College, Cambridge, and later his chief assistant in the study of
the natural sciences, and who afterward became celebrated for his
physical investigations and discoveries, arrives at a like conclusion.
He thinks that “the electric appearances were only occasioned by the
great agitation which the electric fluid was put into by the shock
of so great a mass of the earth.” The great noise which attended the
disturbance of March 8, 1749, he conjectured was “owing to the rushing
or sudden expansion of the electric fluid at the top of St. Martin’s
spire, where all the electric effluvia, which ascended along the large
body of the tower, being strongly condensed, and accelerated at the
point of the weathercock, as they rushed off made so much the louder
expansive explosion.” It may be added here that Dr. Hales is the
one who, at a previous date, had communicated to the Royal Society
his observation of the fact that the electric spark proceeding from
warm iron is of a bright, light colour, while that from warm copper
is green, and the colour from a warm egg of a light yellow. In his
opinion, these experiments appeared to argue that some particles of
those different bodies are carried off in the electric flashes wherein
those different colours are exhibited.
For Stephen Hales, consult the _Phil. Trans._, Vol. XLV. p. 409, as
well as the abridgments of Hutton, Vol. IX. p. 534, and for his
portrait see “Essays in Historical Chemistry,” by T. E. Thorpe, London,
1894.
For Stukeley and for Stephen Hales: consult “General Biographical
Dictionary,” Alex. Chalmers, London, 1814, Vol. XVII. pp. 41–43.
REFERENCES.--Priestley, “History of Electricity,” Part I. period
x. s. 12; _Phil. Trans._, abridged by John Martyn, Part II.
of Vol. X. pp. 406–526, 535, 540, 541, 551; Vol. XLIV-XLV, p.
409; Appendix to the _Phil. Trans._ for 1750, Vol. XLVI; Hale,
“Statical Essays,” II. p. 291; Thomson, “Hist. Roy. Soc.,” 1812,
p. 197.
=A.D. 1749.=--Jallabert (Jean Louis), Professor of Philosophy and
Mathematics at Geneva, is the author of “Expériences sur l’électricité,
avec quelques conjectures sur la cause de ses effets,” of which a
smaller edition had appeared at Geneva in 1748.
He confirms the result obtained by Dr. Watson (A.D. 1745)
that the electric fluid takes the shortest course by passing through
the substance of a conducting wire instead of along its surface. By
making his Leyden experiments with a jar in which the water is frozen,
he shows that ice is a conductor of electricity. He improves upon
Nollet’s experiments, and demonstrates conclusively that plants which
are electrified grow faster and have finer stems, etc., than those not
electrified. He is the first to observe that a body pointed at one
end and round at the other produces different appearances upon the
same body, according as the pointed or the rounded end is presented to
it. The _Dantzig Memoirs_, Vol. II. p. 378, tell us that Carolus
Augustus Van Bergen, Professor of Medicine at Frankfort on Oder, had
previously noticed, “as a small step toward discovering the effect of
pointed bodies,” that sparks taken from a polished body are stronger
than those from a rough one. With the latter he found it difficult to
fire spirits, but he could easily do it with a polished conductor.
M. Jallabert is also known to have effected some medical cures through
the agency of the electric fluid, as related in the “Expériences” above
alluded to.
REFERENCES.--“Biog. Univ.,” Vol. XX. p. 535; Bertholon, “Elec.
du Corps Humain,” 1786, Vol. I. pp. 260, 292, 299, 334, 413, and
Vol. II. p. 291; Beccaria, “Dell’ Elettricismo Naturale,” etc.,
p. 125; “Journal des Sçavans,” Vol. CXLIX. for 1749, pp. 1–18,
441–461; “Medical Electricity,” by Dr. H. Lewis Jones, Philad.
1904, p. 2.
=A.D. 1749.=--Mines are fired by electricity (S. P. Thompson, lecture
delivered October 7, 1882, at the University College, Bristol).
=A.D. 1749.=--Through the important work entitled “Traité sur
l’Electricité,” Louis Elisabeth de la Vergne Tressan secures, a year
later, admission to both the French Académie des Sciences and the
English Royal Society. During 1786, three years after his death, the
above-named work was merged into a publication in two volumes under
the title of “Essai sur le fluide électrique considéré comme agent
universel.”
REFERENCES.--“Biographie Générale,” Vol. XLV. pp. 623–626;
Larousse, “Dictionnaire Universel,” Vol. XV. p. 474.
=A.D. 1749.=--Duhamel (Henri Louis, du Monceau) (1700–1782), member
of the French Royal Academy of Sciences, develops, in conjunction
with M. Antheaulme, the method introduced by Gowin Knight (A.D. 1746)
for making artificial magnets, which latter process was found to be
defective when applied to very large bars. To Le Maire, however, is due
(_Mem. de l’Acad. de Paris_, 1745 and 1750), the notable improvement
which consists in magnetizing at the same time two steel bars of any
shape by placing them parallel to each other and connecting their
extremities, with pieces of soft iron placed at right angles, in order
to form a closed rectangular parallelogram. Two strong magnets, or two
bunches of small magnetic bars, with their similar poles together, are
then applied to the centre of one of the bars to be magnetized and are
drawn away from each other, practically as in Dr. Knight’s method,
while being held at an inclination of about forty-five degrees. The
operation is repeated upon the other bar and continued alternately
until sufficient magnetism is imparted to both, it being borne in mind
that before the treatment is given to the second bar the poles must in
each instance be reversed, _i. e._ the pole which was to the right hand
should be turned to the left. The entire operation is to be repeated
upon the reverse side of both bars.
REFERENCES.--Harris, “Rudim. Magn.,” I. and II. pp. 85 and 86;
P. Larousse, “Dict. Univ.,” Vol. VI. p. 1363; “Biog. Générale,”
Vol. XV. pp. 106–107; Condorcet, “Eloge de Duhamel”; I. M. Des
Essarts, “Siècles littéraires”; Georges Cuvier, “Hist. des Sc.
Naturelles,” Vol. V; Thos. Thomson, “Hist. of the Roy. Soc.,”
London, 1812, p. 45.
=A.D. 1750–1753.=--In M. Arago’s “Historical Eloge of James Watt,”
translated by James P. Muirhead and published in London during the year
1839, it is said, at p. 6, that Watt constructed, at about the period
first mentioned herein, a small electrical (his earliest) machine, the
brilliant sparks from which became a subject of much amusement and
surprise to all the companions of the poor invalid (“James Watt,” by
Andrew Carnegie, New York, 1905).
=A.D. 1750.=--Wargentin (Pierre Guillaume--Perh Vilhelm--) (1717–1783),
Secretary to the Swedish Academy of Sciences and a distinguished
astronomer, addresses, on the 21st of February, a letter to the Royal
Society, of which a copy is to be found in Vol. XLVII. p. 126 of the
_Phil. Trans._ In this he gives his observations of the result produced
on the magnetic needle by the aurora borealis.
We have already seen (under the A.D. 1683 date), that the discovery
of the fact that magnets are affected by the polar lights has been
ascribed to Wargentin, and we have also learned (A.D. 1722) that he
ascertained the diurnal changes of the magnetic needle with more
precision than had been done by George Graham.
REFERENCES.--Walker, “Magnetism,” p. 116; _American Journal
Science and Arts_, 1841, Vol. XXX. p. 227; Celsius, A.D. 1740,
and the abridgments of Hutton, Vol. X. p. 165.
=A.D. 1750.=--Michell (John), an eminent English man of science,
Professor at Queens’ College, Cambridge, publishes “A treatise of
Artificial Magnets, in which is shown an easy and expeditious method of
making them superior to the best natural ones.”
The process introduced by this work is known as that of the “double
touch.” This consists in first joining, at about a quarter of an
inch distance, two bundles of strongly magnetized bars, having their
opposite poles together, and in drawing these bars backward and forward
upon and along the entire length of the bars to be magnetized, which
latter have already been laid down end to end and in a straight line.
The operation is to be repeated upon each side of the bars. The central
bars of a series thus acquire at first a higher degree of magnetism
than do the outer ones, but by transposing the latter and treating all
alike the magnetic virtue is evenly distributed. In this process the
external bars act the same part as do the pieces of soft iron employed
in the Duhamel method.
At Chap. VI. p. 20 of the third volume of his “Rudimentary Magnetism,”
Harris thus expresses himself: “Michell advanced the idea that in
all the experiments of Hauksbee, Dr. Brooke Taylor, William Whiston
and Musschenbroek, the force may really be in the inverse duplicate
ratio of the distances, proper allowance being made for the disturbing
changes in the magnetic forces so inseparable from the nature of the
experiment. He is hence led to conclude that the true law of the force
is identical with that of gravity, although he does not set it down as
certain.”
REFERENCES.--Harris, “Rud. Mag.,” I. and II. pp. 94–95; C. R.
Weld, “Hist. Roy. Soc.,” Vol. I. p. 512; _Phil. Trans._, Vol.
LI. pp. 390, 393, and Hutton’s abridgment, Vol. XI. p. 418;
Gaugain’s observations in “Sc. Am. Suppl.,” No. 7, p. 99.
=A.D. 1750.=--Boulanger--not Boullangère--(Nicholas Antoine)
(1722–1759), a well-known French writer, whose extensive studies were
interrupted by his death, in 1759, at the early age of thirty-seven,
gives, in this “Traité de la cause et des phénomènes de l’électricité,”
accounts of many important observations made in the electrical field.
His attention was carefully given to ascertaining the degrees in which
different substances are capable of being excited, and he gives several
lists of such, inferring therefrom that the most transparent and the
most brittle are always the most electric.
At pp. 64 and 124 of the above-named “Traité” he states that
electricity affects mineral waters much more sensibly than common
water; that black ribbons are more readily attracted than those
of other colours, next to the black being the brown and deep red;
and that, of two glass cylinders exactly alike, except that one is
transparent and the other slightly coloured, the transparent one will
be the more readily excited.
REFERENCES.--The “Traité,” notably at pp. 135 and 164; “Biog.
Générale,” Vol. VI. p. 939; Le Bas, “Dict. Encycl. de la
France”; Quérard, “La France Littéraire”; Chaudon et Delandine,
“Dict. historique.”
=A.D. 1751.=--Adanson (Michael), a French naturalist of very high
reputation, who, before the age of nineteen, had actually described
four thousand species of the three kingdoms of nature, introduces in
his “History of Senegal” the _silurus electricus_, a large species
of eel originally brought from Surinam. Sir John Leslie states that
the _silurus_ is furnished with a very peculiar and complex nervous
apparatus which has been fancifully likened to an electrical battery,
and that, from a healthy specimen exhibited in London, vivid sparks
were drawn in a darkened room. M. Broussonet alludes to the _silurus_
as _Le Trembleur_ in the “Hist. de l’Acad. Royale des Sciences” for
1782, p. 692.
Adanson also called attention, in 1756, to the electrical powers of
the _malapterus electricus_, but, according to the able naturalist,
James Wilson (“Ichthyology,” _Encycl. Brit._), there is a much earlier
account of the fish extracted from the narrative of Baretus and Oviedo
dated 1554.
The Swedish scientist, Karl A. Rudolphi, pupil of Linnæus, called the
_princeps helminthologorum_, has given a detailed description as well
as illustrations of the electric organs of the _malapterus_ in “Ueber
den Zitter-wels,” _Abh. Berl. Acad._ VII.... This fish, which the
Arabs call _Raad_ or _Raash_ (thunder), gives its discharge chiefly
when touched on the head, but is powerless when held by the tail, the
electrical organs in fact not reaching the caudal fin.
To Adanson has been attributed the authorship of an essay on the
“Electricity of the Tourmaline” Paris, 1757, which bears the name of
the Duke de Noya Caraffa.
REFERENCES.--Spreng, “Hist. R. Herb.,” Vol. II; and “Adanson’s
Biog.,” Vol. II. “Encycl. Britannica,” Rees’ “Cycl.” Supplement
and in “Bibl. Universelle,” Vol. I; Chambers’ “Encyl.” for 1868,
Vol. III. p. 822; Cavallo, “Nat. Phil.,” Philad., 1825, Vol. II.
p. 237; _Scientific American Supplement_, No. 457, pp. 7300,
7301; Rozier, Vol. XXVII. p. 139, and W. Bryant in _Trans. Am.
Phil. Soc._ II. p. 166, O. S.
=A.D. 1752.=--Franklin (Benjamin) (1706–1790), an able American
editor, philosopher and statesman, crowns his many experiments with
the brilliant discovery of the identity of electricity and lightning.
Humboldt says: “From this period the electric process passes from the
domain of speculative physics into that of cosmical contemplation--from
the recesses of the study to the freedom of nature” (“Cosmos,” Vol. II.
1849, p. 727). Wall (A.D. 1708) had only alluded to the resemblance of
electricity to thunder and lightning; Grey (A.D. 1720) had conjectured
their identity and implied that they differed only in one degree, while
Nollet (A.D. 1746) pointed out a closer relationship than ever before
adduced between lightning and the electric spark; but it was left for
Franklin to prove the fact with empirical certainty.
Franklin’s attention was first directed to electrical studies in 1745,
by a letter from Peter Collinson, Fellow of the Royal Society of
London, to the Literary Society of Philadelphia, and he first wrote
on the subject to that gentleman on the 28th of July, 1747. This was
followed by several other similar communications up to April 18, 1754,
the whole of which comprise most of what subsequently appeared under
the title “New Experiments and Observations on Electricity, made at
Philadelphia, in America, by Benjamin Franklin, LL.D. and F.R.S.”
Franklin first entertained the idea that lightning was not likely to
be attracted by a pointed rod unless the latter was placed at a great
height, and he therefore waited for the erection of a tall spire in
Philadelphia which he intended to utilize for his observations, but
delay in its completion led him to use a kite pointed with an iron rod,
not doubting that the electric fluid could, during a thunderstorm, be
drawn from it through a string.
The manner of constructing and employing the kite, and the attending
results, are thus given in a letter dated Oct. 19, 1752 (Letter XII,
“Experiments and observations on Electricity”): “Make a small cross
of two light strips of cedar, the arms so long as to reach to the
four corners of a large thin silk handkerchief when extended. Tie the
corners of the handkerchief to the extremities of the cross, so you
have the body of a kite which, being properly accommodated with a
tail, loop and string, will rise in the air like those made of paper;
but, this being made of silk, is fitter to bear the wet and wind of a
thunder-gust without tearing. To the top of the upright stick of the
cross is to be fixed a very sharp-pointed wire, rising a foot or more
above the wood. In the end of the twine, next the hand, is to be held a
silk ribbon, and where the silk and twine join a key may be fastened.
This kite is to be raised when a thunder-gust appears to be coming on,
and the person who holds the string must stand within a door or window,
or under some cover, so that the silk ribbon may not be wet, and care
must be taken that the twine does not touch the frame of the door or
window. As soon as any of the thunder clouds come over the kite, the
pointed wire will draw the electric fire from them, and the kite with
all the twine will be electrified, and the lose filaments of the twine
will stand out every way and be attracted by an approaching finger. And
when the rain has wetted the kite so that it can conduct the electric
fire freely, you will find it stream out plentifully from the key on
the approach of your knuckle. At this key, the phial (Leyden jar)
may be charged, and from electric fire thus obtained spirits may be
kindled, and all the other electric experiments be performed which are
usually done by the help of a rubber glass globe or tube, and thereby
the sameness of the electric matter with that of lightning completely
demonstrated.”
It was during the month of June 1752, on the approach of a storm, that
he and his son walked out upon the Philadelphia Commons and first
raised the kite. At the outset no important results were obtained,
but as soon as the cord became wet by the shower that followed, the
electric sparks were easily drawn from the key and enabled Franklin to
charge and give shocks from a Leyden jar.
Thus, says Sabine, was Benjamin Franklin successful in one of the
boldest experiments ever made by man upon the powers of nature, and
from that moment he became immortal.
He had already, in 1749, made public the following, which is
embodied in one of his letters to Mr. Collinson: “The electrical
spark is zigzag, and not straight; so is lightning. Pointed bodies
attract electricity; lightning strikes mountains, trees, spires,
masts and chimneys. When different paths are offered to the escape
of electricity, it chooses the best conductor; so does lightning.
Electricity fires combustibles; so does lightning. Electricity fuses
metals; so does lightning. Lightning rends bad conductors when it
strikes them; so does electricity when rendered sufficiently strong.
Lightning reverses the poles of a magnet; electricity has the same
effect.”
Franklin had, likewise, published at about the same period the plan
for an experiment to ascertain from elevated structures whether the
clouds that contain lightning are electrified or not. He himself had
proposed to put the plan to execution; but he was led to try the kite
experiment, and, meanwhile, his suggestions had been successfully acted
upon, in France, by M. Dalibard and de Lor, as will be shown later on.
“The lightning, which doth cease to be, ere one can say, ‘it
lightens.’”--Shakespeare.
“First let me talk with this philosopher; what is the cause of
thunder?”--Shakespeare.
“... a way for the lightning of the thunder.”--Job xxviii. 26,
and xxxviii. 25.
