400 cosmos. 



Diodorus Siculus, likewise (lib. iv., cap. 21,5), who lived 

 under Cassar and Augustus, in his account of the progress of 

 Hercules and his battles with the giants in the Phlegreean 

 Fields, describes "what is now called Vesuvius as a kocfrog, 

 which, like .ZEtna in Sicily, once emitted a great deal of fire, 

 and (still) shows traces of its former ignition." He calls the 

 whole space between Cumse and Naples the Phlegrrean Fields, 

 as Polybius does the still greater space between Capua and 

 Kola (lib. ii., cap. 17); while Strabo (lib. v., page 246) de- 

 scribes with much local truth the neighborhood of Puteoli 

 (Dicaearchia), where the great solfatara lies, and calls it 

 'Hpalorov dyopd. In later times the name of rd tyXeypala 

 Tisdla is ordinarily confined to this district, as at this day 

 geologists place the mineralogical composition of the lavas 

 of the Phlegrasan Fields in opposition to those from the 

 neighborhood of Vesuvius. The same opinion that in an- 

 cient times there was fire burning within Vesuvius, and that 

 that mountain had formerly had eruptions, is most distinctly 

 expressed in the architectural work of Vitruvius (lib. ii., cap. 

 6), in a passage which has hitherto not been sufficiently re- 

 garded : "Non minus etiam memoratur, antiquitus crevisse 

 ardores et abundavisse sub Vesuvio monte, et inde evomuisse 

 circa agros flammam. Ideoque nunc qui spongia sixe jmmex 

 Pompejanus vocatur, excoctus ex alio genere lapidis, in hanc 

 redactus esse videtur generis qualitatem. Id autem genus 

 spongiag, quod inde eximitur, non in omnibus locis nascitur, 

 nisi circum iEtnain, et collibus Mysiae, qui a Graecis Karaice- 

 Kavfievoi nominantur." (It is also related that in ancient 

 times the fire increased and abounded beneath Mount Vesu- 

 vius, and vomited out flame from thence on the fields around. 

 So that now what is called spongia, or Pompeian pumex, 

 baked out of some other kind of stone, seems to have been 

 reduced to this kind of substance. But that kind of spongia 

 which is got out of there is not produced in all places, only 

 around ^Etna and on the hills of Mysia, which are called by 

 the Greeks fcara'cefcavfievoL.) Now it can no longer be 

 doubted, since the investigations of Bockh and Hirt, that 



servile war of Spartacus took place in the 681st year of Rome, or 152 

 years before the eruption of Vesuvius described by Pliny (24th of 

 August, 79 A. D.). The circumstance that Florus, a writer who lived in 

 the time of Trajan, and who, being acquainted with the eruption just 

 referred to, knew what was hidden in the interior of the mountain, 

 calls it " cavus," proves nothing, as others have already observed, for 

 its earlier configuration {Florus, lib.i., cap. 16, "Vesuvius mons, iEtnar 

 ignis imitator;" lib. iii., cap. 20, " faucescavi montis"). 



