BOOK V. 



in 



schist, marble, and also in stone which easily melts in fire of the second 

 degree, and which is sometimes so porous that it seems completely decom- 

 posed. Lastly, gold is found in pyrites, though rarely in large quantities. 

 When considering silver ores other than native silver, those ores are 



ARSENICAL MINERALS. Metallic arsenic was unknown, although it has been main- 

 tained that a substance mentioned by Albertus Magnus (De Rebus Metallicis) was the 

 metallic form. Agricola, who was familiar with all Albertus's writings, makes no mention 

 of it, and it appears to us that the statement of Albertus referred only to the oxide from 

 sublimation. Our word " arsenic " obviously takes root in the Greek for orpiment, which 

 was also used by Pliny (xxxiv, 56) as arrhenicum, and later was modified to arsenicum 

 by the Alchemists, who applied it to the oxide. Agricola gives the following in Bermannus (p. 

 448), who has been previously discussing realgar and orpiment : " Ancon : Avicenna 

 " also has a white variety. Bermannus : I cannot at all believe in a mineral of a white 

 " colour ; perhaps he was thinking of an artificial product ; there are two which the Alchemists 

 " make, one yellow and the other white, and they are accounted the most powerful poisons 

 " to-day, and are called only by the name arsenicum." In De Natura Fossilium (p. 219) is 

 described the making of " the white variety " by sublimating orpiment, and also it is noted 

 that realgar can be made from orpiment by heating the latter for five hours in a sealed 

 crucible. In De Re Metallica (Book X.), he refers to auripigmentum facticum, and no doubt 

 means the realgar made from orpiment. The four minerals of arsenic base mentioned by 

 Agricola were : 



Operment . . Orpiment (As? 83 ) . . Orpiment 



Rosgeel . . Realgar (As S) . . Realgar 



Arsenih Artificial arsenical oxide White arsenic 



A uripigmentum 

 Sandaraca 

 Arsenicum 



Lapis subrutilus atque 

 . . splendens 



*Mispickel 



Mistpuckel . . Arsenopyrite (Fe As S) 



We are somewhat uncertain as to the identification of the last. The yellow and red sul- 

 phides, however, were well known to the Ancients, and are described by Aristotle, Theophrastus 

 (71 and 89), Dioscorides (v, 81), Pliny (xxxni, 22, etc.) ; and Strabo (xn, 3, 40) mentions 

 a mine of them near Pompeiopolis, where, because of its poisonous character none but slaves 

 were employed. The Ancients believed that the yellow sulphide contained gold hence 

 the name aunpigmentum, and Pliny describes the attempt of the Emperor Caligula to extract 

 the gold from it, and states that he did obtain a small amount, but unprofitably. So late 

 a mineralogist as Hill (1750) held this view, which seemed to be general. Both realgar and 

 orpiment were important for pigments, medicinal purposes, and poisons among the Ancients. 

 In addition to the above, some arsenic-cobalt minerals are included under cadmia. 



IRON MINERALS. 

 Ferrum purum 

 Terra ferria 

 Ferri vena 



Galenas genus tertium 

 omnis metalli 



Gedigen eistn . . 

 Eisen ertz 

 Eisen ertz 



Native iron 



*Native iron 



mamssimt 

 Schistos 



Ferri vena jecoris 



colore 

 Ferrugo 

 Magnes 



Ochra nativa . . 



Haematites 



Schistos 



Pyrites 



Pyrites argenti coloris 



Misy .. 



Sory .. 



Melanteria 



The classification of iron 



Eisen glantz . . 

 Glaskcipfe oder 

 bliitstein 



Leber ertz 

 Rust . . 

 Siegelstein 

 magnet 

 Berg geel 



Bliit stein 



Glas kopfe 

 Kis 



wasser oder 

 weisser kis 

 Gel atrament 



oder 



Various soft and hard 

 iron ores, probably 

 mostly hematite . . 



Part limonite 



Magnetite 

 Limonite 



Part hematite 

 Part jasper 

 Part limonite . 

 Pyrites 



Marcasite 

 Part copiapite 



Graw und Partly a decomposed 



Schwartz atrament iron pyrite 

 Schwartz und Melanterite (native 



grau atrament vitriol) 



ores on the basis of exterior characteristics, 



Ironstone 



Iron rust 



Lodestone 

 Yellow ochre or 



ironstone 

 Bloodstone or 



ironstone 

 Ironstone 

 Pyrites 



*White iron pyrites 

 Misy (see note on 



P- 573) 

 Sory (see note on 



P- 573) 

 Melanteria (see 



note on p. 573) 

 chiefly hardness and 



