NOttE IV. TUFO. ,381 



and were the forerunners of an eruption, which 

 manifested the greatest activity about the middle 

 of July : the eruption was remarkable on ac- 

 count of the immense quantity of ashes, sand, 

 and light pulverulent scoriae, which issued from 

 its crater*. They covered the mountain, were 

 expanded over a part of Sicily, and carried even 

 as far as Malta. The Chevalier Dangios col- 

 lected, on the terraces of the observatory at that 

 place, a pretty large quantity of black sand, in 

 small hard grains, which were attracted by the 

 magnet: the sand was mingled with small and 

 somewhat transparent crystals, of irregular 

 figure, which, seen through the microscope, 

 appeared to be a porous vitrification ; this sand 

 was borne to Malta by a north-west wind, on 

 the night between the 18th and 19th of July. 



" Many currents of lava were emitted by this 

 eruption, and consequently all those kinds of 

 substances which I have attributed to this crisis. 

 I have received different accounts of this event, 

 which may be serviceable in developing the 

 theory of subterranean fires, and support certain 



* " These numerous products of scorification announce very 

 considerable effervescence, and are constantly attended with a great 

 disengagement of elastic fluids. Hence the column of smoke and 

 flame rose to an immense height j and the atmosphere was infected 

 with the odour of sulphur." 



