Various

We have here combined the best of all books, and the best of all maps, for the study of the most interesting description of geography. Mr Johnston's Physical Atlas, now published in a form which renders it accessible to greater numbers, is without a rival as a companion and guide in this department of study; and by dwelling on its merits and utility, we should be only echoing a verdict which has already been pronounced by almost every journal of scientific or critical celebrity. And, indeed, the same might be said of our commendation of Mrs Somerville's book; our praise comes lagging in the rear, and is well-nigh superfluous. But not only are we desirous to tender our tribute of respect to one who has done more than any other living writer to extend amongst us sound, as well as general knowledge of physical science; we are anxious also to recommend to our youth the enlarged method of studying geography, which her present work demonstrates to be as captivating as it is instructive.

Mrs Somerville's Physical Geography does not assume so profound an aspect, nor has it so lofty an aim, as the Cosmos of Alexander Von Humboldt; neither can it claim, like that work, to be written by one who has himself surveyed the greater part of the terraqueous globe he undertakes to describe. This latter circumstance gives an extraordinary interest to the Cosmos. From time to time the professor of science, gleaning his knowledge from books, and laboratories, and museums, steps aside, and we hear, and almost see, the adventurous traveller, the man Humboldt himself, who seems to speak to us from the distant ocean he has traversed, or the sublime mountain heights he has ascended. Our countrywoman can claim no such peculiar prerogative. Who else can? To few—to none other—has it ever been permitted to combine so wide a range of knowledge with so wide a range of vision—to have carried his mind through all science, and his eye over all regions. He is familiar with all the grandeurs of our earth. He speaks with the air of the mountain still around him. When he discourses of the Himalaya or the Andes, it is with the vivid impression of one whose footsteps are still lying uneffaced amongst their rarely-trodden and precipitous passes. The phenomena he describes he has seen. He can reveal to us, and make us feel with him, that strange impression which "the first earthquake" makes even upon the most educated and reflective man, who suddenly finds his old faith shaken in the stability of the earth. And what lecturer upon electricity could ever arrest the attention of his auditors by so charming a reference to his personal experience as is contained in the following passage?—

"It was not without surprise that I noticed, on the shores of the Orinoco, children belonging to tribes in the lowest stage of barbarism amusing themselves by rubbing the dry, flat, shining seeds of a leguminous climbing plant (probably a negretia) for the purpose of causing them to attract fibres of cotton or bamboo. It was a sight well fitted to leave on the mind of a thoughtful spectator a deep and serious impression. How wide is the interval which separates the simple knowledge of the excitement of electricity by friction, shown in the sports of these naked, copper-coloured children of the forest, from the invention of the metallic conductor, which draws the swift lightning from the storm-cloud—of the voltaic pile, capable of effecting chemical decomposition—of a magnetic apparatus, evolving light—and of the magnetic telegraph!"

The writer naturally reflects on the wide interval which separates the knowledge of electricity shown by these naked children on the banks of the Orinoco, and the inventions of modern science, which have taught the lightnings of heaven to do our messages on the earth. But, to our mind, this wide interval is far more strikingly displayed by the picture which is here presented to the imagination, of the profound and meditative European looking down, pleased and surprised, at the first unconscious steps in experimental philosophy which these copper-coloured children of the forest are making in their sport.

But if Mrs Somerville's book has none of this extraordinary interest which the great traveller has thrown over his work, and if it does not aspire to that philosophic unity of view, (of which a word hereafter, in passing,) it must take precedence of this, and of all other works, as a useful compendium of the latest discoveries, and the soundest knowledge we possess, in the various subjects it embraces. Nowhere, except in her own previous work, The Connexion of the Physical Sciences, is there to be found so large a store of well-selected information, so lucidly set forth. In surveying and grouping together whatever has been seen by the eyes of others, or detected by their laborious investigations, she is not surpassed by any one; and the absence of all higher aim, or more original effort, is favourable to this distinctness of exposition. We have no obscurities other than what the imperfect state of science itself involves her in; no dissertations which are felt to interrupt or delay. She strings her beads distinct and close together. With quiet perspicacity she seizes at once whatever is most interesting and most captivating in her subject.

