234 On the Production of Flames in Volcanoes, 



arid made a discharge, with a noise resembling that of a discharge of can- 

 non. A column of black and fuliginous smoke issued with great vio- 

 lence, and there was thrown up, with the rapidity of lightning, an 

 enormous torrent of inflamed gaseous substances and burning stones, 

 which fell back again like hail, for the most part into the gulf, but 

 partly without it. I was overpowered with the grandeur of the spec- 

 tacle, but I did not fail to observe, in particular, the column of flames 

 which accompanied the explosion. It was the first time that it had 

 fallen to my lot to witness such a phenomenon. The flame rose to 

 the height of 4 or 5 yards, and then disappeared among the volumes of 

 smoke, so that a person whose eye was on a level with the edge of the 

 gulf could not have seen it. I mention this, because when volcanic ex- 

 plosions are viewed from a distance, and from places where the crater in 

 action is not visible, it never happens that the flames are visible ; whence 

 it is that the existence of this phenomenon in volcanic actions has been 

 denied. The flame which I observed was of a very decided violet-red 

 colour. It was very obvious that the gas which produced it became in- 

 flamed by contact with the air, because it burned only on the circumfer- 

 ence of the column, and in the interior was obscure, presenting, on a 

 large scale, what may be seen in a lamp on a small one. After the ex- 

 plosion and fall of stones had terminated, another very remarkable 

 phenomenon was perceived. Insulated flames, disposed in a very 

 picturesque manner, remained in the bottom of the gulf, moved around 

 the mouth, and flickered very slowly about the walls of the funnel ; an 

 appearance which might be compared, in some measure, si licet maxima 

 comparare minimis, to the flame of alcohol burning in a crucible. The 

 beautiful violet colour of the flame was then easily distinguished ; a faint 

 smell of hydrogen gas accompanied these phenomena. I continued for 

 a quarter of an hour gazing on this enchanting spectacle, and during that 

 time I saw five explosions always accompanied by the same appear- 

 ances ; I would have remained longer in the same spot, had not the 

 last of these explosions, which was much more violent than any of the 

 preceding, compelled us hastily to retire. 



I have had no opportunity, since the above noticed occasion, of ob- 

 serving the great opening of a volcano in a state of explosion ; but I have 

 noticed the existence of flames in circumstances nearly similar. 



In the month of June, the following year, Vesuvius was in a state of 

 eruption ; on the evening of the 7th I paid a visit to the crater. The in- 

 terior cone was throwing up stones with such violence that it was im- 

 possible to approach it. A current of lava was spouting out through a 

 fissure at its base. Quite near to me, there was an elevation of a longi- 

 tudinal form, which bore eight small cones, or rather eight large tubes 

 of lava, open at the summit, and throwing out gas and steam with a 

 whistling noise that was quite deafening, and which might be compared 

 to that caused by opening the valves of a high-pressure steam-engine. 

 Favoured by the darkness, we saw that their actions were accompanied 



