50	DE NATURA FOSSILIUM
	Regarding the form of these minerals, sory, chalcilis, misy, and melan-teria usually occur as rounded masses. Sory may have many openings and this is a characteristic of the mineral. Misy, when it occurs as an efflor­escence on another mineral, may have the form of dust, otherwise it oc­curs as rounded masses. Only melanteria occurs like plant down or "foam" of salt. Dioscorides described such a mineral as hanging from the veins in copper mines. However, it should be understood that this mineral does not form in all copper mines but only in those in which pyrite occurs. Native atramentum sutorium occurs in the form of hairs or feathers, in icicles or in rounded forms. The artificial mineral forms in groups of small crystals that resemble cubes and grow together like grapes. When the sub-unctuous mineral is dried over a fire it swells into bubbles in the same manner as nitrum and alum. When it is not sub-unctuous it merely dries out. Each of these minerals is more easily pulverized after heating. All five minerals are soluble in water although the hard sub-unctuous varieties are more slowly soluble than the soft and meager. Atramentum sutorium, having been dissolved in water, is used widely to dye hides and wool black. Dyers also color cloth with madder root in order to darken the natural color of the cloth and then, to make it liver-colored, boil it again in water in which atramentum sutorium has been dissolved. A solu­tion of atramentum sutorium may be used to dye the hair and beard black and sometimes solutions of sory and melanteria are used for the same pur­pose. In all cases dried atramentum sutorium is best. For medicinal pur­poses the natural, blue, heavy, dense and transparent mineral is best wxhile that which is properly called "congealed" is next best. The blue mineral is the most astringent and will heat the body the most. It will check profuse bleeding when sprinkled on a severed vein. It expels pus from ulcers and dries excrement. When a dram is taken internally mixed with honey and water, wine, or especially olive oil it acts as an emetic. When used in eye salves preference is given to the white transparent vari­ety.19 Although sory, chalcitis, melanteria and misy are less astringent