On the Production of Flames in Volcanoes. 235 



with beautiful conical flames, which issued from the tubes with a violence 

 which might be in some measure compared to a flame increased in in- 

 tensity by a blow-pipe. The length of these flames was from 3 to 5 

 inches, and their diameter at the base about an inch and a half; they 

 burnt with a beautiful greenish colour, like alcohol holding boracic acid 

 in solution : such a colour would very likely be produced by the chloride 

 of copper accompanying the gaseous substances. The smoke which 

 escaped from the openings in the cones had an intolerable smell of 

 muriatic acid ; sulphureted hydrogen gas was not perceptible. This was 

 the second time that I observed flames in the crater of Vesuvius, and I 

 saw them in company with my esteemed friend M. Ravergie of Paris, 

 who was my companion in this expedition. 



I saw very beautiful flames from Vesuvius, for the third time, during 

 the great eruption in August 1884. An opening was formed in the vol- 

 cano at its eastern base, and a great current of lava was thrown out, 

 which spread over the fertile lands of Ottajano. In the place where the 

 lava issued, two elevations were formed, which supported twelve small 

 cones, kinds offiomitos, all of which were in great activity, and produced 

 noisy explosions. One of these cones, which appeared the most active, 

 and which I could approach near, notwithstanding the smoke it spread 

 on all sides, was emitting by its opening, besides quantities of stones, a 

 bright flame of a reddish-white colour, which came forth with great 

 violence, and rose to the height of 3 yards. The jet was continuous, 

 like the flame from a high furnace heated by bellows. The smoke was 

 charged with muriatic acid, and, in a few moments, it enveloped Pro- 

 fessor Tosone of Milan and myself in such a manner that we were nearly 

 sufibcated. 



I never had the good fortune to observe flames in Vesuvius in so dis- 

 tinct a manner as on these three occasions. I have never seen them on 

 the surface of currents of lava far from their source. But my friend, M. 

 Maravigna, assures me, that he observed them on a current from Etna, 

 during the eruption of 1819. 



According to all that I have said, my belief is, that volcanic explosions 

 are constantly accompanied with flames. So convinced am I of this 

 truth, in regard to Vesuvius, that I would engage to point them out 

 during any eruption, provided the circumstances were at all favourable. 



I again repeat, that if the existence of this phenomenon has been 

 denied, it is owing to the great difficulty of observing explosions very 

 near at hand ; and when they are observed far from the aperture in 

 action, as is usually the case, the flames are either concealed by the walls 

 of scoriee which surround them, or, if they rise, they disappear among 

 the smoke and jets of stones. 



The phenomenon of which I speak is not an accidental one in the great 

 actions of volcanoes. It is only necessary to see it once to be con- 

 vinced that it is intimately connected with the cause of these actions. It 

 may be said that flames are the most remarkable circumstance in volcanic 



