The Copper is turned into excellent Verdigrease. And so the Oars of Copper, though never so poor, may be extracted, and that with no small benefit: Because the Verdigrease made of the bare Copper is twice the price of the molten Copper it self.
The manner of making good Salt-peter in plenty, out of Kitchin-Salt and Calx-vive.
Take the Stones of Lime, which have been thorowly changed or reduced into Powder by the Air, four parts: of Kitchin Salt, or Common Salt, one part, [by weight, and not by measure] whether pure or impure [it matters not:] and of this mixture is a thickish paste to be made by moistning it with Urine, or, in want of that, with Water; which is to be made up into a Pile with Wood, and so may it be made Stratum super stratum, of what bigness you please: and it may be done in a Furnace made for that purpose, or else in the open Field abroad in the Air. But you must beware in the building up of this Pile, that the mass of Salt and Calx-vive be not too thick laid, and too much; but it would be better to make it up in balls or pellets, that so they may be well fired by the flame, which must penetrate everywhere through the pervious heap or pile: which cannot be, if the mass be spread too broad, and so stop up the passages of the flame.
The heap being made as big as you are minded to have it, the fire must be put under, and so long fed, till all the wood is burnt, and the balls themselves have been red-hot, a whole hour at least: that the Acrimony of the Salt may in so great a heat be changed by the Calx-vive, and get it self a milder nature, and consequently be so much the easier transmuted into Salt-peter.
N. B. The Salt that is on this wise transmuted, is most fit for dunging Lands, and to be used instead of the common beasts dung, as I have at large taught long ago in many places of my Writings.
This is the preparation of turning Salt into Salt-peter, which Artifice, if any be minded to work about, it is necessary for him to order his Operation this following way.
The manner of making Salt-peter out of this prepared Salt.
First of all, this introverted Salt must be exposed to the open Air, and beams of the Sun; but yet so, as that the heap may not be moistned by the Rain, and it must lie in its heap the heighth of some three or four Feet; the which heap is to be wetted either with Man’s piss or Beasts; or if there be not enough of this to be had, then with bare water onely, that so the pellets or balls lying quietly for some days, may be dissolved and be mixed with the rest of the matter.
Now when the warm Air hath consumed all the humidity, and dried up the heap, the aforesaid moistning is to be repeated; which being again consumed, and the heap dried, the labour of repeated moistnings and exsiccations is to be so long continued, as long as necessity requireth: For in long progress of time is the Salt-peter generated, which must be washed out with water, and by decoction be reduced into Stria’s or Crystals.
This generation of Salt-peter proceeds indeed slowly on, but yet it brings a great profit. For if once the Salt-peter be but generated in such an heap of Salt, and the reliques left after the washing out of the Peter be again put to the same heap, there will new Salt-peter be generated in process of time: so that new Salt-peter will every year offer it self to be washt out of the heap: and this work may be continued without end.