ravan under M'Culloch. But Mr Sadler conducts us to the temple of Truth through meads of asphodel, and through forests of fruit-bearing trees. Even they who stop on the journey, and turn back, if such there be,-can do so only from indolence and inactivity; for they can suffer nothing either from hunger or thirst, or dust in their eyes; and though they may have halted too soon, cannot deny that they enjoyed their pilgrimage. But the student and the lover of nature will delight to travel on with such a guide as Mr Sadler to the end of the journey, and only not lament that it is over, because made happy by the beautiful and glorious prospect that spreads around the pitching of their tent. tric science to shew, then the same science leads us to the inevitable conclusion, that every atom of matter, as well as every moment of time, is necessarily included in the divine computation. How beautiful the following sentence, and how profound its significance!" The grain of sand, therefore, falling from the widow's hour-glass, and the instant of time it expresses in its descent, do not mere, ly furnish an illustration, but they form essential parts, of that magnitude, motion, and duration, which constitute the harmony and perpe tuate the existence of the universe." We cannot doubt, that if this Dissertation were enriched with a greater number of illustrations of its argument, it would be most successful as a separate publication in a small pocket volume. Mr Sadler is well read in natural history, especially in zoology; and there is not any part of his argument that would not only admit, but that does not perhaps require, many more illustrations from that branch of knowledge. Meanwhile, we shall do all that in us lies to publish widely its merits; and we cannot do so by any other means so effectually as by an analysis and abridgement of it, accompanied by copious extracts. We are as fond as most people of hearing ourselves speak, but we trust that we can also listen; and we know that our readers will prefer Mr Sadler's words to ours on a subject which he has so profoundly and extensively studied, and of which our account of his Dissertation will shew that he is a perfect master. Mr Sadler begins with the immensities of creation; and asks what is there to sanction the daring idea of any thing there being left disproportionate, or in the slightest degree imaginable erroneous? In one ma jestic paragraph he gives a sweeping view of the mechanism of the skies, as revealed by "the hierophant of this mysterious temple of nature, our immortal Newton ;" and after saying well, that if the magnitudes, motions, and distances of the heavenly bodies are all reciprocally regulated, which it is the legitimate office of geome He then selects some impressive proofs of the same universal adaptations of animal life in all its forms to the elements which it peoples, and again to the changes those elements undergo in consequence of varying climates and seasons, from geology and physical geography, speaking, indeed, like a philosopher. All those adaptations, what would they avail, but for another series of wonders those supplies of food, without which life could not continue in a single instance, and which, to sup port animated nature throughout our earth, must vary with the elements, the situations, the climates, and the seasons, and consequently be adapted to them all! To provide these supplies involves a comprehension of design which none can understand, save He who accomplishes it. But there it is for ever at work, and who shall dare to say, except a Malthusian, that as vast a demand is not made upon Infinite intelligence and benevolence in the conservation as in the creation of the world? And who but a Malthusian would dare to say that beneath that demand that intelligence and benevolence faint and are frustrated? But let us now hear Mr Sadler-not in an abridgement, but in his own flowing and glowing words. "Let us here, then, pause for a moment, and, without again dwelling on the connexion between the minutest existence in creation with its immense masses, or the wonderful adaptations of every climate, element, season, and situation, to the condition and necessities of animal creation, or the intimate relation which its several parts bear to each other and to the whole, let us enlarge our minds, as far as we can do so, to the consideration of the incalculable, and all but infinite, number, for every individual of which this provision has to be made. Placed at the summit of f these, man, concerning whose multiplication so many fears are now afloat, is, compared with most of them, a solitary, with any of them, a sterile being; and yet a thousand millions of his species traverse the earth. Leaving out of our view those larger animals, whose number he generally determines, and looking down through the inferior tribes of creation, in whatever element, how do they multiply! The chain of existence, which at once connects and sustains all animated beings, is seen descending from rank to rank, and still diminishing, till at length it eludes the sight; when the eye, assisted by that science which taught it to penetrate far into boundless space, again pierces deep into an opposite infinity, and traces its catenations, lengthening far below the supposed limits of possibility, till at last vision utterly fails, and thought looks down as from a fearful brink, and beholds the lessening threads of life still sinking into a dark and immeasurable depth, only fathomed by the eye of Omniscience. The links of this chain, sustained by the hand of its eternal Artificer, who can enumerate? As they diminish in magnitude they multiply in number, still augmenting the miracle, till they become at once innumerable and invisible. Compared with these, what are the numbers of the leaves of the