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bird, when it quits the shell; and serves for its Dourishment, till it have learnt to pick its own food. This perfectly resembles the first nutrition of a plant. In the plant, as well as in the animal, the structure has every character of contrivance belonging to it: in both it breaks the transition from prepared to unprepared aliment; in both, it is prospective and compensatory. In animals which suck, this intermediate nourishment is supplied by a different source.

issue, close to each other, two shoots: one bearing the flower and fruit; the other, drawn out into a wire, a long, tapering, spiral tendril, that twists itself round any thing which lies within its reach. Considering, that in this class two purposes are to be provided for, (and together,) fructification and support, the fruitage of the plant, and the sustentation of the stalk, what means could be used more effectual, or, as I have said, more mechanical, than what the structure presents to our eyes? Why, or how, without a view to this double purpose, do two shoots, of such different and appropriate forms, spring from the same joint, from contiguous points of the same stalk? It never happens thus in robust plants, or in trees. "We see not (says Ray) so much as one tree, or shrub, or herb, that hath a firm and strong stem, and that is able to mount up and stand alone without assistance, furnished with these tendrils." Make only so simple a comparison as that between a pea and a bean. Why does the pea put forth tendrils, the bean not; but because the stalk of the pea cannot support itself, the stalk of the bean can? We may add, also, as a circumstance not to be overlooked, that in the pea tribe, these clasps do not make their appearance till they are wanted; till the plant has grown to a height to stand in need of support.

This word "support" suggests to us a reflection upon a property of grasses, of corn, and canes The hollow stems of these classes of plants are set, at certain intervals, with joints. These joints are not found in the trunks of trees, or in the solid stalks of plants. There may be other uses of these joints; but the fact is, and it appears to be, at least, one purpose designed by them, that they corroborate the stem; which, by its length and hollowness, would otherwise be too liable to break or bend.

In all subjects, the most common observations are the best, when it is their truth and strength which have made them common. There are, of this sort, two concerning plants, which it falls within our plan to notice. The first relates to, what has already been touched upon, their germination. When a grain of corn is cast into the ground, this is the change which takes place. From one end of the grain issues a green sprout; from the other a number of white fibrous threads. How can this be explained? Why not sprouts from both ends? why not fibrous threads from both ends? To what is the difference to be referred, but to design; to the different uses which the parts are thereafter to serve; uses which discover themselves in the sequel of the process? The sprout, or plumule, struggles into the air; and becomes the plant, of which, from the first, it contained the rudiments: the fibres shoot into the earth; and, thereby, both fix the plant to the ground, and collect nourishment from the soil for its support. Now, what is not a little remarkable, the parts issuing from the seed take their respective directions, into whatever position the seed itself happens to be cast. If the seed be thrown into the wrongest possible position; that is, if the ends point in the ground, the reverse of what they ought to do, every thing, nevertheless, goes on right. The sprout, after being pushed down a little way, makes a bend, and turns upwards; the Grasses are Nature's care. With these she fibres, on the contrary, after shooting at first up- clothes the earth; with these she sustains its inwards, turn down. Of this extraordinary vegeta- habitants. Cattle feed upon their leaves; birds ble fact, an account has lately been attempted to upon their smaller seeds; men upon the larger: be given. "The plumule (it is said) is stimulated for, few readers need be told that the plants, which by the air into action, and elongates itself when produce our bread-corn, belong to this class. In it is thus most excited; the radicle is stimulated those tribes, which are more generally considered by moisture, and elongates itself when it is thus as grasses, their extraordinary means and powers most excited. Whence one of these grows up- of preservation and increase, their hardiness, their ward in quest of its adapted object, and the other almost unconquerable disposition to spread, their downward." Were this account better verified faculties of reviviscence, coincide with the intenby experiment than it is. it only shifts the con- tion of nature concerning them. They thrive trivance. It does not disprove the contrivance; under a treatment by which other plants are deit only removes it a little farther back. Who, to stroyed. The more their leaves are consumed, use our author's own language," adapted the ob- the more their roots increase. The more they are jects?" Who gave such a quality to these connate trampled upon, the thicker they grow. Many of parts, as to be susceptible of different "stimula- the seemingly dry and dead leaves of grasses retion;" as to be "excited" each only by its own ele-vive, and renew their verdure in the spring. In ment, and precisely by that which the success of the vegetation requires? I say, "which the success of the vegetation requires;" for the toil of the husbandman would have been in vain; his laborious and expensive preparation of the ground in vain; if the event must, after all, depend upon the position in which the scattered seed was sown. Not one seed out of a hundred would fall in a right direction.