The Cosmos of Humboldt has the ambitious aim of presenting to us the universe, so far as we know it, in that beauty of harmony which results from a whole. Thus, at least, we understand his intention. He would domineer, as with an eagle's glance, over the known creation, and embrace it in its unity, displaying to us that beauty which exists in the harmony of all its parts. The attempt no one would depreciate or decry, but manifestly the imperfect state of science forbids its execution. We have attained no point of view from which we can survey the world as one harmonious whole. Our knowledge is fragmentary, uncertain, imperfect; and the most philosophic mind cannot reduce it into any shape in which it shall appear other than uncertain and fragmentary. We cannot "stand in the sun," as Coleridge says in his fine verse, and survey creation; we have no such luminous standing-point. There never, indeed, was a time when the attempt to harmonise our knowledge, and view the universe of things "in the beauty of unity," was so hopeless, so desperate. For the old theories, the old methods of representing to the imagination the more subtle and invisible agencies of the physical world, are shaken, or exploded, and nothing new has been able to take their place. What is new, and what is old, are alike unsettled, unconfirmed. In reality, therefore, the work of Mrs Somerville is as much a Cosmos as that of Von Humboldt; and, as a work of instruction, is far better for not aiming higher than it does. Mrs Somerville presents to us each gospel of science—if we may give that title to its imperfect revelations—and does not bewilder or confuse by attempting that "harmony of the gospels" which the scientific expositor is, as yet, unable to accomplish.

As yet, we have said—but, indeed, will science be ever able to realise this aspiration of the intellect after unity and completeness of view? To the reflective mind, human science presents this singular aspect. Whilst the speculative reason of man continually seeks after unity, strives to see the many in the one—as the Platonist would express himself—or, as we should rather say, strives to resolve the multiplicity of phenomena into a few ultimate causes, so as to create for itself a whole, some rounded system which the intellectual vision call embrace; the discoveries of science, by which it hopes and strives to realise this end, do in fact, at every stage, increase the apparent complexity of the phenomena. The new agencies, or causes, which are brought to light, if they explain what before was anomalous and obscure, become themselves the source of innumerable difficulties and conjectures. Each discovery stirs more questions than it sets at rest. What, on its first introduction, promised to explain so many things, is found, on further acquaintance, to have added but one more to the inexplicable facts around us. With each step, also, in our inquiry, the physical agents that are revealed to us become more subtle, more calculated to excite and to elude our curiosity. Already, half our science is occupied with matter that is invisible. From time to time some grand generalisation is proposed—electricity is now the evoked spirit which is to help us through our besetting difficulties—but, fast as the theory is formed, some new fact emerges that will not range itself within it; the cautious thinker steps back, and acknowledges that the effort is as yet premature. It always will be premature.

There is a perpetual antagonism between the intellectual tendency to reduce all phenomena to a harmonious and complete system, and that increase of knowledge which, while it seems to favour the attempt, renders it more and more impracticable. With our limited powers, we cannot embrace the whole; and therefore it must follow, that it is only when our knowledge is scanty, that we seem capable of the task. Every addition to that knowledge, from the time that Thales would have reduced all things to the one element of water, has rendered the task more hopeless. And as science was never so far advanced as at the present time, so this antagonism was never so clearly illustrated between the effort of reason to generalise, and the influx of broken knowledge, reducing the overtasked intellect to despair. How much has lately been revealed to us of the more subtle powers and processes of nature—of light, of heat, of electricity! How tempting the generalisations offered to our view! We seem to be, at least, upon the eve of some great discovery which will explain all: an illusion which is destined to prompt the researches of the ardent spirits of every age. They will always be on the eve of some great discovery which is to place the clue of the labyrinth into their hand. The new discovery, like its predecessor, will add only another chamber to the interminable labyrinth.

Let us, for instance, suppose that we have discovered, in electricity, the cause of that attraction to which we had confided the revolution of the planets; of that chemical affinity to which we had ascribed the various combinations of those ultimate atoms of which the material world is presumed to be composed; of that vital principle which assimilates in the plant, and grows and feels in the animal. Let us suppose that this is a sound generalisation; yet, as electricity cannot be alone both attraction in the mass, and chemical affinity in the atom, and irritability and susceptibility in the fibre and the nerve, what has the speculative reason attained but to the knowledge of a new and necessary agent, producing different effects according to the different conditions in which, and the different co-agencies with which it operates? These conditions, these co-agencies, are all to be discovered. It is one flash of light, revealing a whole world of ignorance.

