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Book III about halite and nitrium, alum and acrid juices and related minerals, sulphur, bitumen, realgar, and orpiment; the fourth, chrysocolla, aerugo, caeruleum, ferrugo

Book III about halite and nitrium, alum and acrid juices and related minerals, sulphur, bitumen, realgar, and orpiment; the fourth, chrysocolla, aerugo, caeruleum, ferrugo Page of 251 Book III about halite and nitrium, alum and acrid juices and related minerals, sulphur, bitumen, realgar, and orpiment; the fourth, chrysocolla, aerugo, caeruleum, ferrugo Text size:minus plus Restore normal size   Mail page  Print this page
BOOK III
43
cial nitrum is made, even today, from the natural mineral and this is called tincar by the Arabs. I call this material by the Greek name chrysocolla, which it actually is, or by the Arabic name borax.,8 A third form of this mineral is made from burnt oak or hard wood and I shall explain the process of making it in the book De Re Metallica.
One nitrum will differ from another in color. That from Chalastra is white; aphronitrum looks more like foam than "nitrum foam." Dioscorides discusses a red nitrum in conjuction with the white. Aphronitrum may be purplish white. The inferior variety from Egypt is dark colored. Con­cerning transparency, native nitrum from which they make chrysocolla is transparent. The taste is variable. The Egyptian material is bitter and the "foam" quite bitter. Some native nitrum is so weakly bitter that the senses cannot detect it, for example, the material used in making chry­socolla. The word halmirhaga signifies a salty taste and this is detected by the tongue. Chalastraeum has a salty bitter taste. Nitrum has no odor but when it is burnt an odor can be detected but when it is adulterated with lime it gives off a strong odor.
Some nitrum is incoherent and pulverent, for example, "flowers of nitrum," foam-like aphronitrum, and halmirhaga. Some, although compact and dense, is soft and can be crushed with ease, for example, the best variety from Egypt and chrysocolla. Some is hard and dense and na­tive aphronitrum is similar to stone. The Egyptian mineral that has been allowed to stand in the open in large mounds is hard as a rock and this material is called βουνό·* by the Greeks because they look like hills. All the pulverent, fragile material is loose-textured and light, for example, halmirhaga and "nitrum foam." Some is compact such as aphronitrum and chrysocolla while some is dense and heavy such as certain varieties of the native mineral.
Nitrum varies most in form. The native mineral occurs in formless lumps and icicles. The aphronitrum of Lydia occurs in the form of lozenges. Artificial chrysocolla forms in rectangular crystals with pyramidal ter­minations. The Egyptain material is sometimes porous, sometimes spongy. Nitrum neither decrepitates nor flies out of a fire although the native mineral swells up and intumesces. Artificial nitrum and chrysocolla are soluble in water, the hard and dense varieties being slowly soluble. Nitrum, because it removes dirt, is used by fullers in solutions to clean spots from cloth and dyers treat wool with a similar solution so that it will take the dye evenly. Ancient peoples were accustomed to wash them­selves in the public baths in water containing aphronitrum so that they would be clean and healthy. Pliny states that the very fine sand of the Nile which contained nitrum was used for whitening the bodies of wres­tlers from Patrobius who had been freed by Nero. He also writes that dyers used an impure variety. Actually dyers who have no nitrum use the
8 Borax is a French word derived from the Arabic buraq.
Book III about halite and nitrium, alum and acrid juices and related minerals, sulphur, bitumen, realgar, and orpiment; the fourth, chrysocolla, aerugo, caeruleum, ferrugo Page of 251 Book III about halite and nitrium, alum and acrid juices and related minerals, sulphur, bitumen, realgar, and orpiment; the fourth, chrysocolla, aerugo, caeruleum, ferrugo
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