Miscellanies. 169 



ble light of the stars enabled us to perceive, on the commencement 

 of the acclivity of the upper cone, a white space whose color was 

 caused by the alteration of the rocks, and by saline efflorescences 

 having a very styptic taste. In the midst of this space, at several 

 points, we distinguished pale and scarcely luminous flames, which 

 seemed to issue from the earth; they occu,:'ed the orifices of sev- 

 eral irregular openings, which were from one to two yards in width, 

 and were only the enlargements of a tortuous crevice. These 

 flames were evidently produced by a gas disengaged from the cre- 

 vice, and which did not find the oxygen necessary for its combus- 

 tion till it reached the external air. The combustion took place 

 almost exactly at the level of the surface of the ground. The flame 

 rarely rose to the height of a yard ; it produced a sound somewhat 

 intermittent, pretty analogous to that of several lighted faggots, or 

 rather that which is heard at the bottom of a blast-furnace when the 

 blowing apparatus is badly constructed. The gases produced by 

 the combustion did not impede the breathing, and had a strong odor 

 of sulphurous acid. Sulphuretted hydrogen was also perceptible, 

 but I did not recognize the odor of muriatic acid. Every circum- 

 stance, then, announced that the flame was supported by sulphuret- 

 ted hydrogen, and afterwards, when the sun lighted up the moun- 

 tain, a long bluish cloud was seen taking its rise from that particular 

 point. 



In the interior of the great crater I found several portions of 

 snow, but from many other points of its angular bottom there issued 

 hot vapors, having a whitish color, more or less dense, composed 

 chiefly of watery vapor, but having nevertheless a strong odor of 

 sulphurous and muriatic acids ; one or the other of these acids pre- 

 dominated alternately. The surfaces across which the vapors were 

 disengaged were in part covered by saline efflorescences, which were 

 sometimes white, and sometimes colored of an orange-yellow tint 

 by the chloruret of iron, or of a canary-yellow by particles of lava 

 altered by the acid vapors. In some fissures I found white fibrous 

 gypsum, mixed with altered pulverulent yellow lava in which some 

 small nodules of sulphur were disseminated. 



The above account of the observations of this distinguished geol- 

 ogist is followed by a statement of his theory of the formation of 

 the mountain. After alluding to the changes of form that have re- 

 sulted from the frequent production of extensive longitudinal fissures 

 by the earthquakes that accompany or precede an eruption of the 



Vol. XXXI.— No. 1. 22 