“It related not to the instances of the _magneticalness_ of
lightning.”--“Hist. of Roy. Soc.,” by Thomas Birch, Vol. IV. p.
253.
When specifying the great points of coincidence existing between the
ordinary electric discharge and lightning, Franklin, as already partly
stated, had remarked that flashes of lightning are frequently waving
and crooked, of a zigzag or forked appearance, sometimes diffused
and sometimes coloured (“On the Nature of Thunderstorms,” W. Snow
Harris, London, 1843, p. 24; Priestley, “History and Present State
of Electricity,” London, 1769, p. 166; “Encycl. Metropol.,” article
“Electricity”; Biot, “Traité de Physique,” Vol. II). In treating of
the subject of lightning flashes, Dr. L. D. Gale (trans. of M. F. J.
F. Duprez’s paper on “Atmospheric Electricity,” taken from the memoirs
of the Royal Academy of Brussels) alludes to the attempts made by C.
G. Helvig to determine the velocity of the linear flashes (Gilbert’s
_Annalen_, Vol. LI. pp. 136 and 139, ss. 2, 10) which he estimated to
be 40,000 to 50,000 feet in a second, and states that M. Weigsenborn,
of Weimar (_Comptes Rendus_, Vol. IX. p. 218), calculated the velocity
of a flash observed in 1839 to be more than two leagues, while M.
François Arago (“Annuaire,” etc., pour l’année 1838, pp. 249, 255,
257, 459, estimated the lengths of certain flashes to be 3·3, 3·6,
3·8 leagues. The views of Messrs. Logan (_Phil. Trans._, 1735, Vol.
XXXIX. p. 240), L. J. Gay-Lussac (_Ann. de Chim. et de Phys._, 1805,
Vol. XXIX. p. 105), H. W. Brandes (“Beiträge zur Witterungskunde,”
etc., 1820, p. 353), C. H. Pfaff and L. E. Kaemtz (J. S. T. Gehler,
“Dict. de Phys.,” Vol. I. p. 1001, and “Lehrbuch d. Meteor,” Vol. II.
p. 430), Gabriel Lamé (“Cours. de Phys. de l’Ecole Polytech.,” Tome II.
2^e partie, p. 82), Becquerel (_Comptes Rendus_, 1839, Tome VIII. p.
216), Faraday (_Philos. Magazine_, 1841, Vol. XIX. p. 104), Pouillet
(“Eléments de Phys. et de Météor,” Tome II. p. 808), Parrot (J. S. T.
Gehler, “Dict. de Phys.,” Vol. I. p. 999), are also set forth in the
above-named translation of M. Duprez’s valuable work.
Humboldt informs us that “the most important ancient notice of
the relations between lightning and conducting metals is that of
Ctesias, in his _Indica_, Cap. IV. p. 169. He possessed two iron
swords, presents from the King Artaxerxes Mnemon, and from his mother
Parysatis, which, when planted in the earth, averted clouds, hail and
_strokes of lightning_. He had himself seen the operation, for the king
had twice made the experiment before his eyes” (“Cosmos,” Vol. II. N.
186). Ctesias was a man of great learning. He was a contemporary of
Xenophon, and lived for a number of years at the Court of Artaxerxes
Mnemon as private physician to the king. Diodorus states that Ctesias
was highly honoured at the Persian court. An abridged edition of the
_Indica_ was printed by Stephens in 1594 (“Hist. Roy. Soc.,” C. R.
Weld, London, 1848, Vol. II. p. 93; “La Grande Encyclopédie,” Vol.
XIII. p. 536; “Biographie Générale,” Vol. XII. p. 568).
In imitation of Franklin, Doctor Lining, of Charleston, in South
Carolina, sent a kite into a thunder cloud, and by that means
dissipated the lightning (_Philosophical Transactions_ for 1754, Vol.
XLVIII. p. 757).
The opinion entertained by Franklin regarding the nature of electricity
differs from that previously submitted by Dufay (A.D. 1733),
in the manner shown by Noad at p. 6 of his Manual, London, 1859 edition.
What Dufay considered to be two distinct species of electricities,
_vitreous_ and _resinous_, Franklin conceived to be two different
states of the same electricity, which he called _positive_ and
_negative_. This, which constitutes the foundation of the present
theory of electricity, is usually called the Franklinian theory, but it
can be said to belong equally to Dr. Watson, for he had communicated it
to the Royal Society before Franklin’s opinion on the subject was known
in England (_Phil. Trans._ for 1748, Vol. XLV. pp. 49, 491; Thomson,
“Hist. Roy. Soc.,” p. 436). Noad, in paragraph 12, applies the latter
theory to the case of a charged Leyden jar, alluding to Franklin’s
discovery of the location of electricity in the jar, wherefrom is
drawn the conclusion that it is upon the glass that the electricity
is deposited, and that the conducting coatings serve “only, like the
armature of the loadstone, to unite the forces of the several parts and
bring them at once to any point desired” (see “Œuvres de Franklin,”
trans. of Barbeu-Dubourg, Tome II. p. 16, 3^e lettre).
Of his _plus_ and _minus_ theory, Franklin thus wrote to Mr. Collinson:
“To electrise _plus_ or _minus_ no more needs to be known than this,
that the parts of the tube or sphere that are rubbed do, in the
instant of the friction, attract the electrical fire, and therefore
take it from the thing rubbing; the same parts, immediately as the
friction upon them ceases, are disposed to give the fire they have
received to any body that has less.”
In an appendix to his official report as U.S. Commissioner at the
Paris Universal Exposition of 1867, entitled “Franklin and Electrical
Semaphores,” Professor Samuel F. B. Morse, LL.D., expressed himself as
follows:
“It has frequently been asserted (on what authority I know not) that
the first idea of an electric semaphore originated with Franklin. I
have sought in vain in the publication of Franklin’s experiments and
works for anything confirmatory of this assertion. On mentioning the
subject to my friend Professor Blake, he kindly proposed examining the
writings of Franklin in order to elicit the truth. From him I have
received the following:
“‘I consulted several works for the purpose of ascertaining, if
possible, the foundation for the statement that Franklin suggested the
idea of semaphores by static electricity. I have not yet found any
such suggestion, but I have noted that, following the experiments by
Dr. Watson and others, in England, to determine the _velocity_ of
the electric discharge, and the time supposed to be required for the
electrical discharges across the Thames, by which spirits were kindled,
etc. (in 1747), Dr. Franklin (in 1748) made some similar experiments
upon the banks of the Schuylkill, and amused his friends by sending a
spark “from side to side through the river without any other conductor
than the water” (vide Priestley’s “History of Electricity”). This was
in 1748, at the end of the year. In 1756 “J. A., Esq.,” of New York
(James Alexander), presented to the Royal Society a proposition “to
measure the time taken by an electric spark in moving through any
given space” by sending the discharge or spark down the Susquehanna or
Potomac, and round by way of the Mississippi and Ohio rivers, so that
the “electric fire” would have a circuit of some thousands of miles to
go. All this was upon the supposition or assumption that the electric
fire would choose a continuous water conductor rather than to return
or pass through the earth. Franklin presented a paper in reply, in
which he says “the proposed experiment (though well imagined and very
ingenious) of sending the spark round through a vast length of space,
etc. etc., would not afford the satisfaction desired, though we could
be sure that the motion of the electric fluid would be in that tract,
and not underground in the wet earth by the shortest way”’ (‘Franklin’s
Experiments on Electricity, and Letters and Papers on Philosophical
Subjects,’ 4to, London, MDCCLXIX, pp. 282, 283).
“Can it be possible that Franklin’s experiment of firing spirits and
showing the spark and the effects of the electric discharge across the
river originated, or forms the foundation for, the statement that he
suggested the semaphoric use of electricity?”
After speaking of the experiments, to which allusion was made (at
Watson, A.D. 1745), Franklin writes: “... It is proposed to
put an end to them for this season, somewhat humorously, in a party of
pleasure, on the banks of the Schuylkill. Spirits at the same time are
to be fired by a spark sent from side to side through the river without
any other conductor than the water--an experiment which we some time
since performed to the amazement of many. A turkey is to be killed for
our dinner by the electrical shock, and roasted by the electrical jack,
before a fire kindled by the electrified bottle, when the healths of
all the famous electricians in England, Holland, France and Germany are
to be drank in electrified bumpers under the discharge of guns from the
electrical battery.”
It was toward the close of the year 1750 that Franklin entertained the
practicability of a lightning conductor (see Winckler, A.D.
1733), and, for this, he says, he was indebted to an experiment made
by his friend Mr. Thomas Hopkinson (vide Franklin’s “Complete Works,”
London, 1806, Vol. I. p. 172). In his “Poor Richard’s Almanac” for
1753, he refers to the lightning rod as security for “habitations and
other buildings from mischief by thunder and lightning.”
REFERENCES.--J. B. Le Roy, “Lettera al Rozier,” etc., Milano,
1782; “Rec. de Mém. de l’Acad. des Sc.” for 1770 and 1773;
_Jour. de Phys._, 1773, Vol. II; Memoirs of M. Beyer, Paris,
1806–1809, and Delaunay’s explanation of his theories at pp.
193–198 of his 1809 Manuel.
The many notable observations, experiments and discoveries of Franklin
are nowhere more ably reviewed than by his great admirer Dr. Priestley,
who devotes much space thereto in his justly celebrated work on
electricity.
At p. 92 of his “New Experiments,” etc., London, 1774, Franklin alludes
to the failure of many European electricians in firing gunpowder by the
electric spark, and gives his own method by using a battery of four
large glass jars, while at p. 423 of the London edition of his “Letters
and Papers,” etc., Franklin relates curious observations which are
worth mentioning here. He says that he sent a charge of electricity
“through a small glass tube that had borne it well when empty, but when
filled with water was shattered to pieces and driven all about the
room. Finding no part of the water on the table, I suspected it to have
been reduced to vapour. I was confirmed in that suspicion afterward
when I had filled a like piece of tube with ink and laid it on a sheet
of paper, whereon after the explosion I could find neither any moisture
nor any sully from the ink. This experiment of the explosion of water,
which I believe was first made by that most ingenious electrician,
Father Beccaria, may account for what we sometimes see in a tree struck
by lightning, when part of it is reduced to fine splinters like a
broom; the sap vessels being so many tubes containing a watery fluid,
which, when reduced to vapour, sends every tube lengthways. And,
perhaps it is this rarefaction of the fluids in animal bodies killed
by lightning or electricity, that by separating its fibres renders
the flesh so tender and apt so much sooner to putrefy. I think, too,
that much of the damage done by lightning to stone and brick walls may
sometimes be owing to the explosion of water found during showers,
running or lodging in the joints or small cavities or cracks that
happen to be in the walls.”
REFERENCES.--Majus--May--(Heinrich), “Disp. de fulmine” and
“Disp. de tonitru,” Marp., 1673, as at Pogg., _Annalen_, Vol.
II. p. 21; Giuseppe Saverio Poli, “La formazione del Tuono,”
etc., 1772, and his other works on the same subject which
appeared during the years 1773, 1779 and 1787; _Phil. Trans._
for 1751, Vol. XLVII. pp. 202, 289, 362; W. de Fonvielle,
“Eclairs et Tonnerres”; “Terrestrial Magn.” for June 1903;
_Jour. of the Franklin Institute_ for 1836, Vol. XVII., p.
183; M. le Docteur Sestier, “De La Foudre”; “Lightning-Rod
Conference,” Reports of Delegates, by G. J. Symons, 1882;
Chap. III. s. 3, vol. i. of Van Swinden’s “Recueil,” etc.,
1784; _Lumière Electrique_, Tome XL. No. 23, p. 497; Giovanni
Cardan’s work, Lyons, 1663; “Library of Literary Criticism,”
C. W. Moulton, Buffalo, 1901–1902, Vol. IV. pp. 79–106; “An
Outline of the Sciences of Heat and Electricity,” by Thos.
Thomson, London, 1830, pp. 347, 423, 432–433; “The Electrical
Researches of the Hon. Henry Cavendish,” Cambridge, 1879, Nos.
350, note, 363; “Works of Benj. Franklin,” Jared Sparks, London,
1882; _Phil. Trans._, Vols. XLVII. p. 565; XLIX. pp. 300, 305,;
L. p. 481; LI. p. 525; LII. 456; also Hutton’s abridgments,
Vol. X. pp. 189, 212, 301, 629, 632; Vol. XI. pp. 189, 435,
609; “Bibliothèque Britannique,” Genève, 1796, Vol. LI. p. 393
(letter to M. Marc Auguste Pictet); Stuber, “Continuation of
the Life of Dr. Franklin”; “An Essay on the Nature of Heat,
Light and Electricity” (on the Franklinian hypothesis), by Chas.
Carpenter Bompass, London, 1817, Chap. III. s. 3, p. 217; “List
of Books written by or relating to Franklin,” by Paul L. Ford,
1889; L. Baldwin, “Mem. of Amer. Acad.,” O. S. I. part i. p.
257; Sturgeon’s “Researches,” p. 524; J. Bart. Beccari, “De
Artif. elect ...”; likewise all the references that are given
at pp. 26–27 of Ronalds’ “Catalogue”; “Journal des Savants” for
June 1817, pp. 348–356.
=A.D. 1752.=--Dalibard (Thomas François), French botanist and amateur
in physics, carries out very carefully the suggestions embodied in
Franklin’s printed letters and constructs an atmospherical conductor at
Marly-la-Ville, about eighteen miles from Paris, where Nollet likewise
experimented. Dalibard’s apparatus consisted of a pointed iron rod,
one inch in diameter and about forty feet long, which was protected
from the rain by a sentry box and attached to three long wooden posts
insulated by silken strings.
On the 10th of May, 1752, during Dalibard’s absence, an old soldier
by the name of Coiffier, who was at the time employed as a carpenter
and who had been left in charge, on observing the approach of a storm,
hurried to the apparatus prepared to carry out the instructions
previously given him. It was not long before he succeeded in obtaining
large sparks on presenting a phial to the rod, and these sparks, which
were all accompanied by a large snapping noise, were likewise obtained
by the curate of Marly, M. Raulet, whom he had sent for and with whose
aid Coiffier subsequently succeeded in charging an electric jar. On the
13th of May, Dalibard made, to the French Academy of Sciences, a report
of the results thus obtained by Coiffier, to whom, it may be said,
properly belongs the distinction of having been _the first man who
saw the electric spark drawn from the atmosphere_.
On the 18th of the same month of May, M. de Lor, of the French
University, drew similar sparks from a rod ninety-nine feet high at
his house in the Estrapade, at Paris, and the same phenomenon was
afterward exhibited to the French King. It is said that the conductor
afforded sparks even when the cloud had moved at least six miles from
the place of observation. Other experiments of a like nature were made
a few days later by Buffon at Montbar, and, during the ensuing months
of July and August, in the vicinity of London, by Canton, who, it is
said, succeeded in drawing atmospheric electricity by means of a common
fishing rod (Dissertation Fifth, Eighth “Britannica,” Vol. I).
An account of the Dalibard and de Lor experiments was transmitted by
the Abbé Mazéas, on the 20th of May, to the Royal Society of London.
Mazéas erected, in the upper section of his residence, a magazine
consisting of several insulated iron bars connected with the pointed
rod. The lightning was brought into the house by means of a projecting
wooden pole, having at its extremity a glass tube filled with resin
which received a pointed iron rod twelve feet long. This apparatus was,
however, too much exposed to afford reliable observations, and Mazéas
therefore arranged to make more accurate experiments at the Château
de Maintenon, during the months of June, July and October 1753. The
results he obtained were communicated to the English Royal Society by
Dr. Stephen Hales. The letters of the Abbé Mazéas to the Rev. Stephen
Hales, detailing some of M. Le Monnier’s experiments as well as
observations made by M. Ludolf at Berlin and transmitted by M. Euler,
are to be found at pp. 354–552, Vol. XLVII. _Phil. Trans._ for 1753.
For Mazéas, see also _Phil. Trans._, Vol. XLVII. p. 534, Vol. XLVIII.
part i. p. 377, and Hutton’s abridgments, Vol. X. pp. 289, 434.
Thomas Ronayne in Ireland, and Andrew Crosse[51] in England (see
“Account of an apparatus for ascertaining and collecting the
electricity of the atmosphere”) made use of long wires in horizontal
positions insulated by being attached to glass pillars, but Mazéas, in
his Maintenon experiments, attached the iron wire by a silken cord to
the top of a steeple ninety feet in height, whence it entered an upper
room of the castle, a total distance of 370 feet. With this, Mazéas
ascertained that electric effects are produced at all hours of the
day during clear, dry and particularly hot weather, the presence of
a thunderstorm not being requisite for the production of atmospheric
electricity. In the driest summer nights he could discover no signs of
electricity in the air, but when the sun reappeared the electricity
accompanied it, to vanish again in the evening about half an hour after
sunset.
