410 THOUGHTS ON THE NATURE OF THINGS. all languages, in all their prodigious variety, are trol nature by a counter- reck on ing, in giving m compounded of a few simple characters, so, in her account; that is, that when they see acme like manner, are the agencies and powers of the I body, which had previously been full in the eye universe composed of a few primary properties or I of sense, make its escape and vanish, they should original springs of motion. And disgraceful would it be to mankind, to have studied with such pertinacious exactness the tinkle of their own utterance; but to have been in the tongue of nature unlearned, and like the barbarians of primeval times, before letters were invented, dis tinguishing only the compounded sound or ex pression, but incapable of analyzing it into elementary tones and characters. Of a fixed Sum of Matter, and that Change takes place without Annihilation of Substance. V. That all things change, that nothing really perishes, and the mass of matter remains abso lutely the same, is sufficiently evident. And as the Divine omnipotence was required to create any thing out of nothing, so also is that omnipo tence to make any thing lapse into nothing. Whether that would take place, by a withdrawing of the preserving energy, or by the act of anni hilation, is of no importance; this much is neces sary, the interposition of a decree of the Creator. Having laid down this as an aphorism, we would, in order to fix the wandering of the mind, and prevent the supposition that we mean some in vented matter of the schools, intimate thus much in further explanation; namely, that the matter here introduced by us, is such, and with such attributes invested, that it may be truly affirmed of it, that more of that matter is present in one body, and less (though they occupy the same dimensions) in another. For instance, there is more of it in lead, less in water, greatly less still in air, and that not in a vague sense, or a dubious and unsatisfactory manner, but specifically, so as to be matter of exact computation, as that there is twice as much of it in this body, thrice as much in that, and so on. If any one w r ere to say, then, that air could be made out of water, or water, again, out of air, I should listen to him; but should he say, that a like quantity of water could be made into a like quantity of air, I should not listen. For that would be equivalent to saying that something could be made into nothing. In like manner, conversely, if he were to say that a not at once, as it were, authenticate and clear off the account of nature, till a correct voucher has been given to them, whither such body has trans ferred itself, and in what it has found a recipient. This, as matters now go, is most carelessly done, and contemplation in general stops with appear ances; thus men are ignorant of the recipient of flame, the most common of substances ; for it is a perfect fallacy to suppose that it is converted into the substance of the air. The second is thus; that while men regard the property inherent in matter of being self-sustained, and not dropping into annihilation or dissolution, as an adamantine necessity of nature, they ought to permit no method to escape them of torturing and agitating matter, if they would detect and drag to light its ultimate workings and obstinately preserved secrets. Now, this may seem to be, what I at once admit that it is, an admonition which it requires little sagacity to give : yet it seems to contain in it something of real use; it is not a counsel that has nothing in it. Let us now, however, add to this subject, if you sprinkling of actual observation. Thus, then, the greatest difficulty man encounters in operation or experiment is, that it is scarcely possible to keep together, act upon, and master the refractory pro perties of a given quantity of matter, without such substance undergoing diminution or augmenta tion ; but a separation of the parts taking place, the effort of experiment is rendered, in the last resort, abortive. Now, separation interposes thus in two ways; either so that a part of the matter flies off, as in extraction, or, at least, that a segre gation of parts takes place, as in cream. The intention, therefore, of a complete a. .d thorough change of bodies is no other than to vex matter by every well digested method of scrutiny; always, however, with due prevention of these two kinds of separation, during the period of such process. For then, and not till then, is matter truly delivered up bound into our hands, when every avenue of escape has been closed up. The third direction is this, that when men behold alterations take place in the same section of mat ter, without its being either increased or dimi nished, they should first free their imagination from determinate quantity of air (that, for example, j the deeply-rooted error, that alteration is effected contained in a vessel of a given measure) could by separation alone; and should then begin pain- be converted into a like quantity of water, it fully and carefully to discriminate the various would be the same as saying that something can j forms of alteration, when they ought to be placed be made out of nothing. From these principles, j to the account of separation, when to that of dis- three rules or practical directions seem to me organization only, and a different collocation of tleducible, in order that men may with greater the same parts, without other separation; when skill, and, in consequence of skill, with greater to that of both together. For I do not believe, success, conduct their trade with nature. The that when we shuffle hard, throw about, and Irst is in this wise, that men ought often to con- ; meliorate in our hands a harsh and untimely pear f