The Fifth Part.

possibly such a proportion of that ingredient may be more convenient than an other for the constituting of such a body.) Thus in a clock the hand is mov’d upon the dyal, the bell is struck, and the other actions belonging to the engine are perform’d, not because the Wheeles are of brass or iron, or part of one metal and part of another, or because the weights are of Lead, but by Vertue of the size, shape, bigness, and co-aptation of the several parts; which would performe the same things though the wheels were of Silver, or Lead, or Wood, and the Weights of Stone or Clay; provided the Fabrick or Contrivance of the engine were the same: though it be not to be deny’d, that Brasse and Steel are more convenient materials to make clock-wheels of than Lead, or Wood. And to let you see, Eleutherius, that ’tis sometimes at least, upon the Texture of the small parts of a body, and not alwaies upon the presence, or recesse, or increase, or Decrement of any one of its Principle, that it may lose some such Qualities, and acquire some such others as are thought very strongly inherent to the bodies they Reside in. I will add to what may from my past discourse be refer’d to this purpose, this Notable Example, from my Own experience; That Lead may without any additament, and only by various applications