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out, we found it was the comet, which had been anxiously expected; but which we had not been able to get a sight of, owing to the continual mist. This comet was Halley's; and you may judge of the speed of it by a diagram, made the same evening of its progress during the space of three hours.

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b

When this comet is nearest to the sun's centre, the sun appears to its inhabitants about four times larger than it does

a Astronomers represent Halley as having been the first to foretel the precise return of a comet, and to have that prediction verified. Whiston, however, attributes it to NEWTON, in regard to the comet of 1736. The data, on which he predicted this return, does not appear; but Whiston says " As far as we yet know, Sir Isaac is the first man, and this the very first instance, where the coming of a comet has been predicted beforehand, and has actually come according to that prediction, from the beginning of the creation to this day.” Whiston is not entirely the only writer, who mentions this prediction and fulfilment; for Thomson alludes to both :

He, first of men, with awful wing pursued
The comet, through the long elliptic curve,

As round innumerous worlds he wound his way;

Till to the forehead of an evening sky

Returned, the blazing wonder glares anew,

And o'er the trembling nations strike dismay.

It is very curious, that neither Bradley nor Arago, nor indeed any other astronomer, except Whiston, has said one word as to the circumstance of this comet's return having been predicted by Newton.

Soon after the return of this comet in 1230, there was a great pestilence; and similar visitations attended its return in 1305 and 1380. As it passes from the region of the Bear, through the middle of Boötes, and thence through the Serpent and OPIUCHUS, it is not impossible that this is the very comet, that was in Milton's mental eye, when he wrote the following passage:—

On the other side,

Incensed with indignation, Satan stood,
Unterrified; and like a Comet burn'd,
That fires the length of OPIUCHUS huge,

In th' arctic sky; and from his horrid hair

Shakes pestilence and war.

b Forty-seven millions of miles.

to us; when at it greatest distance, it cannot appear larger than a star of the first magnitude.

Now let us suppose ourselves, I say, upon the surface of a COMET. If comets are self-luminous", as in numerous instances I am disposed to think they are, we shall see nothing beyond our own globe; our eyes being partly blinded with excess of light. If, however, they are dark spheres, illuminated by other bodies, we for ages behold nebulæ, systems of stars, suns, and comets, unseen by mortal eyes. We, enter, at length, the solar regions. We behold Uranus, and his satellites, moving in a course contrary to all other analogies; we pass the empire of Saturn, encircled by his seven moons and double ring; we come within the orbit of Jupiter and his four companions we pass the Asteroids, and gaze with delight on their diminutive masses, as we had before with amazement on the immensity of others;-we invade the orbit of the earth; we dart through it to those of Venus and Mercury; and then, navigating the more immediate regions of the sun, we pass over on the other side; and commence our return to our secret aphelium in the bosom of space.

a 3,372,000,000 of miles.

b I published some remarks on this subject, three or four years ago, in the LITERARY GAZETTE; wherein I stated my belief that comets carried their own light. This idea seems to be confirmed by what a learned writer in the Quarterly Review states of M. Struvé's observations on the Halley comet :— "It has an elliptical nucleus, the greater diameter of which was from 1.5 to 3" of a degree, and the lesser diameter 0".4. It resembled a burning coal; from thence issued, in a direction nearly opposite to that of a tail, a divergent flame varying in intensity, in form, in direction, sometimes even double ;—one might fancy that luminous gas was issuing from the nucleus."-Quarterly, cix. 221.

⚫ I cannot imagine any comet to move in an hyperbola or a parabola ; because those courses appear to be entirely inconsistent with attraction; viz. that comets, so moving, enter our system for the first time, then depart, and never return. This is beyond the boundaries of our present geometry to prove; whatever we may think. The probability rather is, that if once seen here, the one seen has been seen before, and will be seen again.

THE INVISIBLE UNIVERSE.

TILL the invention of the microscope and micrometer, the invisible universe contained, with its other secrets, more than half the wonders of entomology.

The belief in INVISIBLE BEINGS is many thousand years old. Hesiod and Plato frequently allude to their existence; and Epicurus admitted beings into his philosophy, of a purer nature, and more ample faculties, than those enjoyed by mana. Our late illustrious chemical philosopher, (Davy,) too, distinctly allowed, that there may be beings,-" thinking beings,"-nearly surrounding us, which we can neither see nor imagine. Milton, also, has several passages, implying the same.

Millions of spiritual creatures walk this earth,

Unseen; both when we wake and when we sleep .

In another place, he speaks of creatures, playing in the colours of the rainbow: in a third, thus :

Time may come, when men

With angels may participate, and find
No inconvenient diet, nor too light fare;
And from these corporal nutriments, perhaps,
Your bodies may at last turn all to spirit a.

Poetry sometimes is philosophy: and who can dream of what may be embodied or enveloped in those astonishing agents, HEAT, LIGHT, ELECTRICITY, and ATTRACTION ? In all Nature, there is no vacuity. To insist, that nothing exists,

Hesiod makes them wander over the earth, keeping an account of actions, both just and unjust. Maximus Tyrius entertained the same belief. St. Chrysostom, also, believed that every Christian has a guardian angel.-Homil. de Diabolo, &c, xxii. Cardan insists, that he was attended by one, as Socrates and Jamblichus had been, et innumeris aliis.—De Cardano Judicium. Hermes, a contemporary with St. Paul (Rom. xv. 14), in his work entitled PASTOR, often quoted by the Fathers, assigned to every one not only an angel-guardian, but a devil, who is his tempter.-Vid. Butler's Lives of the Fathers, v. 148. c Comus. d P. L. v.

b P. L. iv.

but what the human eye can see, is more worthy the intellect of a Cloten, or of a Caliban, than that of a Milton, a Newton, a Laplace, or a Davy a.

a The wonders, that are in store for the future knowledge of man may be, in some measure, imagined by what is stated below.

