guiding stars of the constellation of the Bear, as they circle round the arctic pole. There the depths of the earth and the vault of heaven display all the richness of their forms and the variety of their phenomena. There the different climates are ranged the one above the other, stage by stage, like the vegetable zones, whose succession they limit; and there the observer may readily trace the laws that regulate the diminution of heat, as they stand indelibly inscribed on the rocky walls and abrupt declivities of the Cordilleras.2

BELIEF IN A DISCORD OF ELEMENTS DISAPPEARS BEFORE A COMPLETER KNOWLEDGE OF NATURE.

The knowledge of the laws of nature, whether we can trace them in the alternate ebb and flow of the ocean, in the measured path of comets, or in the mutual attractions of multiple stars, alike increases our sense of the calm of nature, whilst the chimera so long cherished by the human mind in its early and intuitive contemplations, the belief in a "discord of the elements," seems gradually to vanish in proportion as science extends her empire. General views lead us habitually to consider each organism as a part of the entire creation, and to recognise in the plant or in the animal, not merely an isolated species, but a form linked in the chain of being to other forms either living or extinct. They aid us in comprehending the relations that exist between the most recent discoveries and those which have prepared the way for them. Although fixed to one point of space, we grasp eagerly at a knowledge of that which has been observed in different and far distant regions. We delight in tracking the course of the bold mariner through seas of polar ice, or in following him to the summit of that volcano of the antarctic pole, whose fires may be seen from afar, even at mid-day.3 It is by an acquaintance with the

1 As the poles are in the equator's horizon, the zenith at mid-day is the nadir at midnight, and the equator is thus the only circle of latitude whose inhabitants in twentyfour hours see the whole heavens. The Southern Cross is the brightest constellation in the sphere. The larger of the two Magellanic clouds, which "circle round the starless desert pole of the South," appears as "a collection of clusters of stars, and nebulæ of different magnitudes, and of large nebulous spots not resolvable." These "clouds" are of great importance in the navigation of the south Atlantic and Pacific oceans. See Kosmos, (Bohn,) i. 69.-See also Art., Magellanic Clouds, infra.

2 The Andes; so termed in Spanish from consisting of parallel chains or cords of mountains. Cordeliers, the Franciscan order of monks, from wearing the knotted cord of their Saint.

See Voyage of the discovery ships Erebus and Terror, in 1841-43

results of distant voyages that we may learn to comprehend some of the marvels of terrestrial magnetism, and be thus led to appreciate the importance of the establishment of the numerous observatories, which in the present day cover both hemispheres, and are designed to note the simultaneous occurrence of perturbations, and the frequency and duration of magnetic storms.1

STUDY OF ALL SCIENCES NECESSARY TO UNIVERSAL

GENERALIZATION.

It is by the tendency to generalization, which is dangerous only in its abuse, that a great portion of the physical knowledge already acquired may be made the common property of all classes of society; but to render the instruction communicated on this principle commensurate with the importance of the subject, it is desirable to deviate as widely as possible from the imperfect compilations designated, till the close of the eighteenth century, by the inappropriate term of popular knowledge. I take pleasure in persuading myself that scientific subjects may be treated of in language at once dignified, grave, and animated, and that those who are restricted within the circumscribed limits of ordinary life, and have long remained strangers to an intimate communion with nature, may thus have opened to them one of the richest sources of enjoyment by which the mind is invigorated by the acquisition of new ideas.2 Communion with nature awakens within us perceptive faculties which had long lain dormant; and we thus comprehend at a single glance the influence exercised by physical discoveries on the enlargement of the sphere of intellect, and perceive how a judicious application of mechanics, chemistry, and other sciences may be made conducive to national prosperity.

A more accurate knowledge of the connexion of physical phenomena will also tend to remove the prevalent error, that all branches of natural science are not equally important in relation to general cultivation and industrial progress. An arbitrary distinction is frequently made between the various degrees of importance appertaining to mathematical sciences,

1 For Magnetic Storms, see Kosmos, (Bohn,) vol. i. p. 170.

2 Humboldt's own works are eminent examples of this possibility; Herschel's Treatise on Astronomy, Dr. Nichol's writings, and those of many distinguished men in various departments of science, form other instances.

to the study of organized beings, the knowledge of electromagnetism, and investigations of the general properties of matter in its different conditions of molecular aggregation; and it is not uncommon presumptuously to affix a supposed stigma upon researches of this nature, by terming them "purely theoretical," forgetting, although the fact has been long attested, that in the observation of a phenomenon, which at first sight appears to be wholly isolated, may be concealed the germ of a great discovery. When Aloysia Galvani1 first stimulated the nervous fibre by the accidental contact of two heterogeneous metals, his contemporaries could never have anticipated that the action of the voltaic pile would discover to us, in the alkalies, metals of a silvery lustre,2 so light as to swim on water, and eminently inflammable; or that it would become a powerful instrument of chemical analysis, and at the same time a thermoscope and a magnet. When Huygens first observed, in 1678, the phenomena of the polarization of light, exhibited in the difference between the two rays into which a pencil of light divides itself in passing through a doubly refracting crystal, it could not have been foreseen that a century and a half later the great philosopher Arago would, by his discovery of chromatic polarization, be led to discern, by means of a small fragment of Iceland spar, whether solar light emanates from a solid body or a gaseous covering; or whether comets transmit light directly or merely by reflection.

