ASCENT OF VESUVIUS, 1834 



issued in a dense cloud from the small crater, and was 

 carried by a strong wind from the northeast across the 

 path we were about to take. After one or two fruitless 

 attempts, the danger of suffocation driving us back, at 

 last, with our handkerchiefs to our faces, we gained the 

 windward side of the cone. It was south of east of this 

 small cone (I so call it to distinguish it from the old and 

 larger one), about twenty rods from it, that the grandest 

 sight was presented us. 



" During the preceding few moments we had moved 

 along with rather a hastened step, on account of the heat 

 of the lava under our feet ; for a red heat was frequently 

 seen in many places within ten or twelve inches of the 

 surface, and the rocks were yellow with an incrustation 

 of sulphur. We were soon on the borders of what was 

 apparently a fountain of melted lava, which, making its 

 way from under the solid lava at the slow rate of a mile 

 an hour, ran down the back side of the mountain towards 

 Pompeii, not proceeding far enough, however, to injure 

 an uninjured country. It resembled much a stream of 

 fused iron. Its width was from four to five feet. From 

 the form of the surface of the surrounding lava, I con- 

 cluded that not long since its place of exit was higher 

 up, and that by the solidification of its surface the change 

 had been produced in the situation of its source, a pro- 

 cess which now appears to be going on. We approached 

 it within four feet. I cannot say that I felt disposed to 

 try the experiment which Dolomieu states to be safe, that 

 is, to walk on it, the heat of the surface, as he says, not 

 being sufficient to burn. It is certain that the reflected 

 heat was sufficient to induce me to preserve the distance 

 above mentioned. With one of our rough canes we took 

 some of the red-hot viscid fluid from the stream, and into 

 it pressed some coins. I have one specimen impressed 

 on one side with the name of our cicerone, Salvatore 

 Madonna; on the other, the time as regards the year 

 when instamped. The lava cools rapidly, hardening into 

 a black scoriaceous, vesicular mass, without the usual 

 crystals of leucite, hornblende, or pyroxene. May not 

 this absence of crystals be owing to the fact that they 

 were taken from the surface, where these minerals, not 

 under pressure, are decomposed by the heat ? The same 

 is the nature of the solidified lava which covers this part 



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