d new Kind of Rain . v 
fpecifically heavier than the air, might defcend in that co- 
loured rain. 
1 muft, however, leave to philofophers (to whom the 
knowledge of natural agents belongs) the examination and 
explanation of fuch phenomena, confining myfelf to obferva- 
tion and chemical experiments 
P. S. On Friday the 4th of May, about a quarter pad three 
in the afternoon, a (light (hock of" an earthquake was felt in 
the country about Etna, which became more fenfible at fome 
didance from the mountain : its direction was from north to 
fouth. The volcano had continued its flames and explofions; 
and the night before, a column of fmoke, compofed of globes 
as it were piled upon each other, had afeended over the crater 
to double the height of the mountain, as far at lead as one could 
judge at the didance of twenty- two miles, which the vertex is 
in a right line from this city. This remained the whole 
night perpendicular, only one of the globfes had feparated and 
lengthened out to the wedward from the iummit. Now and 
then all the infide of the column, and of the lengthened out- 
part, became illuminated by ele&ric fire, which was of a deep 
red colour, and gradually went out again, beginning at the 
bottom, in about two feconds. 
that mu ft be fuppofed, I fhal! mention what was obferved by cicero: Crater e- 
ftamma erumpit, fumo mixta tam copiofo, ut, diem Boreas fpirat , Meliiam ufque per ter & 
ilium fubliman propellat ad IX. millia pajjuum fpatiutn. cic. cle Nat. Deor. lib. II. 
* waller IUS (in his Mineral. Vol. 11 . Hidrol. § 5.) fays : La P hyftquc ejl plus r/tii- 
•verfelle dans fes vues, ct plus pbilofopbique dans fan examen, le phyjicien envifage , ra/onnt , 
r.\ cpliquc, le natter alifte regarde, ramajjc , ct range ; celui-ci votes dira il exijle tel corps 
dans la nature , il eft fait, foit au iledans, foit au dehors de telle oh telle maniere, il eft de 
tel on tel rerne, claffc, ordre, cfpece , varietg ; cclui la pretendra vous exploiter let caufts 
defon exiftcnce , de fes formes, et de fes proprietes. 
The illuftrious LiNNiEus, in Anal. Tranfalp. anno 1740, § 2. fays thus: 
Pbyftca eft fclcntia de qualitatibus elementorum, hiftoria naturalis autem circa cognitionem 
corporum naturalium verfatur. The true naturalift ought to be learned both in 
pbyfics and in chemiftry ; but ftill we know not where the divifion between the* 
two fciences is. 
B 2 The 