To the explanation of the most obstinate of all problems—the nature of the vital principle—we seem to have made a great step when we introduce a current of electricity circulating through the nerves. If this hypothesis be established, we shall probably have made a valuable and very useful addition to our stock of knowledge; but we shall be as far as ever from solving the problem of the vital principle. We have now a current of electricity circulating along the nerves, as we had before a current of blood, circulating through the veins and arteries; the one may become as prominent and as important a fact in the science of the physician as the other; but it will be equally powerless with the old discovery of Harvey to explain the ultimate cause of vitality. To the speculative reason it has but complicated the phenomena of animal life.

Within the memory of a living man, there has been such progress and revolution in science, that not one of the great generalisations taught him in his youth can be now received as uncontested propositions. Not many years ago, how commodiously a few words, such as attraction, caloric, affinity, rays of light, and others, could be used, and how much they seemed to explain! Caloric was a fluid, unseen indeed, but very obedient to the imagination—expanding bodies, and radiating from one to the other in a quite orderly manner. What is it now? Perhaps the vibration of a subtle ether interfused through all bodies; perhaps the vibration of the atomic parts themselves of those bodies. Who will venture to say? Attraction and affinity are no longer the clearly defined ultimate facts they seemed to be; we know so much, at least, that they are intimately connected with electrical phenomena, though not to what extent. That electricity is implicated with chemical composition, and recomposition, is clearly recognised; and Sir J. Herschel has lately expressed his opinion, that it is impossible any longer to attempt the explanation of the movements of all the heavenly bodies by simple attraction, as understood in the Newtonian theory—these comets, with their trains perversely turned from the sun, deranging sadly our systematic views. The ray of light, which, with its reflection and its refraction, seemed a quite manageable substance, has deserted us, and we have an ethereal fluid—the same as that which constitutes heat, or another—substituted in its stead. Science has no language, and knows not how to speak. If she lectures one day upon the "polarisation" of light, she professes the next not to know what she means by the term; she is driven even to talk of "invisible rays" of light, or chemical rays. Never was it so difficult to form any scientific conception on these subjects, or to speak of them with any consistency. Mrs Somerville is a correct writer; yet she opens her brief section upon magnetism thus:—"Magnetism is one of those unseen imponderable existences, which, like electricity and heat, are known only by their effects. It is certainly identical with electricity, for," &c. It is like, and it is identical, in almost the same sentence.

Even in the fields of astronomy, where we have to deal with large masses of matter, it is no longer possible for the imagination to form any embraceable system. We are plunged into hopeless infinitude, and the little regularities we had painfully delineated on the heavens are all effaced. The earth had been torn from its moorings and sent revolving through space, but it revolved round a central stationary sun. Here, at least, was something stable. The sun was a fixed centre for our minds, as well as for the planetary system. But the sun himself has been uprooted, and revolves round some other centre—we know not what—or else travels on through infinite space—we know not whither. A little time ago, the stately seven rolled round their central orb in clear and uninterrupted space; their number has been constantly increasing; we reckon now seventeen planetary bodies that can be reduced to no law of proportion or harmony, either as to their size, their orbits, the inclination of their axes, or any other planetary property;[15] and the space they circulate in is intruded on by other smaller and miscellaneous bodies, asteroids, and the like, some of which, it seems, occasionally fall to the earth. Comets come sweeping in from illimitable space, requiring, it is thought, some eight thousand years for their revolution round the sun. Some of these cross each other's orbits: one has crossed the orbit of the earth; and their decreasing circle round the sun, gives notice of some unknown ether suffused through the interstellar spaces. The outlying prospect, beyond our system, grows still more bewildering. The stars are no longer "fixed," nor is their brilliancy secured to them; this increases and diminishes with perplexing mystery. What seemed a single point of light, resolves itself into two stars revolving round each, perhaps reciprocally sun and planet. The faint and telescopic nebula, just reached by the glass in one age, is found in the next to be a congregation of innumerable stars. Our milky way is, at the same distance, just such another nebula. "The elder Herschel calculates that the light of the most distant nebula, discovered by his forty-feet refractor, requires two millions of years to reach our eyes." Oh, shut up the telescope! the reason reels.