Our second observation is upon a general property of climbing plants, which is strictly mechanical. In these plants, from each knot or joint, or, as botanists call it, axilla, of the plant,

Darwin's Phytologia, p. 144.

lofty mountains, where the summer heats are not sufficient to ripen the seeds, grasses abound, which are viviparous, and consequently able to propagate themselves without seed. It is an observation, likewise, which has often been made, that herbivorous animals attach themselves to the leaves of grasses; and, if at liberty in their pastures to range and choose, leave untouched the straws which support the flowers.*

The GENERAL properties of vegetable nature, or properties common to large portions of that kingdom, are almost all which the compass of our argument allows to bring forward. It is impossible

* Withering, Bot. Arr. vol. i p. 28. ed. 2d.

to follow plants into their several species. We may be allowed, however, to single out three or four of these species as worthy of a particular notice, either by some singular mechanism, or by some peculiar provision, or by both.

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structure of this plant, we find that instead of its being neglected, Nature has gone out of her course to provide for its security, and to make up to it for all its defects. The seed-vessel, which in other plants is situated within the cup of the flower, or 1. În Dr. Darwin's Botanic Garden (1. 395, just beneath it, in this plant lies buried ten or note,) is the following account of the vallisneria, twelve inches under ground within the bulbous as it has been observed in the river Rhone. root. The tube of the flower, which is seldom 'They have roots at the bottom of the Rhone. more than a few tenths of an inch long, in this The flowers of the female plant float on the sur-plant extends down to the root. The stiles in all face of the water, and are furnished with an elas- cases reach the seed-vessel; but it is in this, by an tic, spiral stalk, which extends or contracts as the elongation unknown to any other plant. All these water rises or falls; this rise or fall, from the tor-contribute to one end.. "As this plant blossoms rents which flow into the river, often amounting late in the year, and probably, would not have to many feet in a few hours. The flowers of the time to ripen its seeds before the access of winter, male plant are produced under water; and, as which would destroy them; Providence has consoon as the fecundating farina is mature, they se- trived its structure such, that this important office parate themselves from the plant; rise to the sur-may be performed at a depth in the earth out of face; and are wafted by the air, or borne by the reach of the usual effects of frost."* That is to currents, to the female flowers." Our attention say, in the autumn nothing is done above ground in this narrative will be directed to two particu- but the business of impregnation; which is an aflars: first, to the mechanism, the "elastic, spiral | fair between the antheræ and stigmata, and is prostalk," which lengthens or contracts itself accord-bably soon over. The maturation of the impreg ing as the water rises or falls; secondly, to the nated seed, which in other plants proceeds within provision which is made for bringing the male a capsule, exposed together with the rest of the flower, which is produced under water, to the fe- flower to the open air, is here carried on, and dur male flower which floats upon the surface. ing the whole winter, within the heart, as we may II. My second example I take from Wither-say, of the earth, that is, "out of the reach of the ing's Arrangement, vol. ii. p. 209. ed. 3. "The cuscuta europaea is a parasitical plant. The seed opens, and puts forth a little spiral body, which does NOT seek the earth, to take root; but climbs in a spiral direction, from right to left, up other plants, from which, by means of vessels, it draws its nourishment." The "little spiral body" proceeding from the seed, is to be compared with the fibres which seeds send out in ordinary cases: and the comparison ought to regard both the form of the threads and the direction. They are straight; this is spiral. They shoot downwards; this points upwards. In the rule, and in the exception, we equally perceive design.

usual effects of frost." But then a new difficulty presents itself: seeds, though perfected, are known not to vegetate at this depth in the earth. Our seeds, therefore, though so safely lodged, would, after all, be lost to the purpose for which all seeds are intended. Lest this should be the case, “a second admirable provision is made to raise them above the surface when they are perfected, and to sow them at a proper distance; viz. the germ grows up in the spring, upon a fruit stalk, accompanied with leaves. The seeds now, in common with those of other plants, have the benefit of the summer, and are sown upon the surface. The order of vegetation externally is this:-The III. A better known parasitical plant is the ever-plant produces its flowers in September; its leaves green shrub, called the mistletoe. What we have and fruits in the spring following. to remark in it, is a singular instance of compensation. No art hath yet made these plants take root in the earth. Here therefore might seem to be a mortal defect in their constitution. Let us examine how this defect is made up to them. The seeds are endued with an adhesive quality, so tenacious, that if they be rubbed upon the smooth bark of almost any tree, they will stick to it. And then what follows? Roots, springing from these seeds, insinuate their fibres into the woody substance of the tree; and the event is, that a mistletoe plant is produced next winter. Of no other plant do the roots refuse to shoot in the ground; of no other plant do the seeds possess this adhesive, generative quality, when applied to the bark

of trees.