REFERENCES.--W. Sturgeon, “Lectures,” London, 1842, pp. 182,
183; _Phil. Trans._, Vol. XLVIII. part i. pp. 370, 377, etc.;
Dalibard’s “Franklin,” Vol. II. p. 109, etc.; “Mém. de l’Acad.
des Sciences,” for May, 1762; Nollet, “Letters,” Vol. I. p. 9;
Franklin’s Works, Vol. V. p. 288; English Cyclopædia, “Arts and
Sciences,” Vol. III. pp. 804–805; “Letters of Thomas Ronayne, to
Benjamin Franklin,” at p. 137 of Vol. LXII of _Phil. Trans._,
likewise Ronayne both in _Journal de Physique_, Tome VI, and
in the _Phil. Trans._ for 1772, Vol. LII. pp. 137–140; also
Hutton’s abridgments, Vol. XIII. p. 310; Geo. Adams, “Essay on
Elect.,” London, 1785, p. 259.
=A.D. 1752.=--Freke (John), surgeon to St. Bartholomew’s Hospital,
London, gives, in the Second Part of “A Treatise ... of Fire,” the
third edition of his “Essay to Show the Cause of Electricity,” etc.,
originally published in 1746, while in the Third Part of the same work
he shows the “Mechanical Cause of Magnetism, and why the compass varies
in the manner it does.”
He says (pp. 90–91): “It had been impossible that this wonderful
_Phenomenon_ of Electricity should ever have been discovered, if there
had not been such things as are non-electricable; for, as fast as this
Fire had been driven on anything its next neighbour would have carried
it farther; but, when it was most wonderfully found, that anything
which was suspended on a silk cord (that being non-electricable) was
obliged to retain the Fire, which by Electrical Force was driven on
it; and when, moreover, it appeared, that any person or thing, being
placed on a cake of beeswax (which is also a non-electricable) could
no more part with its Fire than when suspended in [_sic_] a silk
cord; I think it will become worthy of inquiry, why they are not
electricable.” And, at p. 136, he adds: “I think it a great pity that
the word _Electricity_ should ever have been given to so wonderful a
_Phenomenon_, which might properly be considered as the first principle
in nature. Perhaps the word _Vivacity_ might not have been an improper
one; but it is too late to think of changing a name it has so long
obtain’d.” In the Third Part, he explains that “by the Fire passing
from and to the Sun, it so pervades iron aptly placed, as to make it
attractive and produce the various operations of magnetism.”
REFERENCE.--“Gentleman’s Magazine,” London, Vol. XVI for 1746,
pp. 521, 557.
=A.D. 1752.=--In this year was published at Leipzig the “Biblia
Naturæ,” written by John Swammerdam, a celebrated Dutch natural
philosopher (1637–1682), all of whose works were translated into
English and published in folio during the year 1758.
In the second volume of the _Biblia_, he thus alludes to one of many
experiments made by him in 1678, before the Grand Duke of Tuscany: “Let
there be a cylindrical glass tube in the interior of which is placed a
muscle, whence proceeds a nerve that has been enveloped in its course
with a small silver wire, so as to give us the power of raising it
without pressing it too much or wounding it. This wire is made to pass
through a ring bored in the extremity of a small copper support and
soldered to a sort of piston or partition; but the little silver wire
is so arranged that on passing between the glass and the piston the
nerve may be drawn by the hand and so touch the copper. The muscle is
immediately seen to contract.”
Through Swammerdam, the Germans lay claim to the origin of what
has been called galvanism. It certainly cannot be denied that the
above-described experiment closely resembles that which made Galvani
famous (A.D. 1786).
REFERENCES.--Swammerdam’s Biography, also Dissertation Fifth,
in the eighth edition “Encycl. Brit.”; the note at p. 491 of
Ronalds’ “Catalogue”; “Gen. Biog. Dict.,” London, 1816, Vol.
XXIX. pp. 45–47; Eloy, “Dict. Hist. de la Méd.,” Vol. IV;
“Biog. Générale,” Vol. XLIV. pp. 706–708; Cuvier, “Hist. des
Sc. Naturelles,” Vol. II. pp. 427–433; Schelhorn, “Amænitates
liter.,” Vol. XIV; “Biblioth. Hulthemiana,” Gand, 1836, Vol. II;
Boerhaave, Preface to “Biblia Naturæ.”
=A.D. 1752.=--On the 16th of April, 1752, is read before the Royal
Society a letter written by John Smeaton, a very prominent English
engineer and inventor (1724–1792), to Mr. John Ellicot, giving an
account of the electrical experiments _in vacuo_ made with his
improved air pump at the request of Mr. Wilson. This account, fully
illustrated, appears in the Society’s Vol. LXVII for the years 1751 and
1752, pp. 415–428.
He observes that, upon heating the middle of a large iron bar to
a great heat, the hot part can be as strongly electrified as the
cold parts on each side of it. He also finds that if anybody who is
insulated presses the flat part of his hand heavily against the globe,
while another person standing upon the floor does the same, in order to
excite it, the one who is insulated will hardly be electrified at all;
but that, if he only lays his fingers lightly upon the globe, he will
be very strongly electrified.
REFERENCES.--Wilson, “Treatise on Electricity,” pp. 129–216;
_Phil. Trans._ XLVI. p. 513; “Dict. of Nat. Biography,” Vol.
LII. pp. 393–395; “Biog. Univ.” (Michaud), Vol. XXXIX. p. 445;
Smile’s “Lives of the Engineers--Smeaton and Rennie”; Flint’s
“Mudge Memoirs,” Truro, 1883.
=A.D. 1752–1753.=--M. de Romas, Assessor to the Presideal of Nerac,
in France, repeats the experiment of Benjamin Franklin, and succeeds
finally in bringing from the clouds more electricity than had before
been taken by any apparatus.
He constructed a kite seven feet five inches high and three feet wide,
with a surface of eighteen square feet, and, having wound fine copper
wire around a strong cord through its entire length of about eight
hundred feet, he raised the kite to a height of five hundred and fifty
feet on the 7th of June, 1753. Sparks two inches in length were at
first drawn by a discharging rod, and, when the kite was afterwards
allowed to reach an elevation of six hundred and fifty feet, he
received many flashes one foot long, three inches wide and three lines
diameter, accompanied by a noise audible at as great a distance as five
hundred feet.
On the 16th of August, M. de Romas raised the kite with about one
thousand feet of string and obtained thirty beams of fire, nine or ten
feet long and about an inch thick, accompanied by a noise similar to
that of a pistol shot (“Encycl. Britannica,” eighth edition, Vol. VIII.
p. 582). Three years later, August 26, 1756, and also during the year
1757, De Romas obtained similar results from numerous experiments.
He finally apprehended much danger from the raising of the kite and
thereafter coiled the string upon a small carriage, which he drew along
by means of silken lines as the cord was being unwound.
The researches of De Romas concerning the electricity of isolated
metallic bars are embraced in six letters addressed by him to the
Bordeaux Academy of Sciences between July 12, 1752, and June 14, 1753.
It is reported that they have never been printed and that they are
kept, together with other manuscript matter of the same physicist, in
the private archives of the institution.
The experiments of De Romas upon isolated bars were first repeated by
Boze at Wittenberg, by Gordon at Erfurt, and by Lomonozow in Russia
(_Phil. Trans._, Vol. XLVIII. part ii. p. 272). M. Veratti, of Bologna,
obtained the electric spark in all weathers, through a bar of iron
resting in sulphur, and Th. Marin, of the same city, by means of a long
iron pole erected upon his dwelling, studied the relationship of rain
and atmospheric electricity (Musschenbroek, “Cours de Physique” Vol. I.
p. 397).
REFERENCES.--_Journal des Sçavans_ for October, 1753, p. 222;
“Mémoire sur les moyens,” etc., par De Romas, Bordeaux, 1776;
Sturgeon’s “Annals,” etc., Vol. V. p. 9; Harris, “Electricity,”
p. 176; Priestley, “History,” etc., 1775, pp. 326–329; “Mémoires
de Mathématique,” etc., Vol. II. p. 393, and Vol. IV. p. 514;
“Etude sur les travaux de De Romas,” p. 491, by Prof. Mergey, of
Bordeaux, which latter work won a prize for its author in 1853;
Becquerel, “Traité expérimental,” etc., 1834, Vol. I. pp. 42–43;
likewise the results obtained by Prof. Charles in “Traité de
Physique Expérimentale,” etc., par Biot, Paris, 1816, Vol. II.
pp. 444, 446, and in Peltier’s Introduction to his “Observations
et Recherches Expérimentales,” etc., Paris, 1840, p. 7, as well
as Brisson’s “Dict. de Phys.,” Paris, 1801, Vol. II. p. 174, and
“Mémoires des Savants Etrangers,” 1755, Vol. II. p. 406.
=A.D. 1753=.--M. Deslandes, member of the French Royal Academy of
Sciences, is the author of “Recueil de Différents traités de Physique,”
the third volume of which contains his memoir on the effects of thunder
upon the mariner’s compass. He alludes to the observations made thereon
by Dr. Lister of London (well known by his “Historiæ Animalium Angliæ,”
Lugd., 1678), as well as to many experiments made by Musschenbroek and
by others noted in the _Philosophical Transactions_.
=A.D. 1753.=--Prof. George William Richmann (1711–1753), native
of Sweden and member of the Imperial Academy of St. Petersburg, who
had already constructed an apparatus for obtaining atmospherical
electricity according to Franklin’s plans, was attending a meeting of
the Russian Academy of Science, on the 6th of August, 1753, when his
ear caught the sound of a very heavy thunder clap. He hastened away
in company with his engraver, M. Sokolow, and upon their arrival home
they found the plummet of the electrometer elevated four degrees from
the perpendicular. Richmann stooped toward the latter to ascertain the
force of the electricity, and “as he stood in that posture, a great
white and bluish fire appeared between the rod of the electrometer
and his head. At the same time a sort of steam or vapour arose, which
entirely benumbed the engraver and made him sink on the ground.”
Sokolow recovered, but Richmann had met with instant death.
REFERENCES.--“Library of Useful Knowledge,” London, 1829;
“Electricity,” p. 59, also p. 33; “Lettre sur la mort de
Richmann,” par C. A. Rabiqueau, Paris, n. d.; “Comment. Acad.
Petrop.,” XIV. pp. 23, 301–302, also the “Novi Comment.,” IV.
pp. 25, 235 and 299; “Biog. Générale,” Vol. XLII. p. 258;
“Gentleman’s Magazine,” London, Vol. XXIII., 1753, p. 431 and
Vol. XXV. for 1755, p. 3; Singer, “Electricity,” p. 217; Harris,
“Electricity,” p. 177; _Phil. Trans._, Vol. XLVIII. part ii.
pp. 763–765, 772; also Vol. XLIX. part i. pp. 61, 67, and the
abridgments by Hutton, Vol. X. pp. 525, 574–577; “La physique
à la portée de tout le monde,” par le Père Paulian, Vol. II.
p. 357; “Hist. de l’Acad. des Sciences,” pour 1753, p. 78;
“Franklin in France,” 1888, Part. I. p. 5.
=A.D. 1753.=--Canton (John), an English savant (1718–1772), announces
his most important discovery that vitreous or resinous electricity
may be produced at will in the same tube. This he proves on taking a
tube, which had been roughened by grinding it with thin sheet-lead
and flour-of-emery mixed with water, and which developed vitreous
electricity when rubbed with dry oil silk, and resinous or negative
electricity when rubbed with new flannel. Rough quartz will, it is
said, show like results. He also took a tube, of which only one-half
had been made rough while the other half was polished, and he
demonstrated that the different electricities are produced at a single
stroke with the same rubber.
He likewise discovered that the exciting power of the rubber or cushion
of the electrical machine will be very greatly increased by applying to
it an amalgam of mercury and tin mixed with a little chalk or whiting
(see Winckler, at A.D. 1733, for the introduction of the
cushion).
His very remarkable experiments upon many descriptions of tourmaline,
reported to the Royal Society in December 1759, were followed by
many others detailed by Priestley, at pp. 298–301 of his “History of
Electricity,” London, 1775, and Canton was the first to discover the
electrical properties of the topaz, which latter were made known during
the early part of the year 1760. (Consult Wilhelm Hankel, “Uber die
therm. eigen. des Topases,” Leipzig, 1870.)
He was also the first to establish properly the fundamental fact of
electrification by induction, or, as he terms it, “relating to bodies
immerged in electric atmospheres,” which afterward led Wilcke (A.D.
1757) and Æpinus (A.D. 1759) to the method of charging a plate of
air like a plate of glass, and to make the most perfect imitation
of the phenomena of thunder and lightning (George Adams, “Essay on
Electricity,” London, 1799, pp. 351–356; Noad, “Manual,” Chapter I,
and Priestley, “History,” etc., s. 5). The paper containing an account
of Canton’s experiments was read before the Royal Society, December 6,
1753. The principle enounced is that “the electric fluid, when there
is a redundancy of it in any body, repels the electric fluid in any
other body when they are brought within the sphere of each other’s
influence and drives it into the remote parts of the body; or quite
out of it, if there be any outlet for that purpose. In other words,
bodies immerged in electric atmospheres always become possessed of the
electricity contrary to that of the body in whose atmosphere they are
immerged.”
Canton is the first to show that the air of a room can be electrified
either positively or negatively, and can be made to retain the
electricity when received. He thus explains his method: “Take a charged
phial in one hand and a lighted candle insulated in the other, and,
going into any room, bring the wire of the phial very near to the
flame of the candle and hold it there about half a minute, then carry
the phial and candle out of the room and return with the pith balls
(suspended by fine linen threads) held out at arm’s length. The balls
will begin to separate on entering the room and will stand an inch and
a half or two inches apart when brought near the middle of it.”
The construction of artificial magnets by Canton, through the
combination of the Duhamel (A.D. 1749) and the Michell (A.D. 1750)
methods, as well as without the aid of natural loadstones or artificial
magnets, is detailed by Noad at Chapter XV of his “Manual,” London,
1859.
REFERENCES.--_Phil. Trans._, Vol. XXXV. p. 137 (Berlinghieri, V.
L.); Vol. XXXVII. p. 294 (Marcel, A.); Vol. XLVII. p. 31; Vol.
XLVIII. part i. pp. 350, 356, and Part II. pp. 780, 782 and 784,
also Vol. XLIX. part i. p. 300; Vol. LI. pp. 398, 403, and Vol.
LII. part ii. pp. 457, 461; and the abridgments of Hutton, Vol.
X. pp. 131, 421, 532; Vol. XI. pp. 421, 609; A.D. 1722, and A.D.
1752; “A Course of Lectures on Nat. Philos. and the Mechanical
Arts,” by Thos. Young, London, 1807, Vol. I. p. 372; II. pp.
64, 243; “The Electrical Researches of Hon. Hy. Cavendish,”
1879, Nos. 117, 205; Descriptions and Drawings of the various
electric friction machines can be seen in Priestley’s “History,”
Plates IV-VIII, and in Albrecht’s “Geschichte d. Electricität,”
1885, pp. 20–30; _Acta Acad. Petr._, I., 1778; “Gentleman’s
Magazine” for Sept. 1759. See likewise the _Phil. Trans._ for
Monday, January 21, 1666, p. 375, and George Adams’ “Essay on
Electricity,” etc., London, 1799, p. 579, for method of making
the artificial Bolonian stone or Canton’s phosphorus.
=A.D. 1753.=--Beccaria (Giovanni Baptista) (1716–1781), a very
ingenious and industrious Italian electrician and astronomer, is the
author of several quite important works on electricity.
Father Beccaria, as he is sometimes called from having been a member
of the religious order of the Pious Schools, proved at the time
to be the most indefatigable follower of Franklin in the study of
atmospheric electricity. He was the first who recorded the phenomena
of thunderstorms, and his many observations thereon are detailed
throughout Part I. period x. and s. 10 of Priestley’s great work on
electricity. Beccaria says that all clouds, whether of thunder, rain,
snow or hail, are formed by the electric fluid; that the electric
matter is continually darting from the clouds in one place at the
same time that it is discharged from the earth in another; and that
the clouds serve as conductors to convey the electric fluid from those
places of the earth which are overloaded with it to those which are
exhausted of it. Having shown that the polarity of the magnetic needle
is determined by the direction in which the electric current has passed
through it, he suggests taking the polarity acquired by ferruginous
bodies as a test for ascertaining the kind of electricity with which
the thunder cloud is charged.
He also shows that the meteor called a _falling star_ is an electrical
appearance, explains the cause of the peculiar noise attending the
electric spark, and states that the passage of electricity is not
instantaneous through the best conductors. He found a spark to occupy
at least half a second in passing through 500 feet of wire, and six and
a half seconds through a hempen cord of the same length, although when
the cord was dampened it passed through it in two or three seconds.
He was the first to show the electric spark while in its passage
through water, and he observed that the water sank in the tubes
whenever a spark passed from one to the other as the air was repelled
by the electric fluid. He found the effect of the electric spark upon
water greater than the effect of common fire on gunpowder, and says
he does not doubt that, if a method could be found of managing them
equally well, a cannon charged with water would be more effective
(“dreadful”) than one charged with gunpowder.