Science, in short, presents before us a field of perpetual activity—of endless excitement, and that of the highest order—of practical results of the greatest utility and most beneficial description; but it gives no prospect of any resting-place—any repose for the speculative reason—any position with which the scientific mind shall be content, and from which it shall embrace the scene before it in its unity and harmony. Always will it be

Having touched upon these subtle agencies of light, and heat, and electricity, and on the increasing difficulty we have of framing to ourselves any distinct conception of them, we cannot refrain from alluding to a little work or pamphlet, by Mr Grove, entitled, The Correlation of Physical Forces, in which this subject is treated with great originality. Mr Grove has made himself a name in experimental science by his discoveries in electricity and chemistry; in this pamphlet he shows, that he has the taste and power for enlarged speculation on the truths which experiment brings to light. We would recommend the perusal of his pamphlet to all who are interested in these higher and more abstract speculations. How far the wide generalisation he adopts is sustained by facts, we are not prepared to say. But it is a powerful work, and it is a singular one; for it is not often, in this country at least, that a man so well versed in the minutiÆ of science ventures upon so bold a style of generalisation. After reviewing some of the more lately discovered properties of electricity, heat, light, and magnetism, and showing how each of them is capable of producing or resolving itself into the others, he reasons that all the four are but the varied activity of one and the same element. He adds, that this element is probably no other than the primitive atom itself; and that, in fact, these may be all regarded as affections of matter, which follow in their legal sequence, and not as the results of separate fluids or ethers. We are not sure that we do justice to his views, as we have not the work at hand, and it is some time since we read it; but we are persuaded that its perusal will be of interest to a philosophic reader, though its reasoning should fail to satisfy him.

But we have not placed the title of Mrs Somerville's book at the head of this paper, as an occasion to involve ourselves in these dark and abstract discussions. We are for out-of-door life; we would survey this visible round world, whose various regions, with their products and their inhabitants, she has brought before us.

Physical geography stands thus in contrast with political and historical geography. Russia is here no despotism, and America no democracy; they are only portions of the globe inhabited by certain races. To some persons it will doubtless seem a strange "geography" that takes no notice of the city, and respects not at all the boundaries of states. Those to whom the name recalls only the early labours of the school-room, when counties and county-towns formed a great branch of learning—where the blue and red lines upon the map were so anxiously traced, and where, doubtless, some suspicion arose that the earth itself was marked out by corresponding lines, or something equivalent to them—will hardly admit that to be geography which takes no note of these essential demarcations, or allow that to be a map in which the very city they live in cannot be found. To them the Physical Atlas will still seem nothing but a series of maps, in which most of the names have still to be inserted. They unconsciously regard cities and provinces as the primary objects and natural divisions of the earth. They share something of the feeling of that good man, more pious than reflective, who noted it as all especial providence that all the great rivers ran by the great towns.

Others, however, will be glad to escape for a time from these landmarks which man has put upon the earth, and to regard it in its great natural lineaments of continent and sea, mountain and island. To do this with advantage, it is necessary to disembarrass ourselves, both in the book and the map, of much that in our usual nomenclature ranks pre-eminently as geography. Nor is it easy to study this, more than the older branch of geography, without an appropriate atlas. To turn over the maps of Mr Johnston's, and con the varied information which accompanies them, is itself a study, and no disagreeable one. Of the extent of this information we can give no idea by extract or quotation; it is manifestly in too condensed a form for quotation; it is a perfect storehouse of knowledge, gathered from the best authorities.

The first thing which strikes an observant person, on looking over a map, or turning round a globe, is the unequal division and distribution of land and water. Over little more than one-fourth of the surface of the earth does dry land appear; the remaining three-fourths are overflowed by water. And this land is by no means equally disposed over the globe. Far the greater part of it lies in the northern hemisphere. "In the northern hemisphere it is three times greater than the south."