IV. Another instance of the compensatory system is in the autumnal crocus, or meadow saffron (colchicum autumnale.) I have pitied this poor plant a thousand times. Its blossom rises out of the ground in the most forlorn condition possible; without a sheath, a fence, a calyx, or even a leaf to protect it: and that, not in the spring, not to be visited by summer suns, but under all the disadvantages of the declining year. When we come, however, to look more closely into the

* Withering, Bot. Arr. vol. i. p. 203. ed. 2d.

"Its

When

V. I give the account of the dionœa muscipula, an extraordinary American plant, as some late authors have related it: but whether we be yet enough acquainted with the plant, to bring every part of this account to the test of repeated and familiar observation, I am unable to say. leaves are jointed and furnished with two rows of strong prickles; their surfaces covered with a number of minute glands, which secrete a sweet liquor that allures the approach of flies. these parts are touched by the legs of flies, the two lobes of the leaf instantly spring up, the rows of prickles lock themselves fast together, and squeeze the unwary animal to death." Here, under a new model, we recognise the ancient plan of nature, viz. the relation of parts and provisions to one another, to a common office, and to the utility of the organized body to which they belong. The attracting syrup, the rows of strong prickles, their position so as to interlock the joints of the leaves; and, what is more than the rest, that singular irritability of their surfaces, by which they close at a touch; all bear a contributory part in producing an effect, connected either with the defence or with the nutrition of the plant.

* Withering, ubi supra, p. 360.

† Smellie's Phil. of Nat. Hist. vol. i. p. 5.

CHAPTER XXI.

The Elements.

phere raises the water and leaves the salt. Pure and fresh as drops of rain descend, they are collected from brine. If evaporation be solution (which seems to be probable,) then the air dissolves the water, and not the salt. Upon whatever it be founded, the distinction is critical; so much so, that when we attempt to imitate the process by art, we must regulate our distillation with great care and nicety, or, together with the water, we get the bitterness, or at least, the distastefulness, of the marine substance: and after all it is owing to this original elective power in the air, that we can effect the separation which we wish, by any art or means whatever.

WHEN We come to the elements, we take leave of our mechanics; because we come to those things, of the organization of which, if they be organized, we are confessedly ignorant. This ignorance is implied by their name. To say the truth, our investigations are stopped long before we arrive at this point. But then it is for our comfort to find, that a knowledge of the constitution of the elements is not necessary for us. For instance, as Addison has well observed, "we know water sufficiently, when we know how to boil, By evaporation, water is carried up into the how to freeze, how to evaporate, how to make it air; by the converse of evaporation, it falls down fresh, how to make it run or spout out, in what upon the earth. And how does it fall? Not by quantity and direction we please, without know- the clouds being all at once reconverted into ing what water is." The observation of this ex-water, and descending like a sheet; not in rushing cellent writer has more propriety in it now, than it had at the time it was made: for the constitution, and the constituent parts, of water, appear in some measure to have been lately discovered; yet it does not, I think, appear, that we can make any better or greater use of water since the discovery, than we did before it.

We can never think of the elements, without reflecting upon the number of distinct uses which are consolidated in the same substance. The air supplies the lungs, supports fire, conveys sound, reflects light, diffuses smells, gives rain, wafts ships, bears up birds. 'E UTOS TO #UT: water, besides maintaining its own inhabitants, is the universal nourisher of plants, and through them of terrestrial animals; is the basis of their juices and fluids; dilutes their food; quenches their thirst, floats their burdens. Fire warms, dissolves, enlightens; is the great promoter of vegetation and life, if not necessary to the support of both.

We might enlarge, to almost any length we pleased, upon each of these uses; but it appears to me almost sufficient to state them. The few remarks which I judge it necessary to add, are as follow:

down in columns from a spout; but in moderate drops, as from a colander. Our watering-pots are made to imitate showers of rain. Yet, a priori, I should have thought either of the two former methods more likely to have taken place than the last.