He demonstrates that air, contiguous to an electrified body, gradually
acquires the same electricity; that the electricity of the body is
diminished by that of the air; that there is mutual repulsion between
air and the electric fluid, and that the latter, in passing through any
portion of air, creates a temporary vacuum.
The production of what he calls his _new inventive phosphorus_ and
the method he employs for _revivifying metals_, are described,
respectively, at pp. 365 and 282 of his “Lettere dell’ elettricismo.”
REFERENCES.--Beccaria, “Lettere,” etc., Bologna, 1758, pp. 146,
etc., 193, 266, 268, 290, 310, 345; likewise his “Elettricismo
Artificiale,” Turin, 1753, pp. 110, 114, 227; _Phil. Trans._
for 1760, Vol. LI. p. 514; 1762, p. 486; 1766, Vol. LVI. p.
105; 1767, Vol. LVII. p. 297; 1770, Vol. LX. p. 277; 1771, p.
212, also Hutton’s abridgments, Vol. XI. p. 435; Vol. XII, pp.
291, 445; Vol. XIII. p. 50; Wartmann, “Mém. sur les Etoiles
filantes”; Humboldt, “Relation historique,” Tome I; Lardner,
“Lectures,” Vol. I. pp. 429–444; Sturgeon’s _Annals_, Vol. VI.
pp. 415–420, 425–431, and Vol. VIII. p. 180; Noad, “Manual,”
London, 1859, p. 197; Louis Cotte, “Observation ...” Paris,
1769 and 1772; “Mém. de Paris” for the same years and _Jour. de
Phys._ for 1783; Ant. Maria Vassalli-Eandi, “Notizia sopra la
vita ... di Beccaria,” 1816; Carlo Barletti, “Nuove Sperienze
...” Milano, 1771; “Biog. Générale,” Vol. V. pp. 77–78; “The
Electrical Researches of Hon. Henry Cavendish,” Cambridge, 1879,
No. 136; Hale, “Franklin in France,” Boston, 1888, Part I. p.
447; Humboldt, “Cosmos,” London, 1859, Vol. I. pp. 113–136, 202,
337; Vol. V. pp. 217–219, for the observations of Beccaria,
Rozier, Kepler, Benzenberg, Brandes, Bogulawski, Nicholson,
Arago and others on atmospheric electricity, aerolites, etc. See
likewise Beccaria’s letters to Jean Claude Fromond, the Italian
physicist (1703–1795), relating his experiments tending to prove
that electric motions do not occur _in vacuo_, also his letters
to the Princess Giuseppina di Carignano on the electricity of
the moon, as well as to Jean Baptiste Le Roy and to Jacopo
Bartolommeo Beccari relative to experiments with his kite;
“Scelta di Opuscoli,” of Amoretti, Campi, Fromond and Soave,
Vols. XIX. XXI. XXXII.; “Opuscoli Scelti,” II. 378; III. 243,
284, 377; V. 19.
=A.D. 1753.=--Bazin (Gilles Augustin), French physician and
naturalist, publishes, at Strasbourg, an illustrated treatise on
Magnetic Currents (“Description des Courants Magnétiques,” etc.), which
also contains his observations upon the magnet, and a supplement to
which appears during the year 1754.
REFERENCES.--“La Grande Encyclopédie,” Vol. V. p. 974; Michaud,
“Biog. Univ.,” Vol. III. p. 353; Ninth “Britannica,” Vol. XV. p.
242.
=A.D. 1753.=--C. M., _i. e._ Charles Morrison and not Charles Marshall,
of Greenock, Scotland, writes, from Renfrew, February 1, 1753, to
the _Scots’ Magazine_, a letter entitled “An Expeditious Method of
Conveying Intelligence,” wherein is first suggested a practical manner
of transmitting messages by frictional electricity.
A full copy of this letter appears at pp. 7–9 of Robert Sabine’s
“Electric Telegraph,” London, 1872, and at p. 9, 103, No. 570, of the
_Scientific American Supplement_ for December 4, 1886, the last-named
also reproducing some correspondence establishing the identity of
Charles Morrison which was found in the papers of Sir David Brewster.
In the article of Auguste Guérout, which appeared in _La Lumière
Electrique_ early in 1883, C. M. is alluded to as Charles Marshall.
This is likewise the case in Johnson’s Encyclopædia, 1878, Vol. IV.
p. 757. Fahie gives (“History of the Electric Telegraph,” London,
1884, pp. 68–77) a full account of the many inquiries instituted to
establish the identity of C. M., which he admits to stand for Charles
Morrison, although, at p. 81 of the same work, is given a letter of Sir
Francis Ronalds alluding to Charles Marshall, of Renfrew. An article in
_Cornhill Magazine_, Vol. II for 1860, pp. 65–66, speaks of an elderly
Scotch lady who remembered a very clever man named Charles Marshall,
who could make “lichtnin’ write an’ speak” and who could “licht a room
wi’ coal-reek” (coal-smoke).
In his remarks upon the afore-named letter, made during the year 1859,
Sir David Brewster says: “Here we have an electric telegraph upward of
a hundred years old, which at the present day would convey intelligence
expeditiously, and we are constrained to admit that C. M. was the
inventor of the electric telegraph.... Everything done since is only
improvement.”
REFERENCES.--_Scots’ Magaz._, XV. p. 73; “Le Cosmos,” Paris,
Feb. 17, 1854; “Dict. of Nat. Biog.,” Vol. XXXIX. p. 107;
_Athenæum_ of Nov. 5, 1864; Lesage, at A.D. 1774; Th. Du Moncel,
“Exposé des applications de l’électricité,” Paris, 1874, Vol.
III. pp. 1 and 2.
=A.D. 1754.=--Diwish (Prokop), Diviss--Divisch (Procopius), a monk of
Seuftenberg, Bohemia (1696–1765), erects, June 15, 1754, a lightning
protector upon the palace of the curator of Prenditz, Moravia. The
apparatus was composed of a pole surmounted by an iron rod supporting
twelve curved up branches and terminating in the same number of
metallic boxes filled with iron ore and closed by a boxwood cover
traversed by twenty-seven sharp iron points which plunged at their base
in the ore. All the system of wires was united to the earth by a large
chain. The enemies of Diwish, jealous of his success at the court of
Vienna, excited the peasants of the locality against him, and, under
the pretext that his lightning rod was the cause of the great drought,
they made him take down the lightning rod which he had utilized for
six years and then imprisoned him. What is most curious is the form of
this first lightning rod, which is of multiple points, like the one M.
Melseu afterward invented.
REFERENCES.--_Poggendorff_, Vol. I. p. 580, for Procopius
Divisch’s “Erfand einen Wetter Ableiter”; _Scientific American_,
Sept. 10, 1887, p. 160; “Kronika Prace,” by Pokorny, of Prague;
“Historical Magazine,” Feb. 1868, Art. XII. p. 93; “Prague
News,” for 1754, art. of Dr. Scrinci.
=A.D. 1754.=--Ammersin (Rev. Father Windelinus), of Lucerne,
Switzerland, announces in his “Brevis relatio de electricitate,” etc.,
that wood properly dried till it becomes very brown is a nonconductor
of electricity. We have already mentioned the observation made by
Benjamin Wilson (A.D. 1746) that, when a dry, warm piece of
wood is broken across, one of the pieces becomes vitreously and the
other resinously electrified.
Ammersin advises boiling the dried wood in linseed oil or covering
it with varnish to prevent the possible return of moisture, and he
states that wood thus treated seems to afford stronger appearances of
electricity than does even glass (_Phil. Trans._, Vol. LII. part
i. p. 342).
REFERENCES.--Ammersin, “Kurze Nachricht,” etc., pub. at Basel,
1771, and translated the same year by Jallabert, who embodied it
in his “Versuche über die Elektricität,” etc.
=A.D. 1754.=--In his “Dissertations sur l’incompatibilité de
l’attraction,” etc., Le Père Gerdil, Professor of Philosophy in the
Royal University of Turin, speaks of agencies of which we shall never
know anything and of others with which we shall inductively become
acquainted, although we shall always ignore many of their respective
quantities, qualities and differences. He says that the electric fluid
explains the sympathy known to exist between amber and straws--shown by
the analogy observed between electricity and magnetism to be the same
as that existing between iron and the loadstone.
=A.D. 1754.=--Mr. Strype produces the sixth and last edition of
the original “Survey of London” by John Stow, which first appeared
during the year 1598.
In his account of Cornehill Ward, allusion is made to the “fair new
steeple” of the Church of Saint Michael th’ Archangel, “begun to be
built in the year 1421,” and, at p. 74, occurs the following: “As I
have oft heard my father report, upon St. James’ night, certain men
in the loft next under the bells, ringing of a peal, a tempest of
lightning and thunder did arise, an ugly shapen sight appeared to
them, coming in at the South window and lighted on the North, for fear
whereof they all fell down and lay as dead for the time, letting the
bells ring and cease of their own accord; when the ringers came to
themselves, they found certain stones of the North window to be razed
and scratched, as if they had been so much butter, printed with a
lion’s claw; the same stones were fastened there again and so remain to
this day.”
In one of the notes to William T. Thoms’ reprint of the above-named
“now perfectly invalyable” work, he says: “It is quite clear from the
tone in which Stow speaks of this ‘ugly shapen sight’ and the marks
‘printed with a lion’s claw,’ that he suspected this instance of the
power of the electric fluid to be nothing less than a visitation from
the foul fiend himself.”
Speaking of St. Paul’s Cathedral, Stow tells us that its pulpit cross
“was by tempest of lightning and thunder defaced,” and that “on
Wednesday, the fourth of June (in the year 1561), betweene three, four
and five of the clock, in the after-noone, the steeple of Paule’s in
London, being fired by lightning brast forth (as it seemed to the
beholders) two or three yards beneath the foote of the crosse, and from
thence burnt downe the speere to the stone worke and bels, so terribly,
that within the space of foure houres, the same steeple with the roofes
of the church ... were consumed.” Very curious and interesting reading
will be found in the “Burnynge of Paule Church, London, in 1561, and
the iiii day of June, by lyghtnynge at three of the clocke ...” by
Wyllyam Seres, London, 1563; as well as in his previous work on like
subject, published in 1561. See Report in “Archæologia,” London, 1794,
Vol. XI. pp. 72–86; likewise the entry at A.D. 1769, relative
to another lightning stroke in 1772.
Stow is perhaps best known by his “Annales, or a Generalle Chronicle
of England.” In that portion of the latter work devoted to “the
life and raigne of Queene Elizabeth” he states (London ed., 1631,
p. 809) “that the knowledge and use of the sea compasse or needle
was neither familiar nor understood but few yeeres before” the time
of the navigators John Hawkins, Francis Drake, Martin Frobisher and
Thomas Candish, and he adds (at p. 810) “that the honour of that
invention, as touching the propertie of the Magneticall needle in
pointing towards the Poles is attributed by (Flavius) Blondus in his
_Italia Illustrata_ (in the description of Campadia Felix) and by
the great writer Paulus Jovius in lib. xxv. of his History in the end
[_sic_], to the citizens of Amalfi.... The author’s name is no
more particularly recorded, then [_sic_] to be one Flavio ... for
to him that honour is given by Francis Lopez, of Gomara, in his West
Indian History, lib. i. cap. 9, and by Peter Ciezius, in lib. ii. cap.
9, of his Indian Story, and by Pandulph: Collenutius in his History of
Naples, who, three hundred yeeres since, namely in the yeere of our
Saviour 1305, discovered that propertie in the Magnes and applied it to
navigation” (see, for Flavius Blondus: George Hakewill, “An apologie,”
etc., Oxford, 1635, lib. iii. s. 4, and lib. v. p. 60; “Blondi Flavii
Fortiriensis ... Italia Illustrata,” 1531, folio; Flavius Blondus
(Flavio Biondo), “Roma Ristaurata et Italia Illustrata,” Vinezia, 1558,
12mo; Niceron, “Mémoires ... des hommes illustres,” Paris, 1731, Vol.
XVI. pp. 274–281).
A contemporary of Flavius Blondus, by name Michael Angelus Blondus
(1497–1560), author of “De Ventis et Navigatione,” published at Venice
in 1546, likewise alludes to the polarity of the needle, and gives a
curious illustration of a mariner’s compass at Chap. XXIV. p. 15, of
the last-named work. (For M. A. Blondus, see “La Grande Encyclopédie,”
Vol. VI. p. 899.)
Stow makes reference (p. 810) to Dr. Gilbert’s _De Magnete_, to
the “diuision of the plot or playne of the compasse into the thirty-two
points,” considered by “Goropius in his lib. iii. _De Origin.
Hispanicis_, to have been the inuention of some Germane,” and to
the manner and “meanes saylers vsed to sayle, before they atteined the
knowledge of the compasse.”
=A.D. 1755.=--Eeles--Eales (Henry), a prominent scientist of Lismore,
Ireland, communicates to the Royal Society, on the 25th of April, 1755,
a paper concerning the electrical property of steam and exhalations of
all kinds. Eeles’ theory of the electricity of vapour (“On Vesicles
and Atmospheres of Electricity”), afterward developed by Sir John
Herschel, is fully explained in the “Encycl. Brit.” article on
“Meteorology” (par. 135, etc.), and is also alluded to at p. 43 of
Harris’ “Electricity” as well as at p. 153, Vol. XLIX. part i. of the
_Philosophical Transactions_.
Mr. Eeles showed, that while the Leyden jar is being charged, both
the inside and the outside have the same kind of electricity and
that the negative electricity does not appear until the machine has
ceased turning. Eeles’ hypothesis, extracted from his “Philosophical
Essays,” and from the analysis of a course of lectures delivered at
Trinity College, Cambridge, by Mr. Atwood, is treated of at length
by George Adams in the fourth chapter of his “Essay on Electricity,”
wherein pertinent allusion is also made to the fact of Mr. Eeles having
been purposely shut out of Priestley’s “History and Present State of
Electricity.”
REFERENCES.--_Philosophical Transactions_, Vol. XLVII. p. 524;
_Phil. Mag. and Journal_, Vol. XLIV. p. 401 (1814).
=A.D. 1756.=--Le Chevalier Jacques C. F. de la Perriere de Roiffé
(not Reiffé) is the author of “Méchanismes de l’Electricité et de
l’Univers,” published at Paris, wherein he pretends to account for all
electrical phenomena.
At p. 12 of his Préface, he curiously states that as everybody
comprehends the distinction between elastic and non-elastic bodies,
likewise the existence, nature and diversity of the properties of
atmospheric fluids, with which all bodies are impregnated and by which
they are surrounded, also the various expansive modes of activity to
which they are subject, as well as their immiscibility as regards the
surrounding air, without which latter they could not, however, subsist,
he will in his new theory apply these principles to the mechanisms of
electricity and of the universe as affected by the general laws and the
invariable results attaching to shock and motion.
=A.D. 1756.=--In the “Subtil Medium Proved,” etc., of Mr. R.
Lovett, lay-clerk of the cathedral church at Worcester, England, are
shown numerous medical cures successfully made by electricity. He
asserts that the electric fluid is almost a specific in all cases of
violent pains, like obstinate headache, the toothache, sciatica, etc.,
but that it has not succeeded so well in rheumatic affections. He
states that electricity properly administered has never caused injury,
and he alludes to equally successful cures made by the Rev. John Wesley
and by Dr. Wetzel, of Upsal.
The well-known physician, Antonius de Haen, during several years’
experience, made many cures of paralysis, St. Vitus’ dance, etc., by
the agency of electricity, as related in his _Ratio Medendi_, Vol. I.
pp. 199, 200, 233, 234 and 389. Allusion has been made in these pages
to the employment of electricity for medical purposes by Kratzenstein
(A.D. 1745) and by Jallabert (A.D. 1749), and Priestley named many
others who have likewise used it successfully in their practice.
REFERENCES.--“Subtil Medium Proved,” etc., pp. 76, 101 and 112;
also his “Philosophical Essays,” Worcester, 1761 and 1766, and
his “Electrical Philosopher,” 1774; Wesley’s “Desideratum,
or Electricity made Plain and Useful,” p. 3; Joseph Veratti,
“Observations ... pour guérir les paralytiques....” La Haye,
1750.
=A.D. 1757.=--Dr. Darwin, of Lichfield, addresses to the Royal
Society of London a paper which is read May 5, 1757, and in which he
gives an account of experiments to prove that the electric atmosphere
does not displace air, and that all light, dry, animal and vegetable
substances, in particular, are slow to part with the electricity with
which they have been charged (_Phil. Trans._, Vol. L. part i. pp.
252 and 351).
=A.D. 1757.=--Euler (Leonard), a native of Switzerland, who
studied under the Bernoullis, and who succeeded Daniel Bernoulli as
Professor of Mathematics at St. Petersburg, was undoubtedly one of the
greatest analysts the world has ever produced (“Encycl. Brit.,” Fifth
Dissertation of the eighth edition, Vol. I. p. 742).
