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to cover their estimation with the multitude. On the contrary, we earnestly wish them to be amplified, and improved, and held in increased regard; as it is no part of our ambition to withdraw men either all, or altogether, or all at once from what is established and current. But as an arrow or other missile, while carried directly onward, still nevertheless during its progress incessantly whirls about in rapid rotation; so we, while hurrying forward to more distant objects, are carried round and round by these popular and prevalent opinions. And, therefore, we do not hesitate to avail ourselves of the fair services of this common reason and these popular proofs; and shall place whatever conclusions have been discovered or decided through their medium (which may, indeed, have much of truth and utility in them) on an equal footing with the rest; at the same time protesting against any inferences thence to be drawn in derogation of what we have above stated about the incompetency of both this reason and of these proofs. We have rather, in fact, thrown out the preceding hints as it were occasionally for the sake of such as, feeling their progress impeded by an actual want either of talent or of leisure, wish to confine themselves within the ancient tracts and precincts of science, or at least not to venture beyond their immediately contiguous domains; since we conceive that the same speculations may (like tents or resting places on the way) minister ease and rest to such as, in pursuance of our plan, seek the true interpretation of nature, and find it; and may, at the same time, in some slight degree, promote the welfare of man, and infuse into his mind ideas somewhat more closely connected with the true nature of things. This result, however, we are far from anticipating in confidence of any faculty which we ourselves possess, but we entertain no doubt that any one even of moderate abilities, yet ripened mind, who is both willing and able to lay aside his idols, and to institute his inquiries anew, and to investigate with attention, perseverance, and freedom from prejudice, the truths and computations of natural history, will of himself, by his genuine and native powers, and by his own simple anticipations penetrate more profoundly into nature than he would be capable of doing by the most extensive course of reading, by indefinite abstract speculations, or by continual and repeated disputations; though he may not have brought the ordinary engines into action, or have adopted the prescribed formula of interpretation.

In this, however, we do not wish to be considered as demanding for our own dogma the authority which we have withheld from those of the ancients. We would rather indeed testify and proclaim, that we are far from wishing to be ourselves peremptorily bound by what we are about to bring forward, of whatever character it may be, to the maintenance of the whole of our secondary and inductive philosophy. The result of our meditations we have determined to offer loosely, and unconfined by the circumscription of method; deeming this a form both better adapted to sciences newly springing up as from an old stock, and more suitable to a writer whose present object it is not to constitute an art from combined, but to institute a free investigation of individual existences.

F. W.

END OF THE INSTAURATIO.

POSTHUMOUS TRACTS.

THOUGHTS ON THE NATURE OF THINGS.

Of the Division of Bodies, of Continuity, and a Vacuum.

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THOUGHT I.

THE theory of Democritus relating to atoms is, if not true, at least applicable with excellent effect to the exposition of nature. For it is not easy, except on the hypothesis of atomic particles, either to grasp in thought, or express in words, the real exility of parts in nature, such as it is discoverable in objects themselves.

Now the term atom is taken in two senses, not materially different from one another. It is taken either to signify the ultimate term, the minutest subdivision, in the section or breaking down of bodies; or a corpuscle containing in it no vacuum. As relates to the first, the two following principles may be safely and surely laid down. The first is, that there exists in objects an attenuation and minuteness of particles, far exceeding all that falls under ocular observation. The second is, that it is not carried to infinity, or endless divisibility. For if one heedfully attend, he will find that the corpuscles composing bodies which possess continuity, far transcend in subtilty those which are found in broken and discontinuous ones. Thus we see a little saffron, intermixed and stirred in water (a cask of water for instance), impart to it such a tincture, that even by the the eye it is easily distinguishable from pure water. The particles of the saffron thus disseminated through the water, certainly exceed in fineness the most impalpable powder. This will become still clearer, if you mingle with the water a small portion of Brazilian-wood ground to a powder, or of pomegranate flowers, or of any other very high coloured substance, yet which wants the susceptibility of saffron to diffuse itself in liquids, and incorporate with them.

It was therefore absurd to take atoms to be those minute particles which are visible by the aid of the sun's light.

