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.

REFERENCES.--Arago, “Eloge Historique de Volta” and “Notices

Biographiques,” Tome I. p. 234 (“Raccolta Pratica di Scienze,”

etc. for March and April 1835); London _Times_ of January 26,

1860; the eulogies pronounced by Giorn. Fogliani at Como and

by G. Zuccala at Bergamo, the year of Volta’s death, 1827; P.

Sue, “Histoire du Galvanisme,” Tome II. p. 267; _Journal de

Leipzig_, Tome XXXIV; _Scelta d’ Opuscoli_, Vols. VIII. p.

127; IX. p. 91; X. p. 87; XII. p. 94; XIV. p. 84; XXVIII. p.

43; XXXIV. p. 65; _Opuscoli Scelti_, Vols. I. pp. 273, 289;

VII. pp. 128, 145; XV. pp. 213, 425; XXI. p. 373; “Mem. dell’

I. R. Istit. Reg. L. V.,” Vol. I. p. 24; “Mem. dell’ Istit.

Nazion. Ital.,” Vol. I. p. 125; “Memor. Soc. Ital.,” Vols. II.,

pp. 662, 900; V. p. 551; “Bibl. Fisica d’Europa” for 1788;

“Giornale Fis.-Med.,” Vols. I. p. 66; II. pp. 122, 146, 241,

287; III. p. 35; IV. p. 192; V. p. 63; “Giornale dell’ Ital.

Lettera,” etc., Vol. VIII. p. 249; L. V. Brugnatelli, “Annali

di Chimica,” etc., Vols. II. p. 161; III. p. 36; V. p. 132;

XI. p. 84; XIII. p. 226; XIV. pp. 3, 40; XVI. pp. 3, 27, 42;

XVIII. pp. 3, 7; XIX. p. 38; XXI. pp. 79, 100, 163; XXII. pp.

223–249 (Aless. Volta and Pietro Configliachi); Aless. Volta

and Angelo Bellani, “Sulla formazione,” etc., Milano, 1824; F.

A. C. Gren, _Neues Journal der Physik_, Vols. III and IV for

1796 and 1797; Rozier, _Observ._, Vols. VII, XXII and XXIII for

1776, 1873; J. B. Van Mons, _Journal de Chimie_, No. 2, pp. 129,

167; Sédillot, “Receuil Per. de la Soc. de Méd. de Paris,” IX.

pp. 97, 231; _Journal de Phys._, Vols. XXIII. p. 98; XLVIII.

p. 336; LI. p. 334; LXIX. p. 343; _Annales de Chimie_, Vols.

XXX. p. 276; XLIV. p. 396; _Nicholson’s Journal_, Vol. XV. p.

3; _Phil. Tr._ for 1778, 1782 and 1793; “Soc. Philom.,” An.

IX. p. 48, An. X. p. 74; “Bibl. Brit.,” Vol. XIX. p. 274; _Le

Correspondant_ for August, 1867, p. 1059, and _Les Mondes_,

December 5, 1867, p. 561; Highton, “The Elec. Tel.,” 1852,

pp. 13 and 28; Robertson, “Mémoires Récréatifs,” 1840, Vol.

I. chaps, x. and xiii.; Miller, “Hist. Philos. Illustrated,”

London, 1849, Vol. IV. p. 333, note; Achille Cazin, “Traité

théorique et pratique des piles électriques,” Paris, 1881;

“Mémoires de l’lnstitut” (Hist.) An. XII. p. 195; Andrew Crosse,

“Experiments in Voltaic Electricity,” London, 1815 (_Phil.

Mag._, Vol. XLVI. p. 421, and Gilbert’s “Annalen,” Bd. s. 60);

“Lettere sulla Meteorol.,” 1783; Theod. A. Von Heller, in Gilb.

“Annal.,” Vols. IV and VI, 1800; and _Gren’s Neues Journ._,

1795, 1797; “L’Arc Voltaique,” by M. Paul Janet, in “Revue

Générale des Sciences,” May 15, 1902, pp. 416–422; “L’Académie

des Sciences,” par Ernest Maindron, Paris, 1888, pp. 245–251;

“Philosophical Magazine,” Vol. IV. pp. 59, 163, 306; Vol. XIII.

pp. 187–190 [_re_ prize founded by Napoleon); Vol. XXI. p. 289

(electrophorus); Vol. XXVIII. p. 182 (theory of Pierre Hyacinthe

Azais), and p. 297 (Paul Erman on “Voltaic Phenomena”); Thomson,

“Hist. of Chemistry,” Vol. II. pp. 251–252; “Dict. de Gehler,”

Vols. III. p. 665; VI. pp. 475, 484; Thomas Thomson, “Hist. of

the Royal Soc.,” London, 1812, p. 451; Young’s “Lectures,”

Vol. I. pp. 674, 677, 678, 683; see likewise the “Theory of

the Action of the Galvanic Pile,” as given by Dr. Wm. Henry

at s. 5 Vol. I. of his “Elements of Experimental Chemistry,”

London, 1823; also _Nicholson’s Journal_ for Henry’s essay in

Vol. XXXV. p. 259; M. De Luc’s papers in Vol. XXXII. p. 271,

and Vol. XXXVI. p. 97; Mr. Singer on the “Electric Column” in

Vol. XXXVI. p. 373; Dr. Bostock’s essay in Thomson’s “Annals,”

Vol. III. p. 32; Sir H. Davy’s chapter on “Electrical Attraction

and Repulsion,” in his “Elements of Chem. Philos.,” p. 125;

the first volume of Gay-Lussac and Thénard’s “Recherches”;

Johann Mayer, “Abhandlungen ... Galvani, Valli, Carminati u.

Volta,” etc., Prague, 1793; _Lehrbuch der Meteor._, von L. F.

Kaemtz, Halle, 1832, Vol. II. pp. 398, 400, 418; M. Detienne

et M. Rouland in _Jour. de Phys._, Vol. VII. for 1776; J.

N. Hallé, “Exposition Abrégée,” etc. (“Bull. des Sc. de la

Soc. Philom.,” An. X. No. 58); C. B. Désormes’ very extended

observations recorded in the _An. de Ch._, Vol. XXXVII. p. 284;

Volta’s letter to Prof. F. A. C. Gren in 1794, and Wilkinson,

“El. of Galv.,” Vol. II. pp. 314–325; J. F. Ackerman (“Salz.

Mediechirurg,” 1792, p. 287); Cadet (_An. de Ch._, Vol. XXXVII.

p. 68); letter written by Volta to M. Dolomieu (“Bull. de la

Société Philom.,” No. 55, p. 48); Friedlander’s “Experiments”

(_Jour. de Phys._, Pluvoise, An. IX. p. 101); Paul Erman (_Jour.

de Phys._, Thermidor, An. IX. p. 121); Gilbert’s “Annalen,”

VIII, X, XI, XIV); _Jour. de Phys._, Tome LIII p. 309; _Jour. de

Médecine_, Nivose, An. IX. p. 351; P. C. Abilgaard,“Tentamina

Electrica”; C. H. Wilkinson, “Elements of Galvanism,” etc.,

London, 1804, 2 vols. _passim_; A. W. Von Hauch’s Memoir read

before the Copenhagen Acad. of Sc. (Sue, “Hist. du Galv.,” 1802,

Vol. II. p. 255); Alexander Nicoläus Scherer’s Journal, 31st

book; “Abstracts of Papers of Roy. Soc.,” Vol. I. p. 27; also

Hutton’s abridgments of the _Phil. Trans._ Vol. XV. p. 263;

Vol. XVII. p. 285; Vol. XVIII. pp. 744, 798; _Phil. Magazine_,

Vol. IV. pp. 59, 163, 306; “Bibliothèque Britannique,” Genève,

1796, Vol. XV. an. viii. p. 3; Vol. XIX for 1802, pp. 270,

274, 339; Vol. XVI, N.S. for 1821, pp. 270–309; account of the

immense electrophorus constructed for the Empress of Russia, in

Vol. I. of “Acta Petropolitana” for 1777, pp. 154, etc. In the

_Philosophical Transactions_ for 1778, pp. 1027, 1049, will be

found Ingen-housz’s paper relating to the then recent invention

of Volta’s _electrophorus_ and to Mr. Henley’s experiments. It

is said that at about this time (1778), John Jacob Mumenthaler,

Swiss mechanic, constructed very effective electrophori and

electric machines out of a very peculiar kind of paper. M. F.

Vilette also made a paper electrophorus which is alluded to by

J. A. Nollet (“Experiments Letters,” Vol. III. pp. 209, etc.).

Consult, besides, Carlo Barletti, “Lettera al Volta ...” Milano,

1776; W. L. Krafft, “Tentatem theoriæ ...” Petropol, 1778; J. C.

Schäffer, “Abbild. Beschr. d. elek. ...” Regensberg, 1778; Georg

Pickel, “Experimenta physico-medica ...” Viceburgi, 1778–1788;

J. A. Klindworth, “Kurze Beschr. ...” Gotha, 1781–1785;

(Lichtenberg’s “Magazin,” I. 35–45;) while for Klindworth, M.

Obert and M. Minkeler, see the “Goth. Mag.,” I. ii. p. 35; V.

iii. pp. 96, 110; E. G. Robertson, “Sur l’électrophore résineux

et papiracé,” Paris, 1790; (_Journal de Physique_, Vol. XXXVII;)

M. Robert on the electrophorus (Rozier, XXXVII. p. 183); S.

Woods, “Essay on the phenomena ...” London, 1805; (_Phil. Mag._,

Vol. XXI. p. 289;) M. Eynard’s “Mém. sur l’electrophore,” Lyon,

1804; John Phillips, “On a modification of the electrophorus,”

London, 1833 (_Phil. Mag._, s. 3, Vol. II); G. Zamboni, “Sulla

teoria ...” Verona, 1844 (“Mem. Soc. Ital.,” Vol. XXIII); F. A.

Petrina, “Neue theorie d. elect. ...” Prag., 1846.

=A.D. 1776.=--Borda (Jean Charles), French mathematician and

astronomer, improves upon the work of Mallet (at A.D. 1769), and is

the first to establish accurately the knowledge of the third and most

important element of terrestrial magnetism, viz. its _intensity_.

To him is exclusively due the correct determination of the difference

of the intensity at different points of the earth’s surface by

measuring the vibrations of a vertical needle in the magnetic meridian.

This he determined during his expedition to the Canary Islands, and his

observations were first confirmed through additional experiments which

the companion of the unfortunate La Pérouse, Paul de Lammanon, made

during the years 1785–1787, and which were by him communicated from

Macao to the Secretary of the French Academy.

REFERENCES.--Borda’s biography in the “Eng. Cycl.,” and in the

eighth “Britannica”; Walker, “Magnetism,” p. 182; Humboldt

on magnetic poles and magnetic intensity, embracing the

observations of Admiral de Rossel, and “Cosmos,” Vol. V. 1859,

pp. 58, 61–64, 87–100; also Vol. I. pp. 185–187, notes, for the

history of the discovery of the law that the intensity of the

force increases with the latitude; Norman (A.D. 1576).

=A.D. 1777.=--Lichtenberg (Georg Christoph), Professor of

Experimental Philosophy at the University of Göttingen, reveals the

condition of electrified surfaces by dusting them with powder.

The _figures_, which bear his name, are produced by tracing any desired

lines upon a cake of resin with the knob of a Leyden jar and by

dusting upon the cake a well-triturated mixture of sulphur and of red

lead. These substances having been brought by friction into opposite

electrical conditions, the sulphur collects upon the positive and the

lead upon the negative portions of the cake: positive electricity

producing an appearance resembling feathers, and negative electricity

an arrangement more like stars.

REFERENCES.--Harris, “Frict. Elect.,” p. 89; eighth

“Britannica,” Vol. VIII. p. 606; E. Reitlinger, “Sibven Abh.

...” (Wien Acad.); illustrations in _Sc. Am. Suppl._, No. 207,

p. 3297; Noad, “Manual,” p. 132; Erxleben’s “Physikalische

Bibliotek,” s. 514; L. F. F. Crell, _Chemische Annalen_ for

1786; “Göttingisches Magazin,” J i., S ii., pp. 216–220;

Lichtenberg’s “Math. u. Phys. Schriften,” etc., Vol. I. p. 478.

See also Dr. Young’s “Lectures on Nat. Phil.,” London, 1807,

Vol. II. pp. 119, 419 for additional references, and p. 426 for

Lichtenberg’s “Table of Excitation.”

=A.D. 1777.=--Pringle (Sir John), a man of great scientific

attainments--who was physician to the Duke of Cumberland as well as to

the Queen’s household, became a baronet in 1766, and afterward received

many distinguished honours from foreign learned bodies--resigns the

Presidency of the English Royal Society, which he had held since the

year 1772. In this, as will be seen at a later date, he was succeeded

by Sir Joseph Banks (at A.D. 1820), who continued in the

office a period of over forty-two years. The cause which led to his

resignation is best given in the following extract from his biography

in the English Cyclopedia:

“During the year 1777 a dispute arose among the members of the Royal

Society relative to the form which should be given to electrical

conductors so as to render them most efficacious in protecting

buildings from the destructive effects of lightning. Franklin had

previously recommended the use of points, and the propriety of this

recommendation had been acknowledged and sanctioned by the Society

at large. But, after the breaking out of the American Revolution,

Franklin was no longer regarded by many of the members in any other

light than an enemy of England, and, as such, it appears to have been

repugnant to their feelings to act otherwise than in disparagement

of his scientific discoveries. Among this number was their patron

George III, who, according to a story current at the time, and of the

substantial truth of which there is no doubt, on its being proposed to

substitute knobs instead of points, requested that Sir John Pringle

would likewise advocate their introduction. The latter hinted that the

laws and operations of nature could not be reversed at royal pleasure;

whereupon it was intimated to him that a President of the Royal

Society entertaining such an opinion ought to resign, and he resigned

accordingly.”

In Benjamin Franklin’s letter to Dr. Ingen-housz, dated Passy, Oct.

14, 1777, occurs the following: “The King’s changing his _pointed_

conductors for _blunt_ ones is therefore a matter of small importance

to me. If I had a wish about it, it would be that he had rejected them

altogether as ineffectual.” It was shortly after the occurrence above

alluded to that the following epigram was written by a friend of Dr.

Franklin:

“While you Great George, for knowledge hunt,

And sharp conductors change for blunt,

The nation’s out of joint:

Franklin a wiser course pursues,

And all your thunder useless views,

By keeping to the _point_.”

Thomson informs us (“Hist. Roy. Soc.” pp. 446–447) that the Board

of Ordnance having consulted the Royal Society about the best mode

of securing the powder magazine, at Purfleet, from the effects of

lightning, the Society appointed Mr. Cavendish, Dr. Watson, Dr.