He adopted the theory of Descartes that the magnetic fluid moves
from the equator to the poles, and he endeavoured to determine
mathematically the course of the magnetic needle over the earth’s
surface. He announces that “the magnetic direction on the earth follows
always the small circle which passes through the given place and the
two magnetic poles of the earth,” or, as worded by Sir David Brewster,
that “the horizontal needle is a tangent to the circle passing through
the place of observation and through the two points on the earth’s
surface where the dipping needle becomes vertical or the horizontal
needle loses its directive power.”
He entertained very peculiar ideas regarding the source of power
in the loadstone, the pores of which he imagined were filled with
valves admitting of the entrance of the current and preventing its
return. His notions on this subject are best given in his own words:
“Non-magnetic bodies are freely pervaded by the magnetic matter in all
directions; loadstones were pervaded by it in one direction only ...
water, we know, contains in its pores particles of air ... air, again,
it is equally certain, contains in its pores a fluid incomparably
more subtile, viz. _æther_, and which, on many occasions, is
separated from it, as in Electricity; and now we see a still further
progression, and that ether contains a matter much more subtile than
itself--the magnetic matter which may, perhaps, contain in its turn
others still more subtile.... The loadstone, besides a great many pores
filled with ether, like all other bodies, contains some still much more
narrow into which the _magnetic matter_ alone can find admission.
These pores are disposed in such a manner as to have communication with
each other, and constitute tubes or canals through which the magnetic
matter passes from the one extremity to the other. Finally, this matter
can be transmitted through these tubes only in one direction, without
the possibility of returning in the opposite direction.... As we see
nothing that impels the iron toward the loadstone, we say that the
latter attracts it. It cannot be doubted, however, that there is a
very subtile, though invisible matter, which produces this effect by
actually impelling the iron towards the loadstone.”
REFERENCES.--“Journal des Savants” for March and April 1868;
Euler’s “Letters,” translated into English, 1802, Vol. I. p.
214, and Vol. II. pp. 240, 242, 244; “Berlin Memoirs,” for
1746, p. 117; 1757, p. 175; 1766, p. 213; _Poggendorff_, Vol.
I. p. 702; “Nova Act. Petropol.” for 1779, Vol. III; “Pièces de
Prix de l’Acad. des Sc. de Paris,” Vol. V. Mém. II and IX, this
last-named publication, containing likewise a joint Memoir of D.
Euler, J. Bernoulli and E. F. Dutour upon the mariner’s compass,
which appeared in Paris during 1748; Whewell, “History of the
Inductive Sciences,” 1859, Vol. I. pp. 225, 367, 370; Vol. II.
pp. 32, 40.
His son, Albert Euler, censured Halley’s magnetical hypothesis, and
proposed, in 1766, a theory requiring the assumption of only two poles,
distinct, however, from those of the terrestrial axis.
=A.D. 1757.=--Dollond (John), who was at first a silk weaver
at Spitalfields, England, which occupation he abandoned in order to
give his exclusive attention to scientific experimental studies,
discovered the laws of the dispersion of light and constructed the
first achromatic telescope as well as several improved instruments for
magnetic observations. A full description of the most important of
these, accompanied by illustrations, can be found in the articles of
the “Encyclopædia Britannica” on magnetic instruments.
REFERENCES.--Kelly’s “Life of John Dollond,” London, 1808;
_Phil. Mag._, Vol. XVIII. p. 47; Thomas Thomson, “Hist. of Roy.
Soc.,” London, 1812, pp. 379–382; “Directions for using the
Electric Machine made by P. and J. Dollond,” London, 1761.
=A.D. 1757.=--Wilcke (Johann Karl), a very distinguished scientist
of Stockholm (1732–1796), introduces new phenomena respecting the
production of electricity produced by melting electrical substances,
which he discovers in continuation of experiments begun by Stephen
Grey. He gives the name of _spontaneous_ to the electricity
produced by the liquefaction of electrics, observing that the
electricity of melted sulphur does not appear until it commences to
cool and to contract, its _maximum_ being reached at its point of
greatest contraction. Melted sealing wax, he says, becomes negatively
electrified when poured into glass, but, when poured into sulphur, it
is positively electrified, leaving the sulphur negative (Sir Humphry
Davy, “Bakerian Lectures,” London, 1840, p. 36 and notes).
While in Berlin, he and Æpinus investigate the subject of electric
atmospheres, and they are led to the discovery that plates of air
can be charged in the same manner as plates of glass. (See Canton,
A.D. 1753.) This they did by suspending large wooden boards,
which were covered with tin and whose flat surfaces were held parallel
to and near each other. They found that upon electrifying one of the
boards positively the other was always negative, and that with them
could be given shocks like those produced by a Leyden jar. They likened
the state of the boards to the condition of the clouds and the earth
during a thunderstorm, the earth being in one state and the clouds in
the opposite, the body of air between them answering the same purpose
as the small plate of air between the boards or the plate of glass
between the two metallic coatings of the Leyden jar.
In Wilcke’s treatise, alluded to below, he defines the two
electricities much more clearly than had previously been done.
He distinguishes three causes of excitation, viz. _warming_,
_liquefaction_ and _friction_; the _spontaneous electricity_ already
alluded to, he further says, is the result of the apposition or
mutual action of two bodies, in consequence of which one of them
is electrified positively and the other negatively; _communicated
electricity_, on the other hand, is that which is superinduced upon the
whole or part of a body, electric or non-electric, without the body
having been previously heated, melted or rubbed, or without any mutual
action between it and any other body. This distinction is, in general,
very obvious, but Mr. Wilcke defines it throughout his work in a very
clear manner, citing cases wherein they are frequently confounded.
Wilcke and Anton Brugmans (A.D. 1778) first propounded the theory of
two magnetic fluids, which was afterward established by Coulomb (A.D.
1785) and perfected by the great mathematician Poisson (A.D. 1811).
The hypothesis of the two fluids supposes that a magnet contains
minute invisible particles of iron, each of which possesses by itself
the properties of a separate magnet. It is assumed that there are two
distinct fluids--the _austral_ and the _boreal_--which reside in each
particle of iron. These fluids are inert and neutral when combined, as
in ordinary iron, but when they are decomposed the particles of the
_austral_ attract those of the _boreal_, and _vice versa_, while they
each repel one another.
REFERENCES.--Wilcke, “Disputatio inauguralis physica,” etc.,
published Rostock, 1757, also his “Herrn Franklin’s briefe von
der electricitat,” etc., Leipzig, 1758, his “Jal om Magneten,”
1764, and his “Über den Magneten,” Leipzig, 1758; besides
1794–1795; likewise his different Memoirs in the “Swedisches
Musæum,” Vol. I. p. 31, and in both the “Schwedischen Akad.
Abhandlungen,” etc. (also _Neue Abhand_.) and the “Vetensk Acad.
Handl.” for 1758, 1759, 1761–1763, 1766–1770, 1772, 1775, 1777,
1780, 1782, 1785, 1786, 1790; “The Electrical Researches of Hon.
Hy. Cavendish,” 1879, No. 134.
=A.D. 1759.=--Hartmann (Johann Friedrich), of Hanover, is the
author of three works on electricity, published in that city during
1759, 1764 and 1766, wherein he gives an account of several very
curious electrical experiments. One of the most interesting of these
demonstrates the progressive motion of the electrical discharge. When
he passes the shock through many small cannon balls, sometimes to
the number of forty, placed upon small drinking goblets close by one
another, all the sparks are seen and all the cracklings are heard
at the same moment; but when he substitutes eggs (preferably ten or
twelve) for the balls, the progress of the explosion is visible, every
two giving a flash and a report separately.
He remarks that upon one occasion, as he re-entered a room which he
had just before left, after making therein a number of experiments, he
observed a small flame following him as he walked about swiftly while
holding a lighted candle in his hand. The flame vanished whenever he
stopped to examine it, and he attributed its appearance to the presence
of sulphur thrown into the air by continued violent electrification.
REFERENCES.--Hartmann, “Abhandlung von der verwandschaft,” etc.,
Hanover, 1759, pp. 58, etc., and 135; also his “Electrische
experimente,” etc., Hanover, 1766, and his “Anmerkungen,” etc.,
1764, 4to, p. 38; Friedrich Saxtorph, “Elektricitätsläre,”
Vol. II; _Hamburgisches Magazin_ (also _Neues Hamb. Mag._)
for 1759, Vol. XXIV, and for 1761, Vol. XXV; “Nov. Acta Acad.
Nat. Curios,” Vol. IV. ss. 76–82, 126; “Göttingischen gemein.
Abhand.,” von Jahr 1775.
=A.D. 1759.=--Wesley (John), the founder of Methodism (1703–1791)
and the most eminent member of a very distinguished English family,
publishes “The Desideratum; or Electricity made Plain and Useful, by
a Lover of Mankind and of Common-sense.” In this, he relates at great
length the cures of numerous physical and moral ailments, attributed
to the employment of the electric fluid, under such curious headings
as “Electricity, the Soul of the Universe,” “Electricity, the Greatest
of all Remedies,” etc. (“The Library of Literary Criticism,” C. W.
Moulton, Buffalo, 1901–1902, Vol. IV. pp. 110–129).
=A.D. 1759.=--Æpinus (Franz Maria Ulrich Theodor) (1724–1802),
celebrated German natural philosopher, member of the Scientific
Academies of Berlin and St. Petersburg, publishes in the latter
city his most important work, “Tentamen Theoriæ Electricitatis et
Magnetismi,” wherein he adopts, as did Wilcke, all the general
principles of Franklin’s theory of positive and negative electricities.
Therein he also shows that the phenomena of electricity depend mainly
upon the tendency of the fluid to attain a state of equilibrium by
passing from bodies containing an excess to others which have less
than the natural quantity; that the electric fluid existing in the
pores of all bodies moves without obstruction in non-electrics and
with much difficulty in electrics; that all bodies contain a fluid
whose particles mutually repel one another with forces decreasing as
the distance between them increases, and, according to the same law,
attract the particles of the bodies with which they are in combination.
It has already been shown that, in conjunction with Wilcke, he found
the means of charging a plate of air. This experiment, suggested by
some of the observations made by Canton and Franklin, led to what
may be considered one of the greatest discoveries in the science of
electricity, for in this was first demonstrated the grand principle
of induction (see Grey at A.D. 1720), and the result led to
Volta’s discovery of the _electrophorus_. Volta, also, was the
first to apply to an electrometer the apparatus invented by Æpinus for
condensing electricity.
Æpinus first discovers to its fullest the affinity existing between
electricity and magnetism, explaining nearly all the phenomena of
magnetism (“De Similitudine vis electricæ et magneticæ”; “Similitudinis
effectuum vis magnet. et. elect.: novum specimen” in the “Novi Comment.
Acad. Petrop.,” Vol. X. p. 296). He improves upon the methods employed
by both Duhamel and Michell for the construction of artificial magnets
in a different line from that employed by John Canton, A.D.
1753. He lays the bar to be magnetized upon the ends of the opposite
poles of two powerful field magnets, and places two bunches of magnetic
bars upon the middle of the bar, separating the bunches by a piece of
wood and keeping together the poles of each of the same name as that
of the powerful fixed magnet nearest to it. These two bunches are then
held at an inclination of 15 to 20 degrees, and are drawn away from
each other to the end of the bar which is to be magnetized, so that
each half of the bar receives the same number of strokes. When the bar
is very thick, the process should be repeated upon its reverse, and
in order to make the result more effective, the united ends of the
bars should at the outset be ground together, and pressure should be
applied while the operation is going on.
Æpinus was the first to discover the polarity of the tourmaline. After
M. Lechman acquainted him with its attractive power, he made many
experiments, of which he communicated the very important results,
during the year 1756, to the Academy of Sciences and Belles-Lettres at
Berlin. Up to this time but little was known regarding the necessity
of heat to excite the tourmaline. Æpinus found that he could electrify
it to a high degree by placing the stone in boiling water, and that
it was necessary to heat it to between 99½ degrees and 212 degrees
Fahrenheit to develop its attractive powers. One of the extremities of
the tourmaline terminated by the six-sided pyramid then becomes charged
with positive electricity, while the other extremity is negative. When
the stone is of considerable size, flashes of light can be seen along
its surface.
M. De Romé Delisle, in his “Essai de Cristallographie,” Paris, 1772, p.
268, alludes to what has already been stated relative to the necessity
of heating the tourmaline (see J. G. S. at A.D. 1707, and
Leméry at A.D. 1717), and he gives an extract from the work
attributed to Adanson, as mentioned at A.D. 1751. Delisle’s
references embrace: “Act. Paris,” 1717, p. 9; “Act. Berolin,” 1756,
p. 105; “Lettre du Duc de Noya Caraffa à M. de Buffon,” Paris, 1759;
_Ascendrecker, Aschentrecher, Aschenzicher_ (_tire-cendre_),
“Trip: Tourmaline, Vog. min.” 191; “Act. Holmens,” 1768, p. 7; besides,
at pp. 209, 233 and 245 he speaks of the electrical and phosphorescent
properties of crystals, showing that the _lapis lyncurius_ of the
ancients is the hyacinth or zircon of to-day (see B.C. 321),
and not, as many believe, either amber or belemnite (_pierre de
foudre_, _lapis fulminaris_), while the hyacinth of old was a
purple stone which, if now found, would be classed among the amethysts.
REFERENCES.--“Allgemeine Deutsche Biographie,” Leipzig, 1875,
Vol. I. p. 129; Æpinus, “Sermo Acad. de similitudine,” etc.,
1758, and his “Recueil ... sur la tourmaline,” 1762; “Novi. Com.
Petropol.,” for 1761, 1764, 1768; “Acta Acad. Moguntinæ,” Vol.
II. p. 255; Leithead, “Electricity,” p. 289; _Phil. Trans._,
Vol. LI. p. 394, and Vol. LVII. part i. p. 315; “Encycl. Brit.,”
articles “Electricity” and “Magnetism”; Bigeon’s report in the
“Annales de Ch. et de Phys.,” 2^e série, Tome XXXVIII. p. 150;
Van Swinden, “Recueil,” etc., La Haye, 1784, Vols. I and II
_passim_; Becquerel in _Annales de Chimie et de Physique_, Vol.
XXXVI. p. 50; Thomson, “Hist. Roy. Soc.,” 1812, p. 184; “The
Electrical Researches of the Hon. Henry Cavendish,” Cambridge,
1879, Nos. 1, 134, 340 and 549; Lord Kelvin (Sir Wm. Thomson),
“Æpinus atomized,” in _Phil. Mag._ for March 1902, p. 257, etc.,
and in _Journal de Physique_ for Sept. 1902, p. 605.
=A.D. 1759.=--Symmer (Robert) assails the theory announced by Dufay
(see Franklin, A.D. 1752), and shows, in a paper submitted to the Royal
Society, December 20, 1759, that all the electrical phenomena are
produced by two distinct but coexistent fluids not independent of, but
counteracting each other. He says that equal quantities of these fluids
are contained in all bodies while in their natural condition; that when
a body is positively electrified it does not hold a larger share of
electric matter, but a larger portion of one of the active powers, and
when negatively electrified a larger portion of the other, and not, as
Franklin’s theory supposes, an actual deficiency of electric matter.
Symmer’s theory is perhaps best explained in his own words, as follows:
“It is my opinion that there are two electric fluids (or emanations of
two distinct electric powers), essentially different from each other;
that electricity does not consist in the efflux and afflux of these
fluids, but in the accumulation of the one or the other in the body
electrified; or, in other words, it consists in the possession of a
larger portion of the one or of the other power than is requisite to
maintain an even balance within the body, and lastly, that according as
the one or the other power prevails, the body is electrified in one or
the other manner.”
Very curious reading may be had by reference to the volumes of the
_Philosophical Transactions_ named below, in which Symmer details many
experiments with pieces of silk, as well as with white and coloured,
new and newly cleansed silk and worsted stockings. Therein he shows
his ability to charge the Leyden jar with either positive or negative
electricity, according as he presents a black or white stocking to the
wire of the phial. These experiments, which Symmer admits to have made
for the express purpose of proving the existence of two electricities,
further illustrate the phenomenon of electrical cohesion, although
the latter is still better demonstrated by means of panes of ordinary
glass. He thus expresses himself: “Upon these considerations, we may
expect, from the experiment in hand, the means of determining whether
the distinction of electricity into two different kinds is merely
nominal, or if there is an essential difference between them; for,
after the glass plates have been electrified in one position, so as to
be incapable of receiving any more electricity, if they be inverted,
and in that new position presented to the chain and wire, and the globe
again be put in motion, according as one or other of those opinions
hold, corresponding effects will follow.”
Symmer also proves his two distinct powers of electricity by the
experiment of passing the electric shock through a quire of paper
instead of through a single card (“Lib. Useful Knowledge,” London,
1829, “Electricity,” p. 44).
REFERENCES.--“Electricity in the Service of Man,” R. Wormell,
London, 1900, p. xiv; _Philosophical Transactions_, Vol. LI.
part i. pp. 171, 340, 366, 373, etc., 389, and Vol. LVII. p.