Of the form which this land assumes, the following peculiarities have been noticed:—

These are peculiarities interesting to notice, and which may hereafter explain, or be explained by, other phenomena. Resemblances and analogies of this kind, whilst they are permitted only to direct and stimulate inquiry, have their legitimate place in science. It was a resemblance of this description, between the zig-zag course of the metalliferous veins, and the path of the lightning, which first suggested the theory, based, of course, on very different reasonings, that electricity had essentially contributed to the formation of those veins—a theory which Mrs Somerville has considered sufficiently sound to introduce into her work.

What lies within our globe is still matter of conjecture. The radius of the earth is 4000 miles, and by one means or another, mining, and the examination of the upheaved strata, and of what volcanoes have thrown out, we are supposed to have penetrated, with speculative vision, to about the depth of ten miles.

Perhaps these "immense lakes or seas of liquid fire" are a little too hastily set down here in our geography. But of these obscure regions beneath the earth, the student must understand he can share only in the best conjectures of scientific men. Geology is compelled, at present, in many cases, to content herself with intelligent conjecture.

To return again to the surface of the earth, the first grand spectacle that strikes us is the mountains. Before it was understood how the mountain was the parent of the river, the noble elevation was apt to be regarded in the light of a ruin, as evidence of some disastrous catastrophe, and Burnett, in his Theory of the Earth, conceived the ideal or normal state of our planet to be that of a smooth ball, smooth as an egg. The notion not only betrays the low state of scientific knowledge in his age, but a miserable taste in world-architecture, which, we may remark in excuse for poor Burnett, was, almost as much as his scientific ignorance, to be shared with the age in which he lived. For it is surprising, with the exception of a few poets, how destitute men were, in his time, of all sympathy with, and admiration of, the grander and more sublime objects of nature. "We have changed all that!" The mountain range, pouring down its streams into the valleys on both sides, is not only recognised as necessary to the fertility of the plain; but, strange to say, we become more and more awake to its surprising beauty and magnificence. The description of the mountain ranges of the several continents of the world, forms one of the principal attractions of the study of physical geography, and one of the great charms of Mrs Somerville's book.

The mountains of Asia take precedence of all others in altitude and length of range.

The table-lands of Asia are on a scale corresponding with its mountains. But the same elevation, it is remarked, is not accompanied with the same sterility in these parts of the world, as in the temperate zone. Corn has been found growing at heights exceeding the summit of Mont Blanc. "According to Mr Moorcroft, the sacred lake of Manasa, in Great Tibet, and the surrounding country, is 17,000 feet above the sea, which is 1240 feet higher than Mont Blanc. In this elevated region wheat and barley grow, and many of the fruits of Southern Europe ripen. The city of H'Lassa, in eastern Tibet, the residence of the Grand Lama, is surrounded by vineyards, and is called by the Chinese 'the Realm of Pleasure!'" Nevertheless the general aspect of the table lands is that of a terrific sterility. Here is a striking description of them. We should have been tempted to say, that in this singularly dark appearance of the sky at mid-day, there was something of exaggeration, if our own limited experience had not taught us to be very cautious in attributing exaggeration where the scenic effects of nature are concerned.

The description of the territory of the East India Company will be read with interest. We cannot afford space to extract it. Plains and valleys the very richest in the globe are to be found here, as also much rank marshy land, and also much jungle. "It has been estimated that a third of the East India Company's territory is jungle."

As a set-off against this jungle we have it intimated that, if proper search were made, gold would probably be found in this territory, as abundantly as in California. We sincerely hope no such discovery will be made. If there is a sure specific for demoralising a people, it is to involve them in the chase for gold, instead of that profitable industry which produces the veritable wealth for which gold has become the symbol and representative. The discovery of gold in one of our colonies would not only demoralise, it would impoverish. It would demoralise, by substituting for steady industry, with steady returns, a species of enterprise which has all the uncertainty and fluctuation of gambling; and it would finally impoverish by diverting labour from the creation of agricultural and manufacturing wealth, to the obtaining of the dry barren symbol of wealth, which, apart from its representative character, has but very little value whatever.

