ASCENT OF VESUVIUS, 1834 



took place, and a shower of lava fell on all sides of us, 

 causing us to hurry, and soon we were again upon the 

 heated though solid lava of the plain, or old crater. On 

 our return we went around to the north, thus making the 

 circuit of the cone. In this direction there were numer- 

 ous fissures, freely emitting smoke and showing a red 

 heat to the surface. The walls of the old crater, which 

 here remain, are a perpendicular bank of rock, exhibiting 

 the edges of alternating layers of compact lava, and loose 

 scoria with disintegrated lava. The compact contains 

 numerous small imperfect crystals of leucite and horn- 

 blende. 



' The time before us would not permit me to make 

 many examinations with regard to the volcanic minerals 

 here to be obtained. The following I purchased of our 

 cicerone, who collects and keeps for sale Vesuvian speci- 

 mens. He pointed out to me a large box that he had 

 just closed for Professor Buckland of England. Some of 

 the specimens had passed through the fires without the 

 least change. Their well-known names will distinguish 

 them among the following: granite; mica, one specimen 

 and an aggregation of black scales, another of a brownish- 

 yellow color; crystallized calcareous spar or limestone; 

 idocrase in a micaceous gangue ; spinelle with the green 

 mica; sommite; Iceland spar in tabular crystals; dolo- 

 mite ; calcareous mesotype in irregular spheroidal masses 

 cemented together by carbonate of lime; stilbite in the 

 cavities of the lava ; leucite in crystals, with twenty-four 

 trapezohedral faces, from one-eighth to three-quarters of 

 an inch in diameter; muriate of copper incrusting a speci- 

 men of lava; specular iron, in flat lenticular crystals 

 covering lava; a compound of chloride of sodium and 

 muriate of ammonia similarly situated ; and a specimen 

 of recent calcareous conglomerate, containing petrifac- 

 tions, among which there is a species of the genus pect 'en, 

 also of cardium and of what appears to be z.donax ; and, 

 in addition, some small turreted univalves. I have other 

 minerals, but their names I cannot state with certainty. 

 The labels of many that I purchased were evidently wrong. 



" We descended the cone at a rapid rate, along a steep 

 declivity of loose cinders and volcanic sand. Not till the 

 fifth of June was there any change of consequence in the 

 state of the volcano. On this day (Friday) a slight 



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