SPECTATOR'S LIBRARY.

NATHRAL PHILOSOPHY,

Cosmos: Sketch of a Physical Description of the Universe. By Vexander Von Humboldt. Translated utder the superintendence of Lieutenant-Colonel Edward

Sabine, RA., For. Sec. H.S. Volume 1. Longman and 00.

HISTORY,

The Church in the Catacombs: a Description of the Primitive Church of Rome, Illus- trated by its Sepulchral Remains. By Charles Maitland, M.D.. •Longman and Co.

TRAVELS,

Prose from the South. By John Edmund Heade, Author of "Italy," &e. In two

volumes Other.

FICTION,

Heidelberg; a Romance. By G. P. R. James, Esq., Author of "The Smuggler," " Arrah Neil," " The Step-Mother," , &c. In three volumes.

Smith, Rider, and Co.

HUMBOLDT'S COSMOS.

IT is impossible to rise from the perusal of this great work without reflect- ing on the fulness and grandeur of modern speculations, compared with those which occupied the Greeks. They, too, contemplated the universe as a majestic whole—as a Cosmos—whose secret ongoings they strove to penetrate; but they did so because of the scantiness, not of the amplitude of their knowledge. No one in those days was regarded as a philosopher who did not run the round of human knowledge, embracing every field of investigation. Nom, men called philosophers not only renounce such ambitious aims, but are content to devote themselves to the investigation of some minute part of a small branch of a science. This is the con- sequence of that division of the sciences which increasing development rendered imperative. It is a sign of intellectual wealth ; but a cause also of intellectual narrowness. From the difficulty of now keeping on a level with all scientific knowledge, men have more and more given up that cul- tivation of general views, which alone can give dignity and elevation to the mind, and without which, all special facts, observations, and experi- ments, would be worthless. The narrowness of mere men of science is proverbial. Their bigotry, prejudices, and absolute incapacity when re- moved from the small sphere of their own special studies, and above all their fanatical hatred to all general views, which they disdainfully christen "mere theories," have gone far towards bringing their studies into dis- repute.

Against this excessive specialization of the sciences, which rapid pro- gress in each department daily makes more imperative, a better spirit has long protested. But in vain have men exclaimed, Do not merge science in the sciences ; do not allow special investigations to usurp the throne of philosophy ; but understand that special investigations are, and must ever be, subordinate to general views; and these general views, well coiirdinated, must form the philosophia prima. Reckless of the danger, or ignorant of it, scientific men pursued their course. Those who saw the danger were fond of pointing to the large and elevated views of the Greeks; forgetting to add, that the Greeks, if they specu- lated at all, could not help assuming such a philosophic position, simply be- cause the humbler one, namely, that of special investigation, was then undreamt of.

Here, however, is a work which unites the grandeur and extent af early speculations, with the fulness and precision of modern science. Akin to the Timoms of Plato in its artistic repose, in solemn earnestness, and calm magnificence of diction, its most astounding speculations are based upon severe and rigorous investigation. It treats of the old problem, but treats of it on the method of modern science. By setting aside those inquiries which are beyond the sphere of human certitude, and by restraining its flights within that vast immeasurable sphere, Humboldt is enabled to produce a Cosmos which is as grand as the Timaus in its scope and more certain in its results. He well says-

" Those who by the light of history should trace back through past ages the progress of physical knowledge to its early and remote sources, would learn how for thousands of years the human mind has laboured to lay hold of the sure thread of the invariability of natural laws, amid the perplexities of ceaseless change; and in so doing has gradually conquered, so to speak, great part of the physical universe. In following back this mysterious track, still the same image of the Cosmos reappears; which in its earlier revelation showed itself as a pre- sentiment of the true harmony and order of the universe, and which in our Mip presents itself as the fruit of long-continued and laborious observation. Each of these two epochs of the contemplation of the external world has its own proper enjoyment: that belonging to the first awakening of such reflections is well suited to the simplicity of the earlier ages of the world; to them the undisturbed =- cession of the planetary movements, and the progressive development of animal and vegetable life, were pledges of an order yet undiscovered mother relations, but of which they instinctively divined the existence. To us in an advanced civilization belongs the enjoyment of the precise knowledge of phenomena. From the time when man in interrogating nature began to experiment, or to produce phainomena under definite conditions, and to collect and record the fruits of expo- Hence, so that investigation might no longer be restricted by the short limits of a single life, the philosophy of nature laid aside the woe and poetic forms with which she had at first been clothed, and has adopted a more severe character: she now weighs the value of observations, atid no longer divines, but combines and reasons."

