iv Count de Gioeni’s Account of 
of violent heat * * * § , cannot be otherwife compofed than in a vol* 
cano -f. 
As to their dreaded effects on animals and vegetables, every 
one knows the advantageous ufe, in medicine, both of the one 
and the other, and this in the fame form as they are thus pre- 
pared in the great laboratory of nature. 
Vegetables, even in flower, do not appear in the leaf mace- 
rated, which has formerly happened from only Ihowers of 
find j. 
How 7 this volcanic production came to be mixed with water 
may be conceived in various ways. 
Etna, about its middle regions, is generally furrounded with 
clouds that do not always rife above its l'ummit, which is 
2900 paces § above the level of the fea. This matter being 
thrown out, and delcending upon the clouds below it, may 
happen to mix and fall in rain with them in the ufual way. 
It may alio be conjedtured, that the thick fmoke which the 
volcanic matter contained might, by its rarefaction, be car- 
ried in the atmoiphere by the winds, over that tradt of 
country || ; and then, cooling fo as to condenfe and become 
fpecifically 
* The burning of lime-ftone may indeed produce the compofitiou from whence 
refults the calcareous fait : but it is evident, that l'uch a quantity could only pro- 
ceed from a volcano. 
f Many and repeated experiments on the produce of Etna have perfuaded me, 
that marine lalt is one of the chief and moft abundant ?mnftrua which excite the 
effervefcence of a volcano, or that it is the balls of it (as a friend of great knowledge 
has lately made me believe). I find calcareous fait in the old lava, and common fait 
lnblimated to ammoniac in the filfures and openings of the new irruptions. But 
this is not the place for that which requires a larger volume. I may, perhaps, fay 
more of it on another occafion. 
1 1 have repeatedly obferved, that the fand-lhowers of our mountain are moftly 
eompoied ot calcined matter, and of little cryftals of lchorl, with a fmall portion 
of arlenical and fometimes ialine fulphurcous particles, which unites the 
fchorl to the other fubftances, fo that the particles or grains are thereby enlarged. 
Sometimes the rain falls to the ground lUll warm. 
§ 1 he meafure of the height of the mountain has twice come out to be thus 
delcribcd ; not, however, that I give it for certain, well knowing that altimetry 
requires exa£t inllruments and repeated obfervations. I mean to try it with the 
barometer, when convenient. 
Ii 1 hat this hypothefis may not appear exaggerated as to. the quantity of fmoke 
that 
