which streams and murmurs on the surface of the continents, or which tosses in the bosom of the seas? in the winds which course with terrible rapidity and sweep the soil that we tread under our feet, covering it with ruins? Has it not its sympathies and antipathies in those mysterious elective affinities of the different molecules of matter which chemistry investigates? Has it not the powerful attractions of bodies to each other, which govern the motions of the stars scattered in the immensity of space, and keep them in an admirable harmony? Do we not see, and always with a secret astonishment, the magnetic needle agitated at the approach of a particle of iron, and leaping under the fire of the northern light? Place any material body whatever by the side of another, do they not immediately enter into relations of interchange, of molecular attraction, of electricity, of magnetism? The disturbance of the equilibrium at one point induces another elsewhere, and the movement is propagated to infinity. And what will it be, if we rise to the contemplation of all the phenomena together, of this order, which are presented by a vast country-by an entire continent?

It is thus that, in inorganic nature also, all is acting, all is changing, all is undergoing transformation. Doubtless this is not the life of the organized being, the life of the animal; but is not this assemblage of phenomena also a life? If, taking life in its most simple aspect, we define it as a mutual exchange of relations, we cannot refuse this name to those lively actions and reactions, to that perpetual play of the forces of matter of which we are every day the witnesses. It is indeed life, but undoubtedly in a very inferior order of things. It is life; the thousand voices of nature which make themselves heard around us, and which in so many ways betray that incessant and prodigious activity, proclaim it so loudly, that we cannot shut our ears to their language.

This general life, this physical and chemical life, belongs to all matter: It is the basis of the existence of all superior beings, not as the source, but as the condition: It is in the plant, it is in the animal; only here it is in the service of a principle of higher life of a spiritual nature, of a principle of unity, of which the mysterious force, referring all to a centre, modifies it, controls it, and organizes it, for the benefit of an individual.-GUYOT.1

1 Arnold Guyot is Professor of Physical Geography and History at Neufchatel in Switzerland: the little work from which our extracts are selected consists of Lectures

CONTENTS OF SPACE.

The first and most general consideration of the Kosmos is that of the contents of space-the distribution of matter over that wide field in which the creative energy of the Infinite Power has been exerted. We see matter either agglomerated into rotating, revolving spheres of different density and size, or scattered through space in the form of self-luminous vapour. If we consider first the cosmical vapour dispersed in definite nebulous spots, its state of aggregation will appear constantly to vary. Sometimes appearing separated into round or elliptical discs, single or in pairs, occasionally connected by a thread of light; whilst at another time these nebulæ occur in forms of larger dimensions, and are either elongated or curiously branched, or fan-shaped, or appear like well-defined rings enclosing a dark interior. It is conjectured that these bodies are undergoing variously developed formative processes, as the cosmical vapour becomes condensed in conformity with the laws of attraction, either round one or more of the nuclei. Between two and three thousand of such unresolvable nebulæ, in which the most powerful telescopes have hitherto been unable to distinguish the presence of stars, have been counted, and their positions determined.1

The genetic evolution-that perpetual state of development which seems to affect this portion of the regions of spacehas led philosophical observers to the discovery of the analogy existing among organic phenomena. As in our forests we see the same kind of tree in all the various stages of its growth, and are thus enabled to form an idea of progressive, vital development; so do we also, in the great garden of the universe,2 recognise the most different phases of sidereal formation.-HUMBOLDT.

LOCALITY OF THE SOLAR SYSTEM.3

Considerations regarding the different intensity of light in

delivered in America, translated by Professor Felton of Harvard University, Massachusetts. 1 The great telescope of Lord Rosse has materially affected the conclusions of preceding science with respect to the nature of the "nebula."-See Art., infra, on Rosse's Telescope.

2 See note on this expression in Kosmos, i. 70.

3 Almost every popular work on astronomy will furnish information on this subject, which, since the discoveries of Sir W. Herschel's telescope, has become one of the most interesting topics of the science. Herschel first " gauged" the heavens.

stars, and their relative number-that is to say, their numerical frequency on telescopic fields of equal magnitude-have led to the assumption of unequal distances and distribution in space in the strata which they compose. Such assumptions, in as far as they may lead us to draw the limits of the individual portions of the universe, cannot offer the same degree of mathematical certainty as that which may be attained in all that relates to our solar system, whether we consider the rotation of double stars with unequal velocity round one common centre of gravity, or the apparent or true movements of all the heavenly bodies. If we take up the physical description of the universe from the remotest nebulæ, we may be inclined to compare it with the mythical portions of history. The one begins in the obscurity of antiquity, the other in that of inaccessible space; and at the point where reality seems to flee before us, imagination becomes doubly incited to draw from its own fulness, and give definite outline and permanence to the changing forms of objects.

