BOOK V. Ill 



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 Melnllicis) was the 

 metallic form. Agricola, who was familiar witli all Albcrtus'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 arrhcnicum, 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 auripigmenlitm faclicum, and no doubt 

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

 Agricola were : — 



Operment . . Orpiment (As2 S3 ) . . Orpiment 



Rosgeel . . Realgar (As S) . . Realgar 



Arsenik .. Artificial arsenical oxide White arsenic 



Auripigmentum 

 Sandaraca 

 Arsenicum 



Lapis subrulilus aique 

 . splendens 



Mistpuckel 



*Mispickel 



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 (xxxm, 22, etc.) ; and Strabo (xii, 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 auripigmentum, 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 

 Galenae gettus tertium 



omnis metalli 



inanissimi 

 Schislos 



Ferri vena jecoris 



colore 

 Ferrugo 

 Magnes 



Ochra nativa . . 



Gedigen eisen. 

 Eisen erlz 

 Eisen ertz 



Haematites . . 



Sckisios 

 Pyrites 

 Pyrites argenti coloris 



Misy .. 



Sory . . 



Eisen glantz . . 

 Glaskopfe oder 

 bliitstein 



Leber ertz 

 Rilst . . 

 Siegelstein oder 



magnet 

 Berg geel 



BlUt stein 



Glas kopfe 

 Kis 

 wasser oder 



weisser kis . . 

 Gel atrameni . . 



Native iron 



Various soft and hard 

 iron ores, probably 

 mostly hematite . . 



♦Native iron 



Ironstone 



Part limonite 



Magnetite 

 Limonite 



Part hematite 

 Part jasper 

 Part limonite . . 

 Pyrites 



Marcasite 

 Part copiapite 



Graw und Partly a decomposed 



Schwartz atrament iron pyrite . . 



Melanteria . . . . Schwartz und Melanterite (native 



grau atrameni vitriol) 



The classification of iron ores on the basis of exterior characteristics, 



Iron rust 



Lodestone 

 Yellow ochre or 



ironstone 

 Bloodstone or 



ironstone 

 Ironstone 

 Pyrites 



*White iron pjn-ites 

 Misy (see note on 



P- 373) 

 Sory (see note on 



P- 573) 

 Melanteria (see 

 note on p. 573) 

 chiefly hardness and 



