Let plates of Copper bee dipt in spirit of Salt, or Salt-Petre, and let them bee hanged in the Aire until they begin to be green, which indeed wil quickly be, wash off this greennesse with cleer fountaine-water, dry the plates with some cloath, and wet them again with the spirit of Salt, and Salt Nitre, and do again as before, so long until the water bee apparently green, or much Vitriall swim on the top: then poure away the water, or evaporate it, and thou hast a most excellent Vitriall for medicine. In Alchymie there is not a fairer, more excellent, and better Vitriall then what is made by Aqua fortis, or Aqua regis, or spirit of Salt Armoniacke. And the processe is this.
Let plates of Copper be melted with one of the aforesaid waters, & as soon as the greeness is extracted, and the plates dryed, let the greeness be taken off with the foot of a Hare, or some other way as you please, as Ceruse is taken off from the plates of Lead: let them bee again wetted as before, until the plates bee wholly consumed, thereby is made a most glorious Vitriall, that thou canst not choose but wonder at it.
How water of Salt-petre and Salt-armoniack is made.
The water of Salt Petre is made thus. Purifie, and powder it; afterwards dissolve it of it selfe in a bladder, put in boyling water. So thou shalt have the water of Salt Petre.
The water of Salt Armoniacke is made thus: Calcine Salt Armoniack, and dissolve it in a Cellar upon a Marble, and this is water of Salt Armoniack.
Verdegrease may be made two wayes.
But to make Verdegrease out of Copper, there are divers wayes which it is not needful here to recite. Wee shall describe only two, but with a double preparation, viz. The one for Physicke, the other for Alchymie. The processe therefore of Verdegrease to be used in Physick is this.
How verdegrease to be used in physick is to be prepared.
Take plates of Copper, which wet over with the following matter. Take Honey, and Vineger, of each a like quantity, of Salt as much as wil serve to make them up into a thick past. Mixe them well together, then put them into a reverberatory, or Potters furnace so long as the Potter is burning his pots, and thou shalt see the matter that stickes to the plates to bee very black, but let not that trouble thee. For if thou settest those plates in the Aire, all the black matter wil in a few days become green, and become a most excellent Verdegrease, The Balsom of Copper.which may bee called the Balsome of Copper, and is commended by all Physitians. But neverthelesse do not thou wonder that this Verdegrease becomes green in the Aire, and that the Aire can change the black colour into so fair a green.
Aire changeth the Colours of things burnt.