Franklin, Mr. Robertson and Mr. Wilson a committee to examine the

building and report upon it. These gentlemen went accordingly, and

the first four recommended the erecting of pointed conductors in

particular parts of the building, as a means which they thought

would afford complete security. Mr. Wilson dissented from the other

gentlemen, being of the opinion that the conductors ought not to be

pointed but blunt, because pointed conductors solicit and draw down

the lightning which might otherwise pass by. He published a long paper

on the subject, assigning a great variety of reasons for his preference

(_Philosophical Transactions_, Vol. LXIII. p. 49). It was this

dissent of Mr. Wilson which produced between the electricians of the

Royal Society a controversy respecting the comparative merits of

pointed and blunt conductors, which continued a number of years, and

a variety of papers in support of which made their appearance in the

_Philosophical Transactions_. The controversy, in fact, engaged

almost the exclusive attention of the writers on electricity for

several successive volumes of that work.

REFERENCES.--William Henley, “Experiments ... pointed and

blunted rods ...” in _Phil. Trans_, for 1774, p. 133; P. D.

Viegeron, “Mémoire sur la force des pointes ...”; Edward Nairne,

“Experiments ... advantage of elevated pointed conductors,” in

_Phil. Trans._ for 1778, p. 823; Lord Mahon, “Principles ...

superior advantages of high and pointed conductors,” London,

1779; Hale’s “Franklin in France,” 1880, Part I. p. 91, and

Part II. pp. 254–256, 279, for some of his other correspondence

with Dr. Ingen-housz; likewise Part II., pp. ix, 273, 441–451,

regarding the first publication of copies of letters written

by Franklin to Sir Joseph Banks, which “for some curious

reason,” Mr. Hale remarks, were not publicly read and were

never included in the _Philosophical Transactions_, as Franklin

intended they should be. Consult also Thomas Hopkinson on “The

Effects of Points,” etc., in Franklin’s “New Experiments,”

etc., London, 1754; Tilloch’s _Philosophical Magazine_ for

1820; Hutton’s abridgments, Vol. XIII. p. 382; “Memoir of Sir

J. Pringle” in Weld’s “Hist. of Roy. Soc.,” Vol. II. pp. 58–67,

102; Jared Sparks’ edition of Franklin’s “Works,” and Sir John

Pringle’s discourse delivered at the Anniversary Meeting of

the Royal Society, Nov. 30, 1774, a translation of the last

named appearing at p. 15, Vol. XV of the “Scelta d’ Opuscoli.”

J. Clerk Maxwell, “Electrical Researches of the Hon. Henry

Cavendish,” 1879, pp. 52–54.

=A.D. 1778.=--Martin (Benjamin), English artist and mathematician,

who had already written an “Essay on Electricity” and a prominent

supplement thereto (1746–1748), publishes an enlarged edition in three

volumes of his “Philosophia Britannica,” originally produced in 1759.

At Vol. I. p. 47 of the last-named work, he states that his experiments

indicate a magnetic force inversely as the square roots of the cubes

of the distances. Noad, treating of the laws of magnetic force, says

(“Electricity” p. 579) that Martin and Tobias Mayer both came to the

conclusion that the true law of the magnetic force is identical with

that of gravitation, and that, in the previous experiments of Hauksbee

and others, proper allowance had not been made for the disturbing

changes in the magnetic forces so inseparable from the nature of the

experiments.

His first Lecture explains all the phenomena of electricity and

magnetism, the appendix thereto detailing numerous experiments of

Mr. John Canton, and giving many additional facts concerning the

manufacture of artificial magnets. From his preface the following

extracts will, doubtless, prove interesting: “We are arrived at great

dexterity since Sir Isaac Newton’s time; for we can now almost prove

the existence of this _aether_ by the phenomena of electricity;

and then we find it very easy to prove that electricity is nothing

but this very _aether_ condensed and made to shine. But I believe,

when we inquire into the nature and properties of this _aether_ and

electricity, we shall find them so very different and dissimilar, that

we cannot easily conceive how they should thus mutually prove each

other.... I see no cause to believe that the matter of electricity is

anything like the idea we ought to have of the _spiritus subtilissimus_

of Sir Isaac.... The smell also of _electrical fire_ is so very much

like that of _phosphorus_, that we may be easily induced to believe a

great part of the composition of both is the same.”

REFERENCES.--“Encycl. Britan.,” 1857, Vol. XIV. p. 320; Antoine

Rivoire (Rivière), “Traité sur les aimants ...” Paris, 1752;

Nicolaus von Fuss, “Observations ... aimants ...” Petersburg,

1778; Le Noble, “Aimants artificiels ...” Paris, 1772, and

“Rapport ... aimants,” 1783 (Mém. de Paris); Wens, “Act. Hill,”

Vol. II. p. 264; C. G. Sjoestén (Gilbert, _Annalen der Physik_,

Vol. XVII. p. 325); Rozier, IX. p. 454.

=A.D. 1778.=--Toaldo (Giuseppe) Abbé, celebrated Italian physicist,

who had in 1762 been made Professor at the Padua University and was

the first one to introduce the lightning rod in the Venetian States,

makes known the merits of the last-named invention through his “Dei

conduttori per preservare gli edifizj,” etc., which work embraces

most of his previous treatises on metallic conductors as well as the

translation of H. B. de Saussure’s “Exposition abrégée,” etc., Geneva,

1771, and of M. Barbier de Tinan’s “Considérations sur les conducteurs

en général.”

The above was followed by many highly interesting memoirs containing

valuable meteorological observations, notably those in continuation of

the work of J. Poleni, made close up to the time of Toaldo’s sudden

death at Padua, Dec. 11, 1798. His complete works, covering the

period 1773–1798, were published in Venice through M. Tiato, with the

assistance of Vincenzo Chiminello, during the year 1802.

REFERENCES.--In addition to the last-named publication (entitled

“Completa Raccolta d’ Opuscoli,” etc.), “Mem. della Soc. Ital.,”

Vol. VIII. pt. i. p. 29 (“Elogio ... da A. Fabbroni,” 1799);

note at Beccaria, p. 42 of Ronalds’ “Catalogue”; Larousse,

“Dict. Universel,” Vol. XV. p. 251; “Biographie Générale,” Vol.

XLV. p. 450; “Biografia degli Italiani Illustri,” etc., by

E. A. Tipaldo, Vol. VIII; “Padua Accad. Saggi,” Vol. III. p.

cv; “Opusc. Scelti,” Vol. VI. p. 265; Vol. VII. p. 35; “Nuovo

Giornale Enciclopedico di Vicenza” for 1784; Antonio Maria

Lorgna, “Lettera ... parafulmini,” 1778; G. Marzari (Vol. II.

p. 73, of “Treviso Athenæum”); Fonda “Sopra la maniera ...”

Roma, 1770; G. Marzari e G. Toaldo, “Memoria Descrizione ...”

25 Aprile, 1786; Barbier de Tinan, “Mémoire sur la manière

d’armer,” etc., Strasbourg, 1780; F. Maggiotto’s letter to

Toaldo upon a new electrical machine; Sestier et Méhu, “De la

foudre,” etc., Paris, 1866.

Vincenzo Chiminello, nephew of Giuseppe Toaldo, whom he succeeded

at the Padua Observatory and who continued the _Giornale

Astro-meteorologico_ after his uncle’s death, is the author of works on

the magnetic needle, on lightning conductors, etc., which are treated

of in the columns of the _Mem. Soc. Ital._, Vols. VII and IX; the

_Giornale Astro-met._ for 1801, 1804, 1806, as well as in the _Saggi

... dell’Accad. di Padova_, _Nuova Scelta d’Opuscoli_, and _Opuscoli

Scelti sulle scienze e sulle arti_.

REFERENCES.--Chiminello’s biography, _Giorn. dell’Ital.

Lettera_, etc., Serie II. tome xvii. p. 164, and in “Atti della

Soc. Ital.,” Modena, 1819.

=A.D. 1778.=--Dupuis (Charles François), eminent French writer who, at

the age of twenty-four, became Professor of Rhetoric at the College of

Lisieux, constructs a telegraph upon the plan suggested by Amontons (at

A.D. 1704). By means of this apparatus he exchanged correspondence with

his friend M. Fortin, then residing at Bagneux, until the commencement

of the Revolution, when he deemed it prudent to lay it permanently

aside (_Encyclopædia Britannica_, 1855, Vol. VIII. p. 263).

=A.D. 1778.=--Brugmans--Brugman (Anton), who was Professor of

Philosophy at the University of Francker between 1755 and 1766,

publishes his “Magnetismus, seu de affinitatibus magneticis.” He is,

besides, the author of several works upon magnetic matter and the

magnetic influence, which appeared 1765–1784 and are alluded to by

Poggendorff (“Biog.-Liter. Hand.,” Vol. I. p. 316), as well as in the

“Vaderlandsche Letter” for 1775 and 1776, and at p. 34, Vol. I of Van

Swinden’s “Recueil de Mémoires ...” La Haye, 1784.

It was in this same year, 1778, that Sebald Justin

Brugmans--Brugman--son of Anton Brugmans, a distinguished physician,

naturalist and author who was the successor of Van Swinden at the

Francker University, and became Professor of Botany at Leyden,

discovered that cobalt is attracted while bismuth and antimony are

repelled by the single pole of a magnet, thus laying _the foundation

of the science of diamagnetism_.

Humboldt remarks: “Brugmans, and, after him, Coulomb, who was endowed

with higher mathematical powers, entered profoundly into the nature of

terrestrial magnetism. Their ingenious physical experiments embraced

the magnetic attraction of all matter, the local distribution of

force in a magnetic rod of a given form, and the law of its action at

a distance. In order to obtain accurate results the vibrations of a

horizontal needle suspended by a thread, as well as deflections by a

torsion balance, were in turn employed.”

REFERENCES.--“Biographie Générale,” Vol. VII. p. 582; Larousse,

“Dict. Univ.,” Vol. II. p. 1334; “Catalogue Sc. Papers Roy.

Soc.,” Vol. I. p. 672; W. H. Wollaston, “Magnetism of ... Cobalt

and Nickel” (_Edin. Phil. Jour._, Vol. X. p. 183); Kohl on pure

cobalt (L. F. F. Crell’s “Neusten Ent.,” Vol. VII. p. 39);

Tyndall, “Researches on Dia-Magnetism,” London, 1870, pp. 1, 90,

etc.; Appleton’s Encyclopædia, 1870, Vol. IV. p. 10; Humboldt’s

“Cosmos,” 1859, Vol. V. p. 61; Augustin Roux, “Expériences

nouvelles ...” (_Journal de Médecine_, for November 1773).

Consult also, for Sebald J. Brugmans, “Biog. Générale,” Vol.

VII. p. 582; Bory de Saint Vincent, in the “Annales Générales de

Sciences Physiques,” Vol. II.

=A.D. 1779.=--Lord Mahon, afterward third Earl of Stanhope, an

Englishman of great ingenuity and fertility in invention and a pupil

of Lesage of Geneva (at A.D. 1774), publishes his “Principles

of Electricity,” in which he explains the effects of the _return

stroke_ or _lateral shock_ of an electrical discharge which was

first observed by Benjamin Wilson (at A.D. 1746).

He imagined that when a large cloud is charged with electricity it

displaces much of that fluid from the neighbouring stratum of air,

and that when the cloud is discharged the electric matter returns

into that portion of the atmosphere whence it had previously been

taken. According to Lord Cavendish, the theory developed in the

above-named work is that “A positively electrified body surrounded

by air will deposit upon all the particles of that air, which shall

come successively into contact with it, a proportional part of its

_superabundant_ electricity. By which means, the _air_ surrounding the

body will also become _positively_ electrified; that is to say, it will

form round that positive body an electrical atmosphere, which will

likewise be positive.... That the _Density_ of all such atmospheres

decreases when the distance from the charged body is increased.”

Tyndall says (Notes on Lecture VII) that Lord Mahon fused metals and

produced strong physiological effects by the return stroke.

In 1781, the English scientist, John Turberville Needham (1713–1781),

published at Brussels his French translation of Lord Mahon’s work under

the title of “Principes de l’Electricité.” Needham was the first of the

Catholic clergy elected to a fellowship of the English Royal Society,

to whose Transactions he made several contributions. His numerous works

include “A letter from Paris concerning some new electrical experiments

made there,” London, 1746, also a volume of researches upon the

investigations of Spallanzani. The list of his communications to the

_Phil. Trans._ and to the “Mém. de l’Acad. de Bruxelles” will be found

in Watt’s “Bibliotheca Britannica” and in Namur’s “Bibl. Acad. Belge”

(“Dict. Nat. Biog.,” Vol. XL. p. 157; _Phil. Trans._, 1746, p. 247, and

Hutton’s abridgments, Vol. IX. p. 263).

REFERENCES.--“Electrical Researches” of Lord Cavendish, pp.

xlvi-xlvii; _Phil. Trans._ for 1787, Vol. LXXVII. p. 130; Dr.

Thomas Young, “Course of Lectures,” London, 1807, Vol. I. p.

664; Dr. Thomas Thomson, “History of the Royal Society,” London,

1812, p. 449; Sturgeon, “Researches,” Bury, 1850, p. 398.

=A.D. 1779.=--Ingen-housz (Johan), distinguished English physician and

natural philosopher, native of Breda, publishes, _Phil. Trans._, p.

661, an account of the electrical apparatus which is by many believed

to have led to the invention of the plate electrical machine, although

the same claim has been made in behalf of Jesse Ramsden (at A.D.

1768). Dr. Priestley states that Ingen-housz and Ramsden invented it

independently of one another. He describes a circular plate of glass

nine inches in diameter turning vertically and rubbing against four

cushions, each an inch and a half long and placed at the opposite

ends of the vertical diameter. The conductor is a brass tube bearing

two horizontal branches extending to within about half an inch of the

extremity of the glass, so that each branch takes off the electricity

excited by two of the cushions (Dr. Thomas Young, “Course of Lectures,”

Vol. II. p. 432).

The plate machine of Dr. Ingen-housz is illustrated at p. 16 of

“Electricity” in the “Library of Useful Knowledge.” For other plate

machines see, more particularly, Dr. Young’s “Course of Lectures,”

Vol. II. p. 431; _Phil. Trans._ 1769, p. 659; Geo. K. Winter’s

apparatus with ring conductor and peculiar-shaped rubbers, as well

as the great machine at the Royal Polytechnic, and that of Mr.

Snow Harris, illustrated and described in Vol. III. p. 787, “Eng.

Ency.--Arts and Sciences,” and at pp. 223, 224 of J. H. Pepper’s

“Cyclopædic Science,” London, 1869; “Allg. deutsche Biblioth.,” B.

XXIV. Anh. 4, Abth., p. 549, 1760 (Poggendorff, Vol. II. p. 465),

relative to the machines of Martin Planta, Ingen-housz and Ramsden;

Reiser’s plate machine (Lichtenberg and Voigt’s “Magazin für das

Neueste aus der Physik,” Vol. VII. St. 3, p. 73); Ferdinando Elice,

“Saggio sull’Elettricita,” Genoa, 1824 (for two electricities); J. J.

