of its excessive coldnesse and moisture is unfit for that particular kind of operation; for which though a few lines before he prescribes in general the Mercuries of Metalline Bodies, yet he chiefly commends that drawn by art from silver. And elsewhere, in the same Book, he tells us, that he himself tryed, that by bare coction the quicksilver of Tin or Pewter (argentum vivum ex stanno prolicitum) may by an efficient cause, as he speaks, be turn’d into pure Gold. And the Experienc’d Alexander van Suchten, somewhere tells us, that by a way he intimates may be made a Mercury of Copper, not of the Silver colour of other Mercuries, but green; to which I shall add, that an eminent person, whose name his travells and learned writings have made famous, lately assur’d me that he had more then once seen the Mercury of Lead (which whatever Authors promise, you will find it very difficult to make, at least in any considerable quantity) fixt into perfect Gold. And being by me demanded whether or no any other Mercury would not as well have been changed by the same Operations, he assured me of the Negative.
And since I am fallen upon the mention of the Mercuries of metals, you will perhaps expect (Eleutherius!) that I should say something of their two other principles; but must freely confess to you, that what Disparity there may be between the salts and sulphurs of Metals and other Menerals, I am not my self experienced enough in the separations and examens of them, to venture to determine: (for as for the salts of Metals, I formerly represented it as a thing much to be question’d, whether they have any at all:) And for the processes of separation I find in Authors, if they were (what many of them are not) successfully practicable, as I noted above, yet they are to be performed by the assistance of other bodies, so hardly, if upon any termes at all, separable from them, that it is very difficult to give the separated principles all their due, and no more. But the Sulphur of Antimony which is vehemently vomitive, and the strongly scented Anodyne Sulphur of Vitriol inclines me to think that not only Mineral Sulphurs differ from Vegetable ones, but also from one another, retaining much of the nature of their Concretes. The salts of metals, and