ble velocity, and finally almost cover the whole sky up to the zenith, and produce an appearance as if a vast tent was expanded in the heavens, glittering with gold, rubies, and sapphire. As soon as the phenomena of electricity, and the laws by which they are governed, were tolerably understood, philosophers very naturally had recourse to this agent, as affording a satisfactory explanation of the aurora borealis. The brilliancy of its light, the rapidity of its motions, and the instantaneous changes of form which it underwent, all seemed plainly to point to this powerful element as the cause of these striking phenomena. A small quantity of electricity excited in a highly rarefied atmosphere, or in a medium approaching to a perfect vacuum, will exhibit luminous appearances entirely resembling the aurora borealis, for a very considerable space of time. With respect to the variations of colour which we find in the aurora borealis, these seem fairly ascribable to the different degrees of rarefaction of the air; for the same electricity which appears white in a very rare medium, becomes blue, purple, or red, in a medium of increased density; as is fully evinced by the following experiment. Let an electrical machine and an air-pump be so disposed, that while the machine is worked, a succession of strong sparks shall be communicated from the prime conductor to a metallic knob attached to the top of the receiver of the air-pump. Let now the exhaustion of the receiver proceed, and we shall soon perceive the electricity forcing itself through the air within it in a visible stream. At first this stream is of a deep purple colour; but, as the exhaustion advances, it changes to blue; and at length to an intense white, with which the whole receiver becomes completely filled. This experiment would appear to establish the identity of the aurora borealis with electric light; and it may be mentioned as collateral proofs of this identity, that the atmosphere is found by the electrometer, to abound with electricity when the aurora shines forth; that the aurora when strong, is accompanied with the whizzing or crackling sound of electricity; and that the magnetic needle is evidently disturbed by the aurora as well as by the aetion of an electrical machine, or by the natural electricity of a thunder storm. The course of the aurora is uniformly from the poles towards the equator; and supposing it to consist in a stream of electric light, the following reasons may be assigned for its constantly preserving this course. Extreme cold renders almost all bodies electric, or disposed to accumulate electricity; while heat and moisture occasion a conducting power. Air, when dry and cold, is powerfully electric; and hence the beautiful phenomena of the aurora are confined to the polar regions, and appear by night and not by day, and in winter rather than in summer. The inferior part of the atmosphere, between the tropics, is violently heated, during the daytime, by the reflection of the sun's rays from the earth, while the superior parts retain their original cold. It is also impregnated with moisture exhaled by the powerful heat which then acts upon the earth. It is therefore in the conducting state, and readily communicates the electricity of the superior regions to the clouds which float in it, or to the body of the earth. Hence the awful electrical phenomena of the tropical regions, exhibited in thunder and lightning, water-spouts, whirlwinds, and the most tremendous tempests. The electrical fluid is thus conveyed in great quantities from the upper parts of the atmosphere between the tropics, to the lower stratum, and thence to the earth; and the inferior and warm atmosphere, having once exhausted itself, must necessarily be recruited from the upper and colder regions. CHAP. XXII. THE CONCLUSION. HAVING thus gone through a particular description of the earth, let us now pause for a moment to contemplate the great picture before us. The universe may be considered as the palace in which the Deity resides; and this earth as one of its apartments. In this, all the meaner races of animated nature mechanically obey him; and stand ready to execute his commands without hesitation. Man alone is found refractory; he is the only being endued with a power of contradicting these mandates. The Deity was pleased to exert superior power in creating him a superior being; a being endued with the choice of good and evil; and capable, in some measure, of co-operating with his own intentions. Man, therefore, may be considered as a limited creature, endued with powers imitative of those residing in the Deity. He is thrown into a world that stands in need of his help; and has been granted a power of producing harmony from partial confusion. If, therefore, we consider the earth as allotted for our habitation, we shall find that much has been given us to enjoy, and much to amend ; that we have ample reasons for our gratitude, and still more for our industry. In those great outlines of nature, to which art cannot reach, and where our greatest efforts must have been ineffectual, God himself has finished these with amazing grandeur and beauty. Our beneficent Father has considered these parts of nature as peculiarly his own; as parts which no creature could have skill or strength to amend: and therefore made them incapable of alteration, or of more perfect regularity. The heavens and the firmament show the wisdom and the glory of the workman. Astronomers, who are best skilled in the symmetry of systems, can find nothing there that they can alter for the better. God made these perfect, because no subordinate being could correct their defects. When, therefore, we survey nature on this side, nothing can be more splendid, more correct, or amazing. We there behold a Deity residing in the midst of a universe, infinitely extended every way, animating all, and cheering the vacuity with his presence! We behold an immense and shapeless mass of matter, formed into worlds by his power, and dispersed at intervals, to which even the imagination cannot travel! In this great theatre of his glory, a thousand suns, like our own, animate their respective systems, appearing and vanishing at Divine command. We behold our own bright luminary fixed in the centre of its system, wheeling its planets in times proportioned to their distances, and at once dispensing light, heat, and action. The earth also is seen with its twofold motion; producing, by the one, the change of seasons; and by the other, the grateful vicissitudes of day and night. With what silent magnificence is all this performed! with what seeming ease! The works of art are exerted with interrupted force; and their noisy progress discovers the obstructions they receive: but the earth, with a silent steady rotation, successively presents every part of its bosom to the sun; at once imbibing nourishment and light from that parent of vegetation and