We will not look back towards Chimborazo and the Andes, as we should involve ourselves in long and tempting descriptions. In Africa, it is remarkable that we are little acquainted with the mountains. "No European has yet seen the Mountains of the Moon!" What a challenge to enterprising travellers! We know the level sands of Africa better than these elevations which have assumed so magnificent a title. What a terrific sterility does a large portion of this the most ill-fated of the great continents present! "On the interminable sands and rocks of these deserts no animal—no insect—breaks the dread silence; not a tree nor a shrub is to be seen in this land without a shadow. In the glare of noon the air quivers with the heat reflected from the red sand, and in the night it is chilled under a clear sky sparkling with its host of stars." The wind of heaven, which elsewhere breathes so refreshingly, is here a burning blast fatal to life; or else it drives the sand in clouds before it, obscuring the sun, and stifling and burying the hapless caravan.

In the new continent of America—if it still retains that title—the desert is comparatively rare. But its enormous forests have, in some regions, proved that excessive vegetation can assume almost as terrific an appearance as this interminable sterility.

One of the most interesting subjects, of which mention is made in the work before us, is the gradual elevation and subsidence observed in some portions of these continents themselves. Just when the imagination had become somewhat familiar with the sudden but very partial upheaving of the earth by volcanic agencies, this new discovery came to light of the slow rising and sinking of vast areas of the land, and unaccompanied with any earthquakes or volcanic eruptions. In some parts the crust of the earth has sunk and risen again; in others, sort of see-saw movement on a most gigantic scale has been detected.

It is evident that the elevation of the land, in relation to the level of the sea, may be produced either by an uprising of the continent or a depression of the bed of the ocean, permitting the waters to sink; as also the apparent depression of the land may be occasioned by an elevation in the bed of the ocean. This renders the problem somewhat more difficult to solve, because the causes we are seeking to discover may be sometimes operating at that part of the crust of the earth which is concealed from our view. Mr Lyell, who, in his Principles of Geology, has collected and investigated the facts bearing upon this subject, mentions the following as probable causes of the phenomena:—

Two agencies of the most opposite, character have apparently been, at all times, acting on the crust of the earth to change its form, or add to the surface of dry land—the volcano and the insect!—the one the most sudden and violent imaginable, producing in a short time the most astonishing effects; the other gradual, silent, and imperceptible, yet leaving the most stupendous monuments of its activity. The volcano has thrown up a mountain in a single night; there is an instance, too, on record, where a mountain has quite as suddenly disappeared, destroying itself in its own violent combustion, and breaking up with repeated and terrific explosions. On the other hand, besides what has been long known of the works of the coral insect, the microscope has revealed to us that huge cliffs have been constructed of the minute fossil shells of animalcule. These creatures, abstracting from the water, or the air, or both, the minute particles of vegetable or other matter they hold in solution, first frame of them their own siliceous shells, and then deposit these shells by myriads, so as ultimately to construct enormous solid mounds out of imperceptible and fluent particles.

Astonishing, indeed, is the new world of animals invisible to the naked eye, which science has lately detected.

With every great change, however brought about, in the surface of the earth, and the climate of its several regions, it appears that, either by the direct agency of the Omnipotent Creator, or through the intermediate operations of laws which are at present profound secrets to us, a corresponding change takes place in the forms of animal life, and in the whole vegetable kingdom. Modern science presents no subject to us of more interest than this, and none apparently so inscrutable. Nor does the examination of the globe, as it exists before us at this moment, with its various floras and faunas, at all assist us in forming any conception of the law by which the geological series (if we may so term it) of animal life, has been regulated, for the distribution of the several animals over the several countries and climates of the world follows no rule that one can detect. Of course, no animal can exist where provision has not been made for its subsistence, but the provision has been made with the same abundance in two countries, and in the one the animal is found, and the other not. We should ask in vain why the horse was found a native of the deserts of Tartary, and why it was originally unknown to the plains of America? Nor can any cause be detected for the difference between the congeners, a representative species of one continent or island, and those of another. And not only have the larger animals an arbitrary territory marked out to them by nature, but birds, and even insects, are separated and grouped together in the same unaccountable manner. The chapters which Mrs Somerville has devoted to this subject will be read, especially by those to whom the topic is new, with extreme interest. They are enlightened and judicious.

