ARENA. 
193 
a fact now perfectly ascertained, it was not known to Pliny, that 
tbe obsidian stone itself is nothing- more than glass thrown up by a 
volcano ; notwithstanding that the exact resemblance between it 
and the manufactured glass had occasioned them, as he mentions, 
to be mistaken for each other ; and hence it continued to retain 
the names of XiQog o^iavog in Greek, and lapis obsidianus in Latin. 
The learned Salmasius has ridiculed Pliny for his description 
of the obsidian, and has attempted to prove that he was wrong 
in calling it obsidianus,'' or saying it was discovered by Obsi- 
dius in ^^thiopia ; but, with deference to such high authority, I 
still must think, that without better arguments than those he has 
given, Pliny is much more likely to be correct in his statement, 
especially as his description is now found to agree very accurately 
with the specimens of that very kind which is termed o^tocvog in 
the Periplus ; whereas the description of the stone by Salmasius 
is extremely inaccurate. Dr. Vincent was the first person 
who suspected that the opsian stone might be found near 
this point, but, owing to the extreme incorrectness of the charts 
previously to Lord Valentia's survey of the coast, he was unable 
to find any bay from Massowa to Beloul, answering to the one 
described in the Periplus. As I have since had the good 
fortune, to ascertain this point satisfactorily, I have done myself 
the pleasure of dedicating my chart of the Bay to Dr. Vincent, as 
a trilling testimony of friendship and of the obligation which I 
feel for the very candid manner in which he treated my former 
remarks respecting the Adulitic inscription.* 
* Vide " The Voyage of Nearchus, and the Periplus of the Erythrean Sea, translated 
from the Greek, by Dr. Vincent, p, 118, 119, Oxf. 1809." 
