BOOK VII.

229

m\ *> vrws s rrm m ryrj + mlm

Wm.

mm

A —Scorifier. B —Triangular crucible. C—Cupel.

fat from the ashes, still the cupels which are made from such ashes are notvery good because they often contain charcoal dust, sand, and pebbles.Some make them in the same way out of any kind of ashes, but first of allpour water into the ashes and remove the scum which floats thereon ; then,after it has become clear, they pour away the water, and dry the ashes ; theythen sift them and make the cupels from them. These, indeed, are good,but not of the best quality, because ashes of this kind are also not devoid ofsmall pebbles and sand. To enable cupels of the best quality to be made, allthe impurities must be removed from the ashes. These impurities are oftwo kinds; the one sort light, to which class belong charcoal dust and fattymaterial and other things which float in water, the other sort heavy, suchas small stones, fine sand, and any other materials which settle in thebottom of a vessel. Therefore, first of all, water should be poured into theashes and the light impurities removed; then the ashes should bekneaded with the hands, so that they will become properly mixed withthe water. When the water has become muddy and turbid, it should bepoured into a second vessel. In this way the small stones and fine sand, orany other heavy substance which may be there, remain in the first vessel,and should be thrown away. When all the ashes have settled in this secondvessel, which will be shown if the water has become clear and does not tasteof the flavour of lye, the water should be thrown away, and the asheswhich have settled in the vessel should be dried in the sun or in a furnace.This material is suitable for the cupels, especially if it is the ash of beechwood or other wood which has a small annual growth ; those ashes madefrom twigs and limbs of vines, which have rapid annual growth, are not so