It is a natural supposition to make, that, in the series of animals which at great geological periods have been introduced upon the earth, there has been a progression, so that each new form of animal life has been, in some marked manner, superior to that which is substituted. The comparative anatomist has not sanctioned this opinion; he tells us that he finds the same "high organisation" in the fossil saurians of a bygone world, as in the lions and leopards of the present day. But we would observe that the presence of this "high organisation" is not sufficient to determine the question. We should be surprised, indeed, if any creature were to be found whose structure was not perfectly adapted to the mode of life it was destined to lead. But it is permissible to compare one animal with another in its whole nature, and the character of its existence. The pig has the same high organisation as the dog, yet we should certainly prefer the one animal to the other; we should say that it was calculated for a happier life. We cannot suppose that a bird is not a more joyous creature than the worm or the snail. The adaptation of the whole form and structure to a pleasurable existence, and not what is termed high organisation, is that which we must regard, in estimating the superiority of one animal to another. Now, in this respect, there surely has been a progression from the earliest epochs. The crocodile and the tortoise are, amongst the animals which now exist, those which most resemble some of the more remarkable of the extinct genera. They are as perfectly adapted, no doubt, as any other creature, to their peculiar mode of being; but that mode of being is not an enviable one. The long stiff unwieldy body of the one, and the slow movement, with the oppressive carcase, of the other, are not consistent with vivid animal enjoyment. The crocodile, accordingly, lies motionless for hours together—waits for its prey—and slumbers gorged with food. And for the tortoise, it appears to lead a life as near to perpetual torpor as may be. Pass through a museum, and note those huger animals, the elephant and the rhinoceros, the seal or walrus, all those which most remind us of the gigantic creatures of the antediluvian world, and compare them with the horse, the deer, the dog, the antelope. Surely the latter present to us a type of animal life superior to the former—superior, inasmuch as the latter are altogether calculated for a more vivacious, sprightly, and happy existence. We must not venture to remark on their greater comparative beauty, for we shall be told that this is a matter for our own peculiar taste. We should not be contented to be so easily silenced on this head, but we should require far more space than we have now at our disposal to defend our Æsthetic notions.

We have found ourselves imperceptibly conducted from the inanimate to the animate creation; we shall proceed, therefore, with the same topic, in the few farther extracts we shall be able to make from the work before us. Indeed, with so vast a subject, and so brief a space, it would be idle to affect any great precision in the arrangement of our topics; enough if they follow without abruptness, and are linked together by natural associations of thought.

"Three hundred thousand insects are known!" and every day, we were almost going to add, increases the number. They abound, as may be expected, in equatorial regions, and decrease towards the poles. "The location of insects depends upon that of the plants which yield their food; and as almost each plant is peopled with inhabitants peculiar to itself, insects are distributed over the earth in the same manner as vegetables; the groups, consequently, are often confined within narrow limits, and it is extraordinary that, notwithstanding their powers of locomotion, they often remain within a particular compass, though the plant, and all other circumstances in their immediate vicinity, appear equally favourable for their habitation."

Mountain-chains, Mrs Somerville observes, are a complete barrier to insects; they differ even in the two sides of the Col de Tende in the Alps, and they are limited in the choice of their food. If a plant is taken to a country where it has no congeners, it will be safe from the insects of that country; but if it has congeners, the insect inhabitants will soon find the way to it. Our cabbages and carrots, when transplanted to Cayenne, were not injured by the insects of that country; and the tulip tree, and other magnolias brought here, are not molested by our insects.

The insect is a race, or order, of creatures not friendly to man, or any of the larger animals.

"The mosquito and culex are spread over the world more generally than any other tribe; they are the torment of men and animals from the poles to the equator, by night and by day; the species are numerous, and their location partial.... Of all places on earth, the Orinoco, and other great rivers of tropical America, are the most obnoxious to this plague. The account given by Baron Humboldt is really fearful; at no season of the year, at no hour of the day or night, can rest be found; whole districts in the Upper Orinoco are deserted on account of these insects. Different species follow one another with such precision, that the time of day or night may be known accurately from their humming noise, and from the different sensations of pain which the different poisons produce. The only respite is the interval of a few minutes between the departure of one gang and the arrival of their successors, for the species do not mix. On some parts of the Orinoco, the air is one dense cloud of poisonous insects to the height of twenty feet."