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BOOK IX.

covered with lids a digit thick, and they are smeared over on the inside withliquid litharge, and on the lid are placed heavy stones. The pots are set onthe furnace, and the ore is heated and similarly exhales quicksilver, whichfleeing from the heat takes refuge in the lid ; on congealing there, it fallsback into the ashes, from which, when washed, the quicksilver is collected.

A— Pots. B— Lids. C —Stones. D —Furnace.

By these five methods quicksilver may be made, and of these not one isto be despised or repudiated ; nevertheless, if the mine supplies a greatabundance of ore, the first is the most expeditious and practical, because alarge quantity of ore can be reduced at the same time without great expense.

88 Historical Note on the Metallurgy of Quicksilver. The earliest mention ofquicksilver appears to have been by Aristotle (Meteorologica IV, 8, 11), who speaks of itas fluid silver (argyros chytos). Theophrastus (105) states : “ Such is the production of

“ quicksilver, which has its uses. This is obtained from cinnabar rubbed with vinegar in a“ brass mortar with a brass pestle.” (Hill’s Trans., p. 139). Theophrastus also (103)mentions cinnabar from Spain and elsewhere. Dioscorides (v, 70) appears to be the first todescribe the recovery of quicksilver by distillation : “ Quicksilver ( hydrargyros, i.e., liq ul 4silver) is made from ammion, which is called cinnabari. An iron bowl containing cinnabaw“ is put into an earthen vessel and covered over with a cup-shaped lid smeared with clay-“ Then it is set on a fire of coals and the soot which sticks to the cover when wiped off and“ cooled is quicksilver. Quicksilver is also found in drops falling from the walls of the silver“ mines. Some say there are quicksilver mines. It can be kept only in vessels of glass, lea >“ tin (?), or silver, for if put in vessels of any other substances it consumes them and flow