But what a long series of investigations and brilliant discoveries sepa- rate these two epochs! How many thousands have devoted themselves to the often ungrateful task of patient observation, convinced that " Wisdom is ofttimes nearer when we stoop

Than when we soar,"

before a Cosmos could have been planned, much less executed. For its execution, there was needed all Humboldt's varied powers and enormous acquisitions,—the ripe experience of a long and active life. It was no easy task to accumulate the vast quantity of materials necessary for the work; to master them, and made them subordinate to his aim, was a task still greater. So manifold are these materials, that, as he says---

" The multiplicity of diverse objects which I have here purposely crowded to- gether, leads directly to the question, whether general views of nature can posses a sufficient degree of clearness without a deep and earnest application to separate studies, whether of descriptive natural history, of geology, of physics, or oi ma- thematical astronomy? In attempting a reply, we must discriminate carefully between the teacher who undertakes the selection, combination, and presentation of the results, and the person who receives them, when thus presented, an 80M0- thing not sought out by himself, but communicated to him by another. To the fire; some exact knowledge of the special is indispensably necessary; before pro- ceeding to the generalization of ideas' he should have wandered long in the do- mains of fhe separate sciences, and have himself observed, experimented, and measured. I cannot deny that where positive knowledge is wanting in the reader, general results, which in their mutual connexion lend BO great a charm to the contemplation of nature, are not susceptible of being always developed with equal clearness; but, nevertheless, I permit myself the pleasure of thinking, that in the work which I am preparing the greater number of the truths presented will admit of being exhibited without the necessity of always reaseending to fundamental principles and ideas. The picture of nature thus drawn, even though some parts of its outlines may be less sharply defined, will still possess truth and beauty, and will still be suited to enrich the intellect, to enlarge the sphere of ideas, and to nourish and vivify the imagination."

And this presentation of results, unaccompanied by the proofs, will have another effect, viz, that of drawing more attention towards the philoso- yhia prima, which uses these results as its data. Moreover, as he says, the separation of the general from the special not only renders it possible to embrace at one view, with greater clearness, a wider field of know- ledge, but it also lends to the treatment of natural science a character of greater elevation and grandeur. By the suppression of details the masses are better seen, and the reasoning faculty is enabled to grasp that which might otherwise escape our limited powers of comprehension.

Humboldt, though a German, has none of the metaphysical tendency which enervates Germany. Strive as he may after the redaction of laws to laws still simpler and more general, he indulges in no chimerical hopes of ever wringing from Nature the metaphysical secret of her ongoings. - We are yet very far from the time, even supposing it possible that it should ever arrive, when a reasonable hope could be entertained of reducing all that is perceived by our senses to the unity of a single principle. The complication of the problem, and the immeasurable extent of the Cosmos, seem to forbid the expec- tation of such success in the field of natural philosophy being ever achieved by man; but the partial solution of the problem—the tendency towards a general comprehension of the phrenomena of the universe—does not the less continue to be the high and enduring aim of all natural investigation. For my own part, faithful to the character of my earlier writings, and to that of the labours which have oc- cupied my scientific career, in measurements, experiments, and investigation of facts, I limit myself in the present work to the sphere of empirical conceptions. It is the only ground on which I feel myself able to move without a sense of in- security. This mode of treating an aggregation of observed facts does not exclude their combination by reasoning, their arrangement under the guidance of leading ideas, their generalization wherever it can be justly effected; and the constant ten- dency to the discovery of laws. A purely rational conception of the universe, founded on principles of speculative philosophy, would no doubt assign to the science of the Cosmos a still more elevated aim. I am far from blaming efforts which I have not myself attempted, solely because their success hitherto has been extremely doubtful. Contrary to the wishes and counsels of those profound and powerful thinkers who have given new life to speculations belonging to antiquity, systems of a philosophy of nature have in our country (Germany) turned men's minds for a time from the graver studies of the mathematical and physical sciences. The intoxication of supposed conquests already achieved—a novel and extrava- gantly symbolical language—a predilection for formulae of scholastic reasoning snore contracted than were ever known to the middle ages—have, through the youthful abuse of noble powers, characterized the short saturnalia of a purely ideal science of nature. I say abuse of powers, for superior minds, which have embraced both speculative studies and the experimental sciences, took no part in these sa- turnalia. The results obtained by serious investigations in the path of induction cannot be at variance with atone philosophy of nature. If there is contradiction, the fault must be either in the unsoundness of the speculation, or in the ex- aggerated pretensions of empiricism, which thinks that it has proved by its ex- periments more than is really deducible from them."

In a word, minds occupied only with the loftiest objects of science will End him a noble guide; while even the merest collector of stray facts will find in him an appretiator.

