for it. But in order that Mercury may be calcined, I have already said that this must be done in sharp aqua fortis, which must be abstracted by distillation, and the precipitation is made. But in order that Mercury may be reduced to cinnabar,[1] you must first of all mortify it, and liquefy it, with salt and yellow sulphur. Reduce it to a white powder, then put it in a cucurbite; place an aludel above, and sublimate with great fluxion, as is customary. Thus the cinnabar ascends into the aludel and adheres to it, as hard as hæmatite.
The mortification of lead, in order that it may be reduced to white lead, is two-fold, one for Medicine, the other for Alchemy. The preparation of cerussa for Medicine is as follows: Suspend plates of lead in an unglazed vessel over strong vinegar made from wine, the vessel being well closed so that no spirits may escape. Place the vessel in warm ashes, or, in winter, behind the fire. Then, after ten or fourteen days, you will find the very best cerussa adhering to the plates. Scrape this off with a hare's foot, and replace the plate over the vinegar until you have sufficient cerussa. The other preparation of cerussa for Alchemy is like the former, save that a quantity of the best sal ammoniac must be dissolved in the vinegar. In this way you will have a very beautiful cerussa, most subtle for purging tin or lead, or for removing whiteness from copper. But if we wish to make red lead out of the lead, it must first be calcined to ashes, and afterwards burnt laterally in a glazed jar, stirring it continually with an iron wire until it grows red. This minium is at once the best and the most valuable, and should be used in Medicine as well as in Alchemy. The other, which dealers sell in the shops, is of no use. It is made up only of the ashes which remain in the liquefaction of lead ore, and the potters buy it for encrusting vessels. Such minium is useful only for pictures, but neither for Medicine nor for Alchemy.
In order to reduce lead to a yellow colour a process is required not altogether unlike the preparation of minium. Here, too, the lead must be calcined with salt, and reduced to ashes. Afterwards it must be stirred continually with iron in one of the wide dishes used by those who test minerals, over a moderate coal fire, careful watch being kept lest the heat should be too great or the stirring neglected. Otherwise it would melt and produce yellow glass. In this way you will have excellent yellow lead.
The mortification of silver so that lazurium, or some similar substance, may be produced from it, is brought about as follows: Let Luna be made into plates, mixed with Mercury, and suspended in a glazed jar over the best vinegar in which auratæ have been previously boiled. Afterwards dissolve in it sal ammoniac and calcined tartar. In all other particulars proceed as directed in the case of cerussa. Then, after fourteen days, you will have the most precious and beautiful lazurium adhering to the silver plates, which you will wipe off with a hare's foot.
- ↑ The physicians of Montepessulano and Salerno committed the error of supposing that cinnabar was different from mercury, when it is clear that they are the same.—De Tumoribus, etc., Morbi Gallici Lib. I., c. 8. Cinnabar i extracted from Saturn and Mars by means of mercury.—Ibid., Lib. III., c. 7.
