repose equivalent to peace. It is certain, therefore, that if the poets will insist on the homogeneity of chaos, they must erase all which they have added concerning the wild confusion of contrary seeds, of the undigested mass, and of the perpetual combat of conflicting principles. "Passing over this contradiction we shall find sufficient subject for opposing them in other particulars. Let us recommence the attack on eternity. There is nothing more absurd than to admit, for an infinite time, the mixture of the insensible particles of four elements; for as soon as you suppose in them the activity of heat, the action and reaction of the four primary qualities, and besides these, motion towards the centre in the elements of earth and water, and towards the circumference in those of fire and air, you establish a principle which necessarily separates these four kinds of bodies, the one from the other, and for which a definite period alone is necessary. Consider a little, that which is denominated "the vial of the four elements". There are put into it some small metallic particles, and then three liquids, the one much lighter than the other. Shake these well together, and you no longer discern any of these component parts singly; each is confounded with the other. But leave your vial at rest for a short time, and you will find every one of them resume its pristine situation. The metallic particles will reassemble at the bottom of the vial, the lightest liquid will rise to the top, and the others take their stations according to their respective degrees of gravity. Thus a very short time will suffice to restore them to the same relative situation which they occupied before the vial was shaken. In this vial you behold the laws which nature has given in this world to the four elements, and, comparing the universe to this vial, we may conclude, that if the earth reduced to powder had been mingled with the matter of the stars, and with that of air and of water, in such a way as that the compound exhibited none of the elements by themselves, all would have immediately operated to disengage themselves, and at the end of a certain time, the particles of earth would form one mass, those of fire another; and thus of the others in proportion to the lightness or heaviness of each of them."