458; also Hutton’s abridgments, Vol. XI. p. 405; Nollet,
“Lettres,” etc., Vol. III. p. 42; “Encycl. Brit.,” article
“Electricity”; “Library of Useful Knowledge,” London, 1829,
“Electricity,” Nos. 160 and 161.
=A.D. 1760.=--Mayer (Johann Tobias, Sen.) (1723–1762), one of the
most celebrated German astronomers, director of the observatory at
Göttingen, is the first to make known the law of the inverse square
resulting from actual experimental investigation. This he does in a
paper, “Inclination and Declination of the Magnetic Needle, as deduced
from theory,” read before the Royal Society at Göttingen, wherein he
states that the intensities of the magnetic attractions and repulsions
vary inversely as the squares of the distances from the pole of a
magnet. Consult “Magnetism,” in the ninth edition of the “Encyclopædia
Britannica,” for additional reference to the above paper, also section
14 of the same work for an account of Mayer’s dipping needle as
constructed by General Sabine.
REFERENCES.--Delambre’s notice of the life of J. T. Mayer in the
“Biographie Universelle”; Hutton’s “Mathem. Dict.”; Montucla,
“Histoire des Mathématiques”; list of his works added to the
éloge pronounced by Kaestner, Göttingen, 1762; “Abhandlungen
von Galvani und andern,” Prague, 1793; Whewell, “History of
the Inductive Sciences,” 1859, Vol. II. pp. 206, 221; Coulomb,
“Mémoires Acad. Paris” for 1786 and 1787; “Royal Soc. Cat. of
Sc. Papers,” Vol. IV. pp. 311–314; Lambert, “Reports of the
Berlin Academy” for 1776.
Mayer (Johann Tobias, Jr.), 1752–1830, is the author of Memoirs on the
magnetic needle as well as upon many electrical experiments, of which
details may be found in the _Journal der Physik_ of Friedrich A.
C. Gren and in the “Comment Soc. Göttingen recent.”
=A.D. 1760.=--Delaval (E. H.) communicates between 1760 and 1764
several papers to the London Royal Society in reference to experiments
made for the purpose of ascertaining the conducting powers of a body
in different states. Therein, he shows that animal and vegetable
substances lose their conducting powers when reduced to ashes, and that
while metals are the best conductors, their oxides are non-conductors.
His experiments made with _island_ (Iceland) _crystal_ (well
known for its extraordinary property of double refraction), proved that
it is affected by heat differently from other substances named, since
the temperature necessary to render them electric makes the crystal
non-electric. He had a piece of crystal of which, he said, one part
became non-electric when greatly heated, while the other part, with the
same or even a much greater heat, remained perfectly electric. These
experiments did not, however, succeed with Sir Torbern Bergman, who
repeated them with great care and who found that _island crystal_
was a conductor in all cases, to whatever degree of heat it was
exposed.
REFERENCES.--_Phil. Trans._, Vol. LI. part i. p. 83; Vol LII.
part i. pp. 353, etc., and part ii. p. 459; also Vol. LIII.
part i. pp. 84–98; and Hutton’s abridgments, Vol. XI. pp. 334,
589; Vol. XII. p. 140; Thomas Thomson, “Hist. of Roy. Soc.,” p.
443; Thos. Young, “Course of Lectures,” 1807, Vol. II. p. 679,
for notes on Dr. Wm. H. Wollaston’s paper concerning the double
refraction of Iceland crystal.
=A.D. 1760–1762.=--Bergman--Bergmann--(Torbern Olof), celebrated
Swedish astronomer, naturalist and chemist, writes several letters to
Mr. Wilson, which are read before the Royal Society, Nov. 20, 1760, and
March 18, 1762, wherein he alludes to the possibility of electrifying
plates of ice in the same manner as plates of glass. In a subsequent
letter he details experiments with silk ribbons of different colours,
almost as curious as those of which an account has already been
given (by Symmer at A.D. 1759), and from which he concludes
that there is a certain fixed order regarding positive and negative
electricity in which all bodies may be placed while other circumstances
remain unchanged.
REFERENCES.--Bergman’s “Bemerkung ... Isländischen Krystales,”
“Comment ... electrica turmalini,” “Elektrische Versuche,”
etc., and his other works referred to in the _Philosophical
Transactions_, Vol. LI. p. 907; Vol. LIII. p. 97; Vol. LIV. p.
84; Vol. LVI. p. 236; also Hutton’s abridgments, Vol. XI. pp.
506, 705; Vol. XII. pp. 109, 343; “Nova Acta Soc. Upsal.,” “K.
Schwedischen Akad. Abhand.,” “Aus dem Schwed. Magazine,” _Phil.
Mag._, IX. p. 193; “Eng. Cycl.,” Vol. I. pp. 664–665; Gmelin’s
“Chemistry,” Vol. I. p. 320; Thomas Thomson, “Hist. of the Royal
Society,” London, 1812, pp. 444, 475–477.
=A.D. 1761.=--The many experiments made at this period by Ebenezer
Kinnersley, of Philadelphia, relative to the two contrary electricities
of glass and sulphur, are endorsed by his close friend Benjamin
Franklin in his _Letters_ at pp. 99, 100 and 102–105. He makes
several curious observations on the elongation and fusion of fine iron
wires whenever a strong charge is passed through them while in a state
of tension, to which Dr. Watson makes special reference in a paper
read before the Royal Society. He believes that lightning does not
melt metal by a cold fusion, as Dr. Franklin and himself had formerly
supposed, and that when it passes, for instance, through the blade of
a sword, if the quantity is not very great, it may heat the point so
as to melt it, while the broadest and the thickest part may not be
sensibly warmer than before.
To ascertain the effects of electricity upon air, Kinnersley devised
an instrument which he called an _electrical air thermometer_,
and which is described at p. 626, Vol. VIII of the 1855 “Encyclopædia
Britannica.” With this he could show the sudden rarefaction which air
undergoes during the passage of the electric spark through it, heat
being produced without accompaniment of any chemical change in the
heated body.
Some other important observations made by Kinnersley, who, besides
being an intimate friend, was the original associate of Ben. Franklin,
are summed up as follows: A coated flask containing boiling water
cannot be charged, the electricity passing off with the steam; but when
the water gets cold the flask may be charged as usual. A person in a
negative state of electricity standing upon an electric, and holding up
a long sharp needle out of doors in the dark, observes light upon the
point of it. No heat is produced by electrifying a thermometer, nor by
passing shocks through large wire, but small wire is heated red-hot,
expanded and melted (_Phil. Trans._ for 1763, Vol. LIII. p. 84;
Thomson, “Hist. Roy. Soc.,” p. 445).
In the New York “Electrical Review” of May 13, 1905, will be found
the following curious reference to the Boston Art Club exhibits of
President R. H. W. Dwight:
“Among these is an interesting broadside, which gives a summary of
two lectures on electricity by Ebenezer Kinnersley delivered in
Faneuil Hall in September, 1751--the first lectures probably ever
delivered on the then new subject of electricity. Kinnersley was an
Englishman, who was head master in English literature in the College
of Philadelphia, from 1753 to 1773, a student of science, who made a
number of discoveries in electricity and invented a number of quaint
electrical devices. He and Franklin were on intimate terms, and were
closely associated in their electrical experiments. Kinnersley has
been erroneously cited as an anticipator of Oersted’s discovery of the
deflection of a magnetic needle by an electric current. The former’s
experiment, however, was purely electrostatic. In the summary of these
two lectures, among other things, it states that electricity ‘is an
extremely subtile fluid; that it doth not take up any perceptible time
in passing through large portions of space; that it is mixed with the
substance of all other fluids and solids of our globe; that our bodies
at all times contain enough of it to set a house on fire.’”
The exhibits of President Dwight are:
“An artificial spider animated by the electric fire so as to act like
a live one; a shower of sand which rises again as fast as it falls; a
leaf of the most mighty of metals suspended in the air, as is said of
Mahomet’s tomb; electrified money which scarce anybody will take when
offered to them; a curious machine, acting by means of the electric
fire, and playing a variety of tunes on eight musical bells.”
This broadside of 1751 appears to antedate any other similar notice of
electrical experiments.
The “Electrical Review” of April 23, 1904, p. 621, had published copy
of an advertisement from the Massachusetts _Gazette_ of March 7,
1765, giving notice of a course of lectures by David Mason, illustrated
by “entertaining experiments on electricity similar to those cited in
the broadside under date of 1751.” The advertisement of 1765, here
referred to, appears at A.D. 1771.
REFERENCES.--Sturgeon’s “Lectures,” London, 1842, p. 169; “The
Electrical Researches of Hon. Henry Cavendish,” 1879, Nos. 125,
137, 213; _Phil. Trans._, Vol. LIII. part i. pp. 84–87; Vol.
LIV. p. 208; Vol. LXIII, 1773, part i. p. 38; also the Hutton
abridgments, Vol. XI. p. 702, and Vol. XIII. p. 370; Bertholon,
“Elec. du Corps Humain,” 1786, Vol. I. pp. 23, 33, 214, 217, 220.
=A.D. 1762.=--Sulzer (Johann Georg), a Swiss philosopher, member
of the Berlin Academy of Sciences, in his “Theory of Agreeable and
Disagreeable Sensations” (“Theorie d. angenehmen u. unangenehmen
Empfindungen,” Berlin, 1762), thus expresses himself: “When two pieces
of metal, one of lead and the other of silver, are so joined together
that their edges make one surface, a certain sensation will be produced
on applying it to the tongue, which comes near to the taste of martial
vitriol (vitriol of iron); whereas each piece by itself betrays not the
slightest trace of that taste” (F. C. Bakewell, “Manual of Electricity”
London, 1857, Chap. III. p. 28).
The passage in the edition “Nouvelle Théorie des Plaisirs,” published
in 1767, is thus given by Sabine, “Electric Telegraph,” 1872, p. 15:
“On taking two pieces of different metals--silver and zinc--and placing
one of them above and the other underneath his tongue, he found that,
so long as the metals did not make contact with each other, he felt
nothing; but that when the edges were brought together over the tip
of his tongue, the moment contact took place and during the time it
lasted, he experienced an itching sensation and a taste resembling
that of sulphate of iron....” Sulzer does not appear to have been much
surprised at the result, thinking it “not improbable that, by the
combination of the two metals, a solution of either of them may have
taken place, in consequence of which the dissolved particles penetrate
into the tongue; or we may conjecture that the combination of these
metals occasions a trembling motion in the respective particles, which,
exciting the nerves of the tongue, causes that peculiar sensation.”
And thus, remarks Pepper, a prominent fact has slept in obscurity from
the time of Sulzer to the time of Galvani.
REFERENCES.--Izarn, “Manuel,” Paris, 1804, p. 4; Sturgeon,
_Annals_, Vol. VIII. p. 363; also note at p. 491 of Ronalds’
“Catalogue”; _Mém. de l’Acad. de Berlin_, “Théorie Générale du
Plaisir”; also “Temple du Bonheur,” published at Bouillon (Pays
Bas), 1769, Tome III. p. 124, this last-named work being alluded
to in the _Journal des Débats_, 7 Vendémiaire, au X; Edm. Hoppe,
“Geschichte,” 1884, p. 128; C. H. Wilkinson, “Elements of
Galvanism,” Vol. I. p. 69, note; Albert’s “Amer. Ann. d. Artz,”
Vol. II. Bremen, 1802.
=A.D. 1762.=--Ledru Comus, French Professor of Natural Philosophy,
invents a mode of telegraphing which is described and fully
illustrated in Vol. I of Guyot’s “Nouvelles Récréations Physiques
et Mathématiques,” Paris, 1769; as well as at p. 278 of “Mémoires,
Correspondance et Ouvrages Inédits de Diderot,” Paris, 1821, in one of
the letters to Mlle. Voland dated July 28, 1762.
His apparatus consisted of two dials, each bearing upon it twenty-five
letters of the alphabet, which were moved by the agency of magnets and
of magnetized needles; but Auguste Guérout considers the contrivance
to have been merely a speculative one, as will be seen by his article,
reproduced from “La Lumière Electrique” of March 3, 1883, in No. 384 of
the “Scientific American Supplement.”
REFERENCES.--_Journal de Physique_ for 1775, Vols. V and VI;
for 1776, Vol. VII; and for 1778, Vol. I; “Scelta di Opuscoli,”
Milano, 1776.
=A.D. 1765.=--Cigna (Giovanni Francesco), native of Mondovi, Italy, and
nephew to the electrician Beccaria (A.D. 1753), became secretary to
the society of savants who gave birth to the Royal Academy of Sciences
at Turin, and whose Memoirs contain his work, “De novis quibusdam
experimentis electricis,” 1765.
At pp. 31–65 of the above Memoirs is given a full account of Cigna’s
many curious observations made with silk ribbons placed in various
positions, and in contact with different surfaces, instead of with
the silk stockings employed by Symmer (A.D. 1759). He thus supplies
the main defect of Dufay’s theory (A.D. 1733) by proving that the two
opposite electricities are produced simultaneously. On p. 47 of the
same work will be found a report of Cigna’s experiment with ice to
ascertain whether electric substances contain more electric matter than
other bodies.
REFERENCES.--Vol. III. p. 168 of Nollet’s “Letters,” for an
account of his observations upon the electric attraction and
repulsion between conducting substances immersed in oil; as well
as Chap. II. s. 3., vol. i. of Van Swinden’s “Receuil,” etc.,
published at La Haye, 1784. Should also be consulted: Cigna’s
“Memoirs on Electricity and Magnetism” in the “Miscellanea
... Taurinensia,” and the several communications made by him
to Priestley, Lagrange and others in 1775 concerning Volta’s
electrophorus; likewise “Memorie istorische ... di Gianfrancesco
Cigna de Antonmaria Vassalli Eandi,” Torino, 1821.
=A.D. 1766–1776.=--Lambert (Johann Heinrich), a profound German
mathematician, native of Upper Alsace, publishes in Vol. XXII of the
“Reports of the Berlin Academy” two beautiful Memoirs upon the “Laws of
Magnetic Force” and upon the “Curvature of the Magnetic Current,” both
of which, according to Dr. Robison, would have done credit to Newton
himself.
In the first Memoir, says Harris, the author endeavours to determine
two very important laws; one relating to the change of force as
depending upon the obliquity of its application, the other as referred
to the distance. In the second Memoir the curves of the magnetic
current are investigated by the action of the directive or polar force
of a magnet upon a small needle. Lambert concludes that the effect
of each particle of the magnet on each particle of the needle, and
reciprocally, is as the absolute force or magnetic intensity of the
particles directly, and as the squares of the distances inversely.
Noad states (“Manual,” London, 1859, p. 580) that Lambert’s deductions
were confirmed twenty years later by Coulomb, through the agency of his
delicate torsion balance, and more recently (about the year 1817) by
Prof. Hansteen, of Christiania.
Previous to the above-named date, in 1760, Lambert had published,
both at Leipzig and at Augsburg, his “Photometria, sive de Mensura et
Gradibus Luminis, Colorum et Umbræ,” the sequel to a tract printed two
years before, wherein he indicates the mode of measuring the intensity
of the light of various bodies. The celebrated mathematician and
astronomer, Pierre Bouguer (1698–1758), who had published, in 1729, his
“Essai d’Optique,” etc., which was greatly enlarged in his “Traité,”
etc., brought out by La Caille in 1760, may be considered the founder
of this branch of the science of optics, to which the name _photometry_
has been given by English writers. The photometer designed by Sir
Benjamin Thompson, _Count Rumford_ (entered at A.D. 1802), has been
described in _Phil. Trans._ for 1794, Vol. LXVII. His method is to cast
two shadows of a given object near each other on the same surface, the
lights being removed to such distances that the shadows appear equally
dark.
REFERENCES.--Sir John Leslie’s “Fifth Dissertation” in the
eighth “Encycl. Brit.”; Count Rumford’s photometer illustrated
at Plate XXVII. figs. 387, 388, vol. i. of Dr. Thomas Young’s
“Course of Lectures,” London, 1807; also Vol. II. pp. 282 and
351 of the same work, concerning photometry generally; Dredge
and others, “Electric Illumination,” etc. (chiefly compiled from
London _Engineering_), Vol. II. pp. 101–117; Brewster’s “Edin.
Jour. of Sc.,” 1826, Vol. II. p. 321; Vol. III. p. 104; Vol.
V. p. 139, for William Ritchie’s articles on the photometer of
Mr. Leslie, and relative to an improved instrument upon the
principles of Bouguer (_Edin. Transactions_, Vol. X. part. ii.);
Lambert’s biography and the article “Magnetism” in the “Encycl.
Brit.”; Harris, “Rudim. Magn.,” Part III. pp. 20, 33, 191–203.
It may be added that all the valuable manuscripts left by Lambert were
purchased by the Berlin Academy, and were afterward published by John
Bernoulli, a grandson of the celebrated John Bernoulli alluded to at
A.D. 1700.
