Page:Philosophical Transactions - Volume 003.djvu/197

 fire, a way found out in Peru in such difficult cases; but all to no purpose; so froward a matter it was, that it could not be brought to receive Mercury, neither-by fair means, nor by foul. Then I devised a way to torment it with a Corrosive of ordinary separating water, impregnated with common salt, and it made a dissolution, like that of Gold; which, thus dissolved, I shew'd to a Mineralist, who had been versed all his life time in the separatory Art of Gold and Silver; and he would not believe but that it was true gold. But having steam'd away the Aqua fortis, I found my hopes turn'd into a dirt something yellow, out of which, with distill'd vineger, enforc'd with its own tartareous Salt, I extracted a Tincture more curious, than useful.

The said Mineralist would not despair yet, but taking a quantity of the golden dull, he cemented it with the powder of vulgar sulphur, stratum super stratum, and this in a moderate fire for three days together, hoping, the Sulphur would consume all the impediments, which kept the Mercury from entring. But (as I told him before-hand) it only serv'd to clog the matter with more sulphureous unctuosity, than it had before.

I brought for a curiosity some of this Mineral from the Indies into Spain, where some of our friends had a view of it; but have not been able hitherto, to do any good upon it. What I learnt by these Tryals, was not only Caution, but several secrets of extracting Mettals by Quick-silver; in which there are so many Cautions and observations, that it would require much writing to rehearse them.

I shall only subjoyn the grand use of Mercury in separating Silver in the Indies, when that Mettal is generated (as commonly 'tis) in certain rocky stones, abounding with bituminous and corrosive mixtures, so as 'tis impossible to free it totally from its corrupt Matrix by the violent way of melting, whatever auxiliary Ingredients may be added, as Lead and artificial salts, and the like, because those sulphureous and vitriolic compounds, (in the way of fusion) melting together with the Silver, sublime part of it away in a volatile fume by their corroding acrimony, calcinaring and vitrifying the other parts, and robbing the Artificer of half his gain. In this case the use of Quick-silver is found most advantageous; the practice whereof, because I am Rh