Stones which the _Germans_ call _Quartzens_ and _Hornstein_, containing pure and corporeal gold, although mixt with silver and copper, may be burnt and ground, and extracted with Mercury, and if they abound with gold, be purged by flux; which labours are usual with diggers and dealers in metals, of which I do not intend to write, because others have heretofore writ of them. But those flints _Quartzen_ and _Hornstein_ every where almost to be found, containing but a mean quantity of dispersed iron-like Gold, Marcasite-like, and that either fixt or volatile, cannot be separated with gain, to wit, neither by Mercury nor by Flux, wherefore they are neglected by the Miners, either out of ignorance or for the intolerable costs. But I having tryed those base stones, that how little gold soever they possess; yet may it be separated with great gain, I would not intermit to publish this knowledge for my Christian neighbours sake, not doubting but this publication will be profitable to very many. For I am not ignorant that there are as well learned, as unlearned, noble as ignoble, secular as spiritual, either by war or otherwise exposed to poverty, so that they are hardly able to maintain their family, _&c._ and for their sakes and others in want. I have published this secret, which rightly handled may bring no small gain yearly, but especially where those stones are plentiful, and also that spirit of salt, whereof the description is given in the first part of the Philosophical Furnaces, and hereafter there shall be given a better, if nothing hinder; in the mean while use and enjoy these. And if it happen so that thou canst not rightly perform all things of the aforesaid tractate, blush not to learn the manual Operations [which cannot be so exactly described] from those that are experienced, lest you hereafter unprofitably spend your labour and costs. As for those stones know that very many of them are found in several places, chiefly in those that are sandy and mountainous, but in some more and better than in others: for there is seldom seen sand without flints, and oft-times the sand it self, though very little doth not want Gold. But they are very likely to be found on the shoars of Rivers, where the waters washing away the sand from the flints they are found in great abundance, though they are not so easily known by their outside, as those which were found clean in the sand, because they are covered with slime. Wherefore they must be broken with a hammer, that that may be seen which is in them, which may better appear if they be burnt, and quencht in cold water. For the stone retaining its whiteness when it is burnt and quencht doth contain nothing; but acquiring a redness it shews there is something in it, and the more red it is the better token it is.