1 74 Prof. Ferrara's Account of the Earthquakes 



numerous inhabitants of these regions, were always preceded 

 and followed by subterranean murmurs and distant explo- 

 sions. Under these places it seems that those substances were 

 deposited which ^^tna inflamed and ejected from its mouth 

 in the following May; because, after the eruption commenced, 

 Madonia was left in quiet, while >32tna, which till this time, 

 and during the agitations of Madonia, had remained perfectly 

 calm, became convulsed with earthquakes. They accom- 

 panied the eruption. 



With the extinction of the conflagration in August all the 

 phaenomena ceased, and the earth was no longer agitated. 

 But in 1822 ^"Etna showed that the fermentation within its 

 furnaces was again at work. On the 5th of April rumblings 

 and continued explosions were heard, which were followed 

 by great clouds of smoke violently driven from the crater by 

 the impetuous current of elastic vapours. A shower of sul- 

 phurous ashes fell all around. On the 6th a violent shock 

 convulsed all the towns between ^Etna and Madonia — Capizzi, 

 Cesara, Sperlinga, Troina, Gangi, Gagliano ; but in the midst 

 of these Nicosia seemed the centre of impulse in all the shocks 

 which followed throughout the month. Its soil appeared on 

 the point of being torn up by force ; many buildings were de- 

 stroyed, and its inhabitants fled in consternation to find ah 

 asylum in the country. The immense clouds of smoke and 

 earthy ashes which were ejected from .Tune to October — which 

 covered the more lofty part of the mountain with a gray stra- 

 tum — which filled the atmosphere and gave out through the 

 whole region a strong odour of sulphur, clearly prove that 

 all these commotions were produced by forces collected in the 

 recesses of ^tna*. 



While 



* From June to October 1822 Mina. emitted great quantities of volcanic 

 ashes, which were scattered all over the mountain ; on the plain about the 

 crater it fell to the depth of a foot. From the mouth of the crater and through 

 fissures near the mouth, so dense a smoke and such copious streams of aque- 

 ous vapour were given out, that when they were condensed by the lower 

 temperature of the air the ground about these orifices was drenched with 

 water. The vapour, which was still suspended by the caloric imparted to it 

 by that already condensed, fell soon after in the form of a brine, acidified by 

 the mixture of sulphurous vapour contained in the smoke, and to which was 

 owing the odour of sulphur given out by the ashes wherever it fell. All the 

 ashes about the crater was saturated with this brine. The vapour of water 

 is always found in the smoke of jEtna, but in much greater quantities at the 

 time of an eruption. In my relation of that of 1792, 1 mentioned that at a 

 little distance from the crater a new orifice was made by the force of the 

 vapour, from which for a long time pieces of old lava and scoriae and ar- 

 gillaceous earth saturated with water, were ejected ; that standing there to 

 observe it, I was continually bathed in the brine which fell from the smoke. 

 This phEenoracnon of .Etna in 1822 has been much misrepresented in foreign 



journals, 