Metzger’s machine (Elice, “Saggio,” second edition, p. 55); Marchese

C. Ridolfi, for a description of Novelluccis’ plate electrical machine

(“Bibl. Italiana,” Vol. LXIII. p. 268; “Antologia di Firenze,” for

August 1824, p. 159); Robert Hare, “Description of an Electrical Plate

Machine,” London, 1823 (_Phil. Mag._, Vol. LXII. p. 8). See,

besides, the machines of Bertholon (rubber in motion) in Lichtenberg

and Voigt’s “Magazin,” Vol. I. p. 92 and Rozier XVI. p. 74; of Brilhac

(Rozier, XV. p. 377); of Saint Julien (Rozier, XXXIII. p. 367); of Van

Marum (Rozier, XXXVIII. p. 447).

Dr. Ingen-housz also constructed a small magnet, of several laminæ of

magnetised steel firmly pressed together, capable of sustaining one

hundred and fifty times its own weight, and he found that pastes into

the composition of which the powder of the natural magnet entered

were much superior to those made with the powder of iron; the natural

magnet, he observed, having more coercitive force than iron.

REFERENCES.--_Journal de Physique_ for February 1786, and for

May 1788, containing the letters of Dr. Ingen-housz, which

show that the vegetation of plants is in no sensible degree

either promoted or retarded by common electricity. An account

is also given of his experiments in “Versuche mit Plantzen,”

Vienna, 1778, in the “Catalogue of the Royal Society,” p.

313, in “Goth. Mag.,” Vol. V. iii. 13; Rozier, XXXII. p. 321;

XXXIV. p. 436; XXXV. p. 81; _Journal de Physique_, Vol. XXXV

for 1789. See also, _Journal de Physique_, XLV (II), 458;

Rozier, XXVIII. p. 81; M. Nuneberg, “Osservazioni ...” Milano,

1776 (“Scelta d’Opuscoli,” XVII. p. 113); Pietro Moscati,

“Lettera ...” Milano, 1781 (“Opus Scelti,” IV. p. 410); H. B.

de Saussure (_Journal de Physique_, Vol. XXV for 1784); G. da

San Martino, “Memoria ...” Vicenza, 1785; M. Schwenkenhardt,

“Von dem Einfluss ...” (Rozier, XXVII. p. 462; _Journal de

Physique_ for 1786, Vol. I); A. M. Vassalli-Eandi in the “Mem.

della Soc. Agr. di Torino,” Vol. I for 1786, particularly

regarding the experiments of Ingen-housz and Schwenkenhardt;

also in the “Giornale Sc. d’una Soc. Fil. di Torino,” Vol.

III; N. Rouland, “Elec. appliquée aux vegétaux” (_Journal de

Physique_, 1789–1790); Ingen-housz, Rouland, Dormoy, Bertholon

and Derozières (Rozier, XXXV. pp. 3, 161, 401; XXXVIII. pp. 351,

427, and in _Journal de Physique_, Vols. XXXII, XXXV, XXXVIII);

M. Carmoy, on the effects of electricity upon vegetation, in

Rozier, XXXIII. p. 339; _Jour. de Physique_ 1788, Vol. XXXIII;

M. Féburier, “Mémoire sur quelques propriétés ...”; G. R.

Treviranus, “Einfluss ...” Kiel, 1800 (Gilbert’s _Annalen_,

Vol. VII for 1801 and “Nordisches Arch. f. Nat. u. Arzneiw.,”

1st Band, 2tes Stück); C. G. Rafn (“Mag. Encyclopédique,” No.

19, Ventose An. X. p. 370), Paris, 1802; J. P. Gasc, “Mémoire

sur l’influence ...” Paris, 1823; E. Solly, “On the influence

...” London, 1845 (“Journ. of the Hortic. Society,” Vol. I. part

ii.); E. Romershausen, “Galv. El. ... Vegetation,” Marburg,

1851; M. Menon, “Influence de l’électricité sur la végétation,”

and his letters to R. A. F. de Réaumur. Consult likewise J.

Browning’s letter to H. Baker, Dec. 11, 1746 (_Phil. Trans._

for 1747, Vol. XLIV. p. 373); G. Wallerius, “Versuch ...”

Hamb. and Leipzig, 1754; (“K. Schwed. Akad. Abh.,” XVI. p.

257; also “Vetensk Acad. Handl.,” 1754;) L. F. Kamtz (Kaemtz),

“Über d. Elek ...” Nürnberg, 1829; (Schweigger’s _Journal f.

Chemie u. Physik_, Vol. LVI;) Bartolomeo Zanon, “Intorno un

punto ...” Belluno, 1840; Francesco Zantedeschi “Dell influsso

...” Venezia, 1843; (“Mem. dell Instit. Veneto,” I. p. 269;)

E. F. Wartmann, “Note sur les courants ...” Genève, 1850;

(“Bibl. Univ. de Genève,” for Dec. 1850;) T. Pine, “Connection

between Electricity and Vegetation,” London, 1840; (“Annals of

Electricity,” Vol. IV. p. 421.) For the effects of galvanism

on plants, see Giulio in “Bibl. Ital.,” Vol. I. p. 28; also

E. J. Schmuck “On the Action of Galvanic Electricity on the

_Mimosa Pudica_,” and M. Rinklake, as well as Johann W. Ritter,

“Elektrische versuche an der _Mimosa Pudica_.” For an account of

M. P. Poggioli’s observations on the influence of the _magnetic_

rays on vegetation, and the reply of F. Orioli thereto,

see Vol. I of the “Nuova collezione d’opuscoli scientifici

...” Bologna, 1817. Dr. Thomas Young’s “Course of Lectures,”

Vol. II. pp. 432–433; N. K. Molitor’s “John Ingen-housz.

Anfangsgrunde ...” 1781; Geo. Adams, “Lectures on Nat. and Exp.

Philosophy,” London, 1799, Vol. I. pp. 512–515; John Senebier,

“Expériences,” etc., 1st and 2nd Memoirs, Genève and Paris,

1788; Becquerel in the _Comptes Rendus_ for November 1850,

also Tome XXXI. p. 633; M. Buff (_Phil. Mag._ N. S. Vol. VII.

p. 122); Priestley’s “History ...” 1775, p. 487; Walsh at A.D.

1773; Cavallo’s “Exper. Philosophy,” 1803, Vol. III. p. 357;

Pouillet (Poggendorff’s _Annalen_, Vol. XI. p. 430); Reiss, in

Poggendorff’s _Annalen_, Vol. LXXIX. p. 288; G. F. Gardini, “De

inflvxu ...” s. 7, p. 10; _Philosophical Transactions_ for 1775,

1778, p. 1022; 1779, p. 537; _Journal de Physique_, Vol. XVI for

1780; “Erxleben’s phys. bibliothek,” s. 530; papers relative to

the effects of electricity upon vegetation alluded to in “Le

Moniteur Scientifique,” more particularly at pp. 904, 907, 1026,

Vol. XX for 1878, and at p. 23, Vol. XXI for 1879.

=A.D. 1780.=--Spallanzani (Lazaro), celebrated Italian naturalist,

to whom the French Republic vainly offered the Professorship of

Natural History at the Paris _Jardin des Plantes_, and who has been

already particularly alluded to in connection with John Walsh, at

A.D. 1773, writes a second treatise upon the operations of Charles

Bonnet, of Geneva, as regards the effects of electricity upon nerves

and muscles. He is also the author of works upon electrical fishes as

well as upon meteors, etc., which will be found detailed in Vol. VII

of the “Biographie Médicale,” as well as at Vol. XLIII. p. 246, of the

“Biographie Universelle.”

REFERENCES.--Alibert’s Eloge in Vol. III of the “Mém. de la Soc.

Médicale d’Emulation”; “Catal. Roy. Soc. Sc. Papers,” Vol. V. p.

767; “Opus. Scelti,” Vols. VII. pp. 340, 361; VIII. p. 3; XIV.

pp. 145, 296; Brugnatelli, “Ann. di chimica” for 1793 and 1795;

“Mem. Soc. Ital.,” Vols. II. p. 11; IV. p. 476.

=A.D. 1780–1781.=--Bertholon de Saint Lazare (Pierre), French

physician and Professor of Natural Philosophy, and a great friend of

Dr. Franklin, publishes at Paris his “Electricité du Corps Humain

...” in which he relates more particularly his general observations

upon atmospheric electricity as affecting the human body while in a

healthy state and while in a diseased condition. He likewise treats of

the effects of electricity upon animals, and details very interesting

experiments upon the _torpedo_, which latter, he remarks, establishes

the closest possible resemblance to the Leyden phial.

He is also the author of “Electricité des Végétaux” (1783), as well

as of “Electricité des Météores” (1787), and of a volume entitled

“Electricité des Métaux.” J. C. Poggendorff says (“Biog.-Lit. Handw.

...” Vol. II. p. 102) that J. Ferd. Meidinger (1726–1777) had

previously written concerning the action of electric fire upon metals

and minerals. Johann Jacob Hemmer published, at Mannheim in 1780, “Sur

l’Electricité des Métaux” (“Ob. sur la Physique,” July 1780, p. 50),

and A. A. De La Rive wrote in 1853 “De l’Elect. Développée ...” (“Bibl.

Univ.,” Vol. LIX).

REFERENCES.--Young’s “Course of Lectures,” Vol. II. p. 431;

Ingen-housz at A.D. 1779; _Journal de Physique_, Vol. XXXV;

“Biographie Universelle,” Vol. IV. p. 149; “Biographie

Générale,” Vol. V. p. 722; Larousse, “Dict. Univ.,” Vol.

II. p. 618; “La Grande Encyclopédie,” Vol. VI. p. 450. See

also Bertholon’s “Nouvelles Preuves ...” pp. 18–19; Arago,

“Notices Scientifiques,” Vol. I. pp. 338–340, 386; “Mercure

de France,” 1782, No. 52, p. 188; Abbé d’Everlange de Wittry,

“Mém. sur l’Elec. ... dans les végétaux et le corps humain,”

read June 24, 1773--“Anc. Mém. de l’Acad. Belge,” Vol. I.

p. 181; Vassalli-Eandi, “Esame della Elett. delle Meteore

del Bertholon,” Torino, 1787; account of the experiments to

ascertain the effects of electricity on vegetation, made in

France during the summer of 1878 by MM. Grandeau, Celi and

Leclerc; and a curious publication, “Les Animaux et les Métaux

deviennent ils Electriques par communication,” by L. Béraud

(Bérault), alluded to in Poggendorff, Vol. I. p. 146.

=A.D. 1780–1783.=--Prof. Samuel Williams, at Cambridge, Mass., makes

the earliest known observations of the magnetic dip in the United

States, and publishes them in the “Memoirs of the American Academy of

Arts,” Vol. I. pp. 62, 68. According to this authority, the dip in 1783

was 69° 41’. The next dip observations are those made during Long’s

expedition to the Rocky Mountains in 1819.

REFERENCES.--“American Journal of Science,” Vol. XLIII. pp. 93,

94; “Trans. Amer. Phil. Soc.,” O. S., Vol. III. p. 115.

=A.D. 1780–1794.=--Le Père Amyot (Amiot), learned French Jesuit,

who was sent in 1751 as a missionary to Pekin, where he resided till

his decease in 1794, writes, on the 26th of July 1780, and also on

the 20th of October 1782 that, as a result of a great number of

observations, he finds no change in the variation of the magnetic

needle, _i. e._ that “the point which indicates the north declines

westerly from 2 to 2½ degrees, rarely more than 4½ degrees, and never

less than 2 degrees.”

REFERENCES.--“Mémoires concernant l’histoire,” etc., Saillant et

Nyon, Vol. X. p. 142; Davis, “The Chinese,” Vol. III. p. 13.

=A.D. 1781.=--The so-called compass plant (_Silphium lancinatum_) is

first introduced from America into Europe by M. Thouin and blooms for

the first time in the Botanic Gardens of Upsala, Sweden.

In the “Scientific American” of February 26, 1881, reference is made

to the interesting account of this plant given by Sir J. D. Hooker

in Curtis’ “Botanical Magazine,” as well as to the following extract

from Prof. Asa Gray’s report concerning it: “The first announcement

of the tendency of the leaves of the compass plant to direct their

edges to the north and south was made by General (then Lieutenant)

Alvord, of the U.S. Army, during the year 1842, and again in 1844, in

communications to the American Association for the Advancement of

Science.... The lines in “Evangeline” (familiar to many readers):

“Look at this delicate plant that lifts its head from the meadow,

See how its leaves all point to the north as true as the magnet;

It is the compass plant that the finger of God has suspended,

Here on its fragile stalk, to direct the traveller’s journey,

Over the sealike, pathless, limitless waste of the desert----”

were inspired through a personal communication made by General Alvord

to the poet Longfellow.

In this connection, the following article, headed “A Wonderful Magnetic

Plant,” translated from _La Nature_ by the London _Court Journal_, will

prove interesting: “There has been discovered in the forests of India a

strange plant (_Philotacea electrica_) which possesses to a very high

degree astonishing magnetic power. The hand which breaks a leaf from

it receives immediately a shock equal to that which is produced by the

conductor of an induction coil. At a distance of six metres a magnetic

needle is affected by it, and it will be quite deranged if brought

near. The energy of this singular influence varies with the hours

of the day. All powerful about two o’clock in the afternoon, it is

absolutely annulled during the night. At times of storm its intensity

augments to striking proportions. While it rains the plant seems to

succumb: it bends its head during a thunder-shower and remains without

force or virtue even if one should shelter it with an umbrella. No

shock is felt at that time in breaking the leaves, and the needle is

unaffected by it. One never by any chance sees a bird or insect alight

on this electric plant; an instinct seems to warn them that in so doing

they would find sudden death. It is also important to remark that where

it grows none of the magnetic metals are found, neither iron, nor

cobalt, nor nickel--an undeniable proof that the electric force belongs

exclusively to the plant. Light and heat, phosphorescence, magnetism,

electricity, how many mysteries and botanical problems does this

wondrous Indian plant conceal within its leaf and flower!”

The results of some interesting researches on plant-electricity have

been reported by A. D. Waller, who finds that whenever a plant is

wounded, a positive electric current is established between the wounded

part and the intact parts. This may start with an electromotive force

of 0·1 volt, but it afterward diminishes. He writes further:

“Actual wounding is not necessary to obtain this manifestation; an

electro-positive current is set up when there is mechanical excitation,

but it is much weaker (0·02 volt). And light acts like mechanical

excitation with certain plants, such as the leaves of the iris, of

tobacco, of the begonia, etc. From the illuminated to the darkened

part flows a positive electric current that may be as strong as

0·02 volt. A similar reaction in the petals is not always observed.

There is a certain correlation between the vigour of a plant and the

electric reaction. The more vigorous the plant is, the stronger the

current. Plants grown from fresh seeds give a more powerful current

than those from old seeds. A bean a year old gave a current of 0·0170

volt; one five years old, a current of 0·0014; and the reaction is

inversely and regularly proportional to the age of the seed from

which the plant springs. There is observed in vegetable tissues,

subjected to an excitation of the same intensity at regular intervals,

the characteristic changes of reaction that are present in animal

tissues--fatigue, recuperation, etc. Temperature plays a part in all

these phenomena; below -4° to -6° C. [+° to + 25° F.] and above 40° C.

