Alchemiae Gebri Arabis philosophi solertissimi, libri, cum reliquis, ut versa pagella indicabit

Purification of other alums.

More alums are still found, all of which are prepared and purified as those already mentioned.

Purification of vitriols.

First, concerning black vitriol likely ferrous sulphate. Black vitriol is purified thus: First, let it be dissolved in clean vinegar, afterwards let it be distilled, and coagulated. Or let it be placed first in an alembic, and all the moisture be extracted. Let the dregs remaining in this distillation be calcined upon porphyry, or dissolved in their own water, and coagulated. Or let the water itself be reserved according to the wish of the artist.

Purification of copperas.

Copperas, or vitriol, is purified like black vitriol. Black vitriol, however, has greater earthiness than green vitriol.

Purification of other vitriols.

There are diverse vitriols, and they are found of diverse colors, which are purified as the aforementioned.

On glass, and boraxes.

Glass and boraxes, if they have been made in due mode, do not need preparation.

Purification of the sharpest vinegar.

Vinegar, and any kind of sharp or acerbic liquid, are subtiliated and depurated, and their virtue or effect is improved through distillation. We have treated sufficiently of their purification and depuration, with which imperfect bodies can be prepared, depurated, improved, and subtiliated, always by means of due fire.