MISCELLANEOUS TRACTS. [TRANSLATED FROM THE LATIN.] THOUGHTS ON THE NATURE OF THINGS.* Of the Division of Bodies, of Continuity, and a Vacuum. 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, ei ther to grasp in thought, or express in words, the real exility of parts in nature, such as it is disco verable 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 princi ples 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 divisi bility. For if one heed fully attend, l^e will find that the corpuscles composing bodies which pos sess continuity, far transcend in subtility 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 eye it is easy 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 pome granate 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
- This is the translation of my friend Wm. G. Glen. [B. M.]
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 successive ly. 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 incon siderable time, and that they can be extracted and cleansed away from these, by the process of rub bing 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 quan tities 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 va cuum ; it was an excellent and valuable distinc tion which Hero so carefully drew, when he de nied 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 repu diated and violated their natures rather than suffer complete disruption from the contiguous body ; he came to the full determination that nature ab horred a vacuum of the larger description, or a vacuum coacervatum. On the other hand, when he observed the same quantity of matter compos ing a body in a state of contraction and coarcta- tion, and again in one of expansion and dilatation, occupyino- and filling unequal spaces, sometimes