[108° F.] there is no reaction.”

=A.D. 1781.=--Lavoisier (Antoine Laurent), an eminent French natural

philosopher, the chief founder of modern chemistry as well as of

the prevailing system of chemical nomenclature which ended in the

expulsion of the phlogistic theory, demonstrates by experiments made in

conjunction with Volta and Laplace that electricity is developed when

solid or fluid bodies pass into the gaseous state. Sir David Brewster

says that the bodies to be evaporated or dissolved were placed upon an

insulating stand and were made to communicate by a chain or wire with a

Cavallo electrometer, or with Volta’s condenser, when it was suspected

that the electricity increased gradually. When sulphuric acid, diluted

with three parts of water, was poured upon iron filings, inflammable

air was disengaged with a brisk effervescence; and, at the end of a

few minutes, the condenser was so highly charged as to yield a strong

spark of negative electricity. Similar results were obtained when

charcoal was burnt on a chafing dish, or when fixed air or nitrous gas

was generated from powdered chalk by means of the sulphuric and nitrous

acids.

The phlogistic theory alluded to above, which was so named by George

Ernest Stahl in 1697 after Johann Joachim Beccher (1635–1682) had

pointed out its principle in 1669, had for its most energetic defender

the editor of the _Journal de Physique_, M. J. C. De La Méthérie,

who is entered at A.D. 1785, and it was in order to offset the

influence which this gave him that the antiphlogistians established the

_Annales de Chimie_, so frequently mentioned in these pages.[52]

REFERENCES.--George Adams’ “Lectures on Nat. and Exp.

Philosophy,” London, 1799, Vol. I. pp. 575–587, wherein

Lavoisier’s system is confuted by the German chemist Wieglib,

whose views are endorsed by Mr. Green, while for Stahl and

Beccher, refer to Sir H. Davy, “Bakerian Lectures,” London,

1840, p. 102, note, to “Biog. Gén.,” Vol. V. pp. 85–87; “Meyer’s

Konvers. Lexikon,” Vol. II. p. 654, and to Thomson’s “Hist. of

Roy. Soc.,” London, 1812, p. 467. See also J. M. G. Beseke,

“Ueber elementärfeuer ...” Leipzig, 1786; G. A. Kohlreif,

“Sollte die elektricität ...” Weimar, 1787; Lavoisier and

Laplace, in the “Mém. de l’Acad. Roy. des Sciences” for 1781, p.

292; Lavoisier’s “Opuscules ...” 1774, and his “Rapport ... mag.

animal.,” Paris, 1784; Dr. Thomas Thomson, “Hist. Roy. Soc.,”

pp. 479–486; Herschel’s “Nat. Phil.,” concerning the third age

of chemistry; Grégoire, “Dict. d’hist.,” etc., p. 1171; Miller’s

“Hist. Phil. Illus.,” London, 1849, Vol. IV. pp. 332–333,

notes. Chap. IV of the “History of Chemistry,” Ernst Van Meyer,

tr. by George McGowan, London, 1898, entitled “History of the

Period of the Phlogiston Theory from Boyle to Lavoisier,” will

prove interesting. “La chimie constituée par Lavoisier,” Jacob

Volhard, in “Le Moniteur Scientifique,” du Dr. Quesneville, Vol.

XIV for 1872, pp. 50–71; “Nouveau Larousse,” Vol. V. p. 608;

“La Révolution chimique,” M. Berthelot, Paris, 1890; “Essays in

Historical Chemistry,” T. E. Thorpe, London, 1894, pp. 87, 110;

“Journal des Savants” for Nov. 1859 and Feb. 1890; “Lives of Men

of Letters and Science,” by Henry, Lord Brougham, Philadelphia,

1846, pp. 140–166.

=A.D. 1781.=--Achard (Franz Carl), able chemist and experimental

philosopher, born in Prussia but of French extraction, communicates

to the “Mém. de Berlin” a report of many very interesting experiments

made by him, which are reviewed by Prince Dmitri Alexewitsch Fürst

Gallitzin, in Vol. XXII of the _Journal de Physique_.

He had previously published essays upon the electricity of ice and

the electricity developed on the surface of bodies, as well as upon

terrestrial magnetism, the electrophorus, etc. He made many notable

investigations to prove that fermentation is checked by electricity and

that putrefaction is hastened both in electrified meats and in animals

killed by the electric shock.

One of his experiments illustrating galvanic irritation so greatly

interested Humboldt that the latter repeated it with different animals,

not doubting but small birds might in many cases be brought back to

life when they fall into a state somewhat resembling death. On one

occasion, he took a linnet about to expire and, having established

the necessary communication, perceived, the moment the contact took

place, that the linnet opened its eyes, stood erect upon its feet and

fluttered its wings; it breathed, he says, during six or eight minutes

and then expired tranquilly.

It was a namesake of Achard who invented the electro-magnetic brake

which will be found described and illustrated in articles from the

London _Engineer_ and _Engineering_, reproduced through the

_Scientific American Supplements_, No. 111, p. 1760, and No. 312,

p. 4974.

REFERENCES.--Poggendorff, “Biog.-Lit. Hand. ...” Vol. I. p.

7; “Biographie Générale,” Vol. I. p. 176; “Cat. Roy. Soc. Sc.

Papers,” Vol. I. p. 9; “Opus. Scelt.,” Vols. III. p. 313; V. p.

351; VI. p. 199; Reuss, _Repertorium_, Vol. IV. p. 351; Dr. G.

Gregory, “Economy of Nature,” London, 1804, Vol. I. p. 317; Van

Swinden, “Recueil ...” La Haye, 1784, Vol. I. p. 24; “Biographie

Universelle,” Vol. I. p. 114; “Journal Lit. de Berlin,” for

1776; Cavallo, London, 1777, p. 403; “Mém. de Berlin” for

1776–1780, 1786, 1790–1791; Sturgeon, “Lectures,” London, 1842,

p. 12; Geo. Adams, “Essay on Electricity,” etc., London, 1785,

pp. 214–220, 277; “Gött. Mag.,” Vol. II. ii. 139; Rozier, VIII.

p. 364; XV. p. 117; XIX. p. 417; XXII. p. 245; XXIII. p. 282;

XXV. p. 429; XXVI. p. 378; _Phil. Mag._, Vol. III. p. 51.

=A.D. 1781.=--Kirwan (Richard), LL.D., F.R.S., an Irish chemical

philosopher of great eminence, who became President of the Dublin

Society and of the Royal Irish Academy, receives from the English

Royal Society its gold Copley medal for the many valuable scientific

papers communicated by him to the latter body. These papers embrace his

“Thoughts on Magnetism,” wherein he treats at length of attraction,

repulsion, polarity, etc., as shown in the review given at pp. 346–353

of the eighth volume of Sturgeon’s “Annals of Electricity,” etc.

It is said that Kirwan first suggested the notion of molecular magnets,

but, according to Dr. J. G. M’Kendrick, it was not till a definite form

was given thereto by Weber that it acquired any importance.

REFERENCES.--_Transactions Royal Irish Academy_, Vol. VI; Ninth

“Encycl. Britannica,” Vol. XV. p. 276; _Phil. Mag._, Vol. XXXIV.

p. 247; Thomson, “Hist. of the Roy. Soc.,” p. 483; “Bibl.

Britan.,” An. VII. vol. xii. p. 105.

=A.D. 1781.=--Mauduyt (Antoine René) (1731–1815), Professor at

the Collège de France, publishes several observations from which he

concludes that the application of electricity is favourable in cases of

paralysis. He was in the habit of placing the patient upon an insulated

stool, in communication with the conductor of an electrical machine.

De La Rive, who mentions the fact (“Electricity,” Chap. III. pp. 586,

587), observes that the effect, if any, could only proceed from the

escape of electricity into the air.

REFERENCES.--Bertholon, _Elec. du Corps. Humain_, 1786, Vol.

I. pp. 275–276, 302, 439, 447, etc., and Vol. II. pp. 7 and

296; “Mémoire sur les différentes manières d’administrer

l’électricité,” etc., Paris, 1784; “Recueil sur l’électricité

médicale,” etc., containing articles by G. F. Bianchini, De

Lassoné, Deshais (_see_ Sauvages), Dufay, Jallabert, Pivati,

Quellmalz, Veratti, Zetzell, etc.; K. G. Kuhn’s works published

at Leipzig, 1783–1797; E. Ducretet in “Le Cosmos,” Paris, Oct.

3, 1891, pp. 269–272; P. Sue, aîné, “Hist. du Galvan,” Paris,

An. X-XIII, 1802, Vol. I. p. 40; and Vol. II. p. 382; “Grande

Encyclop.,” Vol. XXIII. p. 415.

=A.D. 1781–1783.=--Don Gauthey--Gauthier or Gualtier--a monk of the

Order of Citeaux, improved upon the invention of Dupuis (at A.D. 1778)

and constructed a telegraph, which he submitted at the Académie des

Sciences to Dr. Franklin as well as to Condorcet and De Milly, by

whom it was recommended to the French Government. In his prospectus,

published during 1783, he relates that he has discovered a new

mode of rapid transmission enabling him to convey intelligence and

sound, by means of water pipes, a distance of fifty leagues in fifty

minutes. Ternant, who states this at pp. 33 and 34 of _Le Télégraphe_,

Paris, 1881, adds that, as no action was taken at the time upon the

prospectus, it doubtless still lies in the archives of the Academy.

REFERENCES.--Laurencin, _Le Télégraphe_, p. 9; Eng. Cycl., “Arts

and Sciences,” Vol. VIII. p. 65; “Penny Cycl.,” 1842, Vol. IV.

p. 146.

=A.D. 1782.=--Nairne (Edward), an English mathematical instrument

maker, publishes papers on electricity describing his invention of a

cylinder machine which is illustrated and described at p. 15 of the

chapter on “Electricity” in “Library of Useful Knowledge,” 1829. In

this, as has been truly said, are seen all the essential parts of the

frictional apparatus now in use.

This machine, according to Cuthbertson, was originally constructed

in 1774, and was far more powerful than any before made. Nairne also

constructed the largest battery known up to that time. It contained 50

square feet of coated surface, and it could be given so high a charge

as to ignite 45 inches of iron wire ¹⁄₁₅₀ of an inch diameter, which up

to that period was the greatest length of wire ever ignited. Nairne,

while improving upon some of Priestley’s experiments, found that a

piece of hard drawn iron wire, ten inches long and one-hundredth of an

inch diameter, after receiving successively the discharge of 26 feet

of coated glass (nine jars), was shortened three-fortieths of an inch

by such discharge. Dr. Priestley had previously observed that a chain

28 inches long was shortened one quarter of an inch after having had

transmitted through it a charge of 64 square feet of coated glass, and

Brooke Taylor found that by passing a charge of nine bottles of 16

feet of coated surface nine times in succession through a steel wire

12 inches long and one one-hundredth of an inch diameter, the wire was

shortened one and one-half inches, or one-eighth its entire length.

To Nairne was granted the third English patent in the Class of

Electricity and Magnetism, the first having been issued to Gowin

Knight in 1766 (see A.D. 1746) and the second to Gabriel Wright, June

25, 1779, for “a new constructed azimuth and amplitude compass.” Knight

subsequently covered other similar inventions, July 5, 1791, and Jan.

19, 1796. Nairne’s patent bears date Feb. 5, 1782, No. 1318, and is

for what he calls “The Insulated Medical Electrical Machine,” the

conductors of which are so arranged as to readily give either shocks or

sparks. He says that “by means of the conductors and jointed tubes, the

human body can be in any part affected with either kind of electricity

in any convenient manner.”

REFERENCES.--_Philosophical Transactions_ for 1772, 1774,

1778, 1780, 1783, Vol. LXIV. p. 79; Vol. LXVIII. p. 823; Vol.

LXX. p. 334; also Hutton’s abridgments, Vol. XIII. pp. 360

(dipping needle), 498; Vol. XIV. pp. 427–446, 688; Vol. XV.

p. 388; “General Biog. Dict.,” London, 1833, by John Gorton,

Vol. I. (n. p.); Cuthbertson, “Practical Electricity,” London,

1807, pp. 165–168; article “Electricity,” in the “Encycl.

Britannica”; “Description of ... Nairne’s ... Machine,” London,

1783 and 1787; Caullet de Veaumorel, “Description de la machine

électrique négative et positive de Mr. Nairne,” Paris, 1784;

Delaunay’s “Manuel,” etc., Paris, 1809, pp. 7, 12–14.

=A.D. 1782–1783.=--Linguet (Simon, Nicolas, Henri), French advocate

(1736–1794), who was an associate of Mallet du Pan in the preparation

of the _Annales Politiques_ and who was later on committed to the

Bastille in consequence of a visit which he imprudently made to Paris,

writes a letter to the French Ministry proposing a novel method of

transmitting messages of any length or description by means of some

kind of a telegraph, “nearly as rapidly as the imagination can conceive

them.” He adds, “I am persuaded that in time it will become the most

useful instrument of commerce for all correspondence of that kind;

just as electricity will be the most powerful agent of medicine; and

as the fire-pump will be the principle of all mechanic processes which

require, or are to communicate, great force.”

To Linguet has been attributed the authorship of the anonymous letter

which appeared in the _Journal de Paris_ of May 30, 1782, and in

_Le Mercure de France_ of June 8, 1782, wherein it is proposed to

employ twenty-four pairs of gilt wires, placed underground in separate

wooden tubes filled with resin and bearing a knob at each extremity.

Between each pair of knobs was to be placed a letter of the alphabet,

which would become discernible whenever the electric spark was passed

through the wire by means of the Leyden phial.

REFERENCES.--Ternant, _Le Télégraphe_, Paris, 1881, p. 11;

Linguet, “Mém. manuscrit ... signaux par la lumière,” Paris,

1782; all about the “Mercure de France,” in “Bulletin du

Bibliophile” No. 7 of July 15, 1902; “Biog. Dict.,” Alex

Chalmers, 1815, Vol. XX. p. 290; “Nouv. Biog. Gén.” (Hœfer),

Paris, 1860, Vol. XXXI. p. 279; “Biog. Univ.” (Michaud), Vol.

XXIV. p. 565.

=A.D. 1782–1791.=--Cassini (Jean Jacques Dominique, Comte de), son

of Cassini de Thury, eminent astronomer, makes the very important

announcement that, besides the _secular_ variation of the declination,

the magnetic needle is subject to an _annual_ periodical fluctuation

depending on the position of the sun in reference to the equinoctial

and solstitial points.

Cassini’s discovery is contained in a Memoir consisting of two parts,

the first part being a letter addressed to L’Abbé Rosier and published

by him in the _Journal de Physique_, while the second part, composed at

request of the Académie des Sciences, is that which specially treats of

the _annual variation in declination_.