By respiration, flame, putrefaction, air is rendered unfit for the support of animal life. By the constant operation of these corrupting principles, the whole atmosphere, if there were no restoring causes, would come at length to be deprived of its necessary degree of purity. Some of these causes seem to have been discovered; and their efficacy ascertained by experiment. And so far as the discovery has proceeded, it opens to us a beautiful and a wonderful economy. Vegetation proves to be one of them. A sprig of mint, corked up with a small portion of foul air, placed in the light, renders it again capable of supporting life or flame. Here, therefore, is a constant circulation of benefits maintained between the two great provinces of organized nature. The plant purifies, what the animal has poisoned; in return, the contaminated air is more than ordinarily nutritious to the plant. Agitation with water turns out to be another of these restoratives. The foulest air, shaken in a bottle with water for a sufficient length of time, recovers a great degree of its purity. Here then again, allowing for the scale upon which nature works, we see the salutary effects of storms and tempests. The yesty waves, which confound the heaven and the sea, are doing the very thing which was done in the bottle. Nothing can be of greater importance to the living creation, than the salubrity of their atmosphere. It ought to reconcile us therefore to these agitations of the elements, of which we sometimes deplore the consequences, to know that they tend, powerfully to restore to the air that purity, which so many causes are constantly impairing.

I. AIR is essentially different from earth. There appears to be no necessity for an atmosphere's investing our globe; yet it does invest it: and we see how many, how various, and how important, are the purposes which it answers to every order of animated, not to say of organized beings, which are placed upon the terrestrial surface. I think that every one of these uses will be understood upon the first mention of them, except it be that of reflecting light, which may be explained thus:-If I had the power of seeing only by means of rays coming directly from the sun, whenever I turned my back upon the luminary, I should find myself in darkness. If I had the power of seeing by reflected light, yet by means only of light reflected from solid masses, these II. In water, what ought not a little to be admasses would shine indeed, and glisten, but it mired, are those negative qualities which constiwould be in the dark. The hemisphere, the sky, tute its purity. Had it been vinous, or oleaginous, the world, could only be illuminated, as it is illu- or acid; had the sea been filled, or the rivers minated, by the light of the sun being from all flowed, with wine or milk; fish, constituted as sides, and in every direction, reflected to the eye, they are, must have died; plants, constituted as by particles, as numerous, as thickly scattered, they are, would have withered; the lives of animals and as widely diffused, as are those of the air. which feed upon plants, must have perished. Its Another general quality of the atmosphere is very insipidity, which is one of those negative quathe power of evaporating fluids. The adjust-lities, renders it the best of all menstrua. Having ment of this quality to our use is seen in its action no taste of its own, it becomes the sincere vehicle upon the sea. In the sea, water and salt are of every other. Had there been a taste in water, mixed together most intimately: yet the atmos- be it what it might, it would have infected every

thing we ate or drank, with an importunate repe- | ficult to conceive, it is easy to prove. A drop of tition of the same flavour.

Another thing in this element, not less to be admired, is the constant round which it travels; and by which, without suffering either adulteration or waste, it is continually offering itself to the wants of the habitable globe. From the sea are exhaled those vapours which form the clouds: these clouds descend in showers, which, penetrating into the crevices of the hills, supply springs which springs flow in little streams into the valleys; and there uniting, become rivers; which rivers, in return, feed the ocean. So there is an incessant circulation of the same fluid; and not one drop, probably, more or less now than there was at the creation. A particle of water takes its departure from the surface of the sea, in order to fulfil certain important offices to the earth; and, having executed the service which was assigned to it, returns to the bosom which it left.

Some have thought, that we have too much water upon the globe, the sea occupying above three quarters of its whole surface. But the expanse of ocean, immense as it is, may be no more than sufficient to fertilize the earth. Or, independently of this reason, I know not why the sea may not have as good a right to its place as the land. It may proportionably support as many inhabitants; minister to as large an aggregate of enjoyment. The land only affords a habitable surface; the sea is habitable to a great depth.

III. Of fire, we have said that it dissolves. The only idea probably which this term raised in the reader's mind, was that of fire melting metals, resins, and some other substances, fluxing ores, running glass, and assisting us in many of our operations, chymical or culinary. Now these are only uses of an occasional kind, and give us a very imperfect notion of what fire does for us. The grand importance of this dissolving power, the great office indeed of fire in the economy of nature, is keeping things in a state of solution, that is to say, in a state of fluidity. Were it not for the presence of heat, or of a certain degree of it, all fluids would be frozen. The ocean itself would be a quarry of ice; universal nature stiff and dead.