forests, or the sands of the ocean? In ten thousand forms they fill the air we breathe; they cover the earth on which we tread; they saturate the waters of the stream; they tinge the waves of the ocean; they flash like lightning upon its shores. A single leaf, as St Pierre has said, and without an hyperbole, is itself a continent, and a drop an ocean to myriads of animated beings, infinitely diversified, and many of them, if we may believe our best naturalists, invested with a beauty which Nature rarely lavishes upon her larger offspring; at all events, with an organization as perfectly adapted to their condition as that of the mammoth or the leviathan. Rerum natura nusquam magis quàm in minimis tota est.' "Vain then are all human comparisons -vain the power of numbers to describe the flood of vitality which inundates our universe as vain were it to attempt to explain by what process it is sustained: but, though we were not able, even in a single instance, to trace the means of preserving life, so as to extend it by analogy to the whole, still the fact that it is sustained in being and well being; that it is reproduced and continued; is a full and VOL. XXVIII. NO. CLXVIII. everlasting disproof of the daring notion of the superfecundity of animal existences. Driven, therefore, to no absurd or impious notions respecting the operations of the Deity, while contemplating these his astonishing works, which demand the exercise of his boundless perfections, we exclaim, in the language of a poet of antiquity, O GOD! how wonderful are thy works! In wisdom hast thou made them all! The earth is full of thy riches!'" But are there some, or many, who, firmly believing in the Deity, and confessing that His power is boundless, and His wisdom infinite, are yet'astounded by the immensity of the numbers of animated nature, and their prolific powers, and ask, "For multitudes like those can God spread a table in the wilderness ?" As respects his supreme creation, 'man, whose prolificness Mr Malthus pronounces so vastly to exceed the mean's of subsistence which his Maker has prepared for him, do they still more emphatically exclaim, "But can he give bread also? or provide flesh for his people?" If we reason from analogy, and if the laws of matter have such a perfect adaptation to their end —to wit, that of continuing unchanged its present conformations-which science has shewn-then ought we to conclude that the laws relative to life, which are evidently established to preserve and perpetuate it in all its modes, are calculated to effect this object with great precision. But farther, if it can be shewn that it is in the contemplation of the Deity to balance the numbers and food of his offspring, and that he has plainly manifested that intention, then without impiety must we believe that the food and numbers are balanced. The proof of the intention is a moral demonstration of the highest order that the intention has been fulfilled. Mr Sadler thus philosophically expresses his argument: "First. Nature has calculated with the utmost precision, and unalterably settled, the different degrees, as well as periods, of prolificness in all things living; obviously varying both, with reference to the means of sustentation. The presumption, I might say certainty, therefore is, that the laws of reproduction do not tend to excessive increase, but are precisely regulated by those means. "Second. During the process of reproduction, and through the early stages of existence, Nature guards with peculiar H art, and defends with the utmost care, the germs of existence,' as they are de nominated in the theory I am opposing. The presumption, therefore, is increased that those 'germs' are, in no just sense of the term, superfluous. "Third. It is the plain purpose of Nature, indicated by an infinite variety of means, which are in perpetual operation, to sustain her animated offspring when matured. The presumption is, that she is not defeated in that her intention, and consequently, that the numbers preserved are not superfluous. "Fourth. Not only are those necessaries of subsistence, and the means and instruments by which they are obtained, be stowed on all living beings, but, at the same time, facilities of escape or defence are conferred upon each, which preserve that existence as far as is compatible with those plain intentions of Nature, which will be hereafter adverted to. The purpose of Nature is, therefore, preservation; numbers then, in her estimation, are not superfluous. "Fifth. The very means of subsistence, especially those consisting of prey, when duly considered, are in themselves the proof that numbers and food are, and must necessarily remain, perpetually balanced and adjusted to each other; numbers, therefore, compared with food, cannot be superfluous. Lastly. The whole of animate creation, through all its tribes, especially when far removed from human interference, abundantly demonstrates that life and food are in due proportions; or, in other words, that existence is connected with enjoyment that universal misery is not thrown into the scale of being by that hand that created both numbers and food, and sustains the balance in an everlasting equipoise. Numbers and food are, therefore, balanced." To prove these positions is the object of this Dissertation; and we shall accompany the author through his proofs. First. That law of nature which varies the prolificness of different species of animals so extremely, and still, at the same time, preserves that prolificness in the same species in so near and surprising an uniformity, is of itself a satisfactory proof of the first position. Relax or reverse that law, and suppose for a moment the larger animals to be endowed with the fecundity of the smaller ones, and what would be the consequence? Then indeed would the principle