Besides the last named, we have thus far learned of the _secular_

variation discovered by Gellibrand (Hellibrand) in 1635, as well as

of the _diurnal_ and _horary_ variations, first accurately observed

by George Graham during the year 1722, and we have likewise been

informed of the earliest observations of _the dip or inclination_, made

independently by both Georg Hartmann (A.D. 1543–1544) and by Robert

Norman (A.D. 1576), as well as of the determination of the intensity

of the inclination by J. C. Borda (at A.D. 1776). For accounts of

the _secular_ and _annual_, as well as of the _diurnal_ and _horary_

variations of the dip, the reader should consult the First Section of

Humboldt’s “Cosmos” treating of telluric phenomena and some of the very

numerous references therein given.

Speaking of the influence of the sun’s position upon the manifestation

of the magnetic force of the earth, Humboldt remarks that the most

distinct intimation of this relation was afforded by the discovery

of _horary_ variations, although it had been obscurely perceived by

Kepler, who surmised that all the axes of the planets were magnetically

directed toward one portion of the universe. He says that the sun may

be a magnetic body, and that on that account the force which impels

the planets may be centred in the sun (Kepler, in “Stella Martis,”

pp. 32–34--compare with it his treatise, “Mysterium Cosmogr.,” cap.

20, p. 71). He further observes that the _horary_ variations of the

declination, which, although dependent upon true time are apparently

governed by the sun as long as it remains above the horizon, diminish

in angular value with the magnetic latitude of place. Near the equator,

for instance, in the island of Rawak, they scarcely amount to three

or four minutes, whilst the variations are from thirteen to fourteen

minutes in the middle of Europe. As in the whole northern hemisphere

the north point of the needle moves from east to west on an average

from 8½ in the morning until 1½ at midday, in the southern hemisphere

the same north point moves from west to east (Arago, _Annuaire_,

1836, p. 284, and 1840, pp. 330–358). Attention has been drawn, with

much justice, to the fact that there must be a region of the earth,

between the terrestrial and the magnetic equator, where no horary

deviations in the declination are to be observed. This fourth curve

(in contradistinction to the _isodynamic_, _isoclinic_ and _isogonic_

lines, or those respectively of equal force, equal inclination and

equal declination), which might be called the _curve of no motion_, or

rather _the line of no variation of horary declination_, has not yet

been discovered. No point has hitherto been found at which the needle

does not exhibit a _horary_ motion, and, since the erection of magnetic

stations, the important and very unexpected fact has been evolved that

there are places in the southern magnetic hemisphere at which the

_horary_ variations of the dipping needle alternately participate in

the phenomena (types) of the hemispheres.

Humboldt also alludes, in the article on “Magnetic Variation,” to his

recognition of the “four motions of the needle, constituting, as it

were, four periods of magnetic ebbing and flowing, analogous to the

barometrical periods,” which will be found recorded in Hansteen’s

“Magnetismus der Erde,” 1819, s. 459, and he likewise refers to the

long-disregarded _nocturnal_ alterations of variation, for which

he calls attention to Faraday “On the Night Episode,” ss. 3012–3024.

(See also, Poggendorff’s _Annalen der Physik_, Bd. XV. s. 330, and

Bd. XIX. s. 373.)

The _Phil. Trans._ for 1738, p. 395, contain the description of a new

compass for ascertaining the variation “with greater ease and exactness

than any ever yet contrived for that purpose.” This was devised by

Capt. Christopher Middleton, whose many interesting observations are

to be found in the same volume of the _Phil. Trans._, p. 310, as well

as in the volumes for 1726, p. 73; 1731–1732, 1733–1734, p. 127; 1742,

p. 157, and in John Martyn’s abridgment, Vol. VIII. part i. p. 374.

Reference should also be made to the volumes for 1754 (p. 875) and

1757 (p. 329), giving the reports of W. Mountaine and J. Dodson upon

the magnetic chart and tables of 50,000 observations, likewise to

the volume for 1766 containing the report of W. Mountaine on Robert

Douglass’ observation, as well as for the record of investigations of

the variation made by David Ross on board the ship “Montagu” during the

years 1760–1762.

REFERENCES.--Sabine, “On the Annual and Diurnal Variations” in

Vol. II of “Observations made ... at Toronto,” pp. xvii-xx, also

his Memoir “On the Annual Variation of the Magnetic Needle at

Different Periods of the Day,” in _Phil. Trans._ for 1851, Part

II. p. 635, as well as the Introduction to his “Observations

... at Hobart Town,” Vol. I. pp. xxxiv-xxxvi, and his Report

to the British Association at Liverpool, 1854, p. 11--_Phil.

Trans._ for 1857, Art. 1, pp. 6, 7--relative to the _lunar

diurnal magnetic variation_. See likewise C. Wolf, “Histoire

de l’observatoire depuis sa fondation à 1793”; Houzeau et

Lancaster, “Bibl. Gen.,” Vol. II. p. 102; “Mém. de Paris,” Vol.

II. p. 74, and Vol. VII. pp. 503, 530; Walker, “Ter. and Cos.

Magn.,” Chap. III; Mme. J. Le Breton, “Histoire et Applic.,”

etc., Paris, 1884, p. 17; Robison, “Mech. Phil.,” Vol. IV. p.

356; Thos. Young, “Nat. Phil.,” 1845, p. 583.

CASSINI FAMILY

This celebrated family, to which allusion was made under A.D. 1700,

deserves here additional notice.

Giovanni Domenico Cassini (1625–1712), the first and greatest of the

name, succeeded Buonaventura Cavaliéri in the astronomical chair of

the Bologna University in 1650, and remained there until given the

directorship of the Paris Royal Observatory upon its completion in

1670. Partly with the assistance of his learned nephew, James Philip

Maraldi, Cassini made many important discoveries, among which may be

signalled the finding of the first, second, third and fifth satellites

of Saturn, as well as the dual character of that planet’s ring, the

determination of the rotation of Jupiter, Mars and Venus, and the laws

of the moon’s axial rotation. (See Thomson, “Hist. of the Roy. Soc.,”

p. 331; “Anc. Mém. de Paris,” I, VIII, X; Thos. Morrell, “Elem. of the

Hist. of Phil. and Sc.,” London, 1827, pp. 377–379.)

Jacques (James) Cassini (1677–1756), the only son of the preceding,

became director of the Paris Observatory upon the death of his father,

made many very important astronomical observations, and wrote several

treatises upon electricity, etc. In one of his works, “De la Grandeur

et de la Figure de la Terre,” Paris, 1720, he gives an account of the

continuation of the measurement of Picard’s arc of the meridian from

Paris northward, begun by Domenico Cassini and La Hire in 1680, and

recommenced by Domenico and Jacques Cassini in 1700. (See “Mém. de

Paris,” Vol. VII. pp. 455, 456, 508, 572; and for years 1705, pp. 8,

80; 1708, pp. 173, 292; 1729, Hist. I., Mem. 321.)

Cesar François Cassini de Thury (1714–1784), son of Jacques, whom he

in turn succeeded at the Observatory, was, as above stated, the father

of Jean Dominique Cassini (1747–1845). He made numerous researches

while in the Director’s Chair, his most remarkable work being the large

triangulation of France published in 1744, under the title of “La

Méridienne,” etc. (See “Hist. de l’Acad. des Sciences de Paris” pour

1752, p. 10.)

=A.D. 1783.=--Robespierre (François-Maximilien-Joseph-Isidore de),

who afterward became leader of the famous French Jacobin Club, and was

at the time practising law in his native town of Arras, distinguishes

himself by successfully defending the cause of the Sieur de Vissery

de Boisvalé, a landed proprietor of that place, who had erected a

lightning conductor on his house, “much to the scandal of the discreet

citizens” of the locality--“Deistical philosophy; away with it!”

(Eighth “Britannica,” Vol. XIX. p. 233).

Mr. de Boisvalé’s case was an appeal from a judgment delivered by

the sheriff of Saint-Omer, ordering the destruction of the lightning

conductor, and its printed report bears the following epigraph:

“L’usage appuyé sur les temps

Et les préjugés indociles.

Ne se retire qu’à pas lents

Devant les vérités utiles.”

Jean Paul Marat, docteur en médecine et médecin des Gardes de corps de

M. le Comte d’Artois, who, like Robespierre, was a member of the French

National Convention as well as a declared enemy of the Girondins,

and who was killed by Charlotte Corday, July 13, 1793, made many

electrical experiments. These greatly interested Benjamin Franklin,

who used to visit him (Ninth “Encycl. Brit.,” Vol. XV. p. 526). He

was the author of many electrical works during the years 1779–1784,

notably “Découvertes sur le feu, l’électricité et la lumière,”

“Recherches Physiques,” and a memoir on medical electricity (“Œuvres de

Marat,” Paris, 1788; A. Bougeart, “Marat, l’ami du peuple,” 1864; F.

Chevremont, “Jean Paul Marat,” 1881).

REFERENCES.--Ronalds’ “Catalogue,” p. 434; _La Lumière

Electrique_ for Sept. 5, 1891; the _Electrician_, London, Sept.

11, 1891.

=A.D. 1783.=--Wilkinson (C. H.), Scotch physician, publishes at

Edinburgh his “Tentamen Philosophico-medicum de Electricitate,” which

is followed, during 1798 and 1799, by other works upon electricity,

wherein he cites a number of marvellous cures of intermittent fevers

similar to those made by Cavallo, also of amaurosis (_goutte sereine_)

and of quinsy (_squinancie_) like those performed by Lovet, Becket and

Mauduyt.

During the year 1804 appeared the first edition, in two volumes, of

his “Elements of Galvanism in Theory and Practice,” containing a very

comprehensive review of the discovery from the time of Galvani’s early

experiments. In this last-named work, however, he shows that incipient

amaurosis and the completely formed gutta serena have not yielded to

his own treatment by galvanic influence as had been the case with Dr.

C. J. C. Grapengieser, who published many accounts of surprising cures

(Grapengieser, “Versuche den Galvanismus ...” Berlin, 1801 and 1802,

or Brewer and Delaroche, “Essai ...” Paris, 1802). The whole of Chap.

XXXVI is devoted to the application of galvanism to medicine, whereto

allusion had already been made in the first chapter of the same work.

Wilkinson refers also to the electricity of the _torpedo_, and to the

observations made thereon by Hippocrates, Plato, Theophrastus, Pliny

and Ælian, also by Belon, Rondelet, Salviana and Gesner, as well as by

Musschenbroek, Redi, Réaumur, Walsh, Hunter, Spallanzani, ’Sgravesande,

Steno, Borelli, Galvani and others. Much space is likewise given to the

observations recorded on animal electricity, notably by Fontana, De La

Méthérie, Berlinghieri, Vassali-Eandi, Humboldt, Pfaff, Lehot, Hallé,

Aldini, and to the experiments of Valli as they were repeated before

the French Academy of Sciences and before the Royal Society of Medicine

of Paris, in presence of M. Mauduyt. When treating of the powers of

galvanism as a chemical agent, reference is made to the decomposition

of water, thus first effected in 1795 by Creve, the discoverer of

metallic irritation, and to the operations of Nicholson and Carlisle,

Dr. Henry, Cruikshanks, Haldane, Henry Moyes, Richter, Gibbes, etc.

REFERENCES.--J. J. Hemmer, “Commentat Palatinæ,” VI, Phys.,

p. 47; Bertholon, “Elec. du Corps Humain,” 1786, Vol. I. pp.

314, 330, 483, and Vol. II. p. 299; “Bibl. Britan.,” 1808,

Vol. XXXVIII. p. 270 (_Phil. Mag._, No. 105); _Annales de

Chimie_, Vol. LXXVIII. p. 247; _Phil. Mag._, Vol. XXIX. p. 243,

and Vol. XLIX. p. 299; F. Buzzi, “Osservazione ... amaurosi

... elettricita,” Milano, 1783 (“Opus. Scelti,” Vol. VI. p.

359); _Nicholson’s Journal_, Vol. VIII. pp. 1, 70, 206; also

Vol. X. pp. 30–32, for letter relative to certain erroneous

observations of Mr. Wilkinson respecting galvanism, by Mr. Ra.

Thicknesse, who also wrote in Vol. IX. pp. 120–122, explaining

the production of the electric fluid by the galvanic pile.

=A.D. 1783.=--Saussure (Horace-Benedict de), Professor of Physics at

the University of Geneva and founder of the Society for the Advancement

of the Arts in the same city, is the inventor of an electrometer

designed to ascertain the electrical state of the atmosphere, which

will be found described in Vol. VIII. p. 619 of the 1855 “Encycl.

Britannica.”

He observed that electricity is strongest in the open-air, that it

is weak in streets, under trees, etc., and that during the summer

and winter, by night as well as by day, when the atmosphere is free

from clouds, the electricity of the air is always positive. In

contradistinction, Mr. T. Ronayne found in Ireland that the electricity

of the atmosphere is positive in winter when the air is clear, but that

it diminishes in frosty or foggy weather and that he could detect no

electricity in the air during summer except on the approach of fogs,

when the electricity proved to be positive. During the year 1785, M.

de Saussure observed at Geneva that, during the winter, the intensity

of atmospherical electricity attained its first maximum at 9 a.m.,

diminishing from that hour until it reached its minimum at 6 p.m.,

after which it began to increase until attaining its second maximum

at 8 p.m., diminishing gradually thereafter till it recorded its

second minimum at 6 a.m. During the summer he found the electricity

increasing from sunrise till between 3 and 4 p.m., when it would reach

its maximum; after that it appeared to diminish till the dew fell, when

it again became stronger, but was scarcely sensible during the night.

Sir David Brewster informs us in his able article on “Electricity”

in the “Britannica” that De Saussure made a number of elaborate

experiments on the electricity of evaporation and combustion. He

observed at first that the electricity was sometimes positive and

sometimes negative when water was evaporated from a heated crucible,

but in his subsequent trials he found it to be always positive in

an iron and in a copper crucible. In a silver, also in a porcelain

crucible, the electricity was negative and the evaporation of

both alcohol and of ether in a silver crucible also gave negative

electricity. M. de Saussure made many fruitless attempts to obtain

electricity from combustion, and he likewise failed in his efforts to

procure it from evaporation without ebullition.

To De Saussure is often erroneously attributed the authorship of

Lullin’s “Dissertatio physica de electricitate,” alluded to at

A.D. 1766.

REFERENCES.--De Saussure’s “Dissertatio de Igne,” “Exposition

abrégée,” etc. (translated by Giuseppe Toaldo, in both his

“Della maniera,” etc., and “Dei conduttori,” etc., Venezia, 1772

and 1778), “Voyage dans les Alpes,” all published at Geneva,

1759, 1771, 1779, also the important 1786 Neuchatel edition of

the last-named work, more particularly at pp. 194, 197, 203,

205, 206, 211, 212, 216, 218, 219, 228, 252, 254 of Vol. II, and

at pp. 197, 257 of Vol. IV; likewise his Memoirs relative to the

electricity of the atmosphere, of vegetables, of microscopic

animals, etc., etc., alluded to in _Journal de Physique_ for

1773, 1784, 1788; in _Journal de Paris_ for 1784, 1785; in Vol.