In the survey he has taken of the celestial phsenomena, he presents us with an ouranagraphy, or description of the heavens which (except where the results of observations recently made through Lord Rosse's telescope necessarily modify his account of the nebular hypothesis,) may be taken as the expression of all that science has yet discovered. He then de- scends to earth, and presents us with a physical geography, in the widest sense of the term ; including not only a description of the figure, density, temperature of the earth, and its internal as well as external structure, its geological phienomena, but also a survey of organic life, the geo- graphy of plants and animals. In following him through these exten- sive surveys, we are equally surprised at the fulness and minuteness of his knowledge, and the masterly clearness with which his facts are ar- ranged. Indeed, Cosmos is a work of art, almost as much as of philo- sophy. And we know not where to point out its fellow as a composi- tion. Written in the evening of a long life, it has the mellowed light of the setting sun. Nowhere is there a trace of polemical asperity, of restless or ambitious display. Those who imagine that positive science is incompatible with poetical culture, who are alarmed lest the giant strides of science should drive " fancy " and "love of nature" from men's minds, will do well to open Cosmos, and there see a practical refu- tation of their arguments. The present translation was undertaken in compliance with the au- thor's wish ; and is ably executed, reading like an original work, in spite Of an occasional neologism not quite justifiable. 01 course the volume before us—for only one volume of the translation has yet been published—contains innumerable passages for miscellaneous extract. They can be separated, though no doubt the author suffers by the loss of his context. However, we select a few.

• SUBSTANCE AND LIOHT OF COMETS.

There is no doubt that the light of a star of the tenth magnitude passed through very dense nebulous matter on the 29th of September 1835, at a distance of 7".78 from the centre of the nucleus of Bailey's comet, according to Bessel's Meet careful measurement, without experiencing any deflection in its rectilinear course at any moment of its passage. Such an absence of refracting power, if actually extending to the centre of the nucleus, makes it difficult to regard the substance of comets as of a gaseous nature; or is the absence of refracting poker a consequence of the almost infinite rarity of a fluid of that description ? or does the comet consist of "detached particles," forming a comical ckud which no more affects the ray of light passing through it than do the clouds of atmo- sphere, which in like manner have no influence on the zenith distances of the heavenly bodies? In the passage of a comet over a star, there has often been noticed a greater or less diminution of the light of the star; but this has been justly ascribed to the brightness of the ground on which during the coincidence the star is seen.

We are indebted to Amgo's polarization experiments for the Most important and decisive observations on the nature of the light of comets. His polariscope instructs us concerning the physical constitution of the Sun, as well as that of the comets; it informs us whether a luminous ray, which reaches us from a dis- tance of many millions of miles, is a direct, or a reflected or refracted ray; and, if direct, whether the source of light is a solid, a liquid, or a gaseous body. The light of Capella, and that of the great comet of 1819, were examined at the Paris Observatory with the same apparatus. The comet showed polarized, and there- fore reflected light; whilst, as was to be expected, the fixed star was proved to be a self-luminous sun. The existence of polarized cometary light announced itself not only by the inequality of the images, but was shown with still greater cer- tainty at the reappearance of Halley's comet in 1835, by the more striking con- trast of complementary colours, in accordance with the laws of chromatic polariza- tion discovered by Arago in 1811. These fine experiments leave it, however, still undecided, whether, besides this reflected solar light, comets may not have a proper light of their own. Even in planets, in Venus for example, an evolution of independent light appears very probable.

EARTHQUAKES.

Natives of those countries who have experienced many hundred earthquakes believe the difference to be less in the greater or less duration of the shocks, or the slowness or rapidity of the horizontal oscillstion, than in the alternation of motion in opposite directions. The circular (or gyratory) earthquakes are the most rare and at the same time the most dangerous. In the great earthquake of Riobaniba, in the province of Quito, (4th February 1797,) and in that of Cala- bria, (5th February and 28th March 1783,) walls were changed in direction with- out being overthrown straight and parallel rows of trees were inflected, and in fields having two snits of cultivation, one crop even took the place before occu- pied by the other: the latter phienomenon showing either a movement of transla- non, or a mutual penetration of the different strata. When making a plan of the uined city of Riobamba, I was shown a place where the whole furniture of one house had been found under the remains of another; the earth had evidently moved like a fluid in streams or currents, of which we must assume that the direction was first downward, then horizontal, and lastly, again upward. Disputes concerning the ownership of objects which had been thus carried to distances of many hundred yards, were decided by the Audiencia or court of justice.

• SUBTERRANEAN NOISES.