An equal appreciation of all branches of the mathematical, physical, and natural sciences, is a special requirement of the present age, in which the material wealth and the growing prosperity of nations are principally based upon a more enlightened employment of the products and forces of nature. The most superficial glance at the present condition of Europe shows that a diminution, or even a total annihilation of national prosperity, must be the award of those states who shrink with slothful indifference from the great struggle

1 Galvanism, the science which evolves the connexion of electricity with animal magnetism, derives its name from this physician of Bologna: his accidental discovery of the power of electricity to stir the muscles of a dead animal, was published in 1791. Professor Alexander Volta of Pavia followed up the discovery of Galvani by that of the evolution of electrical phenomena from the combination of certain metals.

2 Potassium and sodium.

This distinguished Dutch Philosopher was born at the Hague in 1629, and died at his native place in 1695.-Chromatic polarization, the department of optics which investigates the polarity of light in the evolution of certain phenomena of colour. Besides M. Arago, this important subject in optical science has been pursued by MM. Fresnel and Biot, Sir David Brewster, Sir John Herschel, &c. See Art., Polarization, Encyclop. Brit.

POWER.

of rival nations, in the career of the industrial arts.1 It is with nations as with nature, which, according to a happy expression of Goethe, "knows no pause in progress and development, and attaches her curse on all inaction." The propagation of an earnest and sound knowledge of science can therefore alone avert the dangers of which I have spoken. Man cannot act upon nature, or appropriate her forces to his own use, without comprehending their full extent, and having an intimate acquaintance with the laws of the physical world. Bacon has said that, in human societies, knowledge is Both must rise and sink together. But the knowledge that results from the free action of thought, is at once the delight and the indestructible prerogative of man; and in forming part of the wealth of mankind, it not unfrequently serves as a substitute2 for the natural riches which are but sparingly scattered over the earth. Those states which take no active part in the general industrial movement, in the choice and preparation of natural substances, or in the application of mechanics and chemistry, and among whom this activity is not appreciated by all classes of society, will infallibly see their prosperity diminish in proportion as neighbouring countries become strengthened and invigorated under the genial influences of arts and sciences.

DELINEATION OF NATURE.

Nature, in the manifold signification of the word—whether considered as the universality of all that is, and ever will be -as the inner moving force of all phenomena, or as their mysterious prototype-reveals itself to the simple mind and feelings of man as something earthly, and closely allied to himself. It is only within the animated circles of organic structure that we feel ourselves peculiarly at home. Thus wherever the earth unfolds her fruits and flowers, and gives food to countless tribes of animals, there the image of nature impresses itself most vividly upon our senses. The impression thus produced upon our minds limits itself almost exclusively to the reflection of the earthly. The starry vault and the wide

New views of the necessity of co-national exertion may be discerned in the constitution of the British Association.

2 No nation illustrates this more than Great Britain; every one remembers the description in the Spectator of the original products of this country as limited to "hips and haws, acorns and pignuts."

expanse of the heavens belong to a picture of the universe, in which the magnitude of masses, the number of congregated suns and faintly glimmering nebulae, although they excite our wonder and astonishment, manifest themselves to us in apparent isolation, and as utterly devoid of all evidence of their being the scenes of organic life. Thus, even in the earliest physical views of mankind, heaven and earth have been separated and opposed to one another as an upper and lower portion of space. If, then, a picture of nature were to correspond to the requirements of contemplation by the senses, it ought to begin with a delineation of our native Earth. It should depict first the terrestrial planet as to its size and form; its increasing density and heat at increasing depths in its superimposed solid and liquid strata; the separation of sea and land, and the vital forms animating both, developed in the cellular tissues of plants and animals; the atmospheric ocean, with its waves and currents, through which pierce the forest-crowned summits of our mountain chains. After this delineation of purely telluric relations, the eye would rise to the celestial regions, and the Earth would then, as the well-known seat of organic development, be considered as a planet, occupying a place in the series of those heavenly bodies which circle round one of the innumerable host of self-luminous stars. This succession of ideas indicates the course pursued in the earliest stages of perceptive contemplation, and reminds us of the ancient conception of the "sea-girt disc of earth" supporting the vault of heaven. It begins to exercise its action at the spot where it originated, and passes from the consideration of the known to the unknown-of the near to the distant. It corresponds with the method pursued in our elementary works on astronomy, (and which is so admirable in a mathematical point of view,) of proceeding from the apparent to the real movement of the heavenly bodies.

LIFE OF NATURE.

Nature, which is represented as dead, and contrasted in common language with living nature, because it has not the same life with the animal or the plant, is it then bereft of all life? If it has not life, we must acknowledge that it has at least the appearance of life. Has it not motion in the water