I of Lazaro Spallanzani’s “Opuscoli di fisica,” etc., for 1776;

in Vol. III of the “Opuscoli Scelti di Milano,” and in the

_Philosophical Transactions_. See also Jean Senebier, “Mémoire

historique,” etc., Genève, 1801; Louis Cotte in his “Traité,”

etc., “Mémoires,” etc., “Observation,” etc., Paris, 1762, 1769,

1772; in the “Mémoires de Paris,” Année 1769, “Hist.,” p. 19;

Année 1772, “Hist.,” p. 16, and in the _Journal de Physique_ for

1783, Vol. XXIII; the experiments of MM. Becquerel and Brachet

in Becquerel’s “Traité d’El. et de Magn.,” Paris, 1836, Vol.

IV. p. 110; Theodor Ægidius von Heller, “Beobach d. Atmosphär.

Elektricität.” (F. A. C. Gren, “Neues Journal der Physik”

for 1797, Vol. IV); Faujas de St. Fond, “Description,” etc.,

Vol. II. p. 271, as per George Adams’ “Essay on Electricity,”

London, 1799, p. 419; Noad, “Manual,” etc., London, 1859, p.

16; Poggendorff, Vol. II. p. 755; Rozier, XXXI. pp. 317, 374;

XXXIV. p. 161; articles “Meteorology and Electricity” in the

“Encyclopædia Britannica”; Thomas Young, “Course of Lectures,”

etc., London, 1807, Vol. II. pp. 447, 466–471.

=A.D. 1784.=--Swinden (Jan Hendrik Van) (1746–1823), who had been made

Professor in the University of Franequer at the early age of twenty

(1767), and was at this time occupying the Chair of Natural Philosophy

and Mathematics at Amsterdam, publishes in three volumes, at La

Haye, his “Recueil de Mémoires sur l’Analogie de l’Electricité et du

Magnétisme,” etc. (“De Analogia ...” in Vol. II of the “Neue Abhandl.

der Baierischen Akad. Phil.”). The latter contains all the essays sent

to the Electoral Academy of Bavaria on the subject--“Is There a Real

and Physical Analogy Between Electric and Magnetic Forces; and, if Such

Analogy Exist, in What Manner Do These Forces Act Upon the Animal Body?”

Van Swinden’s essay, which gained him one of the prizes, shows that,

in his opinion, the similarity between electricity and magnetism

amounts merely to an apparent resemblance, and does not constitute a

real physical analogy. He infers from this that these two powers are

essentially different and distinct from one another, but the contrary

opinion was maintained by Profs. Steiglehuer and Hubner, who contended

that so close an analogy as that exhibited by these two classes of

phenomena indicated the effects of a single agent, varied only in

consequence of a diversity of circumstances.

The eminent professor, Gerard Moll, of Utrecht, has communicated to the

Edinburgh _Journal of Science_ (1826, Vol. I. part ii. pp. 197–208)

a biographical notice of Van Swinden, wherein he gives a list of the

latter’s principal works and there speaks of one of his best-known

productions in following manner: “The _Positiones Physicæ_ (Opusc.

Scelti, X. 7), as far as they are published (Harderovici, 1786, Vol.

I and Vol. II. part i.), are allowed to rank among the best elements

of natural philosophy, and have been found by actual experience to

belong to the best sources from which the young student could draw

his information on those parts of natural philosophy, and its general

principles, as are contained in the first volume and part of the

second, which is all that was published. The work itself is on a most

extensive plan; and the multifarious avocations which crowded on Van

Swinden in Amsterdam delayed the publications, and made him afterward

abandon all thoughts of completing a work which would have done the

greatest honour to its author, and which even now, unfinished as it is,

is celebrated as an excellent specimen of sound reasoning and profound

learning.”

Van Swinden was the first President of the Royal Institute of the

Netherlands. He entered with ardour into all the new discoveries of

his day and kept up an extensive correspondence with many of the

leading scientific characters of the time, notably with the Swiss

philosopher, Charles Bonnet (whose “Contemplations de la Nature” he

annotated extensively); with Dr. Matthew Maty (who became secretary

of the Royal Society upon the resignation of Dr. Birch in 1765, and

who was appointed, by the king, principal librarian of the British

Museum upon the death of Dr. Gowin Knight, 1772); with the eminent

French physician, Michel-Augustin Thouret, Dean of the Paris “Faculté

de Médecine”; as well as with Delambre, Euler, De Saussure, and many

others who have been named elsewhere in this “Bibliographical History.”

The following is further extracted from Prof. Moll’s interesting

paper: “Mr. Biot, in his treatise on Natural Philosophy (Tome III. p.

143) asserts that we are indebted to Cassini IV. (see Jean Dominique,

Comte de Cassini, at A.D. 1782–1791) for much of what we know even

about the diurnal variation of the needle. This, I think, is not fair.

We do not mean to undervalue Mr. Cassini’s observations, but it is

unquestionable that long before the publication of that philosopher’s

work, Mr. Van Swinden had observed and published (‘Recherches sur

les aiguilles aimantées et leurs variations’--Mémoires présentés à

l’Académie des Sciences de Paris, Tome VIII--prize essay 1777) that

which Mr. Biot less accurately is pleased to ascribe to his countryman.

In this respect, however, Mr. Van Swinden was treated with more justice

by other eminent philosophers, such as Haüy, Halley and Burkhardt.”

(Consult also the “Acta Acad. Petrop.” for 1780, Part I. Hist. p. 10.)

In the afore-named very meritorious work, “Recueil de Mémoires,”

etc., crowned by the Bavarian Academy, Van Swinden has treated fully

of the then current theories relative to electrical and magnetical

phenomena, reviewing the entire field of their application. In so

doing he has necessarily made numerous references to discoverers and

experimenters of all countries, the names of many of which appear in

the present compilation, and while it is, of course, useless here to

quote these anew, it has been thought best, for a record, to specify

such as are infrequently met with, and which appear in many of his most

important articles, even at the risk of being accused of diffuseness or

prolixity. They are as follows:

REFERENCES.--John T. Needham (Vol. IV, Mem. Brussels Acad. for

1783); _Phil. Trans._, 1746, p. 247; J. G. Lehmann (“Abhandlung

von Phosph.”; “Von Magnet Theilen im Sande,” “Novi Com. Acad.

Petrop.,” Vol. XII. p. 368, etc.); M. De La Cépède, “Essai sur

l’El. nat et artif.”; C. E. Gellert (“Com. Acad. Petrop.,” Vol.

XIII. p. 382, Exp. 15, 16); J. F. Henckel, “Pyritologia,” etc.;

J. E. Von Herbert, “Theor. Phæn. Elect.,” cap. 4, prop. 8; C.

F. M. Déchales, “Mundus Mathematicus,” lib. 1, _Quartus Exper.

Ordo._, exp. 16, Tome II. p. 488, ed. 2, etc.; M. Marcel’s

Dissertation on powdered magnets, which appears in the Dutch

“Uitgezogte Verhandelingen,” Vol. I. p. 261, etc.; Jean M. Cadet

(“Nova Acta. Physico. Med. Acad. Natur. Curios.,” Tome III);

Abbé Giraud-Soulavie (“Comment. ... Œuvres de Mr. Hamilton,”

note 4, p. 303); J. B. Le Roy (“Mém. de l’Acad. de Paris,”

for 1753, p. 447; for 1772, p. 499; _Jour. de Phys._, Vol.

II); Rudolph Richard (“Magazin d. Hamb.,” IV. p. 681); Gilles

A. Bazin, “Descrip. des Cour, Mag.,” Plates 14, 16–18; J. F.

Gross, “Elektrische Pausen,” Leipzig, 1776; _Jour. de Phys._,

Vol. X. p. 235; Niccolo Bammacaro, “Tentamen de vi Electrica,”

etc., s. 6; Samuel Colepress (_Phil. Trans._, 1667, No. 27,

Vol. I. p. 502); E. F. Du Tour, “Discours sur l’aimant,” s.

27; “Recueil des Prix de l’Acad. de Paris,” Tome V. mém. ii.

p. 49; “Mém. Math, et Phys.”; Mr. Calendrin, at Van Swinden’s,

Vol. I. pp. 233, etc.; M. Blondeau (“Mém. de l’Acad. de

Marine,” Brest., Tome I. s. 46, pp. 401–431, 438); J. A. Braun,

“Observations,” etc.; “Novi. Comment. Acad. Petrop.,” Vol. VII.

pp. 388, 407; M. Antheaulme (“Mém. sur les aimants artif.”

(prize essay), 1760; “Mém. de l’Acad. Roy.,” 1761, p. 211; Van

Swinden, 1784, Vol. II. pp. 95, 170); J. N. Reichenberger,

“Directorium magneticum magneticis,” etc., and “Hydrotica,” as

at Van Swinden, 1784, Vol. II. pp. 272–273; Geo. C. Schmidt,

“Beschr., einer Elektrisir Masch.,” etc., 1778; M. De la Folie

(_Jour, de Phys._, 1774, Vol. III. p. 9); Cölestin Steiglehner,

“Obs. phaenom. elect.,” “Ueber die Annal der Elek. und des

Magn.”; Lorenz Hubner, “Abh. u. d. Annal. u. mag. Kraft”; Jos.

Thad. Klinkosch, “Schreiben,” etc., “Beschreib. d. Volta ...

Elektrophors.” Reference should also be made to Noad, “Manual,”

etc., p. 641; Encycl. Brit., 1857, Vol. XIV. p. 6; “Messager des

Sciences et des Arts,” Gand, 1823, pp. 185–201, detailing all of

Van Swinden’s works; Antoine Thillaye’s treatise presented to

the Ecole de Médecine le 15 Floréal, An. XI; Butet (“Bull, des

Sc. de la Soc. Philom.,” No. 43, Vendémiaire, An. IX).

=A.D. 1784.=--Cotugno (Domenico), Professor of Anatomy at Naples, thus

addresses Le Chevalier G. Vivenzio under date October 2, 1784: “The

observation which I mentioned some days ago, when we were discoursing

together of the electrical animals, upon which I said I believed the

mouse to be one of that number, is the following: Toward the latter end

of March, I was sitting with a table before me and observing something

to move about my foot, which drew my attention. Looking toward the

floor I saw a small domestic mouse, which, as its coat indicated,

must have been very young. As the little animal could not move very

quick, I easily laid hold of it by the skin of the back and turned it

upside down; then with a small knife that laid by me, I intended to

dissect it. When I first made the incision into the epigastric region,

the mouse was situated between the thumb and finger of my left hand,

and its tail was got between the last two fingers. I had hardly cut

through part of the skin of that region, when the mouse vibrated its

tail between the fingers, and was so violently agitated against the

third finger that, to my great astonishment, I felt a shock through

my left arm as far as the neck, attended with an internal tremor, a

painful sensation in the muscles of the arm, and such giddiness of the

head, that, being affrighted, I dropped the mouse. The stupor of the

arm lasted upward of a quarter of an hour, nor could I afterwards think

of the incident without emotion. I had no idea that such an animal was

electrical; but in this I had the positive proof of experience.” (See

G. Vivenzio, “Teoria e pratica della elettricità med.” ... Napoli,

1784.)

Cotugno’s observations attracted much attention throughout Italy and

gave rise to many experiments, notably by Vassalli, who, however,

merely concluded from them that the animal’s body could retain

accumulated electricity in some unaccountable manner.

REFERENCES.--_Essai sur l’histoire_, etc., J. B. Biot, p. 9;

_Journal de Physique_, XLI. p. 57; _Mémoires Récréatifs_,

etc., par Robertson, Paris, 1840, Vol. I. p. 233; Cavallo,

_Electricity_, London, 1795, Vol. III. p. 6; Izarn, _Manuel_,

Paris, 1804, p. 4; _Journal Encyclopédique de Bologne_, 1786,

No. 8; Poggendorff, Vol. I. p. 417; Sue, aîné “Hist. du Galv.,”

Vol. I. pp. 1–2.

=A.D. 1785.=--Coulomb (Charles Augustin de), the founder of

_electro-statics_ and of the school of experimental physics in

France, invents the torsion balance, with which he discovers the

true law of electric and magnetic attractions and repulsions. Some

have asserted that Lord Stanhope had previously established the law

with regard to electricity, but it has not been seriously questioned

that its extension to magnetism belongs exclusively to Coulomb.

Johann Lamont (“Handbuch ...” p. 427) gives the credit of the latter

discovery to Giovannantonio Della Bella, of Padua, who is mentioned

by Poggendorff (“Biog.-Liter. Handwörterbuch,” Vol. I. p. 139) as the

author of several works on electricity and magnetism, but the claim

does not appear to be established upon any satisfactory foundation.

With his torsion balance, or rather electrometer, Coulomb measured

the force by the amount of twist it gave to a long silken thread

carrying a horizontal needle, constructed, preferably, of a filament

of gum-lac or of straw covered with sealing-wax. From his experiments

he concluded: That the attractive force of two small globes, one

electrified positively and the other negatively, is in the inverse

ratio of the squares of the distances of their centres, and that the

repulsive force of two small globes, charged either with positive or

negative electricity, is inversely as the squares of the distances of

the centres of the globes (“Mém. de l’Acad. Roy. des Sciences,” 1784,

1785).

In one of his three memoirs to the French Academy during 1785, he

states that a balance used by him was so delicate that each degree of

the circle of torsion expressed a force of only one hundred-thousandth

of an English grain, that another, suspended by a single fibre of

silk four inches long, made a complete revolution with a force of one

seventy-thousandth of a grain, and turned to the extent of a right

angle when a stick of sealing-wax, which had been rubbed, was presented

to it at the distance of a yard. It is said that a similar electrometer

has been constructed in which the movement of one degree recorded a

force not exceeding twenty-one million six-hundred-thousandths of a

grain.

The many valuable experiments made by Coulomb on the dissipation of

electricity and upon the distribution of electricity upon the surfaces

of bodies are fully recorded in the able article of Sir David Brewster

in the “Encyclopædia Britannica” (F. C. Achard, “Mém. de Berlin,”

1780, p. 47); M. Vernier, “De la dist. ... conducteurs,” Paris,

1824; J. L. F. Bertrand, “Programme d’une thèse ...” Paris, 1839; D.

Bourdonnay, “Sur la dist. ... conducteurs,” Paris, 1840; Ed. A. Roche

in “Montp. Acad. Sect. Sciences,” Vol. II. p. 115).

He discovered that shellac is the most perfect of all insulators, also

that a thread of gum-lac insulates ten times better than a dry silken

thread of the same length and diameter: and he established the law that

the densities of electricity insulated by different lengths of fine

cylindrical fibres, such as those of gum-lac, hair, silk, etc., vary as

the square root of the lengths of the fibre.

Besides the communications above alluded to, Coulomb sent to the French

Academy, during the years 1786, 1787, 1788 and 1789, many papers upon

Electricity and Magnetism, and, up to within two years of his death

(1806), he made many notable experiments, especially in magnetism, of

which full accounts are given in several of the Mémoires noted at foot.

The theory of the two magnetic fluids appeared in his 1789 paper. It is

also in this same paper that Coulomb describes his improved method of

making artificial magnets by employing compound magnets as first made

use of by Gowin Knight and as explained at A.D. 1746. Still further

improvements in these were brought about more particularly by the young

Flemish scientist, Etienne Jean Van Geuns (1767–1795), by Jean Baptiste

Biot (see A.D. 1803), and by the Rev. Dr. Scoresby during the year 1836.

