A third kind of cadmia is that found on the sides of the furnace, and which, in consequence of its weight, could not reach the arched vaults of the chimney. This species is called “placitis,”[1602] in reference to its solid appearance, it presenting a plane surface more like a solid crust than pumice, and mottled within. Its great use is, for the cure of itch-scab, and for making wounds cicatrize. Of this last there are two varieties, the “onychitis,” which is almost entirely blue on the exterior, and spotted like an onyx within; and the “ostracitis,”[1603] which is quite black and more dirty than the others, but particularly useful for healing wounds. All the species of cadmia are of the best quality from the furnaces of Cyprus. When used in medicine it is heated a second time upon a fire of pure charcoal, and when duly incinerated, is quenched in Aminean[1604] wine, if required for making plasters, but in vinegar, if wanted for the cure of itch-scab. Some persons first pound it, and then burn it in earthen pots; which done, they wash it in mortars and then dry it.
Nymphodorus[1605] recommends that the most heavy and dense pieces of mineral cadmia that can be procured, should be burnt upon hot coals and quenched in Chian wine; after which, it must be pounded and then sifted through a linen cloth. It is then pulverized in a mortar and macerated in rain water, the sediment being again pounded until it is reduced to the consistency of ceruse, and presents no grittiness to the teeth. Iollas[1606] recommends the same process; except that he selects the purest specimens of native cadmia.
CHAP. 23.—FIFTEEN REMEDIES DERIVED FROM CADMIA. TEN MEDICINAL EFFECTS OF CALCINED COPPER.
Cadmia[1607] acts as a desiccative, heals wounds, arrests discharges, acts detergently upon webs and foul incrustations of the eyes, removes eruptions, and produces, in fact, all the good effects which we shall have occasion to mention when speaking of lead. Copper too, itself, when calcined, is employed for all these purposes; in addition to which it is used for white spots and cicatrizations upon the eyes. Mixed with milk, it is curative also of ulcers upon the eyes; for which purpose, the people in Egypt make a kind of eye-salve by grinding it upon whet stones. Taken with honey, it acts as an emetic. For these purposes, Cyprian copper is calcined in unbaked earthen pots, with an equal quantity of sulphur; the apertures of the vessel being well luted, and it being left in the furnace until the vessel itself has become completely hardened. Some persons add salt, and others substitute alum[1608] for sulphur; others, again, add nothing, but merely sprinkle the copper with vinegar. When calcined, it is pounded in a mortar of Thebaic stone,[1609] after which it is washed with rain water, and then pounded with a large quantity of water, and left to settle. This process is repeated until the deposit has gained the appearance of minium;[1610] after which it is dried in the sun, and put by for keeping in a box made of copper.