=A.D. 1766.=--Lullin (Amadeus), in his “Dissertatio physica
de electricitate,” Geneva, 1766, at p. 26, alludes to Beccaria’s
experiments, saying that he produced much greater effects with the
electric spark by passing the latter through oil instead of water:
oil being a much worse conductor, the spark in it is larger. At p.
38 of the same work he details the experiments made to prove the
correctness of Mollet’s doctrine regarding the constant motion of
electrical atmospheres, and at p. 42 are given his experiments to show
the production of electricity in the clouds. With a long insulated pole
projecting from the mountain side he observed, among other effects,
that when small clouds of vapour produced by the sun’s heat touched
only the end of the pole the latter was electrified, but that it was
not affected if the entire pole was covered by the vapour (“Lib. Useful
Knowledge,” “Electricity,” Chap. XI. Nos. 154, etc.).
Lullin, it is said, proposed a modification of Reusser’s plan of
telegraphing, in manner stated at p. 69 of Reid’s 1887 “Telegraph in
America.”
=A.D. 1766.=--L’Abbé Poncelet, a native of Verdun, France, publishes
at Paris “La Nature dans la formation du Tonnerre,” etc., wherein he
indicates a method of protecting from lightning residences, pavilions
and other structures, by constructing them of resinous woods and lining
them with either silk or waxed cloths. He quaintly remarks that as
they thus present “on all sides resinous surfaces, which never receive
phlogiston by communication, the latter (thunder and lightning), after
having leaped lightly around the pavilion and finding itself unable
to attack it, will probably depart in order to pursue its ravages
elsewhere.”
REFERENCES.--_Scientific American Supplement_, No. 66, p. 1053,
for a copy of the frontispiece of the above-named work; also
Figuier, “Exposition et Histoire,” etc., 1857, Vol. IV. pp. 234,
235.
=A.D. 1767.=--Bozolus (Joseph), an Italian Jesuit, Professor of
Natural Philosophy at Rome, is the first (and not Cavallo, A.D. 1775)
to suggest employing the active principle of the Leyden jar for the
transmission of intelligence.
His plan is to place underground two wires which are to be brought
at each station close enough to admit of the passage of a spark. One
of the wires is to be connected with the inner coating and the other
with the outer surface of a Leyden phial; the sparks observed at the
opening between the wires being there made to express any meaning
according to a preconcerted code of signals.
REFERENCES.--Latin poem entitled “Mariani Parthenii
Electricorum,” in six books, Roma, 1767, lib. i. p. 34
(describing the _telegrafo elettrico scintillante_); also
_Saturday Review_, August 21, 1858, p. 190, and _Cornhill
Magazine_ for 1860, Vol. II. p. 66.
=A.D. 1767.=--Priestley (Joseph), the earliest historian of electrical
science, publishes, by advice of Benjamin Franklin, the first edition
of his great work, “The History and Present State of Electricity,” of
which there were four other separate enlarged issues, in 1769, 1775,
1775 and 1794. During the year 1766 he had been given the degree of
Doctor of Laws by the Edinburgh University and he had also, at the
instance of Franklin, Watson and others, been made a member of the
English Royal Society, which, a few years later, bestowed upon him the
Copley medal.
Speaking of the above-named work, Dr. Lardner says (“Lectures, 1859,
Vol. I. p. 136): “This philosopher did not contribute materially to the
advancement of the science by the development of any new facts; but
in his ‘History of Electricity’ he collected and arranged much useful
information respecting the progress of the science.” Nevertheless,
to him is due the first employment of the conductor supported by an
insulating pillar, as described by Noad, who gives an account of
Priestley’s electrical machine at Chap. IV of his “Manual”; and he is
also the first to investigate upon an extensive scale the chemical
effects of ordinary electricity. The observations of M. Warltire, a
lecturer on natural philosophy, and Priestley’s own experiments in
this line, made by passing the electric spark through water tinged
blue by litmus, also through olive oil, turpentine, etc., as well as
his researches more particularly upon the gases and upon the influence
of the electric fluid in expanding solid bodies, are detailed at the
“Electricity” chapter of the “Encycl. Brit.”
At pp. 660–665 of the fourth edition of his “History,” Priestley
describes the experiments he made to illustrate what he called the
_lateral force of electrical explosions_; that is, the tendency of
the fluid to diverge, as is the case with lightning when any material
obstruction lies in its path.
Perhaps the most important of all Dr. Priestley’s electrical
discoveries (Thomson, “Hist. Roy. Soc.,” p. 445) was that charcoal is
a conductor of electricity, and so good a conductor that it vies even
with the metals themselves. When the conducting power of charcoal was
tried by succeeding electricians, it was found to vary in the most
unaccountable manner, sometimes scarcely conducting at all, sometimes
imperfectly and sometimes remarkably well; a diversity naturally
indicating some difference in the nature of the different specimens
of English charcoal (Priestley’s “History,” etc., Part VIII. s. 3).
Charcoal being examined by Mr. Kinnersley (at A.D. 1761), was
also by him observed to vary in its conducting power. Oak, beech and
maple charcoal he found to conduct satisfactorily; the charcoal from
the pine would not conduct at all, while a line drawn upon paper by a
heavy black lead pencil conducted pretty well (_Phil. Trans._,
1773, Vol. LXIII. p. 38).
REFERENCES.--Priestley’s letter to Dr. Franklin (_Phil. Trans._,
Vol. LXII. p. 360) concerning William Henley’s new electrometer
and experiments; likewise the _Phil. Trans._, Vol. LVIII. p. 68;
Vol. LIX. pp. 57, 63; Vol. LX. p. 192; Vol. LXII. p. 359; and
the abridgments by Hutton, Vol. XII. pp. 510, 600, 603; Vol.
XIII. p. 36; “Trans. of the Amer. Phil. Soc.,” O. S., Vol. VI.
part i. p. 190, containing proceedings of the Society on the
death of Joseph Priestley; Wilkinson’s “Elements of Galvanism,”
etc., London, 1804, Vol. II. pp. 74–80; Noad’s Lectures, No. 4,
Knight’s edition, pp. 182, 183; “Library of Useful Knowledge,”
London, 1829, Chap. “Electricity,” pp. 41 and 45; “Library of
Literary Criticism,” C. W. Moulton, Buffalo, 1901–1902, Vol. IV.
pp. 444–456; “Essays, Reviews and Addresses” by James Martineau,
London, 1890, Vol. I. pp. 1–42; “Mém. de l’Institut” (Histoire),
Tome VI. 1806, p. 29 for Elogium; “Essays in Historical
Chemistry,” T. E. Thorpe, London, 1894, pp. 28, 110; “Science
and Education,” by Thos. Henry Huxley, New York, 1894, pp. 1–37;
“Scientific Correspondence of Jos. Priestley,” by H. C. Bolton,
New York, 1902; Dr. Thos. H. Huxley, “Science Culture,” 1882, p.
102; Warltire, in Muirhead’s translation of Arago’s “Eloge de
James Watt,” pp. 99, 100; also the appendix to the last-named
work, p. 157 and note.
=A.D. 1767.=--Lane (Thomas--Timothy), a medical practitioner of
London, introduces his _discharging electrometer_, which is now to
be found described and illustrated in nearly all works on electricity.
It consists of a bent glass arm, one end of which is attached to a
socket in the wire of the Leyden jar, while the other end holds a
horizontal sliding brass rod, or spring tube, which bears a ball at
each extremity. The rod is usually divided into inches and tenths,
indicating the force of the discharge which takes place when the
knob of the jar is placed in contact with the prime conductor of an
electrical machine, and the charge is strong enough to leap from one to
the other. In Mr. Lane’s experiments the shocks were twice as frequent
when the interval between the balls was one twenty-fourth of an inch
as when twice as much: from which he concluded that the quantity of
electricity required for a discharge is in exact proportion to the
distance between the surfaces of the balls.
A combination of the Lane and other electrometers was made by Mr.
Cuthbertson, as shown at p. 528, Vol. II of _Nicholson’s Journal of
Natural Philosophy_, and at p. 451, Vol. LVII of the _Philosophical
Transactions_.
REFERENCES.--_Phil. Trans._ for 1805; Hutton’s abridgments, Vol.
XII; p. 475; Cavallo, “Elements ... Phil.” 1825, Vol. II. p 197;
Harris, “Electricity,” p. 103; _Monthly Magazine_, December
1805, and _Tilloch’s Philosophical Magazine_, Vol. XXIII. p. 253.
The Hutton abridgments contain, at p. 308, Vol. XV, the description of
a new electrometer by Abraham Brook.
=A.D. 1768.=--Ramsden (Jesse), a very capable English manufacturer of
mechanical instruments, member of the Royal Society and of the Imperial
Academy of St. Petersburg, is said to be the first to construct an
electrical machine wherein a plate of glass is substituted for the
glass globe of Newton and of Hauksbee and for the glass cylinder of
Gordon (at A.D. 1675, 1705 and 1742). The same claim which has been
made for Martin de Planta, Swiss natural philosopher, appears to have
no foundation. (See note at p. 401 of Ronalds’ “Catalogue.”)
REFERENCES.--_Journal des Sçavans_, November 1788, p. 744;
_Phil. Trans._, 1783; “Chambers’ Encyclopædia,” 1868, Vol. III.
p. 812; Mme. Le Breton, “Hist. et app. de l’Electricité,” Paris,
1884, pp. 61, 62.
=A.D. 1768.=--Molenier (Jacob), physician to the French King, Louis
XV, writes “Essai sur le Mécanisme de l’Electricité” for the purpose
of showing the utility of the application of the electric fluid in
medical practice. At p. 60 he explains the effects and results when
applications are made more particularly to the nerves, and at pp. 65–67
he gives certificates of many of the cures he has effected of gout,
rheumatism, tumours, cancers, loss of blood, as well as of pains and
aches of various descriptions.
REFERENCES.--Jallabert (A.D. 1749); Lovett (A.D. 1756);
Bertholon (A.D. 1780–1781); Mauduyt (A.D. 1781); Van Swinden,
“Recueil,” etc., La Haye, 1784, Vol. II. pp. 122–129 for the
experiments of Sauvages, De La Croix, Joseph Elder von Herbert,
H. Boissier and others; Thomas Fowler, “Med. Soc. of London,”
Vol. III; M. Tentzel, “Collection Académique,” Tome XI; the
works of L’Abbé Sans, Paris, 1772–1778; M. de Cazèles Masar’s
“Mémoires et Recueils,” published 1780–1788, and reproduced in
Vols. II and III of the “Mémoires de Toulouse”; Jacques H. D.
Petetin, “Actes de la Soc. de Lyon,” p. 230; M. Partington,
_Jour. de Phys._, 1781, Vol. I; Dr. Andrew Duncan’s “Medical
Cases,” Edinburgh, 1784, pp. 135, 191, 235, 320; C. A. Gerhard,
“Mém. de Berlin,” 1772, p. 141; _Jour. de Phys._, 1783, Vol.
II; J. B. Bohadsch, “Dissertatio,” etc., Prague, 1751; _Phil.
Trans._ for 1752; Patrick Brydone, _Phil. Trans._ for 1757;
Geo Wilkinson, of Sunderland, “An account of good effects,”
etc., in _Medical Facts_, etc., 1792, Vol. III. p. 52; M.
Carmoy, “Observ. sur l’El. Med.,” Dijon, 1784; M. Cosnier, M.
Maloet, Jean Darcet, etc.; “Rapport,” etc., 1783; Le Comus,
“Dissertatio,” etc., 1761; Le Comus, “Osservazioni,” etc., 1776
(_Jour. de Phys._, 1775, Vols. V and VI; 1776, Vol. VII; 1778,
Vol. I; 1781, Vol. II); Ledru, “Sur le traitement,” etc., 1783;
Le Dr. Boudet, “De l’Elec. en Médecine,” conférence faite à
Vienne le 6 Octobre, 1883.
=A.D. 1769.=--Bancroft (Edward Nathaniel), a resident physician of
Guiana, openly expresses the belief that the shock of the _torpedo_
is of an electrical nature. He alludes (“Natural History of Guiana”)
also to the _gymnotus electricus_, which, he says, gives much stronger
strokes than the _torpedo_; the shocks received from the larger animals
being almost invariably fatal.
The discharge of the _gymnotus_ has been estimated to be equal to that
of a battery of Leyden jars of three thousand five hundred square
inches, fully charged. At a later date, the American physicians, Garden
and Williamson, showed that as the fluid discharged by that fish
affects the same parts that are affected by the electric fluid; as it
excites sensations perfectly similar; as it kills and stuns animals in
the same manner; as it is conveyed by the same bodies that carry the
electric fluid and refuses to be conveyed by others that refuse to take
the fluid, it must be the electric fluid itself, and the shock given by
the eel must be the electric shock.
Humboldt, speaking of the results obtained by M. Samuel Fahlberg,
of Sweden, says: “This philosopher has seen an electric spark, as
Walsh and Ingen-housz had done before him at London, by placing the
_gymnotus_ in the air and interrupting the conducting chain by
two gold leaves pasted upon glass and a line distant from each other”
(_Edinburgh Journal_, Vol. II. p. 249). Faraday, who gives this
extract at paragraph 358 of his “Experimental Researches” says he could
not, however, find any record of such an observation by either Walsh or
Ingen-housz and does not know where to refer to that by Fahlberg. (See
the note accompanying afore-named extract.)
REFERENCES.--_Annales de Chimie et de Physique_, Vol. XI; _Phil.
Trans._ for 1775, pp. 94, 102 (letter of Alexander Garden,
M.D.), 105, 395; “Acad. Berlin,” 1770, 1786; fifteenth series
Faraday’s “Exper. Researches,” read December 6, 1838; Wheldon’s
“Catalogue,” No. 74, 1870; Sir David Brewster’s “Edin. Jour.
of Science,” 1826, Vol. I. p. 96, for the observations of
Dr. Robert Knox; G. W. Schilling: at Ingen-housz, “Nouvelles
Expériences,” p. 340, as well as at note, p. 439, Vol. I. of Van
Swinden’s “Recueil,” etc., La Haye, 1784; also G. Schilling’s
“Diatribe de morbo in Europâ penè ignoto,” 1770; article
“Physiology” in the “Encycl. Brit.,” 1859, Vol. XVII. p. 671;
Aristotle (B.C. 341), Scribonius (A.D. 50), Richer (A.D. 1671),
Redi (A.D. 1678), Kaempfer (A.D. 1702), Adanson (A.D. 1751);
_Sc. Am. Suppl._, No. 24, p. 375 (for M. Rouget’s observations
on the _gymnotus_) and No. 457, p. 7300; M. Bajon, “Descrizione
di un pesce,” etc., Milano, 1775 (_Phil. Trans._, 1773, p. 481);
M. Vanderlot’s work on the Surinam eel, alluded to at p. 88 of
“Voyage Zoologique,” by Humboldt, who published in Paris, during
1806 and also during 1819 special works on the _gymnotus_ and
upon electrical fishes generally.
=A.D. 1769.=--Cuthbertson (John), English philosophical instrument
maker, issues the first edition of his interesting work on electricity
and galvanism.
He is the inventor of the _balance electrometer_, employed for
regulating the amount of a charge to be sent through any substance, as
well as of an electrical condenser and of an apparatus for oxidating
metals, all of which are respectively described at pp. 593, 614 and
620, Vol. VIII. of the 1855 “Encycl. Brit.”
At the end of Part VI of his “Practical Electricity and Galvanism,”
Cuthbertson gives the conclusions he reached from his numerous
experiments with wire. These, as well as Mr. George Adams’ own
observations (“Essay,” etc., 1799, p. 285), proved that the quantity of
electricity necessary to disperse a given portion of wire will be the
same, even though the charged surface be greatly varied; and that equal
quantities of electricity in the form of a charge will cause equal
lengths of the same steel wire to explode, whether the jar made use of
be of greater or less capacity (_Nicholson’s Journal_, Vol. II. p.
217).
During his many experiments Cuthbertson made the very extraordinary
discovery that a battery of fifteen jars and containing 17 square feet
of coated glass, which, on a very dry day in March 1796 could only
be made to ignite from 18 to 20 inches of iron wire of ¹⁄₁₅₀ part of
an inch in diameter, took a charge which ignited 60 inches when he
breathed into each jar through a glass tube (Noad, “Manual,” p. 122;
also Cuthbertson, “Prac. Elec. and Magnetism,” 1807, pp. 187, 188).
REFERENCES.--Cuthbertson’s communication to the “Emporium of
Arts,” Vol. II. p. 193, regarding his experiments on John
Wingfield’s “New Method of Increasing the Charging Capacity
of Coated Electric Jars”; Cuthbertson’s “Electricity,” Parts
VIII, IX and XI; Cuthbertson’s letter addressed to _Nicholson’s
Journal_, Vol. II. p. 526, also _Phil. Mag._, Vol. II. p. 251.
for electrometers; “Bibl. Britan.,” Vol. XXXIX. 1808, p. 97;
Vol. XLVII. 1811, p. 233; Cuthbertson’s several works published
at Amsterdam and Leipzig, 1769–1797, and alluded to in _Phil.