Coulomb found that a steel wire is, by twisting, rendered capable of

being nine times more strongly magnetized; that the magnetic power

dwells on the surface of iron bodies and is independent of their mass;

that the directive force of a magnetized bar reached its maximum

when tempered to a bright cherry-red heat at 900 degrees, and that

every substance is susceptible of magnetism to a degree of actual

measurement. This last important research was communicated by him to

the French Institute during the year 1802. His experiments proved

that a grain of iron could communicate sensible magnetism to twenty

pounds’ weight of another substance, and that when even beeswax had

incorporated with it a portion of iron filings equal only to the one

hundred-and-thirty-thousandth part of its weight it was yet sensibly

affected by the magnet.

According to Dr. Thomas Young, Coulomb’s improvements in the theory of

electricity may be considered as having immediately prepared the way

for the elegant inventions of Volta and for the still more marvellous

discoveries of Davy. Dr. Young gives reports of some of Coulomb’s

experiments at p. 439, Vol. II of his “Course of Lectures” London,

1807 (“Journal of the Royal Institution” Vol. I. p. 134; “Décade

Philosophique,” No. 21).

REFERENCES.--“Mém. de l’Acad. Royale des Sciences,” Paris,

1784, p. 266; 1785, pp. 560, 569, 578, 612; 1786, p. 67; 1787,

p. 421; 1788, p. 617; 1789, p. 455; “Mém. de l’Institut,” Vol.

III. p. 176; Vol. IV. p. 565, and Vol. VI. for 1806; “Mém. de

Math. et de Phys.” Vols. VIII and IX; “Mémoires de Coulomb,”

Vol. I of the “Collection de Mémoires relatifs à la Physique,”

Paris, 1884; “Cat. of Sc. Papers Roy. Soc.,” Vol. III. p. 73;

“Abstracts of Papers of Roy. Soc.,” Vol. II. p. 402; “Bull.

de la Soc. Philom.,” Nos. 3, 31, 61, 63, and for 1795, 1802;

_Journal de Physique_, Vols. XLV (II), pp. 235, 448; LIV. pp.

240, 267, 454; LV. p. 450 (for Carradori’s report); Ch. N. A.

De Haldat du Lys (“Mém. de Nancy” for 1841); _Phil. Magazine_,

Vols. XI. p. 183; XII. p. 278; XIII. p. 401; XV. p. 186; Rozier,

XXVII. p. 116; XLIII. p. 247; Gilbert, XI. pp. 254, 367; XII.

p. 194; Dr. Young, “Course of Lectures,” London, 1807, Vol. I.

pp. 682, 685, 686; “Royal Society Cat. of Sc. Papers,” Vol.

II. p. 73; Eighth “Britannica,” Vol. XIV. pp. 37–38; Humboldt,

“Cosmos,” 1859, Vol. V. p. 61; Schaffner, “Manual,” 1859, p.

56; Biot’s article in the “Biographie Universelle” and Biot’s

“Traité de Physique,” Paris, 1816, Vols. II, III; Dr. Thomas

Thomson, “Outline of the Sciences,” etc., London, 1830, pp.

350, 351, 379–422; Harris, “Rudim. Magn.,” Parts I, II. p. 56.

See also description of the electrometer of Colardeau and the

electro-micrometer of Delaunay, in the latter’s “Manuel,” etc.,

Paris, 1809, pp. 66, 76–80, and Plate V. fig. 61, as well as

Libes’ “Dict. de Phys.,” Vol. I. p. 406.

=A.D. 1785.=--The Canon Gottoin de Coma, friend of Alessandro Volta,

observes that an iron wire about thirty feet in length will give a

sound under certain conditions of the atmosphere when stretched in

the open air. The circumstances that accompany, as well as those that

favour the production of the phenomenon, says Prescott, demonstrate

that it must be attributed to the transmission of atmospheric

electricity. This transmission does not occur in a continuous manner,

like that of a current, but is observable by a series of discharges.

REFERENCES.--Knight’s _Mechanical Dictionary_, 1876, Vol. III.

p. 2515; Prescott’s “The Speaking Telephone,” etc., 1879, p.

122; _Encyl. Britannica_, 1860, Vol. XXI. p. 631.

=A.D. 1785.=--Marum (Martin Van), a Dutch electrician who had in 1776

taken the degree of M.D. at the Academy of Gröningen, constructs

for the Teylerian Society at Haarlem, with the assistance of John

Cuthbertson, an electrical machine said to be the most powerful

theretofore made. According to Cavallo (_Nat. Phil._, 1825, Vol. II.

p. 194) it consisted of two circular plates of French glass, each

sixty-five inches in diameter, parallel with each other on a common

axis, and about seven and a half inches apart. Each plate was excited

by four rubbers, the prime conductor being divided into two branches

which entered between the plates and, by means of points, collected the

electric fluid from their inner surfaces only.

In Van Marum’s machine, the positive and negative electricity could

only be obtained in succession, but Dr. Hare, of the University

of Pennsylvania, remedied this by causing the plates to revolve

horizontally. It is said the machine was so powerful that bodies at a

distance of forty feet were sensibly affected; a single spark from it

melted a leaf of gold and fired various kinds of combustibles; a thread

became attracted at the distance of thirty-eight feet, and a pointed

wire was tipped with a star of light at a distance of twenty-eight feet

from the conductor.

Descriptions of his machines are given by Dr. Van Marum in letters

to the Chevalier Marsiglio Landriani and to Dr. Ingen-housz, both

printed in Haarlem during 1789 and 1791. The first quarto volume of

_Nicholson’s Journal_ also contains a reference thereto and gives (p.

83) the extract from a letter read June 24, 1773 (_Phil. Trans._, Vol.

LXIII. pp. 333–339), addressed to Dr. Franklin, F.R.S., by John Merwin

Nooth, M.D., who describes improvements by which machines are rendered

effective in all kinds of weather. Nooth was the inventor of the silk

flap, of which mention was made in the description of Cavallo’s machine

(under A.D. 1775).

Van Marum also constructed a powerful battery, the metallic coatings of

which were equal to 225 square feet, enabling him to give polarity to

steel bars nine inches long, nearly half an inch wide and one-twelfth

of an inch thick, as well as to sever a piece of boxwood four inches

diameter and four inches long, and to melt three hundred inches of iron

wire one hundred-and-fiftieth of an inch in diameter, or ten inches

of one-fortieth of an inch in diameter. It is said that, during these

experiments, the report was so loud as to stun the ears, and the flash

so bright as to dazzle the sight.

Dr. Van Marum likewise made experiments upon the electricity developed

during the melting and cooling of resinous bodies, which are detailed

in the article “Electricity” 8th Edit. “Encyclopædia Britannica,” Vol.

VIII. p. 565, and also upon the effects of electricity on animals and

vegetables, which are given at pp. 49–51 of the article “Electricity”

in the “Library of Useful Knowledge,” as well as in the 1855 Edit.

“Encyclopædia Britannica,” Vol. VIII. pp. 602, 603.

In 1785 again Van Marum discovered that electric sparks, on passing

through oxygen gas, gave rise to a peculiar sulphurous or electrical

odour, which Cavallo called “electrified air,” and the presence of

which Dr. John Davy, brother of Sir Humphry Davy, found the means of

detecting.

During the month of October 1801 Volta wrote a letter to Van Marum

asking him to make, in concert with Prof. C. H. Pfaff, of Kiel, several

experiments on the electricity of the pile with the very powerful

apparatus of the Teylerian Society. The extended researches of these

two scientists are embodied in the _Phil. Mag._, Vol. XII. p. 161,

as well as in the “Lettre à Volta” etc., published at Haarlem during

1802, and are likewise treated of in a very complete manner throughout

Chaps. XVI and XXXII of Wilkinson’s well-known work on galvanism. Their

united observations confirm the doctrine of Volta as to the identity of

the current of the fluid put in motion by the voltaic pile and that to

which an impulsion is given by an electrical machine. Thus is answered

the question asked during May 1801 by the Haarlem Society of Sciences,

viz. “Can the voltaic pile be explained in a satisfactory manner by

the known laws and properties of electricity; or is it necessary to

conclude the existence of a particular fluid, distinct from the one

which is denominated electrical?” They also demonstrated that the

current put in motion by the voltaic pile has an enormous celerity

“which surpasses all that the imagination can conceive.” With a pile

of one hundred and ten pairs of very large copper and zinc plates,

they made experiments on the fusion of iron wires and ascertained the

causes of the more considerable effects of large piles in the fusion

and oxidation of metals, proving, among other facts, as Biot and

Cuvier had already done, that a part of the oxygen is absorbed whether

the operation be carried on in the open air or _in vacuo_ (Biot

and Cuvier, _Soc. Philomathique_, An. IX. p. 40; _Annales de

Chimie_, Vol. XXXIX. p. 247).

Another of Van Marum’s experiments is related in a letter to M.

Berthollet, wherein he says: “... I have succeeded in the decomposition

of water, by means of the current of the electrical machine, provided

with a plate of thirty-one inches diameter, constructed by me on a

new plan (see the _Journal de Physique_ for June, 1795).... I

took a thermometrical tube, of the kind employed in making the most

sensitive thermometers of Crawford and Hunter, for which purpose I

had procured several of these tubes some time before in London. Its

diameter interiorly was not more than the one-hundredth part of an

inch; and I introduced into it an iron wire of the diameter of about

the three-hundredth part of an inch, to the depth of about twelve

inches. I now closed the end of my thermometrical tube with sealing

wax in such a way that the extremity of the iron wire should scarcely

project, and I placed the tube itself, by means of a cork, within a

larger tube containing water. The rest of the apparatus was arranged

in the customary manner. By directing the powerful current of the

above-mentioned machine to this apparatus, the copper ball belonging to

which, placed on the thermometrical tube, was at the distance of about

three or four lines from the conductor, I succeeded in decomposing the

water with a promptitude nearly equal to that which results from a

voltaic pile of a hundred pairs of metallic plates.” This method of

decomposing water is a very tedious one, and is in fact the result of

an interrupted explosion, while the process of Dr. Wollaston (alluded

to at A.D. 1801) is tranquil and progressive.

REFERENCES.--“Biogr. Univ.,” Vol. XLII. p. 600; J. G. Heinze,

“Neue elekt. versuche ...” Oldenberg, 1777; Tries’ claim to

Van Marum’s machine in Rozier, XL. p. 116; Prieur’s extract in

_Annales de Chimie_, Vol. XXV. p. 312; “Verhand. Genootsch.

Rott.,” VI for 1781 and VIII for 1787; _Journal de Physique_,

XXXI, 1787; XXXIII, 1788 (Marum en Troostwyk); XXXIV, 1789;

XXXVIII, 1791; XL, 1792; “Journal du Galvanisme,” XI, Cahier,

p. 187; “Journal des Savants” for August 1905; “Revue

Scientifique,” Paris, April 8, 1905, pp. 428–429; _Nicholson’s

Journal_ for March 1799, Vol. II. p. 527; Harris, “Electricity,”

pp. 62, 90, 171; Cuthbertson, “Practical Electricity,” London,

1807, pp. 166, 172, 197, 225; Cavallo, “Electricity,” 4th ed.,

Vol. II. p. 273; “Lib. of Useful Knowledge,” “Electricity,” p.

45; Wilkinson, “Elements of Galvanism,” etc., London, 1804, Vol.

II. pp. 106–128, 384; “Teyler’s Tweede Genootschap”; Gilbert,

_Annalen_, I. pp. 239, 256; X. p. 121; Rozier, XXVII. pp.

148–155; XXXI. p. 343; XXXIV. p. 274; XXXVIII. pp. 109, 447; XL.

p. 270; “Opus. Scelti,” IX. p. 41; XIV. p. 210.

=A.D. 1785.=--Sigaud de la Fond, Professor at the Collège d’Harcourt

in Paris, publishes in the latter city his “Précis historique et

expérimental des phénomènes electriques,” wherein he states having,

as far back as 1756, made use of a circular plate machine provided

with cushions and similar in shape to that which many claim to have

originated with Ingen-housz and with Ramsden. (See A.D. 1779 and A.D.

1768.)

Sigaud de la Fond is also the author of “Description d’un Cabinet de

Physique” (1784), “Cours de Physique,” etc. (1786), “Examen.,” etc.

(1803) and of several treatises on medical electricity.

REFERENCES.--“Journal de Physique,” Vol. II. 1773; Figuier,

“Exposition et Histoire,” Paris, 1857, pp. 50, 74–76, 178;

Poggendorff, Vol. II. p. 927.

=A.D. 1785.=--In the “Nachricht von einer neuen Elektrisirmaschine

des Herrn Walkiers von Saint Amand,” the last named gives a description

of the electrical machine presented by him in 1784 to the Belgian

Academy of Sciences.

It is also described and outlined in Delaunay’s “Manuel” named below,

but, although very powerful in its effects, cannot be made readily

available in consequence of its huge dimensions. M. Caullet de

Veaumorel suggested the feasibility of changing the cylinders from a

horizontal to a vertical position.

REFERENCES.--“Lichtenberg’s Mag.,” Vol. III. 1 st. p. 118;

Delaunay, “Manuel,” etc., 1809, pp. 14–16.

=A.D. 1785.=--Adams (George), mathematical instrument maker to his

Majesty, writes an enlarged edition of his “Essay on Electricity,”

etc., which first appeared the year previous and wherein, as its full

title indicates, he endeavours to explain the theory and practice

of that science and the mode of applying it to medical purposes. He

illustrates many experiments and gives an Essay on Magnetism, in the

treatment of which latter he acknowledges the valuable aid of Dr. J.

Lorimer.

The fifth and last edition of the “Essay,” which was issued by William

Jones in 1799, four years after Adams’ death, contains a communication

on the subject of Medical Electricity by John Birch, the author of

“Della Forza dell’ Elettricita,” etc., Napoli, 1778.

At p. 86 of the 1799 “Essay,” etc., Adams relates that, while M. Loammi

Baldwin (“Memoirs of Amer. Acad.,” Vol. I. p. 257) held the cord of his

kite during the approach of a thunderstorm, he “observed himself to be

surrounded by a rare medium of fire, which, as the cloud rose nearer

the zenith, and the kite rose higher, continued to extend itself with

some gentle faint flashes.” At pp. 137, 186 and 222, he alludes to “A.

Brook’s Miscellaneous Experiments and Remarks on Electricity,” etc.,

as well as to the Rev. John Lyon’s “Experiments and Observations of

Electricity,” and refers to the “Journal of Natural Philosophy” (Vol.

II. p. 438) for Nicholson’s experiments on the _plus_ and _minus_ of

electricity.

=A.D. 1785.=--La Méthérie (Jean Claude de), French physicist

naturalist, becomes sole editor of the “Journal de Physique, de

chimie et d’histoire naturelle,” and publishes in Paris his “Essai

Analytique,” etc., wherein amongst other observations he asserts that

the electric spark results from the combination of oxygen with hydrogen.

