252 Dr. Daubeny on the Geology of Sueily. 
Amongst the other rocks on the same coast, that of Cas- 
tello d’Aci would appear to be submarine, or at least, of 
subaqueous origin. It consists of a volcanic breccia, the ce- 
menting substance of a sandy nature; the nodules a cellular 
kind of lava. The nodules, however, are not rounded mass- 
es, but result from a sort of irregular cystallization, most of 
them possessing a radiated structure, so that they resemble a 
clusture of prisms meeting in a common centre. The above 
stellular arrangement is the most common, but in other cases 
the prisms have more of a fan-shaped structure ; and in both 
instances, the point towards which they converge, as well as 
the interstices between them, consists of tuff. 
It seems probable, indeed, from many circumstances, that 
the eruptions of mount Etna commenced at an era not only 
antecedent to the time of Homer, but even perhaps to the 
» commencement of the present order of things. If the exist- 
ence of pebbles and other rolled masses, establish the opera- 
tion of a deluge, we have, in the gravel at the foot of Etna, 
abundant evidence of antediluvian eruptions, for both cellular 
and compact lavas are found among these deposits. Nor 
would it be difficult to point out, on the slope of Etna, espe- 
cially on its north-east side, valleys which, from their size and 
figure, seem referable rather to diluvial action, than to the 
effect of torrents. 
Perhaps the beds of lava at Aci Reale, to which Mr. Bry- 
done refers in his entertaining Travels in Sicily,* where he 
% The following is the passage to which I refer. 
“Near to a vault, which is now thirty feet below ground, and has 
probably been a burial place, there is a draw-well, where there are 
several strata of lavas, with earth to a considerable thickness over the 
surface of each stratum. Recupero has made use of this as an argu- 
ment to prove the great antiquity of the eruptions of this mountain. 
For if it requires two thousand years, or upwards, to form but a scanty 
soil on the surface of a lava, there must have been more than that space | 
of time betwixt each of the eruptions which have formed these strata. 
But what shall we say of a pit they sunk, near to Jaci, of a great depth. 
They pierced through seven distinct lavas, one under the other, the 
surfaces of which were parallel, and most of them covered with ja 
thick bed of rich earth. Now, says he, the eruption which formed the 
lowest of these lavas, if we may be allowed to reasou from analogy, 
must have flowed from the mountain at least 14,000 years ago. Recu- 
pero tells me he is exceedingly embarrassed, by these discoveries, in 
writing the history of the mountain; that Moses hangs like a dead 
weight upon him, and blunts all his zeal for inquiry, for he really has not 
