156 
Some are of opinion that the hard bitumen spoken of by Xeno- 
crates, and the substance described by Theophrastus, as found in 
the silver mines of Scaptesyla, and which I have already referred 
to Bovey Coal, was jet. Strabo* speaks of jet, found in Mesopo- 
tamia, as possessing the power of driving away serpents. It is 
evidently the same substance as was described by Nicander, as the 
Thracian stone ; and which was named by Dioscorides, gagas or 
gangas, from its being found near the city of Ganges. Pliny, who 
in speaking of jet, in another place f, confounds it with getites, 
owing to both these kinds of stones being found in the nests of 
eagles, says that it derives its name from the river Gagis in Lycia, 
and that it is thrown up by the waves in Leucola. It is, he says,' 
smooth, brittle, light, and porous, not differing much in appearance 
from wood, and yielding a strong odour when rubbed. It also appears 
to be this substance to which Pliny refers J, when he says, the 
island of Samothracia yields a black and light gem, resembling 
wood, which, deriving its name from that of the place, was called 
the Samothracian gem. Agricola§ informs us of many places in 
which it is found, and is of opinion that Pliny meant this substance 
when speaking of the obsidian stone. But the description of Pliny, 
which is indeed most applicable to the obsidian of the present 
day, can never be admitted to apply to jet. The words of Pliny |1 
are, “In genere vitri et obsidiana numerantur, ad similitudinem 
lapidis, quern in ^Ethiopia invenit Obsidius, nigerrimi colons, ali- 
quando et translucidi, crassiore visu, atque in speculis parietum 
pro imagine umbras reddente. Gemmas multi ex eo faciunt : 
vidimusque et solidas imagines divi Augusti, capti materia hujus 
crassitudinis : dicavitque ipse pro miraculo in templo Concordise 
obsidianos quatuor elephantos.” 
* Strabon. Geogr. lib. xvi. f Lib. x. c. 3. ^ Lib. xxxvii. c. 10. 
§ Lib. xxxvi. c. 19. || Lib. xxxvi. c. 26. 
