Physiologia Epicuro-Gassendo-Charltoniana, or, A fabrick of science natural, upon the hypothesis of atoms founded by Epicurus repaired [by] Petrus Gassendus ; augmented [by] Walter Charleton ...

Assumption the First.

That the superfice of no Visible is so exquisitely smooth, polite, or equal,* 1.1 as not to contain various Inaequalities, i. e. Protuberant and Deprest parts, or certain (Monticuli and Valleculae) small Risings and Fallings: which in some bodies being either larger, or more, are discoverable by the naked intuition of the Eye; and in others, either smaller, or fewer, require the detection of the Microscope.

This is neither Praecarious, nor Conjectural: but warranted by Reason, and autoptical Demonstration. For, if the object assumed be polisht Mar∣ble; since that apparent Tersness in the surface thereof is introduced by the detrition of its grosser inaequalities by Sand, and that Sand is nothing but a multitude of Polyedrical solid Grains, by the acuteness and hardness of their Angles cutting and derasing the more friable particles of the Mar∣ble: it must follow, that each of the grains of Sand must leave an impressi∣on of its edge, and so that the whole superfice must become scarified by innumerable small incisions, variously decussating and intersecting each other. If Steel of a speculary smoothness, such as our com∣mon Chalybeat Mirrours; since the Tersness thereof is artificial, caused by the affriction of Files, which cut only by the acuteness of their teeth, or lineal inaequalities: it is not easie to admit, that they leave no scratches, or exarations on the surface thereof; and where are many Incisions, each whereof must in Latitude respond to the thickness of the Tooth in the File, that made it, there also must

be as many Eminences or small Ridges intercepted among them. And if Glass▪ whose smoothness seems superlative; since it is composed of Sand and Salts, not so perfectly dissolved by liquation, as not to retain various An∣gles: it cannot be unreasonable to inferr, that those remaining points or an∣gular parts must render the Composition in its exteriors full of Asperities. And, as for Autoptical Evidence; that Marble, Steel, and Glass are unequal in their superfice, is undeniable not only from hence, that a good Engyscope, in a convenient light, doth discover innumerable rugosities and Cavities in the most polisht superfice of either: but also from hence, that Spiders and Flyes do ordinarily run up and down perpendicularly on Venice Glass, which they could not do, if there were not in the surface thereof many small Cavities, or Fastnings for the reception of the Uncinulae, or Hooks of their Feet. To which may also be added, the Humectation of Glass by any Li∣quor affused; for, if there were no Fosses and Prominences in the superfice thereof, whereon the Hamous particles of the Liquid might be fastned, it would instantly run off without leaving the least of moisture behind. And hence

Notes

• * 1.1

  Art. 1. That the su∣perfice of no¦body is per∣fectly smooth: evicted by so∣lid Reas••n, and Aut••psie.