dition in which her regular action may be calculated and safely relied upon, and her power bear a fixed and definite relation to that which is destined to govern it,—that of man. In so far as this relation already exists, and the cultivation of Nature has obtained a firm footing, the works of man, by their mere existence, and by an influence altogether beyond the original intent of their authors, shall again react upon Nature, and become to her a new vivifying principle. Cultivation shall quicken and ameliorate the sluggish and baleful atmosphere of the primeval forests, deserts, and marshes; more regular and varied cultivation shall diffuse throughout the air new impulses to life and fertility; and the sun shall pour his most animating rays into an atmosphere breathed by healthful, industrious, and civilized nations. Science, first called into existence by the pressure of necessity, shall afterwards calmly and carefully investigate the unchangeable laws of Nature, review its powers at large, and learn to calculate their possible manifestations; and while closely following the footsteps of Nature in the living and actual world, form for itself in thought a new ideal one. Every discovery which Reason has extorted from Nature shall be maintained throughout the ages, and become the ground of new knowledge, for the common possession of our race. Thus shall Nature ever become more and more intelligible and transparent, even in her most secret depths; and human power, enlightened and armed by human invention, shall rule over her without difficulty, and the conquest, once made, be peacefully maintained. This dominion of man over Nature shall gradually be extended, until, at length, no farther expenditure of mechanical labour shall be