If we compare the regions of the universe with one of the island-studded seas of our own planet, we may imagine matter to be distributed in groups, either as unresolvable nebulæ of different ages, condensed around one or more nuclei, or as already agglomerated into clusters of stars, or isolated spheroidal bodies. The cluster of stars to which our cosmical island belongs forms a lens-shaped, flattened stratum, detached on every side, whose major axis is estimated at seven or eight hundred, and its minor one at a hundred and fifty times the distance of Sirius.

Our starry stratum is a disc of inconsiderable thickness, divided a third of its length into two branches. It is supposed that we are near this division, and nearer to the region of Sirius than to the constellation Aquila, almost in the middle of the stratum in the line of its thickness or minor axis.

This position of our solar system, and the form of the whole discoidal stratum, have been inferred from sidereal scales-that is to say, from that method of counting the stars to which I have already alluded, and which is based upon the equidistant subdivision of the telescopic field of view. The relative depth of the stratum in all directions is measured by the greater or smaller number of stars appearing

in each division. These divisions give the length of the ray of vision in the same manner as we measure the depth to which the plummet has been thrown before it reaches the bottom, although in the case of a starry stratum there cannot, correctly speaking, be any idea of depth, but merely of outer limits. In the direction of the longer axis, where the stars lie behind one another, the more remote ones appear closely crowded together, united, as it were, by a milkywhite radiance, or luminous vapour, and are prospectively grouped, encircling as in a zone the visible vault of heaven. This narrow and branched girdle, studded with radiant light, and here and there interrupted by dark spots, deviates only by a few degrees from forming a perfect great circle round the concave sphere of heaven, owing to our being near the centre of the large starry cluster, and almost on the plane of the Milky Way. If our planetary system were far outside this cluster, the Milky Way would appear to telescopic vision as a ring, and at a still greater distance as a resolvable discoidal nebula.-HUMBOLDT.

CONTENTS OF THE SOLAR SYSTEM.

The solar system, that is to say, the variously formed matter circling round the Sun, consists, according to the present state of our knowledge, of eleven primary planets,1 eighteen satellites or secondary planets, and myriads of comets, three of which, known as the "planetary comets," do not pass beyond the narrow limits of the orbits described by the principal planets. We may, with no inconsiderable degree of probability, include within the domain of our Sun, in the immediate sphere of its central force, a rotating ring of vaporous matter, lying probably between the orbits of Venus and Mars, but certainly beyond that of the Earth, which appears to us in a pyramidal form, and is known as the Zodiacal Light; and a host of very small asteroids, whose orbits either intersect or very nearly approach that of our Earth, and which present us with the phenomena of aërolites and falling or shooting stars. When we consider the complication of variously formed bodies which revolve round the Sun in

1 Since the publication of M. Humboldt's work, this number has been extended by the discovery of four asteroids, and of the great planet Neptune, between the years 1846 and 1848. The "planetary comets" are those of Enke, Biela, and Faye.

orbits of such dissimilar eccentricity, we cannot fail to acknowledge that the planetary system, especially so called, (that is, the group of heavenly bodies which, together with their satellites, revolve with but slightly eccentric orbits round the Sun,) constitutes but a small portion of the whole system with respect to individual numbers, if not to mass.

It has been proposed to consider the telescopic planets, Vesta, Juno, Ceres, and Pallas,1 with their more closely intersecting, inclined, and eccentric orbits, as a zone of separation, or as a middle group in space; and if this view be adopted we shall discover that the interior planetary group (consisting of Mercury, Venus, the Earth, and Mars) presents several very striking contrasts when compared with the exterior group, comprising Jupiter, Saturn, and Uranus.2 The planets nearest the Sun, and consequently included in the inner group, are of more moderate size, denser, rotate more slowly and with nearly equal velocity, (their periods of rotation being almost all about twenty-four hours,) are less compressed at the poles, and, with the exception of one, are all without satellites. The exterior planets, which are farther removed from the sun, are very considerably larger, have a density five times less, more than twice as great a velocity in the period of their rotation round their axes, are more compressed at the poles, and, if six satellites may be ascribed to Uranus, have a quantitative preponderance in the number of their attendant moons, which is as seventeen

to one.

Such general considerations regarding certain characteristic properties appertaining to whole groups, cannot, however, be applied with equal justice to the individual planets of every group; nor to the relations between the distances of the revolving planets from the central body, and their absolute size, density, period of rotation, eccentricity, and the inclination of their orbits and their axes. * * * Mars is smaller than the Earth and Venus, although further removed from the Sun than these last named planets; approaching most nearly in size to Mercury, the nearest planet to the Sun. Saturn is smaller than Jupiter, and yet much larger than Uranus. The zone of the telescopic planets, which have so inconsiderable a volume, immediately

. See note, page 12.

"And Neptune; for the discovery of this planet by Messrs. Adams and Leverrier, see note in "Kosmos," (Bohn,) i. 74; and The Planet Neptune, by Professor Nichol.