369 
Count Stolberg informs us, that immediately beneath the ancient 
city wall of Posidonia, Poestum, or Pesto, a rivulet runs, which has a 
petrifying quality, that was remarked as early as Strabo. Its banks 
are reedy, and some little hollow pillars bear evident marks of being 
themselves petrified reeds*. 
The waters of the Solfatara, or Lago di Bagni, abound with 
calcareous earth in solution. Cardinal D’Este had a canal dug, by 
which the waters of this lake should be carried into the Anio, to 
prevent their overflowing ; but it is remarked by Breislakf , that 
the calcareous deposition is so abundant, that if they did not clean 
it every three years, it would be closed up, notwithstanding its 
width and depth. Its waters, like those already mentioned, cover 
with a calcareous crust the rushes, and other bodies, it finds in its 
course. When the calcareous crust, thus formed, is only a congeries 
of fistuloe, or pipes, possessing but little substance, the name of 
syringites has been applied to them ; but when they are of a thicker 
substance, and have their openings almost closed, they are sometimes 
named osteocollcB. 
It appears to have been, by the formation of a curious species of 
incrustation, in this manner, that nature pointed out to art the ap- 
plication of this property of these waters. This species of incrus- 
tation, represented Plate III. Fig. 2, is termed Lapis Sarnius ; it is 
formed of a tufaceous incrustation of very small twigs, leaves, &c. 
but bearing on its surface most correct impressions of the leaves on 
which it had been formed. These stones have been termed Samian, 
from a river in Campania, (Terra di Lavoro), of which the poet thus 
speaks : 
* Travels through Germany, Switzerland, Italy, and Sicily, by Frederic Leopold, Count 
Stolberg, vol. ii. p. 112. 
f Voyages Physiques et Lythologiques dans la Catnpanie, par Scipion Breislak, tom. ii. 
p. 262. 
VOL. I. 3 B 
