possibility of exploding his electrical pistol at Milan, through wires supported by posts, whenever he discharges a powerful Leyden jar at Como.