of population be a truth of the plain est and most tremendous character. The universe would be dispeopled in a day! Farther, in most of the terrestrial animals, the period and term of gestation is fixed, and the degree of prolificness constantly determined by have not the least control. But physical causes, over which they observe what happens with birds. Undisturbed in the business of reall their tribes, to the laws of nature. production, they conform, through But the ovarious state of their future offspring exposing the measure of their reproduction to accident and depredation, God has given them a mysterious power of supplying such losses before incubation. Nay, destroy their nests with their broods, and by the same physical faculty they can repair their loss, and even repeat, at later periods of the season, the same process. They are gifted, says Mr Sadler, finally, with a sort of "natural arithmetic," which informs them of their right number, and are compelled by a powerful impulse, perfectly distinct from the originating one, to adhere to it, in spite of all interruptions. Can any one bring himself to believe, for a single moment, that that number is not the right number—that is, right in reference to the means and measure of subsistence, without which it would be wrong indeed? "Behold then the fowls of the airthey sow not, neither do they reap, nor gather into barns"-yet the universal Parent "feedeth them." Sparingly-asks Mr Sadler-partiallyuncertainly? No; but by anticipa ted provision, infallibly certain, and abundantly sufficient-so that they "sing among the branches." Second. But how does nature deal with the germs of existence? Are they redundant? And doth she suffer them to perish? No. Look at the extraordinary tenderness and constant protection she displays in regard of the parent existence during the period of gestation. She then invests life itself with additional security-then the little wren is bold as the eagle, the doe fearless as the lioness. We love Mr Sadler as a true ornithologist. To his ear the lark sings of the goodness of God at the gates of heaven-to his eye the lark illustrates the same attribute in the dewy braird "wakening by the daisies' side." "The process of incubation takes place in the case of birds, who would otherwise, under such circumstances, be incapable of flight, and, consequently, be both themselves and their offspring exposed to certain destruction; while, as it respects those powerful and majestic animals which, at such times, are fully capable of defending themselves and their offspring, marked and striking variety, in these transient receptacles of infant life,-the extreme rapidity of their construction, with the one single instrument employed (the beak), increasing the wonder, but I refrain, as not strictly bearing on my subject. I shall therefore proceed to remark, that the still minuter and infinitely more numerous oviparous beings are not less instructed how to deposit the seeds of their future progeny; whether they inject their eggs deep into some solid substance, by means of instruments adapted for that special purpose, which excite the admi ration of the minutest observers of nature, or fix them, by some glutinous fluid with which they are provided, where they will be least exposed to observation or injury, or securely deposit them, in a variety of other ways familiar to the naturalist, till the moment they are vivified by influences, and sustained by means, totally distinct from the parental principle.' Nature seems to confide to them that duty, which few that value existence will rashly interrupt. But it is to her care of the more weak and defenceless tribes that I would especially advert. The security which such seek from those enemies, and those only to which they or their offspring are exposed, is singularly varied in its means, yet all point at the same end. Situations inaccessible to attack are select ed, or artificial guards are interposed; or places of concealment are chosen, or, where there are none, dexterously formed, To advert again to the feathered tribes, as that class of beings which, among those little liable to our interference, is the most obvious to our notice. When the work of reproduction obliges them to become stationary for a considerable period, what infinite address do they exhibit in accomplishing their purposes, particularly that of security! Some of these choose the loftiest trees of the solitary wood; and, lest the tops of these, where there is commonly the greatest luxuriance of foliage, should not sufficiently secure their nests by concealment, they generally build on The unprotected beings all venture the most tapering branches, the thinness into life at the exact season, amidst a of which affords additional safety. Others, profusion of sustentation adapted to which seem to affect human society, build their use, and provided for them by on the pinnacles, or beneath the battleanother world of existence, the vements of our loftiest edifices, always, how-getable kingdom, subject to laws as ever, out of the reach of general molesta tion. Some choose the shelves of inaccessible precipices, or the crevices of rocks that hang beetling over the ocean; others peck their retreat into the centre of trees, which they know well how to select for that purpose; others, more obvious to common notice and constant interruption, nevertheless accomplish their ends with scarcely less certainty and security, though by very opposite means: they have to fix their nests in situations perfectly accessible and near to view; but, by a countervailing provision of nature, they so assimilate them in colour and appearance to the boughs in which they build, or the mossy bank in which they are imbedded, as to render the security from such artful concealment as complete, probably, as