On this account I have been obliged to shew, that air is possessed of weight; that it is proved by other investigation than that of the balance; and … - Jean Rey

Neither can the loss of this heat render them heavy, for I have already proved that nothing increases in weight but by the addition of matter, or by diminution of volume; but here there is nothing of the kind; so that the disappearance of the heat cannot add any thing, and as to its bulk, it is visibly enlarged; the compact and solid substance of the lead being reduced (amenuisée) to so many small parcels, that their number is almost infinite.

With regard to the celestial heat making bodies light, Scaliger very properly objects that the heavens, which abound in this heat, as being the source of it, must be light (feut leger) and consequently univocal (univoque) with the other bodies, which is absurd.

This opinion is defective, to say no worse of it, in many respects. First, in attributing life to lead. Secondly, in supposing that the presence of the celestial heat makes it light, and its absence heavy. Thirdly, because it assigns the same reason for the increased weight of lead by calcination, and of animals by death. There is nothing of the kind. For as to life, how can lead possess it, since it is a homogeneous body, without difference of parts, without organs, and without any vital effect or action? If it move downwards, so does ceruse, which is only its corpse; if it be cooling (rafraischit), so is ceruse. Then how could it preserve this life, under a million of forms, that it may be made to assume and to cast off, yet always continuing to be lead? How, in the furnace (which would be a much greater wonder), where it may be kept in fusion a day, a month, or a whole year? It must have a very tenacious soul to undergo so much without being dislodged!