Mag._, more particularly at Vols. XVIII. p. 358; XIX. p. 83;
XXIV. p. 170; XXXVI. p. 259, as well as at p. 313, Vol. XII.
of J. B. Van Mons’ _Journal de Chimie_; _Nicholson’s Journal_,
Vols. II. p. 525; VIII. pp. 97, 205, and the New Series, Vol.
II. p. 281; Gilbert’s _Annalen_, Vol. III. p. 1; “Bibl. Brit.
Sc. et Arts,” Genève, 1808, Vol. XXXIX. p. 118; Noad’s “Manual,”
p. 118; Van Marum (A.D. 1785); Harris, “Electricity,” p. 103,
and his “Frictional Electricity,” p. 76; C. H. Wilkinson,
“Elements of Galvanism,” etc., London, 1804, Vol. II. pp. 242,
266–268; _Phil. Trans._, 1782, for A. Brook’s electrometer,
which apparatus is described in the latter’s work published,
under the head of “Miscellaneous Experiments,” at Norwich,
1789, as well as in the “Electricity” article of the “Encycl.
Britannica.”
=A.D. 1769.=--St. Paul’s Cathedral, London, is first provided with
lightning conductors. Dr. Tyndall, who mentions this fact (Notes
of Lecture VI, March 11, 1875) likewise states that Wilson, who
entertained a preference for blunt conductors as against the views of
Franklin, Cavendish and Watson, so influenced King George III that the
pointed conductors on Buckingham House were, during the year 1777,
changed for others ending in round balls.
In 1772, St. Paul’s Cathedral was struck by lightning, which “heated to
redness a portion of one of its conductors consisting of a bar of iron
nearly four inches broad and about half an inch thick.” In 1764, the
lightning had struck St. Bride’s Church, London, and “bent and broke
asunder an iron bar two and a half inches broad and half an inch thick”
(Sturgeon, “Sc. Researches,” Bury, 1850, p. 360; _Phil. Trans._ for
1764 and 1762).
The Rev. James Pilkington, Bishop of Durham, published in London a
detailed account of the partial destruction of St. Paul’s Church by
lightning, June 4, 1561, which is also to be found at pp. 53–55 of
Strype’s “Life of Grindall,” published in London, 1710, and of which an
abstract appears under the A.D. 1754 date.
REFERENCES.--Sturgeon’s _Annals_, Vol. X. pp. 127–131; also,
Biography of John Canton in “Encycl. Britannica”; Sir John
Pringle, at A.D. 1777; Hutton’s abridgments of the _Phil.
Trans._, Vol. XII. pp. 620–624.
=A.D. 1769.=--Mallet (Frederick) member of the Royal Society of Upsal
and of the Stockholm Academy of Sciences, acting upon the observations
of Anders Celsius (at A.D. 1740), is the first to make an attempt to
determine the intensity of magnetism simultaneously at distant points.
He ascertains that the number of oscillations in equal times at Ponoi,
China (latitude, 67 degrees 4 minutes north; longitude, 41 degrees
east) are the same as at St. Petersburg, Russia (59 degrees 56 minutes
north latitude; 30 degrees 19 minutes east longitude).
REFERENCES.--Walker, “Magnetism,” Chap. VI; “Novi Commen. Acad.
Sc. Petropol.,” Vol. XIV for 1769, part ii. p. 33; Le Monnier,
“Lois du Magnétisme,” etc., 1776, p. 50; “Biog. Univ.,” Vol.
XXVI. p. 258.
=A.D. 1770.=--The well-known work of Jas. Ferguson, F.R.S., which first
appeared under the title of “Introduction or Lectures on Electricity,”
now becomes still more popular under the head of “Lectures on Select
Subjects,” etc. (Consult likewise his “Lectures on Electricity,”
corrected by C. F. Partington, with appendix, London, 1825.)
In his first lecture he says that the most remarkable properties of the
loadstone are: (1) it attracts iron and steel only; (2) it constantly
turns one of its sides to the north and the other to the south, when
suspended to a thread that does not twist; (3) it communicates all its
properties to a piece of steel when rubbed upon it without losing any
itself. He cites the experiments of Dr. Helsham, according to whom,
says he, the attraction of the loadstone decreases as the square of the
distance increases. He also treats of electrical attraction generally,
and reports in the sixth lecture having “heard that lightning,
striking upon the mariner’s compass, will sometimes turn it round and
often make it stand the contrary way, or with the north pole towards
the south.”
=A.D. 1770.=--Hell--Hehl--Heyl--Höll (Maximilian), Hungarian scientist
(1720–1792), member of the Order of Jesuits and Professor of Astronomy
at Vienna, who had great faith in the influence of the loadstone,
invented a singular arrangement of steel plates to which he afterward
attributed the cure “with extraordinary success” of many diseases, as
well as of a severe attack of rheumatism from which he himself had long
suffered.
He communicated his discovery to Friedrich Anton Mesmer, who was so
strongly impressed by Hell’s observations that he immediately procured
every conceivable description of magnet, with which he made many
experiments that led to his introduction of animal magnetism, or rather
_mesmerism_.
He is the author of many works, the most important being “Elementa
Algebræ Joannis Crivelii magis illustrata et novis demonstrationibus et
problematibus aucta,” Vienna, 1745; “Observ. Astronomicæ,” 1768, and
“Auroræ Boreales Theoria nova,” 1776.
REFERENCES.--Beckmann, Bohn, 1846, Vol. I. p. 44; _Practical
Mechanic_, Glasgow, 1843, Vol. II. p. 71; Van Swinden,
“Recueil,” etc., La Haye, 1784, Vol. II. pp. 303, 304, etc.;
J. Lamont, “Handbuch,” etc., p. 436; M. V. Burq, “Métallo
thérapie,” Paris, 1853; “Biog. Générale,” Vol. XXIII. pp.
836–839; Schlichtegroll, “Nekrol.,” 1792, Vol. I. pp. 282–303;
“Journal des Sçavans,” for July 1771, p. 499; Meusel, “Gelehrtes
Teutschl”; Jer. de la Lande, “Bibliogr. Astronomique,” Paris,
1803, pp. 721–722.
=A.D. 1771.=--Morveau (Baron Louis, Bernard Guyton de), a
very prominent French chemist and scientist, publishes at Dijon
his “Reflexions sur la boussole à double aiguille,” and, later on,
communicates to the _Annales de Chimie_, Vol. LXI. p. 70, and
Vol. LXIII. p. 113, very valuable papers treating on the influence of
galvanic electricity upon minerals, which are read before the French
Institute.
REFERENCES.--Thomson, “Hist. of Chemistry,” Vol. II. 1831;
the translation of Morveau’s letter to Guénaud de Montbéliard
in _Scelta d’ Opuscoli_, Vol. XXXIII. p. 60; Berthollet,
“Discours,” etc., 1816; “Biog. Univ.,” Tome XVIII. pp. 296–298;
“Journal des Savants” for Jan. 1860; “Roy. Soc. Cat. of Sc.
Papers,” Vol. III. pp. 99–102; Vol. VI. pp. 679–680; “Biog.
Univ. et Portative,” etc., 1834, Vol. III. p. 701; _Annales
de Chimie_, Vol. LXI. pp. 70–82; Sir Humphry Davy, “Bakerian
Lectures,” London, 1840, p. 51.
=A.D. 1771.=--In a very interesting article published by the _Gazette_
at Salem (Mass.), August 9, 1889, on the occasion of the formal
opening of the new station of the Electric Lighting Company, the
connection of that city with the progress of electricity was traced in
the following manner:
“In 1771 Col. David Mason, a prominent figure among the patriots
at Leslie’s Retreat, gave a course of lectures on ‘Electricity’ at
his house near North Bridge. The Rev. John Prince, LL.D., minister
of the First Church from 1779 to 1836, was especially interested in
electricity, and is said to have made the first electrical machine
in Salem, if not in the country. Col. Francis Peabody, assisted by
Jonathan Webb, the apothecary, was much interested in the subject, and,
in 1829, gave a series of lectures, illustrated with a machine made
by himself, which had a glass plate wheel imported from Germany at a
reported cost of $1500.
“Dr. Charles Grafton Page, another native of Salem, invented the first
electric motor in which solenoids were used, and as early as 1850
constructed a motor which developed over 10 h.p. The next year he made
a trial trip with his electro-magnetic locomotive over the Baltimore
and Washington Railroad. Prof. Moses Gerrish Farmer lived in Pearl
Street between the years 1850 and 1870, and, as far back as 1859,
illuminated the house with divided electric lights--_probably the
first time that any house in the world was lighted by electricity_.
In 1847 Prof. Farmer had constructed and exhibited in public an
electro-magnetic locomotive drawing a car holding two passengers, on a
track one foot and a half wide.
“Many of Prof. Alexander Graham Bell’s early experiments were conducted
in Salem, and the first lecture on the telephone in this country, if
not in the world, was delivered by him before the Essex Institute
in Lyceum Hall, February 12, 1877. The late Prof. Osbun, teacher of
chemistry and physics at the Normal School in Salem, was also an
electrical expert. He exhibited the first arc lights in Salem, and
was the inventor of the storage battery system from which lights were
exhibited.”
The advertisement of March 7, 1765, previously alluded to herein at
Kinnersley, A.D. 1761, is as follows:
“A COURSE OF EXPERIMENTS ON THE
newly discovered _Electrical Fire_, to be accompanied with methodical
LECTURES on the Nature and Properties of that wonderful Element
will be exhibited by DAVID MASON, at his House opposite Mr. _Thomas
Jackson_; Distiller, near Sudbury-Street.--To consist of two Lectures,
at one Pistareen each Lecture.--The first Lectures to be on Monday and
Thursday, and the Second on Tuesday and Friday Evenings every week,
Weather permitting.
“OF ELECTRICITY IN GENERAL
“That the Electric Fire is a real Element,--That our Bodies at all
Times contain enough of it to set an House on Fire,--That this Fire
will live in Water,--A Representation of the seven Planets, shewing a
probable Cause of their keeping their due Distances from each other,
and the Sun in the Centre,--The Salute repulsed by the Ladies’ Fire,
or Fire darting from a Lady’s Lips, so that she may defy any Person to
salute her,--A Battery of Eleven Guns discharged by the Electric Spark,
after it has passed through eight Feet of Water,--Several Experiments
shewing that the Electric Fire and Lightning are the same, and that
Points will draw off the Fire so as to prevent the Stroke,--With a
number of other entertaining Experiments, too many to be inserted in an
Advertisement.
“TICKETS to be had either at his House above or at his Shop in
Queen-Street.”
Another advertisement, which appeared in the Salem _Gazette_ of
Tuesday, January 1, 1771, is thus worded: “To-morrow evening (if
the Air be dry) will be exhibited A Course of Experiments in that
instructive and entertaining branch of Natural Philosophy called
Electricity; to be accompanied with Methodical Lectures on the nature
and properties of the wonderful element; by David Mason, at his
dwelling-house near the North-Bridge. The course to consist of two
lectures, at a pistareen each lecture.”
=A.D. 1771.=--Milly (Nicolas Christiern de Thy, Comte de) French
chemist, constructs compass needles of an alloy of gold and ferruginous
sand. These needles answered well their purpose, as did also the brass
needle owned by Christian Huyghens (alluded to at A.D. 1706), a fact
which received the confirmation of Messrs. Du Lacque, Le Chevalier
d’Angos and M. Arderon, while the latter further ascertained that he
could impart a feeble though distinct magnetic force to a brass bar
either by striking it or by means of the “double touch.”
REFERENCES.--The Comte de Milly’s “Mémoire sur la réduction des
chaux métalliques par le feu electrique,” read before the Paris
Academy May 20, 1774, brought about many controversial articles,
notably from Sigaud de la Fond, Felice Fontana, Jean M. Cadet,
Jean Darcet, G. F. Rouelle and Le Dru le Comus; “Biog. Univ.,”
Vol. XXVIII. p. 312; _Journal de Physique_, Tome XIII. p. 393;
_Philosophical Transactions_, Vol. L. p. 774; Duhamel, “Hist.
Acad. Reg. Paris,” p. 184; _Journal des Sçavans_, Paris edition
of December 1772, and Amsterdam edition of January 1773.
=A.D. 1772.=--Mesmer (Friedrich Anton), an Austrian physician, who,
upon taking his diploma at Vienna in 1766, had published a thesis
“On the Influence of the Planets upon the Human Body,” begins his
investigations as to the power of the magnet with the steel plates of
Father Hell. The results proved so favourable that Hell was induced
to publish an account of them, but he incurred the displeasure of his
friend by attributing the cures merely to the _form_ of the plates.
Mesmer subsequently arrived at the conclusion that the magnet was
incapable, by itself, of so acting upon the nerves as to produce the
results obtained and that another principle was necessarily involved;
he did not, however, give an explanation of it, and managed to keep his
process a secret for quite a while. He had observed that nearly all
substances can be magnetized by the touch, and in due time he announced
his abandonment of the use of the magnet and of electricity in his
production of what became known as _mesmerism_.
In 1779 he published his “Mémoire sur la découverte du magnétisme
animal,” in which he says: “I had maintained that the heavenly
spheres possessed a direct power on all of the constituent principles
of animated bodies, particularly on the _nervous system_, by
the agency of an all-penetrating fluid. I determined this action
by the intension and the remission of the properties of matter and
organized bodies, such as gravity, cohesion, elasticity, irritability
and electricity. I supported this doctrine by various examples of
periodical revolutions; and I named that property of the animal matter
which renders it susceptible to the action of celestial and earthly
bodies, _animal magnetism_. A further consideration of the subject
led me to the conviction that there does exist in nature a universal
principle, which, independently of ourselves, performs all that we
vaguely attribute to nature or to art.”
The whole theory and practice of mesmerism was, however, openly
rejected by one of Mesmer’s most capable pupils, Claude Louis
Berthollet (A.D. 1803), a very distinguished French chemical
philosopher, founder of the “Société Chimique d’Arcueil,” and who, in
conjunction with Lavoisier (A.D. 1781), Guyton de Morveau (A.D. 1771),
and Fourcroy (A.D. 1801), planned the new philosophical nomenclature
which has since proved of such service to chemical science (“La Grande
Encycl.,” Tome VI. p. 449; “Biog. Universelle,” Tome IV. pp. 141–149).
Mesmer gave all his manuscripts to Dr. Wolfart, of Berlin, who
published in 1814, “Mesmerism ... as the general curative of mankind.”
And it was one of Mesmer’s students, le Marquis de Puységur, who
discovered magnetic somnambulism, an entirely new phenomenon in animal
magnetism. (See the article “Somnambulism” in the “Encyl. Britannica,”
as well as the numerous works therein quoted, relating to the
above-named subjects, notably Mesmer’s own “Précis historique des faits
relatifs au magnétisme animal, jusques en Avril 1781.”)
REFERENCES.--“Bulletin de l’Acad. de Méd.,” Paris, 1837, Tome I.
p. 343, etc., and Tome II. p. 370; Blavatsky, “Isis Unveiled,”
Vol. I. p. 172, etc.; “L’Académie des Sciences,” par Ernest
Maindron, Paris, 1888, pp. 57–63; Richard Harte, “Hypnotism and
the Doctors,” Vols. I and II, New York, 1903 (from Mesmer to
De Puységur, Dupotet, Deleuze, Charcot, etc.); Robert Blakey,
“History of the Philosophy of Mind,” London, 1850, Vol. IV.
pp. 570–582, 639–645; the report of Dr. Franklin and other
Commissioners ... against mesmerism, translated by Dr. William
Bache, London, 1785; J. C. Schäffer, “Abhandlung,” etc., and
“Kräfte,” etc. (1776), “Fernere,” etc. (1777), also “Journal
Encyclopédique” for March 1777; Van Swinden, “Recueil,” etc., La
Haye, 1784, Vol. II. pp. 373–446; C. H. Wilkinson, “Elements of
Galvanism,” etc., Chapter XVIII; Champignon, “Etudes Physiques,”
etc., Paris, 1843; “Archives du Magn. Animal,” published by M.
Le Baron d’Hénin de Cuvillers, Paris, 1820–1823; “Report on
Animal Magnetism” made by Charles Poyen Saint Sauveur, 1836;
Dupotet’s “Manuel,” etc., Paris, 1868; Hale’s “Franklin in
France,” 1888, Part II. chap. v. alluding to an interesting
manuscript of T. Auguste Thouret now in the collection of the
American Philosophical Society.
=A.D. 1772.=--Henley (William T.), F.R.S., invents the _quadrant
electrometer_, an apparatus with which the quantity of electricity
accumulated in a jar or battery can be measured through the amount
of repulsion produced by the fluid upon a pith ball suspended from
the centre of a graduated arc. It is generally attached to the prime
conductor to measure the state of action of the electrical machine.
He is also the inventor of the _universal discharger_, for
directing the charge of jars or batteries (Edw. Whitaker
Gray--1748–1807--“Observations on manner glass is charged and
discharged by the electric fluid” in Hutton’s abridgments, Vol. XVI. p.
407).