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12. Difference between the English porcelain and that of Ger-

many and of the continent, 407

13. Mathematical, philosophical, and chemical instruments, 408

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P. 21, 1. 3 fr. but. for June 11, 1811, read June 18, 1811.—P. 93, 1. 3 fr. top. for
those read these. — P. 37, 1. 4 fr. top, for successively, read successfully, — ^P. 39, 1. 18
fr. bot. for Humphrey, read Humphry,— P. 3US, 1. 3 fr. top, for the Americem elk,
read Cervus Alces, L.


P. 305, 1. 4 fr. top, for bevel read level} 1. 3 fr. bot. ailer wire, add^'^ The num-
ber of divisions was then taken where the arms met." — P. 346, 1. 31 fr. top, for
CoUitelus, read Callitelus,

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Art, I. — Examination of the Theory of a Resisting Medium, in
which it is assumed that the Planets and Comets of our System
are moved; by R. W. Haskins, of Bufialo, N. Y.

In all ages, when astronomy has been cultivated, the opinion
seems to have been entertained, in some one or more of its nurfter-
ous forms and modifications, that the regions around us, beyond our
atmosphere, and to an indefinite extent, are supplied with a rare,
invisible medium, of unknown composition and character, in which
all the bodies of our solar system, and perhaps the .bodies of all
other systems also, in executing the several motions assigned them,
are necessitated to move. To this substance the name of eMer has
usually been applied ; and by this name we propose to designate
it, while we examine into its history, the evidences of its existence,
and its effects'. The period at which this celestial ether was intro-
duced into the science of astronomy, no less than the race of people
by whom it was efiected, is probably beyond the reach of inquiry :
we know only that in the most remote periods of the history of that
science, we find it constituting a prominent part of the celestial
mechanism. The Bramins, of India, whose astronomical tables,
constructed more than three thousand years before the Christian
era, are still preserved to us,(l) assumed its existence, and figura-
tively supposed the stars to move themselves therein, in a manner

(1) Bailly, Traite de rAstronomie Indienne et Orientale: Prof. PIa3rfair's
works, articles Astronomy of the Bramins, and Trigonometry of do. ; Hntton's
History of Algebra, and Rev. S. Vince's complete System of Astronomy, Vol. 2,
p. 353.

Vol. XXXIII.— No. 1. 1

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2 Examination of the Theory of a Resisting Medium.

similar to the movement of fish in water. (2)* The name by which
it was known to them is aJcash ; and Mr. Dow, in his dissertation
upon the religion of the Brarains, defines it to be " a celestial ele-
ment, pure and impalpable, in which the planets move." " This
element," he continues, " according to Bedang, offers no resistance ;
«o that the planets have moved uninterruptedly therein, from their,
first impulsion which they received from the hand of Brama ; and
they will not be arrested until the moment when he shall seize them
in the midst of their course."(3) The Chaldeans, also, held this
opinion, and in the figurative language of the East were wont to
represent the planets, including the sun, the earth and the moon, as
vessels moving therein, and suited to such navigation. (4) Alhazen,
an Arabian optician of the eleventh century, taught the existence of
ether, which he designated " the substance of heaven," and he sup-
posed it situated beyond, and differing in character from, our atmos-
phere.(5) Tycho Brahe reinstated the ether of the ancients in all
its rights. But though he regarded it as existent, he denied to it
the power of causing refraction, which he attributed solely to the
grosser vapours of our atmosphere. Whatever may be the difference
in the natures of these two fluids, says he, the atmosphere so dimin-
ishes in density upward, that at the point where it touches the ether
it differs little from it.(6) Kepler, in following the crowd who had
gone before him, revived this theory, in bis day, and turned the
substance in question to good account in framing some of the absurd
theories which he put forth, along with his immortal discoveries.
In seeking the origin of comets, be supposed them native inhabit-
ants of this ether, as fishes are of the waters of the earth ; and that
God created them to inhabit the immense spaces of the universe,
as be did whales and other monsters to people the vast solitudes of
the opean. The sombre and bloody appearance which the sun
sometimes exhibits he attributed to a coagulation of the ether ; and
when these appearances ceased, that result was produced by a col-
lection of the grosser portions, which had disturbed its transparency,
and their conversion into comets.(7)

C9) Bailly, Histoire de rAstronomie Ancienne, p. 115.

