252 
LETTERS FROM 
lichens, and afterwards of larger plants, 
which take root on its surface. The process 
is always very slow, but some lavas are de¬ 
composed in a much shorter time than 
others. We are informed by a Sicilian 
writer, that a torrent, which Diodorus men¬ 
tions as having been thrown out nearly two 
thousand years ago, is still only partially de¬ 
composed, and it is certain that in a very 
much shorter time than this the lava of some 
eruptions has been converted into a fruitful 
soil. 
We stopped a short time at the town of 
Aci Reale. Many of the people here ap¬ 
peared to be in a deplorable state of poverty, 
and our carriage was surrounded by a com¬ 
pany of half-starved, and more than half- 
naked children, forming a most affecting 
picture of utter destitution and misery. 
Our road continued over the lava till 
