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110 appearance of having been melted in a furnace, and if it is not lacking in scales resembling mica. The solidified juices, azure, chrysocolla, orpiment, and realgar, also frequently contain gold. Likewise native or rudis gold is found sometimes in large, and sometimes in small quantities in quartz, Blue and green copper minerals were distinguished by all the ancient mineralogists. Theophrastus, Dioscorides, Pliny, etc., all give sufficient detail to identify their cyanus and caeruleum partly with modern azurite, and their chrysocolla partly with the modern mineral of the same name. However, these terms were also used for vegetable pigments, as well as for the pigments made from the minerals. The Greek origin of chrysocolla (chrusos, gold and kolla, solder) may be blamed with another and distinct line of confusion, in that this term has been applied to soldering materials, from Greek down to modern times, some of the ancient mineralogists even asserting that the copper mineral chrysocolla was used for this purpose. Agricola uses chrysocolla for borax, but is careful to state in every case (see note xx., p. ): "Chrysocolla made from nitrum," or "Chrysocolla which the Moors call ." Dioscorides and Pliny mention substances which were evidently copper sulphides, but no description occurs prior to Agricola that permits a hazard as to different species.

. So far as we can determine, all of these except the first three were believed by Agricola to be artificial products. Of the first three, galena is certain enough, but while he obviously was familiar with the alteration lead products, his descriptions are inadequate and much confused with the artificial oxides. Great confusion arises in the ancient mineralogies over the terms molybdaena, plumbago, plumbum, galena, and spuma argenti, all of which, from Roman mineralogists down to a century after Agricola, were used for lead in some form. Further discussion of such confusion will be found in note 37, p. 476. Agricola in Bermannus and De Natura Fossilium, devotes pages to endeavouring to reconcile the ancient usages of these terms, and all the confusion existing in Agricola's time was thrice confounded when the names molybdaena and plumbago were assigned to non-lead minerals. . Agricola knew only one tin mineral: Lapilli nigri ex quibus conflatur plumbum candidum, i.e., "Little black stones from which tin is smelted," and he gives the German equivalent as zwitter, "tinstone." He describes them as being of different colours, but probably due to external causes. . (Interpretatio,—spiesglas.) The stibi or stibium of Agricola was no doubt the sulphide, and he follows Dioscorides in dividing it into male and female species. This distinction, however, is impossible to apply from the inadequate descriptions given. The mineral and metal known to Agricola and his predecessors was almost always the sulphide, and we have not felt justified in using the term antimony alone, as that implies the refined product, therefore, we have adopted either the Latin term or the old English term "grey antimony." The smelted antimony of commerce sold under the latter term was the sulphide. For further notes see p.. *. Plumbum cinereum (Interpretatio,—bismut). Agricola states that this mineral occasionally occurs native, "but more often as a mineral of another colour" (De Nat. Fos., p. 337), and he also describes its commonest form as black or grey. This, considering his localities, would indicate the sulphide, although he assigns no special name to it. Although bismuth is mentioned before Agricola in the Nützliche Bergbüchlin, he was the first to describe it (see p. 433). . Apart from native quicksilver, Agricola adequately describes cinnabar only. The term used by him for the mineral is minium nativum (Interpretatio,—bergzinober or cinnabaris). He makes the curious statement (De Nat. Fos. p. 335) that rudis quicksilver also occurs liver-coloured and blackish,—probably gangue colours. (See p. 432).