the prolongation of his life in the silent retirement of that sequestered island was mercifully intended to lead him to a calm reflection on the real value of sublunary possessions: for how very visionary and like a dream must all his former life have frequently appeared to him, when standing on the brow of some precipitous rock, the natural boundary of his insulated prison, he mused on the interminable expanse of the Atlantic; and compared his present desolation with his former glory. Or, if the terrors of Omnipotence failed even then to reach his obdurate heart, his example at least remains a merciful beacon to others; who may learn from his doom, that there is a Power which can say, as easily to the tempestuous ocean of ambition, as to the natural deep, "Hitherto shalt thou come, but no further: " and here shall thy proud waves be stayed."

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CHAP. VI.

Adaptation of the Atmosphere to the Wants of Man.

SECT. I.

The general Constitution of the Atmosphere.

IN the foregoing part of this treatise the physical condition of man has been considered under the view of the general capabilities of his nature, rather than of his actual state: but it is evident

on a moment's reflection that his actual state will be very different at different periods of time, or in different parts of the world at the same period and this observation applies no less to communities than to individuals. How great the contrast, with reference to the case of individuals, between the intellectual powers and attainments of a Newton and a native of New Holland; and in the case of communities, how great the contrast between any of the kingdoms of modern Europe, and the rude tribes from whence they were originally derived.

In proceeding then to illustrate the adaptation of the external world to the physical condition of the human species, we must view individuals or communities under all possible circumstances of existence, and make the illustration of as general application as the nature of the subject evidently demands.

And, in order to effect something like a systematic arrangement of the immense mass of materials whence the following illustration is to be deduced, it is proposed to investigate separately the four kingdoms or divisions of nature, the general characters of which were given in the commencement of this treatise; beginning with the atmospherical and ending with the animal kingdom.

If it were possible, with the bodily as with the mental eye, to behold the constitution of the at

G

mosphere which surrounds our earth, we should view a compound probably the most complex in nature: for into this circumambient ocean of air, as it is called by Lucretius, are carried up whatever exhalations arise not only from the earth itself, but from every organized form of matter whether living or in a state of decomposition that is found upon the earth's surface; the dews of morning, the balms of evening, the fragrance of every plant and flower; the breath and characteristic odour of every animal; the vapour invisibly arising from the surface of the whole ocean and its tributary streams; and, lastly, those circumscribed and baneful effluvia, however generated, which when confined to definite portions of the atmosphere produce those various forms of fever which infest particular districts: or those more awful and mysterious miasmata, which, arising in some distant region, and advancing by a slow but certain march, carry terror and death to the inhabitants of another hemisphere.

Such is the complex character of the atmosphere; and, indeed, from this assemblage of vapours contained in it, it has received its peculiar appellation; being the receptacle, or magazine, as it were, of terrestrial exhalations c.

b Semper enim quodcunque fluit de rebus; id omne

Aeris in magnum fertur mare.

• Ατμων σφαίρα.

Lib. V. 277, 8.

All these various exhalations however may be considered as foreign to the constitution of the air, being neither constantly nor necessarily present anywhere; all, with the exception of that aqueous vapour which is continually rising from the surface of the earth, as well as of the ocean and every lake and river. But, in addition to this aqueous vapour, the air is also charged to a variable extent with light and heat and electricity of which the two first are so obviously adapted to the wants of man as to demand immediate attention. Electricity is probably of equal importance in its relation to man: but the true character of that relation has not yet been sufficiently developed to call for a distinct consideration on the present occasion.

SECT. II.

Light.

The metaphorical expressions of all ages and nations, with respect to light, sufficiently evince the value in which that inestimable gift is held. In the sacred Scriptures indeed, not only are temporal blessings compared to light, and temporal evils to darkness; but holy deeds are frequently described under the character of the former; and unholy deeds under the character of the latter: and, with respect either to classical or oriental literature, a thousand instances might easily be adduced illustrative of the same metaphorical use of the terms in question.

When, after a dark and tempestuous night, the mariner first perceives the dawn of returning day; although that dawn discover to his view the evil plight to which the storm has reduced his vessel, why does he still hail day's harbinger as his greatest relief, but because without the aid of light he could not possibly extricate himself from the difficulties of his situation? Or, when the child, awakened from its sleep, finds itself alone in darkness, why is it overwhelmed with terror, and why does it call out for protection, but from the influence of those undefined fears, which naturally occur to the mind under the privation of light?

There is something so congenial to our nature in light, something so repulsive in darkness, that, probably on this ground alone, the very aspect of inanimate things is instinctively either grateful or the reverse, in consequence of our being reminded by that aspect of the one or of the other so that on this principle, perhaps, particular colours throughout every province of nature are more or less acceptable in proportion as they approach nearest or recede farthest from the character of light, whether reflected immediately from the heavenly bodies, or from the azure of the sky, or from the thousand brilliant hues with which the setting or the rising sun illuminates its attendant clouds.

In illustration of the principle just advanced,