plain and obvious reason, that we have no distinct idea of the terms and no settled premises to build upon.--Of the essence of matter we know nothing: and altogether as little of many of its more active qualities; insomuch, that, amidst all the discoveries of the day, it still remains a controvertible position, whether light, heat, magnetism, and electricity, are material substances, material properties, or things superadded to matter and of a higher rank. If they be matter, gravity and ponderability are not essential properties of matter, though commonly so regarded. And if they be things superadded to matter, they are necessarily immaterial; and we cannot open our eyes without beholding innumerable instances of material and immaterial bodies coexisting and acting in harmonious unison through the entire frame of nature. But if we know nothing of the essence and but little of the qualities of matter, of that common substrate, which is diffused around us in every direction, and constitutes the whole of the visible world, what can we know of what is immaterial? of the full meaning of a term, that, in its strictest sense comprehends all the rest of the immense fabric of actual and possible being, and includes in its vast circumfeence every essence of every other being as well below as above the order of matter, and even that of the Deity himself?"

But if we know nothing of the essence of matter, we know nothing at all; for what is the plain, original meaning of the word, essence, (esse, essentia, ens, ovoia,) but being or existence itself? And what then is the essence of matter, but matter itself, the very existence of matter, of which, if we know nothing, no sense can constitute knowledge? Some effort is indeed made to darken this evident meaning of the term; or rather no meaning at all is of course attached to it, when it is said, that we know nothing about it, yet even the eminent author, in the above passage, acknowledges this meaning, when he calls the essence of matter, "that common substrate, which is diffused around us in every direction and constitutes the whole of the visible world." A simple essence may exist in a compound essence, and be extracted therefrom, as in processes of distillery and a certain use of the term in domestic life, but the mechanic craft has been far outstript by this of philosophy, which has hypocritically refined upon the subject,

until it has refined it wholly away, or out of all entity whatever, and given currency to "one of those remarks, which are repeated, till they pass into axioms, only because they have so litle meaning, that nobody thinks it worth while to refute them at their first appearance." But how mysterious and unaccountable, that rational men should thrust into the most recondite parts of philosophy, or out of all existence, what constitutes the most obvious, self-evident, and universally acknowledged first-principle of all human science. For it is founded on immediate SENSE; OUR FIVE SENSES. Here is the first principle of science; too obvious, by universal consent in every age and clime, to admit of a momentary doubt; and it involves a knowledge of the essence of matter. Hence, if there is any real knowledge to be got on the subject of spirit, or metaphysics, as well as physics, it must be built on this foundation, by a certain analogy or connexion; and "that extensive branch of science," in the words of the author above quoted, (ib.) "which is generally known by the name of Metaphysics, has in modern times been unjustifiably separated by many philosophers from the division of Physics or Natural Philosophy; and made a distinct division by itself. As a part of Physics or Natural Philosophy, it was uniformly arranged by the Greeks; as such it occurs in the works of Aristotle ;-And I may add, that it is very much in consequence of so unnatural a divorce, that the science of Metaphysics has too often licentiously allied itself to imagination, and brought forth a monstrous and chimerical progeny."

On this ground, we shall proceed to run over the more prominent and unsettled points in prevailing systems. As to that connexion of Mathematics with Physics, which has also grown out of these perversions, and covered over a flower garden with weeds, that straining at a gnat and swallowing a camel, that glozing over of a wound unprobed to the bottom, that stirring of dust to conceal defects, that laborious endeavour to supply the accuracy so much wanted in Cartesianism, by the superinduction of mathematical on intellectual speculation, which is the driest and most unedifying? or how has the matter been mended, or not rather made much worse? Newton's Principia Mathematica has succeeded the Principia of Descartes. Observe the sceptical conse

quences of the latter in the country where it arose, until it so eminently concurred in the production even of that national misery, so awfully depicted on the page of history, in the Reign of Terror! Observe, also, how the former too has gained so much currency and fashion from the same nation, the same times, and similar causes! "In the sciences," says Madame De Staël, (In. Lit. vol. I, c, 6.) "and particularly in mathematics, France can boast of the greatest men in Europe. The civil commotions amongst the French, far from discouraging emulation in this line, have inspired a wish to take refuge in the study of it.--Men of reflection, disgusted on all sides by the follies of party-spirit, attach themselves to these studies." Thus no sooner had Cartesianism got such mischief into operation, than Newtonianism must step in. Equal consequences have not followed, yet many are the groans of youth under it cramping chains. There is, indeed, scarcely any science it has not invaded; (ib.) theology, morality, metaphysics, political economy, (Say,) medicine, have all met and repelled the attack. But poor, natural philosophy has suffered a complete conquest, inasmuch, as she was more beautiful and tangible in her diversified and sensible nature, she lay more open to the invasion; the natural has become the artificial; the noble and desirable, the dearthy and uninteresting; the simple the complex; the intelligible the unintelligible. Some of these facts may appear more clearly in the sequel. Neither Newton nor even Bacon, if with all their apparent accuracy they proceed on any first principle, pretends to any other than that of Descartes, although the experimental character of the Novum Organum would appear so necessarily to require that of common sense. And is not this a reason why Baconism too, if we may be allowed the expression, has with all its benefits so often degenerated into a kindred speculation, which by a dearthy farrago has so often made physics unpopular? while Bacon himself, at the outset, has fallen into the grand error of pretending to avouch the immateriality of heat? (Reply to Ed. Rev. ag. Ox.)

ON THE MATERIALITY OF FIRE.

Or all the phenomena of matter, none are so wonderful, so distinct, or general, as those produced by what are called the imponderable agents-light, heat, electricity, and magnetism. Not a vapour ascends from the face of the earth; not a flash of lightning crinkles through the atmosphere; not a sunbeam cheers animated nature, or a ray of light discovers to us a star of the firmament, but from the immediate influence of one of these agents. Indeed, it is impossible for us to strain our imagination so far as to conceive of the dearth and desolation which must follow, if the earth were divested of heat or light even for a moment. All the dreariness of winter is the consequence of only a slight failure of these two agents, and all the gaiety of the summer landscape recurs again, when they prevail a little more plentifully. The soul springs from the human body, and leaves it a frozen clod, when a partial absence of caloric in the surrounding atmosphere draws away its quota of vital warmth.

Hence, there is no subject in physics of such fundamental importance as that which treats of the nature of the imponderable agents, as it must involve an account of the causes of the most general and astonishing effects in the physical world. Yet, strange as it may appear, even in this advanced age of experimental philosophy, when so much has been said and done respecting each of these agents, and the arcana of nature have been so incessantly sought after, there is not a subject in all our books of philosophy so enveloped in obscurity as this. Even their materiality is doubted. There is not one of these agents