(3) BailJy, Traite de rAstronomie Indienne et Orientale, p. S06. The work of
Mr. Dow we have not seen.

(4) Bailly, Histoire de rAstronomie Ancienne, p. 139.

(5) Bailly, Histoire de TAstronomie Moderne, tome 1, p. 238.

(6) Ibid, tome 1, p. 404. (7) Ibid, tome 2, p. 124.

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Examination of the Theory of a Resisting Medium. 3

Through the long period of time embraced by these referenoesy
we see the existence of this fluid matter every where accredited ;
yet so vague and indefinite do all ideas respecting it appear to have
been, that rigid investigation of its character or necessity seems to
have been quite neglected ; and even its practical utility, so far as
we know, was but very limitedly considered. But we are now ta
enter upon a new era, and that a very important one, in the history
of this fluid ; for we are to see it elevated from the subordinate sta-
tion hitherto assigned it, to that of a primary agent in carrying out
the great motions of the universe. This application was the oflT-
spring of the genius of Descartes. The conception was a sublime
one which dared to identify the law of the general movement of
the universe, with that of the movement of terrestrial bodies : and
this is due to Descartes. His vortices are a bad explanation of
gravity and of the system of the world, but they are mechanicah
He discovered that the same mechanism moved bodies in the celes-
tial spaces and at the surface of the earth ; and if he was not able
to seize this mechanism, we should not forget that this new and
sublime thought was of his conception.(8) According to this phi-
losopher " matter, possessed only of the properties of extension, im-
penetrability and inertia, was supposed to fill all space, and its parts,
both great and small, to be endued with motion in an infinite variety
of directions. From the combination of these, the rectilineal motion
of the parts became impossible ; the atoms or particles of matter
were continually diverted from the lines in which they had begun
to move ; so that circular motion and centrifugal force originated
from their action on one another. Thus matter came to be formed
into a multitude of vortices, diflfering in extent, in velocity and den-
sity ; the more subtile parts constituting the real vortex, in which
the denser bodies float, and by which they are pressed, though not
equally, on all sides. Thus the universe consists of a multitude of
vortices, which limit and circumscribe one another. The earth
and the planets are bodies carried round in the great vortex of the
solar system ; and by the pressure of the subtile matter, which cir-
culates with great rapidity, and great centrifugal force, the denser
bodies, which have less rapidity, and less centrifugal force, are
forced down toward the sun, the centre of the vortex. In like

(8) Bailly, Histoire de TAstronoinie Ancienne, Discours Preliminaire ; and
Playifair on Mathematical and Physical Science.

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4 Examination of the Theory of a Resiiting Medium.

manner, each planet is itself the centre of a smaller vortex, by the
subtile matter of which the phenomena of gravity are produced, just
as with us at the surface of the earth."(9) In this system of phi-
losophy, if such it may be called, the agency of the ether, in causing
and sustaining the planetary motions, is indispensable ; and when we
consider how universal was the belief, by all learned and scientifick
men, in this doctrine, for more than half a century, we find a ready
excuse for the opinion of the less informed upon the subject. For
more than thirty years after the publication of Newton's discoveries,
this absurd doctrine of vortices kept its ground in France, Germany,
and in the universities of England and Scotland. It was^ finally
driven out of the Cambridge University, in England, by a friend of
Newton's publishing, in 1718, an edition of their Cartesian text
book, with notes, embracing the truths which Newton had disclosed.
These gradually undermined the doctrine of Descartes, and finally
caused its expulsion.(lO) This, however, was a work of time ; and
the absurdities in question were not generally, or even in any con*
siderable degree, driven from the colleges and learned societies of
Europe, before about the year 1720.(11)

When the errours of Descartes were finally removed from the
schools, and from the minds of philosophers, they gave place to the
Copernican system of the universe, as rigidly demonstrated by New-
ton, upon the basis of the laws of Kepler. By this system, and these
demonstrations, the celestial revolutions are shown to be carried
on independently of all assistance from the ether ; and the agency
of that fluid was consequently no longer demanded. But, though
thus discarded from all participation in planetary motion, a belief in

(9) Play fair on Mathematical and Physical Science, part 1, Sec. 4, Art. 4.

(10) Ibid, part 2, Sec. 4.