For these are of the nature of a powder, but an atom, as Democritus said himself, no one either has seen or can possibly see. But this dispersion of substance presents itself in a still more surprising light in odours. For if a little saffron can tinge and impregnate a whole cask of water, a little civet does so to a spacious chamber, and to a second, and a third successively. And let none imagine that odours can be propagated like light, or heat and cold, without a stream of effluvia from the substance, since we may observe that odours are tenacious of solids, of woods, of metallic substances, and for no inconsiderable time, and that they can be extracted and cleansed away from these, by the process of rubbing and washing. But that in these and similar cases, the subtilization is not carried to infinity, no man in his senses will dispute, since this sort of radiation or diffusion is confined to certain spaces, and local boundaries, and to certain quantities of substance, as is very conspicuous in the abovementioned instances.

As relates to atom in its second sense, which presupposes the existence of a vacuum, and builds its definition of atom on the absence of the vacuum; it was an excellent and valuable distinction which Hero so carefully drew, when he denied the existence of a vacuum coacervatum (or fully formed), and affirmed a vacuum commistum (or interstitial vacuum). For when he saw that there was one unbroken chain of bodies, and that no point of space would be discovered or instanced, which was not replenished with body; and much more, when he perceived that bodies weighty and massive tended upwards, and as it were repudiated and violated their natures rather than suffer complete disruption from the contiguous body; he came to the full determination that nature abhorred a vacuum of the larger description, or a vacuum coacervatum. On the other hand, when he observed the same quantity of matter composing a body in a state of contraction and coarctation, and again in one of expansion and dilatation, occupying and filling unequal spaces, sometimes smaller, sometimes greater, he did not see in what manner this going out and in of corpuscles, in reference to their position in that body, could exist, except in consequence of an interspersed vacuum, contracting on the compression, and enlarging on the relaxation, of the body. For it was clear that this contraction of necessity was produced in one of three ways; either in that which we have specified, namely, the expulsion of a vacuum by means of pressure, or the extrusion of some other body

previously incorporated, or the possession by bodies of some natural virtue (whatever it might be) of concentration and diffusion within themselves. As relates to the extrusion of the rarer body, it is a mode of reasoning that involves us in an endless series of such expulsions. For true it is, that sponges and the like porous substances, contract by the ejection of the air. But with respect to air itself, it is clear from manifold experiments that it can be condensed in a known space. Are we then to suppose that the finer part of air itself may be thus eliminated by compressure, and of the eliminated part another part, and so on to infinity? For it is a fact most decidedly adverse to such an opinion that the rarer bodies are they are susceptible of the more contraction; when the contrary ought to be the fact, if contraction was performed by expressing the rarer portion of the substance. As to that other mode of solution, namely, that the same bodies without farther alteration undergo various degrees of rarity and density, it is not worthy of elaborate attention. It seems to be an arbitrary dictum, depending on no cognizable reason, or intelligible principle, like the generality of the dogmas of Aristotle. There remains then the third way, the hypothesis of a vacuum. Should any one object to this, that it appears a difficult and even impossible supposition, that there should exist an interspersed vacuity, where body is every where found; if he will only reflect calmly and maturely on the instances we have just adduced, of water imbued with saffron, or air with odours, he will readily discover that no portion of the water can be pointed out where there is not the saffron, and yet it is manifest by comparing the saffron and the water previous to their intermixture, that the bulk of the water exceeds by many times the bulk of the saffron. Now if so subtile an interspersion is found to take place in different bodies, much more is such interspersion possible in the case of a body and a vacuum.

Yet the theory of Hero, a mere experimentalist, fell short of that of the illustrious philosopher Democritus in this particular point, namely, that Hero not finding in this our globe, a vacuum coacervatum, denied it therefore absolutely. Now there is nothing to hinder the existence of a complete vacuity in the tracts of air, where there are undoubtedly greater diffusions of substances.

And let me give this once the admonition, that, in these and similar investigations, none be overpowered or despair, because of the surpassing subtilty of nature.

Let

VOL. XIV.

F F

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