We see, therefore, that the elements bear not only a strict relation to the constitution of organized bodies, but a relation to each other. Water could not perform its office to the earth without air; nor exist, as water, without fire.

IV. Of light (whether we regard it as of the same substance with fire, or as a different substance,) it is altogether superfluous to expatiate upon the use. No man disputes it. The observations, therefore, which I shall offer, respect that little which we seem to know of its constitution.

Light travels from the sun at the rate of twelve millions of miles in a minute. Urged by such a velocity, with what force must its particles drive against (I will not say the eye, the tenderest of animal substances, but) every substance, animate or inanimate, which stands in its way! It might seem to be a force sufficient to shatter to atoms the hardest bodies.

How then is this effect, the consequence of such prodigious velocity, guarded against? By a proportionable minuteness of the particles of which light is composed. It is impossible for the human mind to imagine to itself any thing so small as a particle of light. But this extreme exility, though dif

tallow, expended in the wick of a farthing candle, shall send forth rays sufficient to fill a hemisphere of a mile diameter; and to fill it so full of these rays, that an aperture not larger than the pupil of an eye, wherever it be placed within the hemisphere, shall be sure to receive some of them. What floods of light are continually poured from the sun, we cannot estimate; but the immensity of the sphere which is filled with particles even if it reached no farther than the orbit of the earth, we can in some sort compute: and we have reason to believe, that, throughout this whole region, the particles of light lie, in latitude at least, near to one another. The spissitude of the sun's rays at the earth is such, that the number which falls upon a burning-glass of an inch diameter, is sufficient, when concentrated, to set wood on fire.

The tenuity and the velocity of particles of light, as ascertained by separate observations, may be said to be proportioned to each other; both surpassing our utmost stretch of comprehension; but proportioned. And it is this proportion alone which converts a tremendous element into a wel come visitor.

It has been observed to me by a learned friend, as having often struck his mind, that if light had been made by a common artist, it would have been of one uniform colour; whereas, by its present composition, we have that variety of colours, which is of such infinite use to us for the distinguishing of objects; which adds so much to the beauty of the earth, and augments the stock of our innocent pleasures.

With which may be joined another reflection, viz. that, considering light as compounded of rays of seven different colours, (of which there can be no doubt, because it can be resolved into these rays by simply passing it through a prism.) the constituent parts must be well mixed and blended together, to produce a fluid so clear and colourless, as a beam of light is, when received from the sun.

CHAPTER XXII.

Astronomy.*

My opinion of Astronomy has always been, that it is not the best medium through which to prove the agency of an intelligent Creator; but that, this being proved, it shows, beyond all other sciences, the magnificence of his operations. The mind which is once convinced, it raises to sublimer views of the Deity than any other subject affords; but it is not so well adapted, as some other subjects are, to the purpose of argument. We are destitute of the means of examining the constitution of the heavenly bodies. The very simplicity of their appearance is against them. We see nothing, but bright points, luminous circles, or the phases of spheres reflecting the light which falls upon them. Now we deduce design from relation, aptitude, and correspondence of parts. Some degree, therefore, of complexity is

*For the articles in this chapter marked with an asterisk, I am indebted to some obliging communications received (through the hands of the Lord Bishop of Elphin) from the Rev. J. Brinkley, M. A. Andrew's Pro fessor of Astronomy in the University of Dublin.

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necessary to render a subject fit for this species of fessed desiderata and desideranda, which impede argument. But the heavenly bodies do not, ex- our investigation of the wisdom of the Deity in cept perhaps in the instance of Saturn's ring, pre- these the grandest of his works, there are to be sent themselves to our observation as compound-found, in the phenomena, ascertained circumed of parts at all. This, which may be a perfection stances and laws, sufficient to indicate an intelin them, is a disadvantage to us, as inquirers after lectual agency in three of its principal operations, their nature. They do not come within our me- viz. in choosing, in determining, in regulating; chanics. in choosing, out of a boundless variety of suppositions which were equally possible, that which is beneficial; in determining, what, left to itself, had a thousand chances against conveniency, for one in its favour; in regulating subjects, as to quantity and degree, which, by their nature, were unlimited with respect to either. It will be our business to offer, under each of these heads, a few instances, such as best admit of a popular explication.