that from apparent inaccessibility. I am tempted to notice the admirable fitness, in shape and size, the exquisite beauty, and the But look next at those numerous tribes of beings in which the efficient preservative of early existence, parental affection, is totally wanting. Has Nature deserted those "orphans of creation ?" No-for them the atmosphere itself performs the work of a mother's love. It broods over them— "Dovelike, hangs brooding o'er the vast abyss, And makes it pregnant." complex as those that govern the animal one, and plainly subservient to it. Here each grub meets its abundant supply, "till it wings its way to reiterate in turn the miracle of its own birth." "But all this ample provision, all this jealous circumspection, all these concealments and defences which Nature has thrown around initial existence, if I may so express myself, do not still satisfy her. She is bent on her work of preservation. After all her solicitudes, the period of infancy, with regard to the animal tribes, is still the period of peculiar danger. Finally, therefore, she shortens that period by a rapidity of growth to which there is nothing corresponding in human beings; bringing them, as it were, to a sudden and almost miraculous maturity, and thus lessening the danger of that state by dimi nishing its duration. I say, almost miraculous, upon any common principles; which any of us may speedily verify, if we weigh, from time to time, the growth of an unfledged bird, for instance, which has just burst from its shell, with the entire weight of what it receives." Third. And how acts Nature towards her offspring, after having conducted them to maturity? Do we not see, throughout air, earth, and water, the plain intention of the Deity to sustain all his creatures ? Mr Sadler exclaims, in an elevated strain that reminds us of Milton, "Let us take a momentary view of the Eternal Pan in providing for the people of his boundless pasture." All the elements-he goes on to say -the various seasons, the different climates, the whole vegetable and animal kingdoms, all alike, by known and perpetually operating laws, furnish their quota to the great storehouse of existence, in which the miracle is equal, that the supply neither fails nor exceeds, and all is so adjusted that, in this infinite variety, there is no confusion! In this eternal plenty there is no superfluity! How interesting to observe how carefully she provides for the weakest of her tribes,-on them, like an indulgent mother, bestowing her tenderest cares! By diversifying the instinctive appetites of the different species of the larger animals, she prevents the monopoly of the means of existence by the ferocious and the strong; in the "refectory of Nature" so unlike that "table" at which Malthus affirms there are no seats for millions on millions, who come there in hunger and in thirst, and certainly not uninvited—the separate species have all " their separate seats and their distinct messes," which, though perfectly agreeable to themselves, the rest refuse to occupy or touch, and thereby the harmony and plenty which, among such various and unnumbered guests, would otherwise be constantly destroyed, is as perpetually preserved. Then, as the food of several of these tribes varies with the change of season, and sometimes of climate and situation, so, too, are their appetites and tastes adjusted to these vicissitudes. Again, the food of whole classes of animals almost totally disappears during the more rigorous seasons of the year. Is there then a superfluity of numbers? Does nature abandon her offspring then? Go to the ant-and learn to see God. What naturalist knows the process by which that creature preserves, for its winter sustenance, grain in the bosom of the earth, without sprouting or being spoiled? Many other similar instincts belong to other animals-and do they belong to a system created by a Being who has not provided adequate nourishment for the mouths he has made? Other creatures are laid asleep in " long inedia" during the winter's severity, and awaken amid the provender of spring. Just on the same principle, says Mr Sadler, whose expressions are always beautifully accordant with the spirit of his subject-shewing the man of genius in every page -as Nature disposes of us and almost all animated nature, when she diurnally withdraws from us that light so necessary to our active existence; and as respects infinitely greater numbers, she limits the period of life to the propitious season, sometimes, indeed, to the shining hours of a single day. But of all the demonstrations of the intention of Nature to provide, under varying emergencies, for all her creatures, what so striking as-Migration! : "I shall confine myself to another order of beings, the same so often referred to the birds-as most obvious to our notice. What does this inexplicable faculty imply, as it regards these? First, it implies, literally speaking, a spirit of prophecy. At the very period when their food abounds (for it is essential to the purpose that the flight should be undertaken while they are in full vigour) they foresee the coming of the unpropitious season. Nor is this indicated by the change of the atmosphere solely it has happened that, where the season has not corresponded with its usual period, still the latter has been punctually adhered to, when thousands of them have perished, as the savans of France have more than once recorded of the most exact of the migratory tribes, the swallow. Secondly, they have a mysterious, but a certain, know most accurately where the regions lie knowledge of physical geography, and to which they proceed, which the greater part of them have never previously beheld, but where, nevertheless, they are assured of the provision that awaits them. They assemble, therefore, and, departing |