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BOOK XI.
it forward and back, and by this means the water flows into the vacantspace in the copper, and he separates the cake from the rest of the mass.If the copper is not perfectly smelted the cakes will be too thick, and can-not be taken out of the crucible easily. Each cake is afterward seized bythe assistant with the tongs and plunged into the water in the tub; the firstone is placed aside so that the master may re-melt it again immediately, for,since some “ slags ” adhere to it, it is not as perfect as the subsequent ones ;indeed, if the copper is not of good quality, he places the first two cakes aside.Then, again pouring water over the wall and the pipes, he separates out thesecond cake, which the assistant likewise immerses in water and places onthe ground together with the others separated out in the same way, whichhe piles upon them. These, if the copper was of good quality, should bethirteen or more in number; if it was not of good quality, then fewer. If thecopper was of good quality, this part of the operation, which indeed is dis-tributed into four parts, is accomplished by the master in two hours ; if ofmediocre quality, in two and a half hours ; if of bad quality, in three. The“ dried ” cakes are re-melted, first in the first crucible and then in thesecond. The assistant must, as quickly as possible, quench all the cakeswith water, after they have been cut out of the second crucible. Afterwardwith the tongs he replaces in its proper place the iron plate which was in frontof the furnace, and throws the charcoal back into the crucible with a shovel.Meanwhile the master, continuing his work, removes the wooden stick fromthe bars of the bellows, so that in re-melting the other cakes he may accom-plish the third part of his process ; this must be carefully done, for if a particlefrom any iron implement should by chance fall into the crucible, or shouldbe thrown in by any malevolent person, the copper could not be made untilthe iron had been consumed, and therefore double labour would have to beexpended upon it. Finally, the assistant extinguishes all the glowing coals,and chips off the dry lute from the mouth of the copper pipe with a hammer;one end of this hammer is pointed, the other round, and it has a wooden handlefive feet long. Because there is danger that the copper would be scattered ifthe pompholyx and spodos, which adhere to the walls and the hood erectedupon them, should fall into the crucible, he cleans them off in the meantime.Every weeklhe takes the copper flowers out of the tub, after having poured offthe water, for these fall into it from the cakes when they are quenched . 26
^Pompholyx and spodos were impure zinc oxides (see note 26, p. 394).
The copper flowers were no doubt cupric oxide. They were used by the Ancients formedicinal purposes. Dioscorides (v, 48) says : “ Of flowers of copper, which some call the“ scrapings of old nails, the best is friable ; it is gold-coloured when rubbed, is like millet in“ shape and size, is moderately bright, and somewhat astringent. It should not be mixed“ with copper filings, with which it is often adulterated. But this deception is easily detected," for when bitten in the teeth the filings are malleable. It (the flowers) is made when the“ copper fused in a furnace has run into the receptacle through the spout pertaining to it,“ for then the workmen engaged in this trade cleanse it from dirt and pour clear water over it“ in order to cool it; from this sudden condensation the copper spits and throws out the“ aforesaid flowers.” Pliny (xxxiv, 24) says : “ The flower, too, of copper (arts flos) is
” used in medicine. This is made by fusing copper, and then removing it to another furnace,“ where the repeated blast makes the metal separate into small scales like millet, known as“ flowers. These scales also fall off when the cakes of metal are cooled in water ; they become“ red, too, like the scales of copper known as ‘ lepis,’ by use of which the flowers of copper are“ adulterated, it being also sold for it. These are made when hammering the nails that are