(246 Dr. Daubeny on the Geology of Sicily. 
Should my inference appear hardly warranted by the 
above considerations, it will be borne out, at least, by the 
fact of the identity of this formation with the marl of Italy, 
described by Brocchi,* which that able geologist seems to 
to have good grounds for referring to the same recent period. 
The greater part of the country, at the foot of the Appenines, 
consists, it would appear, of a calcareous sandstone, and of a 
brown or bluish marl. The recent origin of the latter is 
evinced by the trunks of trees buried in it, and preserved 
nearly fresh, by the leaves of vegetables, and skeletons of 
fish, in which the dried muscular part may be recognised, 
and by the immense number of shells retaining all but their 
animal matters and colour, and sometimes even these. 
It contains, like the blue clay of Sicily, beds of sulphur, 
which is here of a liver colour, and which, according to our 
author, has been sublimed; thus giving rise to the produc- 
tion of the yellow variety, also seen in the marl of Italy, dis- 
tributed through the cavities of the rock. Like the blue clay 
of Girgenti, it gives rise to disengagements of inflammable 
gas, as near Modena.{ It contains mineral pitch, amber, 
sulphate of lime, both massive and crystallized, sulphate of 
strontian, and sulphate of barytes. Common salt abounds in 
the marl of Italy, as in that of Sicily, which is proved by the 
salt springs, 60 common in the vicinity of Cesena, Sienna, and 
Volterra. 
The description given by Brocchi, of the calcareo-arena- 
ceous breccia, which accompanies the marl of Italy, corres- 
ponds equally with what I have observed respecting that of 
Sicily, and strengthens the probability that the two formations 
are identical. 
I have now to describe a series of rocks, which occupy the 
southern portion of the island, extending from Cape Passero, 
(formerly Cape Pachynus,) to the Lake Lentini, where they 
are interrupted by a diluvial tract, termed the Piano di Ca- 
tania, but are seen again northward of that district, near 
* Vide Brocchi Conchologia Subappenina. 
+ These phenomena are called Salses, or Air-Volcanoes. Is it possi- 
ble that the inflammable gas of the Pietra Mala, between Florence and 
Bologna, may have originated from the same stratum, and have found 
its way through clefts in the older rocks, to the summit of the mountain, 
whence it escapes ° 