EXTRAORDINARY ELECTRICAL PHENOMENA.-A great sensation was produced at the meeting of the British Association at Bristol in August, 1836, by the account which a gentleman named CROSSE, gave of the result of a series of electrical experiments which he had been pursuing unnoticed for the last thirty years.

Several rooms in Mr. Crosse's country house are filled with electrical apparatus of great power, and he has also suspended wires from the trees in his park, for the purpose of collecting the subtle fluid with which he works. So powerful is the enginery-if we may use such a phrase-which he has erected, that he can use it with the greatest ease to ignite combustible bodies, tear metals in pieces, and reduce chemical compounds into their elements. The current of electric matter will sometimes cause his "great battery " to make twenty discharges in a minute as loud as cannon; yet he can tame it in the midst of its energies, by simply turning an insulating lever, when the stream descends silently and innocuously into the ground.

The experiments detailed by Mr. Crosse to the Bristol Meeting related to the processes by which Nature forms minerals. In the recent inquiries of the geologist, great difficulties had been experienced in accounting for the insinuation of veins of metallic minerals into minute fissures or openings in other masses, and for several other phenomena in the formation of crystals. Becquerell and Mitcherlich had succeeded in forming crystals by electricity, and thus so far had explained those mysteries of nature. But the subject was still a wonder when Mr. Crosse, prompted by a fine sagacity, conceived the idea, that as nature appears to have produced most of the results, which we observe by a great power operating with a small intensity, and throughout a great space of time, it might be proper to try what could be effected by the same mode in the making of artificial crystals by electricity. It was with this view that he provided himself with apparatus of the power which has been described, some part of which he found he could keep in undiminished action for a whole year, and this by the agency of pure water only. Observing, in a cavern in the Quantock Hills, some calcareous spar formed by water percolating through limestone rock, he collected some of the fluid, and subjected it to the action of his Voltaic apparatus. For nine days he anxiously watched for a result, and was about to resign hope of any occurring, when, on the tenth day, a mineral exactly the same as the calcareous spar appeared. He had thus gone through an exact imitation of what was to our ancestors one of the most mysterious processes in

nature.

Latterly, Mr. Crosse has produced many such results. A gentleman, who visited his house after the Bristol Meeting, found one battery which had been for six months in operation on fluat of silver, and was producing large crystals in six-sided cubes at the negative pole, and crystals of silicia and chalcedony

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THE duration of life appears far more arbitrary, than the duration of unconscious bodies. Some plants rise from seed

at the positive; another, which was acting on nitrate of silver and copper, and producing crystals at the negative pole, and malachite at the positive; besides six or seven others, engaged in the like operations. From fluo-silicic acid he had produced quartz. He found that light was not favourable to the production of the crystals, and that they could be brought to perfection in a much shorter space of time, or with less power, in the dark. He was nevertheless able to observe what no mortal eye had ever before, perhaps, observed, the gradual progress of a quartz crystal from its first foundation to nearly its completion. First, he traced it as a thin six-sided figure then lines radiated from its centre-then lines parallel to the sides were formed: it increased in thickness; but owing to some disturbance in the operation, a second crystal arose, and prevented its arriving at the perfect form.

These experiments are simply attempts to imitate the processes of Nature, and thus ascertain what those processes are. The earth, it appears, is at all times positively electrified; and electricity is every day found to be a more and more important agent in bringing about the results which we observe upon it. Mr. Crosse's experiments give us reason to conclude that this subtle fluid, the very existence of which was not known eighty years ago, is constantly at work beneath our feet in putting matter into new arrangements and new combinations. It is a curious fact, that the rocks of igneous origin, as granite, and the aqueous, as slate, affect opposite states of electricity. Two sheets of rock of these various kinds probably operate in the same way as the alternate plates of copper and zinc in the Voltaic apparatus; and thus, by a process like that of Mr. Crosse, form the singular veins of metallic minerals which pervade their masses. It is to be hoped that, by further experiments, we may be able to come to more distinct conclusions on this interesting point.

In the course of his experiments on crystallisation, towards the close of the year, Mr. Crosse produced results of a still more remarkable kind. He had prepared a fluid for crystals by heating a flint to a white heat, and saturating the powder with muriatic acid. The mixture was placed in a quart basin, and caused by a siphon of flannel to drop upon a piece of ironstone from Mount Vesuvius, which was placed between the two wires of a powerful Voltaic battery. To pursue Mr. Crosse's own account of the experiment:" At the end of 14 days I observed two or three very minute specks on the surface of the stone, white and somewhat elevated. On the 18th day, fine filaments projected from each of these specks, and the whole figure was increased in size. On the 22d day, each of these figures assumed a more definite form; still enlarging. On the 26th day, each assumed the form of a perfect INSECT, standing upright on four or five bristles which formed its tail. On the 28th day, each insect moved its legs, and, in a day or two afterwards, detached itself from the stone, and

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