size was calculated to be 527-3 times smaller than that of the sun, but 17 times larger than that of Jupiter, 25,104 times larger than that of the earth, 1,255,000 times larger than that of the moon, and with an orbit exceeding those of all the planets of our system added together, while its period of revolution is supposed to be not less than 3380 years! At the end of that period, therefore, it may be expected to return, and become again visible; for Nature is

"A solemn institute

Of laws eternal, whose unaltered page
No time can change."

Oct. 10, 1835, our little boy came running from the garden opposite, between six and seven, almost breathless, crying out "God has made a new star all at once.' On looking out, we found it to be 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.*

* Astronomers represent Halley as having been the first to foretell the precise return of a comet, and have the prediction verified. Whiston, however, claims it for 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."

Nor is Whiston 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
Return'd, the blazing wonder glares anew,

And o'er the trembling nations strikes 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.

When this comet is nearest to the sun's centre (forty-seven millions of miles), that luminary appears to its inhabitants about four times larger than it does to us; and when at the greatest distance (3,372,000,000 miles), the sun cannot appear larger than a star of the first magnitude.

But let us suppose ourselves, as I said before, 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 shall 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

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."

* 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 lu minous gas was issuing from the nucleus."-Quarterly, cix., 221.

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, traversing the more immediate regions of the sun, we pass on to the other side, and commence our return to our secret aphelium in the bosom of space.*

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 man.† The late illustrious chymical philosopher (Davy), too, distinctly allowed that there may be beings, "thinking beings," nearly surrounding us, which we can neither see nor

* I cannot imagine any comet to move in a 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.

+ Hesiod makes them wander over the earth, keeping account of human actions, both just and unjust. Maximus Tyrius entertained the same belief. St. Chrysostom also believed that every Christian has a guardian angel. Cardan insists that he was attended by one, as Socrates, and Iamblichus, and many others supposed themselves to have been. 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.

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; and 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 corporeal nutriments, perhaps,
Your bodies may at last turn all to spirit."

Poetry sometimes is philosophy: and who can dream of what may be imbodied or enveloped in those astonishing agents, HEAT, LIGHT, ELECTRICITY, and ATTRACTION? In all Nature there is no vacuity. To insist that nothing exists but what the human eye can see, is more worthy the intellect of a Cloten or a Caliban, than of that of a Milton, a Newton, a La Place, or a Davy.

DURATION.

THE duration of life appears far more arbitrary than the duration of unconscious bodies. Some plants rise from seed in the spring, flower in the summer, shed their seeds, and die in autumn or in winter. Some last two years, and others three; but the principal part are perennial, as grass, all manner of shrubs, and every description of trees. Some blossom only for one day, and others for only one night. The chrysanthemum putrescens bears flowers for the greatest portion of the year; the thuyan of China keeps in full leaf in winter and in summer; while the amaranth and rose of Jericho may be preserved for several years. Most plants live independent of the partial loss of either leaves or flowers, but the death of a blade of the papyrus involves that of the

bud and root attached to it. Some flowers, kept in cold water till they droop, may be restored to life and freshness by being placed in hot water. Then, if the coddled stems be cut off and put into cold water again, they may be preserved even to a third stage of existence.*

The Italian cypress lives two hundred years; there is a tree at Basle two hundred and fifty years old; the oak is one hundred years in arriving at perfection, and lives to the age of three hundred. Date-trees in Spain attain a similar age. Many plantains in India are one thousand years old; and the cedars on Mount Lebanon have an age of not less than two thousand years.

In respect to insects, some have their duration in proportion to the duration of a leaf, some to that of a flower, and others to that of a plant. Earth worms live three years, crickets ten years, bees seven, scorpions from seven to twelve, and toads have been known to arrive even to thirty. Wasps and spiders, on the other hand, live but one year; an ephemeron, in a flying state, only one day. But naturalists

*The Indian fig is subject to a curious kind of paralyzation. Sir James Smith alludes to this circumstance in his Introduction to Physiological and Systematical Botany, p. 260.

This plant is affected by gangrene, and a still more serious disease, called by Thierry 'la dissolution.' This seems to be a sudden decay of the vital principle, like that produced in animals by lightning or strong electricity. In an hour's time, from some unknown cause, a joint, a whole branch, or sometimes an entire plant of this species (Cactus coccinellifer) changes from apparent health to a state of putrefaction or dissolution. One minute its surface is verdant and shining; the next it turns yellow, and all its brilliancy is gone. On cutting into its substance, the inside is found to have lost all cohesion, being quite rotten. The only remedy in this case is speedy amputation below the diseased part. Sometimes the force of the vital principle makes a stand, as it were, against the encroaching disease, and throws off the infected joint or branch. Such is the account given by Thierry, which evinces a power in vegetables precisely adequate to that of the animal constitution, by which an injured part is, by an effort of nature, thrown off to preserve the rest."