And indeed the Ancients have found these glasses questionless by chance, in reducing the calcined bodys into glass by a strong fire, for very many secrets by this means not sought for are found out. Oftentimes it happens to our labors, that past hope we find somthing better or worse, than the thing sought; and I think it hath thus happened with these glasses, but however it be, I am sure these glasses have stood us in much stead; for _Izaak Holland_ saith plainly, That vitrified metals being again brought to metals, by that reduction do give better and nobler metals than the first vitrified; and indeed gold gives a tincture, but silver gold, and copper silver; and so consequently the glass of other metals give better metals in reduction, the truth of which experience proves, and although I have not yet made great tryal in this work, yet I know that metals brought into dead ashes to be turned into clear glass cannot be again reduced into metals without great profit: yet one metal is more pliable than another, nor are our glasses the Artificial stones of gold-smiths fixed to other large ones for ornaments sake, made by the addition of glass made of fusile sand; but ours are made of the juice of metals. But I do not deny the vertue of Venice glass, and others in the mundifying of metals, chiefly copper and tin, which yet is not comparable with metallick juices. I freely confess I have tryed this thing twenty times, and I never was deceived by it: but I know not whether it may prove so in a greater quantity, because I never tryed it, doubting of my vessels not fit to retain fusible glasses a requisit time: for I have spent much labor in making these kind of vessels, but hitherto in vain. For there is very great hope of gain, if thou hast very strong crucibles, nor is this perfection of metals without reason, for whilest the metal is burnt to ashes, much of the superfluous combustible sulphur is burnt (as you may see in Lead, Tin, and Copper, from the sparks appearing in their calcination whilest they are stirred and separating) which if again reduced (_viz._ being calcined) its better and heavier part (by benefit of melting) sinketh to the bottom, the worser flowing on the top is changed into dross or glass. And so the separation of metals is made by the help of the Fire alone, to the ignorant and unexpert incredible: but consider gilt silver to be separated in fusion, which is as it were corrupted by the common sulphur, and the metallick species, being lost, it turns to a black dross before that in melting it forsakes the gold: which way also silver is separated from copper, and this from iron. Observe also that black and crude Antimony, being reduced into ashes by calcination, and melted is separated by a strong Fire, the purer parts descending pure and white like silver, but the impure parts ascending are changed into glass or dross, which separation would never be made without incineration although the Antimony should have stood long influx.