And what we say of their forms, is true of their motions. Their motions are carried on without any sensible intermediate apparatus; whereby we are cut off from one principal ground of argumentation, analogy. We have nothing wherewith to compare them; no invention, no discovery, no operation or resource of art, which, in this respect, resembles them. Even those things which are made to imitate and represent them, such as orreries, planetaria, celestial globes, &c. bear no I. Amongst proofs of choice, one is, fixing the affinity to them, in the cause and principle by source of light and heat in the centre of the syswhich their motions are actuated. I can assign tem. The sun is ignited and luminous; the for this difference a reason of utility, viz. a reason planets, which move round him, cold and dark. why, though the action of terrestrial bodies upon There seems to be no antecedent necessity for this each other be, in almost all cases, through the in-order. The sun might have been an opaque mass; tervention of solid or fluid substances, yet central attraction does not operate in this manner. It was necessary that the intervals between the planetary orbs should be devoid of any inert matter either fluid or solid, because such an intervening substance would, by its resistance, destroy those very motions, which attraction is employed to preserve. This may be a final cause of the difference; but still the difference destroys the analogy.

some one, or two, or more, or any, or all, the planets, globes of fire. There is nothing in the nature of the heavenly bodies, which requires that those which are stationary should be on fire, that those which move should be cold: for, in fact, comets are bodies on fire, or at least capable of the most intense heat, yet revolve round a centre: nor does this order obtain between the primary planets and their secondaries, which are all opaque. When we consider, therefore, that the sun is one;

Our ignorance, moreover, of the sensitive natures by which other planets are inhabited, neces-that the planets going round it are, at least, seven; sarily keeps from us the knowledge of numberless utilities, relations, and subserviencies, which we perceive upon our own globe.

After all; the real subject of admiration is, that we understand so much of astronomy as we do. That an animal confined to the surface of one of the planets; bearing a less proportion to it than the smallest microscopic insect does to the plant it lives upon; that this little, busy, inquisitive creature, by the use of senses which were given to it for its domestic necessities, and by means of the assistance of those senses which it has had the art to procure, should have been enabled to observe the whole system of worlds to which its own belongs; the changes of place of the immense globes which compose it; and with such accuracy, as to mark out beforehand the situation in the heavens in which they will be found at any future point of time; and that these bodies, after sailing through regions of void and trackless space, should arrive at the place where they were expected, not within a minute, but within a few seconds of a minute, of the time prefixed and predicted: all this is wonderful, whether we refer our admiration to the constancy of the heavenly motions themselves, or to the perspicacity and precision with which they have been noticed by mankind. Nor is this the whole, nor indeed the chief part, of what astronomy teaches. By bringing reason to bear upon observation, (the acutest reasoning upon the exactest observation,) the astronomer has been able, out of the "mystic dance," and the confusion (for such it is) under which the motions of the heavenly bodies present themselves to the eye of a mere gazer upon the skies, to elicit their order and their real paths.

Our knowledge, therefore, of astronomy is admirable, though imperfect: and, amidst the con

that it is indifferent to their nature, which are luminous and which are opaque; and also, in what order, with respect to each other, these two kinds of bodies are disposed; we may judge of the improbability of the present arrangement taking place by chance.

If, by way of accounting for the state in which we find the solar system, it be alleged, (and this is one amongst the guesses of those who reject an intelligent Creator,) that the planets themselves are only cooled or cooling masses, and were once, like the sun, many thousand times hotter than red-hot iron; then it follows, that the sun also himself must be in his progress towards growing cold; which puts an end to the possibility of his having existed, as he is, from eternity. This consequence arises out of the hypothesis with still more certainty, if we make a part of it, what the philosophers who maintain it have usually taught, that the planets were originally masses of matter, struck off in a state of fusion, from the body of the sun by the percussion of a comet, or by a shock from some other cause, with which we are not acquainted: for, if these masses, partaking of the nature and substance of the sun's body, have in process of time lost their heat, that body itself, in time likewise, no matter in how much longer time, must lose its heat also, and therefore be incapable of an eternal duration in the state in which we see it, either for the time to come, or the time past.

The preference of the present to any other mode of distributing luminous and opaque bodies, I take to be evident. It requires more astronomy than I am able to lay before the reader, to show, in its particulars, what would be the effect to the system, of a dark body at the centre, and of one of the planets being luminous: but I think it mani

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