PRECIOUS STONES.                            61
	his grosser excrement consisted chiefly of a sandy substance, as if the devoured stones had been in his body dissolved, and crumbled into sand. And indeed this memorable story seems to argue that a natural Menstruum appertaining to the human body, but not so corrosive as to fret the same, may dissolve Stones, Metals, and other compact substances." " Since I have observ'd it to be the main thing that keeps judicious men from seeking, or so much as hoping to discover, noble dissolvents, that they are scarce to be persuaded that there can be considerably piercing Menstruums that are not proportionably corrosive to the bodily tissues, I will here acquaint you with a Liquor that may, I presume, assist you to undeceive some of these men. We take then ordinary Household Bread (I like that of Rye ; but I have divers times us'd that of Wheat), and when it is cut into slices, and some­what dryed, we almost fill a glass retort with it; and placing that in a Sand furnace ; by degrees of fire we draw off what will be made to come over without much difficulty. The Oyl, as useless to our purpose, being by a Filter separated from the rest of the Liquor ; we also by a gentle heat free the Spirit from some of its phlegm, which yet sometimes we find no great necessity to do. And still this Spirit, which you will easily believe is no such Corrosive as Aquafortis, or other distill'd Liquors of Mineral Salts, will work upon the hardest sorts of bodies, and perform things that Chemists, counted of the judiciousest, would not have us expect from the most sharp, and corrosive Menstruums now in use. For with this we have in a short time, and that in the cold, drawn tinctures, not only from crude Corals, and some of the more open Minerals, but likewise from