(11) It is, then, no more than aboat one hundred and seventeen years since even
the learned world became sane upon the grand outline, alone, of the celestial
mechanism. Three of the colleges of our own country were founded prior to
that date, namely, Harvard, in 1638 ; William and Mary, in 1693 ; and Yale, in
1700. At that early period of uur history, and with the professors' chairs, in these
institations, generally occupied by European scholars, we can hardly suppose
wide deviations, in the doctrines taught, from the received opinions in Europe;
and consequently, without any direct proof at hand, upon this point, we from ne-
cessity infer that the New World has just claims to a portion of whatever of re-
nown or reproach may rightfully attach to the inculcation of the Cartesian doc-
trine of the universe, at so late a day ; and that, for a period of eighty years, this
was gravely taught and believed at one, and for shorter periods at two other of
the colleges of our infant country.

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Examination, of the Theory of a Resisting Medium* 5

the existence of this fluid was still retained by Newton, who sought
to employ it in a new capacity. '' And now we might add some*
thing ^concerning a certain most subtile spirit, which pervades and
lies bid in all gross bodies ; by the force and action of which spirit,
the particles of bodies mutually attract one another at near distances,^
and cohere if contiguous ; and electrick bodies operate to greater dis-
tances, as well repelling as attracting the neighbouring corpuscles ;
and light is emitted, reflected, refracted, inflected, and heats bod-'
ies."(i2) He furthermore supposed that this substance is spread
through all the heavens ; and when for lack of demonstration, un-
certainty arose in his mind, he thus queried : ''Is not this medium
much rarer within the dense bodies of the sun, stars, planets and
comets, than in the empty celestial spaces between them? And in
passing from them to great distances, doth it not grow denser and
denser perpetually, and thereby cause the gravity of those great
1»odies towards one another, and of their parts towards the bodies ;
every body endeavouring to go from the denser parts of the medium
towards the rarer?"(13)

In 1762 the Academy of Sciences, of Paris, proposed, for a prize,
the question, '' Do the planets revolve in a medium of which the
resistance produces a sensible effect upon their movements 1" For
this prize JU. Vabbe Bossut was the successful competitor. His cal-
•culations showed him that the effect of resistance, offered to the
planets, would be to diminish the axis of their orbits, and conse-
quently to shorten their periods of revolution. An acceleration in
the movements of the moon had been observed, which was without
explanation, and on applying his reasonings to the motions of this
planet he satisfied himself that the observed acceleration was due to
the resistance of ether, encountered by the moon, in traversing her
orbit. The sum of that resistance he measured ; and this theory
being equally applicable to all the planets, he extended it to them
all, and subjected each to the resisting influence of the etber.(14)

The tails of comets were objects of early attention ; and it was
remarked, both by Fracastor and Apian^ that the tail of the comet

(13) Newton's Mathematicajl Principles of Natural Philosophy, vol. 2, p. 393.
The copjr of Newton to which all references in this article are made is the Eng-
lish translation, by Andrew Motte, 12 mo. edition, in two vols. London, 1729.

(13) Newton's Opticks, third edition, London, 1721, p. 325.

(14) Bailly, Histoire de T Astronomic Modeme, tome 3, p. 237; and Bossat, His-
toire des Mathimatiques, tome 2, p. 409.

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6 Eacamination of the Theory of a Resisting Medium.

of -1531 y and those of two subsequent ones, were all directed op^
posite to thesun.{ 1 5) Pingre subsequently supposed that these tails
are formed of the most subtile portions of the comet's atmosphere,
greatly rarefied by the sun, and driven to the side opposite the
«tfn, by the resistance of the ether ; aided, perhaps, by the solar
rays.(16) This direction of comets' tails, as laid down by Fracastor
and Apian, seems to have been very universally adopted. Newton
says the tails of comets arise from their heads, and tend towards
the parts opposite to the sun.(17) Bailly adopts the same opinion,
in strong language, namely, that the tails are always opposite the
sun.(i8) Delambre is equally unreserved. He says the tail of a
comet is always opposite the sun, or in prolongation of the radius
vector of the sun and the comet.(19) Laplace calls them trains of
vapour, always situated on the other side of the heads of comets, rel-
atively to the sun.(20) Vince says comets are surrounded by a
dense atmosphere, and from the side opposite the sun they send
forth a tail.(21) Bonnycastle denominates them fiery tails, which
continually issue fron) that side of the comets which is farthest from
the sun.(22) Brewster states that when a comet is near its peri-
helion, it is accompanied with a tail or train of light, directly oppo-
»te the sun.(23) Morse avows that comets are usually attended with
a long train of light, always opposite to the sun.(24) Prof Farrary
of Harvard, describes the trains, and adds, their direction is always
opposite to the sun. (25) The younger Herschel describes the nu-
cleus, and adds that from the head, and in a direction opposite to
that in which the siin is situated from the comet, appear to diverge
two streams of light, constituting the tail. (26) Sustained by the
high standing ind great numerical force of these authorities, the po-
sition here assumed has quite regularly found credence and a place

(15) Delambre, Histoire de TAstroiiomie da Moyen Age, p. 390 et 393.