fertility. ces to excite his industry on the other. This habitation, though provided with all the conveniences of air, pasturage, and water, is but a desert place, without human cultivation. The lowest animal finds more conveniences in the wilds of nature than he who boasts himself their lord. The whirlwind, the inundation, and all the asperities of the air, are peculiarly terrible to man, who knows their consequences, and, at a distance, dreads their approach. The earth itself, where human art has not pervaded, puts on a frightful gloomy appearance. The forests are dark and tangled; the meadows overgrown with rank weeds; and the brooks stray without a determined channel. Nature, that has been kind to every lower order of beings, has been quite neglectful with regard to him; to the savage uncontriving man the earth is an abode of desolation, where his shelter is insufficient, and his food precarious. But not only provisions of heat and light are thus supplied, but its whole surface is covered with a transparent atmosphere, that turns with its motion, and guards it from external injury. The rays of the sun are thus broken into a genial warmth; and while the surface is assisted, a gentle heat is produced in the bowels of the earth, which contributes to cover it with verdure. Waters also are supplied in healthful abundance, to support life, and assist vegetation. Mountains arise, to diversify the prospect, and give a current to the stream. Seas extend from one continent to the other, replenished with animals that may be turned to human support; and also serv-cise the industry of a free and a thinking creaing to enrich the earth with a sufficiency of vapour. Breezes fly along the surface of the fields, to promote health and vegetation. The coolness of the evening invites to rest; and the freshness of the morning renews for labour. Such are the delights of the habitation that has been assigned to man! Without any one of these, he must have been wretched; and none of these could his own industry have supplied. But while many of his wants are thus kindly furnished on the one hand, there are numberless inconvenien A world thus furnished with advantages on the one side, and inconveniences on the other, is the proper abode of reason, is the fittest to exer ture. These evils, which art can remedy, and prescience guard against, are a proper call for the exertion of his faculties; and they tend still more to assimilate him to his Creator. God beholds with pleasure that being which he has made, converting the wretchedness of his natural situation into a theatre of triumph; bringing all the headlong tribes of nature into subjection to his will; and producing that order and uniformity upon earth, of which his own heavenly fabric is so bright an example. HISTORY OF ANIMATED NATURE. PART SECOND.-OF QUADRUPEDS. СНАР. І. BOOK I. A COMPARISON OF ANIMALS WITH THE INFERIOR definitions, to distinguish a plant from an animal, yet both possess so many properties so much alike, that the two kingdoms, as they are called, seem mixed with each other. Hence, it frequently puzzles to tell exactly where animal life begins, and vegetative terminates; nor indeed is it easy to resolve, whether some objects offered to view be of the lowest of the animal, or the highest of the vegetable races. The sensitive plant, that moves at the touch, seems to have as much perception as the fresh-water polypus, that is possessed of a still slower share of motion. Besides, the sensitive plant will not reproduce upon cutting in pieces, which the polypus is The known to do; so that the vegetable production seems to have the superiority. But, notwithstanding this, the polypus hunts for its food, as most other animals do. It changes its situation; and therefore possesses a power of choosing its food, or retreating from danger. Still, therefore, the animal kingdom is far removed above the vegetable; and its lowest denizen is possessed of very great privileges, when compared with the plants with which it is often surrounded. HAVING given an account of the earth in general, and the advantages and inconveniences with which it abounds, we now come to consider it more minutely. Having described the habitation, we are naturally led to inquire after the inhabitants. Amidst the infinitely different productions which the earth offers, and with which it is everywhere covered, animals hold the first rank; as well because of the finer formation of their parts, as of their superior power. vegetable, which is fixed to one spot, and obliged to wait for its accidental supplies of nourishment, may be considered as the prisoner of nature. Unable to correct the disadvantages of its situation, or to shield itself from the dangers that surround it, every object that has motion may be its destroyer. However, both classes have many resemblances, by which they are raised above the unorganized and inert masses of nature. Minerals are mere themselves, and waiting some external force to alter their forms or their properties. But it is otherwise with animals and vegetables; these are endued with life and vigour; they have their state of improvement and decay; they are capable of reproducing their kinds; they grow from seeds in some, and from cuttings in others; they seem all possessed of sensation in a greater or less degree; they both have their enmities and affections; and as some animals are, by nature, im But animals are endowed with powers of motion and defence. The greatest part are capable, by changing place, of commanding nature; and of thus obliging her to furnish that nourishment which is most agreeable to their state. Those few that are fixed to one spot, even in this seem-inactive, insensible bodies, entirely motionless of ingly helpless situation, are, nevertheless, protected from external injury, by a hard shelly covering; which they often can close at pleasure, and thus defend themselves from every assault. And here, I think, we may draw the line between the animal and vegetable kingdoms. Every animal, by some means or other, finds protection from injury; either from its force or courage, its swiftness or cunning. Some are protected by hiding in convenient places; and others by taking refuge in a hard resisting shell. But vege-pelled to violence, so some plants are found to tables are totally unprotected; they are exposed exterminate all others, and make a wilderness of to every assailant, and patiently submissive in the places round them. As the lion makes a every attack. In a word, an animal is an organ- desert of the forest where it resides, thus no other ized being, that is, in some measure, provided for plant will grow under the shade of the manchiits own security; a vegetable is destitute of every neel tree. Thus, also, that plant, in the West protection. Indies, called caraguata, clings round whatever But though it is very easy, without the help of tree it happens to approach: there it quickly |