The conceit is surely grounded upon the visible mischief of Glass grosly or coursly powdered, for that indeed is mortally noxious, and effectually used by some to destroy Mice and Rats; for by reason of its acuteness and angularity, it commonly excoriates the parts through which it passeth, and solicits them unto a continual expulsion. Whereupon there ensues fearful symptomes, not much unlike those which attend the action of poison. From whence notwithstanding, we cannot with propriety impose upon it that name, either by occult or elementary quality, which he that concedeth will much enlarge the Catalogue or Lists of Poisons. For many things, neither deleterious by substance or quality, are yet destructive by figure, or some occasional activity. So are Leeches destructive, and by some accounted poison; not properly, that is by temperamental contrariety, occult form, or so much as elemental repugnancy; but because being inwardly taken they fasten upon the veins, and occasion an effusion of bloud, which cannot be easily stanched. So a Sponge is mischievous, not in it self, for in its powder it is harmless: but because being received into the stomach it swelleth, and occasioning a continual distension, induceth a strangulation. So Pins, Needles, ears of Rye or Barley may be poison. So _Daniel_ destroyed the Dragon by a composition of three things, whereof neither was poison alone, nor properly all together, that is, Pitch, Fat, and Hair, according as is expressed in the History. Then _Daniel_ took Pitch, and Fat, and Hair, and did seeth them together, and made lumps thereof, these he put in the Dragons mouth, and so he burst asunder. That is, the Fat and Pitch being cleaving bodies, and the Hair continually extimulating the parts: by the action of the one, Nature was provoked to expell, but by the tenacity of the other forced to retain: so that there being left no passage in or out, the Dragon brake in pieces. It must therefore be taken of grosly-powdered Glass, what is delivered by _Grevinus_: and from the same must that mortal dysentery proceed which is related by _Sanctorius_. And in the same sense shall we only allow a _Diamond_ to be poison; and whereby as some relate _Paracelsus_ himself was poisoned. So even the precious fragments and cordial gems which are of frequent use in Physick, and in themselves confessed of useful faculties, received in gross and angular Powders, may so offend the bowels, as to procure desperate languors, or cause most dangerous fluxes.