47. But this operation ought not to be done in Crucibles made of common Earth, which easily break and spill the metal, but in those that are made of a fat crucible Clay, mix’d with coal dust, as is taught in the fifth part of my Furnaces.
48. As the Sulphur in Tartar coagulates a thin water into a hard Hepar, or Liver so called, so likewise doth a fixt Sulphur coagulate Mercury into Sol and Luna.
49. The often calcining of Salts and dissolving them in Water, doth purifie them, and makes them easily fluxible, and in particular Vitriol may by this means be so purified, as to yield its Oil with a very small heat.
50. The Solution of Saturn and Lune poured into a volatile Spirit of Mars or Venus, draws the tinging volatile Sulphur out of the Water to it self, and makes the same Corporal and fixed.
51. Tartar contains a coagulating and tinging Sulphur, for it coagulates Water into a Hepar, and tinges red metals to a white Stone, which may be pulverized; this Sulphur is the cause why Tartar will not dissolve in cold Water as other Salts.
52. When therefore the Tartar is freed of this Sulphur that coagulates all Water, then much good may be done therewith as well in Physick as Alchimy, and many other Arts besides.
53. Tartar by being boiled in a strong Lye, lets go its coagulating Sulphur, and a neutral Salt proceeds from them both; but if we have a mind to separate the Lye from the purified Tartar we must do it with an acid, that may mortifie the Lye, by which means the purified Tartar will be left snow white.
54. If the Lye be kill’d with a Spirit of Niter or Aqua Fortis, then from both these contraries proceeds a good Niter.
55. But if we make use of a Spirit of Salt, then there is made up of both a tartarized Spirit of Salt.
56. If we take distill’d Vinegar to mortifie the Lye, then from the joyning of those both proceeds a neutral volatile Salt which is a good Diuretick in the Gout and Stone.