(16) Delambre, Histoire de TAstroDomie da Dix Huiti^me Si^cle, p. 680.
Tlic ^ork of Pingr6, namely, Com^tograpkiey we have not seen.

(17) Math. Prin. of Nat. Phil, (vide note 12,) vol. 2, p. 364.

(18) Histoire de I'Astronomie Modeme, tome 2, p. 549.

(19) Astronomie Theoriqoe et Practique, tome 3, p. 401.

(20) Syst^me du Monde, p. 128.

(21) Complete System of Astronomy, vol. 1, p. 444.

(22) An Introduction to Astronomy, p. 44.

(23) Edinburgh Encyclopedia.

(24) American Universal Geography, vol. l,p. 32.

(25) Cambridge course of Natural Philosophy, fourth part, p. 306.

(26) A treatise on Astronomy, first published in 1833 ] American edition, p. 284.

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, ISxamination of the Theory of a Resisting Medium. 7

jn the numerous works of subordinate authors ; insomuch that we
have pretty uniformly recognized it in the elementary works upon
astronomy that we have examined in the English ]anguage.(27)

The cause assigned for this direction of comets' trains, by Pingre,
namely, the resistance of the ether, appears not to have found much
favour in the minds of his successors ; consequently we find, in gen-
eral, the expression employed, namely, " impulsion of the suiCs
rays" to denote both the agent and the manner of that agent's ac-
tion, in producing this result.

Great additional impulse has, within a few years, been given to
the theory of a resisting medium by the detailed and able paper of
Prof. Encke, upon the observed decrease of the times of revolution
of the comet which bears the name of that astronomer. This pa-
per has been translated into English, and is more or less extensively
quoted by almost every writer who lias employed his pen upon ce-
lestial motions, since the date of its appearance. The author says :
^^ If I may be permitted to express my opinion on a subject which,
for twelve years, has incessantly occupied me, in treating which I
have avoided no method, however circuitous, no kind of verification,
in order to reach the truth, as far as it lay in my power; I can-
not consider it otherwise than completely established, that an ex-
traordinary correction is necessary for Pons' [Encke's] comet, and
equally certain that the principal part of it consists in an increase of
the mean motion proportionate to the time.^\28) Dr. Bawditch, by
reference to the memoir of Encke, supposes the existence of a re-
sisting medium highly probable, as there disclosed, in the motions of
Encke's comet, in its successive appearances between the years 1786,.
and 1829.(29) Arago, of the Royal Observatory, at Paris, in an es-
say, in 1832, fully recognizes this resisting medium,, on the author-
ity of Encke, and dwells at considerable length upon its e&cts.(30}
M. Gautier assumes that, results obtained in 1828, from the noave-
raent of Encke's comet, accord with those which Encke had previ-
ously procured, and which induced him, (Encke J m 1823 to sup-
pose the existence of a medium or ethereal fluid, in space, of whicb
the resistance, acting as a tangential force against the motion of the
comet, would augment the power of the sun, and shorten the period

(27) Some of the recent French works, of a similar chai-acter, constitute ex-
ceptions to this rale.
(38) Prof. Encke's Memoir, as quoted in the American Almanack, 1834.

(29) M6caniqae Celeste, (Bowditch,) translator's note, vol. 3, p. 678.

(30) Tract on Comets, by Arago, translated into English, by Prof. Fasrar, Bos-
ton, 1832.