The most striking instance of uninterrupted subterranean noise unaccompanied by any trace of earthquake' is the plitenomenon which is known in the Mexican territory by the name of "the subterranean roaring and thundering (bramidos truenos subterraneos) of Guanaxuato." This rich and celebrated mountain-city is situated at a distance from any active volcano. The noise began on the 9th January 1784, at midnight, and lasted above a month. I have been enabled to give a circumstantial description of the phsenomenon from the report of many wit- nesses, and from the documents of the municipality which I was permitted to make use of. From the 13th to the 16th of Janna7, it was as if there were heavy storm-clouds under the feet of the inhabitants, in which slow rolling thunder alternated with short thunder-claps. The noise ceased gradually, as it had com- menced; it was confined to a small space, for it was not heard in a basaltic dis- trict at the distance of only a few miles. Almost all the inhabitants were terri- fied and quitted the city, in which large masses of silver were stored; .bilt the most courageous, when they had become somewhat accustomed to the subterra nean thunder, returned and fought with the bands of robbers whkhad taken pos- session of the treasure. Neither at the surface, nor in mines 1,598 English feet in depth, could the slightest trembling of the ground be perceived. In no part of the whole mountainous country of Mexico had anything similar been ever lmown before; nor has this awful phrenomenon been since repeated. 'Thus, as chasms in the interior of the earth dose or open, the propagation of the waves of sound is either arrested in its progress or continued nnul it reaches the ear.

GROWTH OF THE DRY LAND.

The following are the results of the investigations which have had for their ob- ject the determination of the extent of the dry land at different epochs. In the most ancient times—during the saurian, devoman, and carboniferous epochs, and even as lately as the triassic period—the portion of the surface supporting land veget tion was exclusively insular. At a subsequent epoch, these islands became connected with each other, forming numerous lakes and deeply-indented bays. Finally, when the mountain chains of the Pyrenees, the Appenmes, and the Car- pathians, were elevated—about the epoch, therefore, of the older tertiary forma- tions—the great continents possessed nearly their present form and extent. During the eilurian epoch, when the cyc,adeai were on the greatest abundance, and the gigantic saurians were living, the whole surface of dry land from pole to pule must have been less than it now is in the Pacific and Indian oceans. We shall sue presmtly how this great ponderance of oceanic surface must have contributed, together with other causes, to equalize climates, and to maintain a high tem- perature. It is only necessary to add here, in reference to the progressive ex- tension of dry land, that a short time before the cataclysms which, at longer or shorter intervals, caused the destruction of so many gigantic vertebrated animals, part of the continental masses presented the same divisions as at present. There prevails, both in South America and in Australia, a great analogy between the living animals and the extinct species of those countries. Fossil species of kan- garoo have been discovered in New Holland; and in New Zealand, the semi- fossilized bones of a gigantic strathious bird, the dinornis of Owen, closely allied to the present apteryx, of the same islands, and remotely soto the recently extinct dodo of the island of Rodriguez.

UNIVERSAL DIFFUSION OF LIFE.

Since the time when, in an earlier work, ("Ansichten der Natur," "Tableaux de Is Nature,") I attempted to describe the universal diffusion of organic life on the surface of the globe, and its distribution in height and in depth, our knowledge has been wonderfully augmented by Ehrenberg's brilliant discoveries, (" fiber dais Ver- batten des kleiusten Lebens in dem Weltmeere wie in dem Else der Polar limier,") which rest not on ingenious combinations and inferences but on direct and exact observation. By these discoveries the sphere of animated existence—we may say the horizon of life—has expanded before our view. "Not only is there no inter- ruption of minute microscopic forms of animal life in the vicinity of either Pole, where larger animals cannot maintain themselves but we find among the micro- scopic animals of the South Polar Seas, collected in the Antarctic expedition of Captain James Ross, a remarkable abundance of new forms, which are often of great elegance. Even in the residuum obtained front melted ice which floats in rounded fragments in latitude 78° 10' S., there have been found above fifty species of siliceous-shelled polygastrica, and even coscinodiscse with green ovaries, which were therefore certainly living and able to resist the extreme severity of the cold."

It is not only in particular localities, in inland watersnr in the vicinity of coasts, i

that the ocean s thus thickly- peopled with living atoms invisible to the naked eye. Samples of water taken up by Scheyer in 573 S. latitude, on his return from Van Diemen Island, as well as those taken between the Tropics in the middle of the Atlantic, show that the ocean-water in its ordinary condition, without any appear- ance of discolonration' contains innumerable microscopic organisms, quite distinct from the siliceous filaments of the genus chmtoceros, floating in a fragmentary state like the oscillatoria of our fresh waters. Some polygastrica which have been found mixed with band and excrements of penguins in the Cockburn Islands, ap- pear to be generally distributed over the globe; other species belong to both the

Arctic and Antarctic Polar regions. Thus we see that animal life reigns in the perpetual night of the depths of the ocean; while on continents, vegetable life, stimulated by the periodical action of the solar rays, chiefly predominates. * • • Not only are earth, air, and water, filled with life, and that at the most different temperatures, but also the interior of the various parts of animal bodies: there are animalcule in the blood of frogs and of salmon: according to Nordmann, the fluids of the eyes of fishes are often filled with a worm which lives by suction (diplos- tomum); and the same naturalist has even discovered in the gills of the bleak an extraordinary double animal (diplozoon paradoxon) having two heads and two caudal extremities disposed in rectangular directions.