He considers that all bodies exist in an electrical or magnetical

condition, that we are only a temporary aggregation of molecules

of matter governed in different ways by nature’s laws, and that

excitability is produced by galvanic action resulting from the

superposition of nervous and muscular fibres.

He is also the author of very interesting treatises on animal

electricity communicated to the _Journal de Physique_ (Vol. XLII. pp.

252, 255, 292), and of which an account is given in Sue’s “Histoire du

Galvanisme,” Paris, 1802, Vol. I. pp. 64–68. The last-named work also

gives, at p. 80, an account of the letter on “Galvanism” sent to M. De

La Méthérie by M. Leopold Vacca-Berlinghieri (_Journal de Physique_,

Vol. XLI. p. 314).

REFERENCES.--“Biographie Générale,” Vol. XXIX. p. 209; Rozier,

XLI. p. 437; Delaunay, “Manuel,” etc., 1809, p. 15, also

Delaunay’s letter in _Phil. Mag._, Vol. XXVII. p. 260; C. H.

Wilkinson, “Elements of Galvanism,” London, 1804, Vol. I. p.

62; Vol. II. p. 9; “Opus. Scelti,” XXI. p. 373; _Journal de

Physique et Chimie_ (of which La Méthérie remained editor up to

the time of his death, during 1817), Vols. LIII, LIV, Pluviose,

An. XI. p. 161; also p. 157 for letter sent him by Giuseppe

Izarn; _Ann. di Chim. di Brugnatelli_, Vol. XIX. p. 156; Aubert,

“Elektrometische Flasche,” Paris, 1789.

=A.D. 1785.=--According to Prof. Tyndall, George Cadogan Morgan

sought to produce the electric spark in the interior of solid bodies.

He inserted two wires into wood and caused the spark to pass between

them; the wood was illuminated with blood-red light or with yellow

light according as the depth at which the spark was produced proved

greater or less. The spark shown within an ivory ball, an orange, an

apple, or under the thumb, illuminates these bodies throughout. A lemon

is especially suited to this experiment, flashing forth, at every

spark, as a spheroid of very brilliant golden light, and a row of eggs

is also brilliantly illuminated throughout, at the passage of every

spark from a Leyden jar. Morgan likewise made several experiments to

ascertain the influence of electricity on the animal functions. These

are alluded to at p. 602, Vol. VIII of the 1855 “Britannica,” and at p.

49 of “Electricity” in the “Library of Useful Knowledge.”

This George Cadogan Morgan (1754–1798) was an English physician and

also a Professor of Natural Philosophy at Hackney, in an establishment

founded by his uncle, Dr. Price. His “Lectures on Electricity” appeared

in Norwich during the year 1794. In the second volume he describes (pp.

225–236) “the form, noise, colours and devastation of the electric

flash,” and treats (pp. 383–397) of the “relation of the electric

fluid to vegetation,” alluding more particularly to the experiments

of Maimbray, Nollet, Achard, Duvernier, Ingen-housz, Van Breda, Dr.

Carmoy and the Abbé d’Ormoy. He likewise gives an account of the

northern lights, as well as descriptions of Bennet’s movable doubler

and electroscope, and of Lane’s electrometer.

REFERENCES.--Morgan’s biography in Larousse, “Dict. Universel,”

Tome XI. p. 562, and in “Biog. Générale,” Tome XXXVI. p. 570;

“Bibl. Britan.” An. VII. vol. ii. pp. 129, 223, and Vol. XII. p.

3.

=A.D. 1786.=--Rittenhouse (David), an American physicist and

astronomer who afterward became F.R.S. and succeeded Dr. Franklin as

President of the Am. Philos. Soc., publishes his theory of magnetism in

a letter to John Page at Williamsburg, which is reproduced at folio 178

of Vol. II, old series, of the Transactions of the above-named Society.

“Were we called upon,” says Renwick, “to assign him a rank among the

philosophers whom America has produced, we should place him, in point

of scientific merit, as second to Franklin alone.”

REFERENCES.--“Trans. Am. Phil. Soc.,” Vol. II, O.S., pp. 173,

175, for Page and Rittenhouse, and Vol. III. for Rittenhouse and

Jones, as well as Rittenhouse and Hopkinson, upon “Meteors and

Lightning.”

=A.D. 1786.=--Galvani (Aloysio or Luigi), an Italian physician, who,

at the age of twenty-five, was Professor of Anatomy at the University

of Bologna, is led to the discovery of that important branch of

electricity which bears his name. The manuscript giving the result of

his experiments upon the Electricity of Metals is dated Sept. 20, 1786.

From papers in the “Bolognese Transactions” noted below, it would

appear that he had, even before the year 1780, made many observations

on the muscular contraction of frogs by electrical agency. Upon

one occasion his wife happened to be holding a scalpel against the

dissected legs and parts of the spine of a frog, which lay in close

proximity to the conductor of an electrical machine recently charged

by one of Galvani’s pupils. She noticed that whenever the dissecting

knife touched the muscles they were violently convulsed, and, upon

communicating the fact to her husband, he repeated and extended the

experiment and found it necessary to pass the electric fluid through a

metallic substance in order to develop the result originally observed.

At first the frogs had been hung upon a copper hook fastened to an

iron railing, but he afterward substituted an arc composed of both

metals and with which he could readily produce the same results as were

obtainable with an electrical machine.

Galvani also made experiments to ascertain the effect of atmospheric

electricity upon the nerves of frogs. He connected the latter with rods

leading to lightning conductors erected upon the roof of his house,

attaching also ground wires to the legs of the animals, and found that

the same convulsions appeared whenever lightning was seen and likewise

when heavy storm clouds passed over the house.

The results of his many interesting observations were first

made public in the celebrated work entitled “Aloysii Galvani de

viribus electricitatis in motu musculari. Commentarius: cum Aldini

dissertatione et notis,” which appeared during 1791–1792. Therein, he

expresses the belief that the bodies of animals possess a peculiar

kind of electricity by which motion is communicated through both nerve

and muscle, positive electricity going to the nerve, while negative

electricity goes to the muscle, and that the muscles represent the

exterior and the nerves the interior of the Leyden jar, the discharge

being similarly produced by the metal which communicates with both.

Galvani’s singular experiments naturally attracted everywhere the

attention of philosophers, by whom they were repeated and varied,

but by none were they more assiduously prosecuted than by Volta, who

was then a Professor at the Pavia University, and who, as already

indicated, was led by them to the discovery of the voltaic pile and of

voltaic or galvanic electricity.

The announcement of Galvani’s observations was made in Germany,

notably by J. F. Ackermann (“Medicinisch-chirurgische Zeitung”), by

M. Er (“Physiologische Darstellung der Lebenskräfte”), by M. Smuck

(“Beiträge zur weiteren Kenntniss,” etc.), and by F. A. C. Gren

(“Journal der Physik,” Vols. VI, VII and VIII), while experiments

were continued upon an extensive scale by the Italians F. Fontana,

Carlo Francesco Bellingeri, M. Giulio and F. Rossi, as well as by

Samuel T. Von Sömmering, by Wilhelm Behrends and by Karl Friedrich

Kielmayer (Kielmaier), Professor of Medicine at the Tübingen University

(Poggendorff, Vol. I. p. 1253). For the curious galvanic experiments

of the celebrated French physician Larrey, and of Stark, Richerand,

Dupuytren and Dumas, see “Bulletin des Sciences de la Société

Philomathique,” 1793, Nos. 23, 24, and “Principes de Physiologie,” Vol.

II. p. 312.

REFERENCES.--C. Alibert, “Eloges Historiques de Galvani,

Spallanzani, Roussel et Bichat ...” Paris and Bologna, 1802–1806

(“Mém. de la Soc. d’Emul. de Paris,” Vol. IV; S. Gherardi,

“Rapporto sui Manoscrotti,” Bologna, 1840, p. 19); Poggendorff,

Vol. I. p. 839; Thomas Thomson, “History of the Royal Society,”

London, 1812, pp. 450, etc.; Thomas Young, “Course of Lectures,”

London, 1807, Vol. II; “Bolognese Transactions” for papers

dated April 9, 1772, April 22, 1773 and Jan. 20, 1774; Sabine,

“El. Tel.,” 1872, pp. 16–18; Knight’s “Mech. Dict.,” Vol.

II. pp. 936, 937, for extract from report of Nat. Inst. of

France, July 4, 1798; “Johnson’s Encyclop.,” 1877, Vol. I. p.

1510; Bakewell’s “Electricity,” p. 26; “Encyclop. Britannica,”

1855, Vol. VIII. p. 530, and Vol. XXI. pp. 609, etc.; Fahie’s

“History,” etc., 1884, pp. 180–185; _Phil. Trans._, 1793;

Miller, “History Philos. Illustrated,” London, 1849, Vol. IV.

p. 333; Thomson, “Hist. of Chemistry,” Vol. II. pp. 251, 252;

Matteucci, “Traité des phénomènes,” etc., Part I. p. 7; the

Address of M. Gavarret made in 1848 before the Paris Medical

Faculty; J. C. I. A. Creve’s treatise on Galvanism (“Jour. de

la Soc. de Méd.,” Vol. XVIII. p. 216); “Mém. de la Soc. Méd.

d’Emul.,” Vol. I. p. 236); Biot et Cuvier (_Ann. de Ch._, Vol.

XXXIX. p. 247); A. Richerand (“Mém. de la Soc. Méd. d’Em.” Vol.

III. p. 311); “Opus. Scelt.,” Vol. XV. p. 113; “Giornale Fis.

Med.,” Vol. II. pp. 115, 131 (letter of B. Carminati); Marsiglio

Landriani, “Lettera,” etc., 1776; Lettre d’un ami au Comte

Prosper Albo (“Bibl. de Turin,” 1792, Vol. I. p. 261; _Jour.

de Phys._, Tome XLI. P. 57); “Comment Bonon. Scient.,” Vol.

VII. p. 363; account of the experiments made by MM. Cortambert

and Gaillard, reported in “Mém. de la Soc. Méd. d’Em.,” Vol.

I. pp. 232, 235; G. Klein’s “Dissert. de Métal,” etc., Maintz,

1794; Ostwald’s _Klassiker_, No. 52, p. 4; C. H. Wilkinson,

“Elements of Galvanism,” etc., London, 1804, 2 Vols. _passim_;

Wm. C. Wells, “Obs. on the Influence,” etc. (_Phil. Trans._,

1795, Pt. XI. p. 246); E. G. Robertson (_An. de Ch._, 1801, Vol.

XXXVII. p. 132; _Jour. de Paris_, 10, 15 and 17 Fructidor de

l’An. VIII); Paul Louis Simon, “Beschreibung neuengalvanisch,”

etc., “Resultate,” etc., and “Versuche,” etc., all published in

1801 (L. W. Gilbert’s _Annalen_, 1801, Book V, _An. de Chimie_,

No. 121, p. 106); L. W. Gilbert’s Book VI of the _Annalen_,

containing the “Memoirs on Galvanism,” by J. L. Boeckmann, L. A.

von Arnim, Paul Erman, M. Gruner and C. H. Pfaff; C. Dupuytren,

“Faits Particuliers,” etc., 1801; J. B. Trommsdorff, “Expér.

Galv.,” 1801; M. Rouppe’s letter of Aug. 28, 1801, in Van Mons’

_Jour. de Ch._, Vol. I. pp. 106, 108; M. Bichat (Sue, “Hist. du

Galv.,” II. p. 216); A. M. Vassalli-Eandi (_Jour. de Phys._,

Frimaire, An. X. p. 476); C. F. Hellwag and M. Jacobi fils,

“Erfahrungen,” etc., 1802; M. le Comte de Pusckin’s experiments

on Galvanism, made Sept. and Dec. 1801, with a _colonne

tournante_ (Sue, “Hist. du Galv.,” Vol. II. pp. 257, 258); Al.

Volta, in _Jour. de Leipzig_, and in “Comment ... Med. gestis,”

1792; Johann Mayer, “Abh. ... Galvani, Valli, Carminati u. Volta

...” Prag, 1793); Junoblowiskiana Society (“Comment ... Med.

gestis,” 1793); “Imperial Dictionary of Universal Biography,”

Wm. McKenzie London, n. d., Vol. II. p. 546; M. Cortambert

(“Mém ... Soc. ... d’Emul.,” I. p. 232); M. Payssé (“Jour. de

la Soc. des Pharm.,” first year, p. 100); Geo. Couvier (_Jour.

de Physique_, Vol. VII. p. 318; “Mém. des Soc. Sav. et Lit.,”

Vol. I. p. 132), 1801; C. Mathieu (“Rec. de la Soc. d’Agr. ...

d’Autun,” An. X. p. 21), 1802; Ponton d’Amécourt, “Exposé du

Galvanisme,” Paris, 1803; Joseph Weber’s works, published in

1802–1803, 1815, 1816, and those of J. K. F. Hauff, Marburg

and Leipzig, 1803, 1804; M. Curtet (_Jour. de Van Mons._, No.

VI. p. 272; _Jour. de Physique_, An. XI. p. 54), 1803; William

Meade (“On the origin and progress of Galvanism”), Dublin, 1805;

J. C. Reil (_Jour. de Van Mons._, No. IV. p. 104; Sue, “Hist.

du Galv.,” Vol. IV. p. 26); J. A. Heidmann (_Phil. Mag._, Vol.

XXVIII. p. 97), 1807; Sir Richard Phillips, “Electricity and

Galvanism explained ...” (_Phil. Mag._, Vol. LVI. p. 195),

London, 1820; B. G. Sage, “Recherches ... Galvanisme”; Leopold

Nobili, “Sur le courant....” Genève, 1827.

=A.D. 1786.=--Hemmer (J. J.), celebrated physician and secretary

of the Meteor. Society of Mannheim, gives, in the “Transactions of the

Electoral Society,” an account of what have been pronounced the most

complete series of experiments ever made upon the electricity of the

human body. They absolutely show that the human subject possesses no

species of electrical organs which are under the regulation of the

will. Of his many observations, the following are worth recording: He

found that the electricity of the body is common to all ages and sexes;

that its intensity and character often vary in the same body (in 2422

experiments, it was 1252 times positive, 771 times negative and 399

times imperceptible); that the electricity of the body is naturally

positive, it being always so when subject to no violent exertion,

and that when the body is subjected to sudden or violent motion the

electricity becomes negative, the case also when the body experiences

either cold or extreme lassitude.

REFERENCES.--“Encycl. Brit.,” Vol. VIII, 1855, p. 571;

“Rheinische Beiträgen zur Gelehrsamkeit” for 1781, Fifth Book,

pp. 428–466; Van Swinden, “Recueil,” etc., La Haye, 1784, Vols.

I and II _passim_; “Observ. sur la Phys.,” July, 1780; _Phil.

Mag._, 1799, Vol. V. pp. 1, 140; “Comment. Acad. Theod.-Palat.,”

Vols. IV, V and VI of _Phys._; “Mém. de l’Acad. de Mannheim,”

Vol. IV; “Pfalzbayr. Beiträge” for 1782.