Dr. Daubeny on the Geology of Sicily. 243 
application of proper tests, that they contain much muriate 
of soda, some sulphate of magnesia, and sulphate of soda. 
These Jatter salts were found also incrusting the sides of 
-vavines, and in other situations exposed to the contact of 
treams of water. The other minerals found in this forma- 
tion are not numerous; iron and copper pyrites are some- 
times met with, and, I believe, sulphate of barytes,.and alum. 
In a country, in short, so replete with sulphur, all the 
combinations of that mineral, or of the sulphurie acid with 
the different bases, are to be looked for; and most of them 
accordingly are found. 
It is, indeed, probable, that the formation of these pon 
salts, and the sublimation of the sulphur, are taking place in 
many parts of this formation, even at the present moment, for 
there are abundance of facts which show that a chemical ac- 
tion is going on among the inflammable materials which “it 
contains, giving rise to the production of heat, and to the 
disengagement of clastic vapours; to phenomena, in short, 
which ent some analogy to those of volcanoes, although 
exhibited on a much smaller scale, BODE 
It is not long since the proprietor of some land in the in- 
terior congratulated himself on his good fortune, in being able 
to collect a large supply of sulphar “Iready purified, by 
merely placing vessels to receive a stre’ 9 of that substance, 
which was constantly issuing from the: Je of a hill. This 
was occasioned a bed of: sulphar im the interior of the 
mountain having caught fire, and the heat generated by the 
combustion of one portion serving to melt the remainder: 
Nature having, in this instance, adopted the wasteful proces: 
employed from time immemorial by the Sicilians, for getting 
rid of the intermixed clay, which consists simply it collecting 
the materials in large heaps, and setting fire to them on the 
surface, thus causing the liquefaction of one portion by the 
combustion of another. 