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8 Examination of the Theory of a Resisting Medium.

of revoIutioD.(31) The younger Herscbel refers to Encke's me^
moir ; admits its conclusibns, if the . premises shall be foond valid,
and adds : '^ accordingly^ (no other mode of accounting for the
phenomenon appearing,) this is the solution proposed by Encke,
and generally received. "(32) Mrs. Somerville, adverting, also, to
Encke's memoir, deems the existence of resisting ether rendered
^' all but certain, within a few years, by the motion of comets ;" and
this insinuated negation she quite recalls some eight pages afterwards,
by substituting the emphatick words, '^ which puts the existence of
ether beyond a doubt." The same pen not only prophesies that
by this resistance, comets will be finally precipitated upon the sun,
but also that '^ the same cause may alSect the motions of the planets,
and be ultimately the means of destroying the solar system."(3S)
Upon this memoir of Encke, theological arguments have been
founded, having for their object to prove the destruction of the so-
lar system, through the agency of this ether ; and so certain has
that result been considered, upon this authority, that the most posi-
tive forms of expression have been en^ployed in pointing to such a

It is believed that we have assembled, above, the leading facts and
arguments upon the affirmative of the position of a resisting medium
to the planets, so far as to embrace all that is requisite and necessary
for a clear understanding and subsequent impartial investigation of
the question. The method df division incident to this arrangement
has been adopted in the belief that such arrangement would afford
a view, more distinct than any other, of the entire question. We
proceed, then, to subject the several positions and arguments to ex-
amination, in the order of their occurrence.

The evidences, if any, upon which the Bramins and the Chalde-
ans founded their belief in the existence of this ether, not having
come down to us, the reasons for their faith are placed beyond in-
vestigation : nor are we better circumstanced in relation to the opin-
ions of Alhazen, Tycho Brahe, and some others who, while they
supposed such ether to occupy the celestial regions, gave no de-
* monstration of the fact, nor made application of it to any of the

(31) Silliman's Journal of Science, vol. 17, p. 389.

(32) A Treatise on Astronomy, American ed. p. 391.

(33) Mrs. Somerville on the connection of the Physical Sciences.

(34) Astronomy and General Physicks, considered with reference to Natnral
Theology (one of the Bridgewater treatises) by the Rev. W. Whewell, of Trinity
College, Cambridge.

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Examination of the Theory of a Resisting Medium. 9

known purposes of the universe. The opinions of Kepler, upon
this subject, may not have received less credence, in the day they

. were uttered, than did his discovery of the fundamental laws of the
celestial movements ; but they were promptly consigned to oblivion
by the subsequent revelation that comets, no less than planets, be-
long to our solar system, and move in ellipses more or less elonga-
ted, about the sun, obeying the same laws as the grosser planets.
Of Descartes' system, and of its fate, we have spoken. That sys-
tem was undermined by the discovery and application of the law of
universal gravitation ; and as this ether constituted all that w^ most
essential to the Cartesian doctrine, the celestial motions were no
sooner found to be carried on independently of its aid, than the
whole theory was abandoned. Newton, himself, as we have seen,
applied this substance, under the name of ^' a most subtile spirit,'*

, to the production of certain results, in his Principles of Natural Phi-
losophy, and again in his Opticks. The passages we have quoted.
These positions appear to have had their origin in a desire so to ex-
plain the doctrine of gravitation as to free it from the implied asser*'
tion that bodies act in places where they are not — a form of attack
which the metaphysicians chose to employ against it. Yet this was
but subjecting the question to new difficulties; as there is nothing
like a satisfactory explanation of gravity in the existence of this elas-
tick ether. True, a fluid disposed as Newton has assumed, would
urge bodies in the direction he supposed; but what could maintain
this fluid in the condition of its density varying according to the as-
sumed law, is as inexplicable as the gravity it was meant to explain.
The nature of such a fluid, if unrestrained, roust be to equalize the
density of all its parts, to the destruction of this hypothesis.(35)
That Newton did not consider gravity inherent in matter is manifest
from the passages under consideration ; and he most fully states this,
in words, in one of his letters to Dr. Bentley, as quoted by Prof.
Playfair. Yet how he should have supposed he had escaped its ne-
cessity by his resort to the agency of this ether — ^since it i? clearly
for this purpose that he sought its aid— may well be deemed inexpli-
cable. " If two particles of matter, at opposite extremities of the di-
ameter of the earth, attract one another, this elSect is just as little in-
telligible, and the modus agendi is just as mysterious, on the sup-
position that the whole globe of the earth is interposed, as on that
of nothing, whatever, being interposed, or of a complete vacuum

Online LibraryJohn RodgersThe American journal of science and arts → online text (page 2 of 42)