and Writings of Baron Leopold von Buck, 209 



Germany, regarding the utter insignificance of volcanic action, 

 and the nature of volcanic rocks. He found there a number 

 of distinctly melted rocks, which resembled basalts in the 

 most remarkable manner, both in form and composition ; and 

 he then first made the observation, which has been so import- 

 ant in its consequences, that certain crystalline constituent 

 parts of basaltic lava, such as Leucite and Augite, must have 

 been of contemporaneous origin with the principal mass of the 

 rock (Journ. de Fhys. vi. 352), a remark which has become the 

 key to the correct view regarding all porphyries and rocks of 

 a Hke nature. Notwithstanding this, however, Buch was still 

 not shaken at that time in his conviction of the Neptunian 

 origin of the German basalts, and of the limitation of volcanic 

 action to the newer epochs ; and probably nothing can afford 

 a more perfect idea of the influence exercised by Werner over 

 his scholars than a letter written from Rome, the 23d Sep- 

 tember 1798, and published in Von Moll's Jahrhuch der Berg- 

 und-Huttenhunde, vol. iii. p. 361. 



After many delays, Buch at last arrived in Naples for the 

 first time, on the 19th February 1799. He there studied 

 Vesuvius, and has given us an incomparably beautiful and 

 animated description of every thing connected with this re- 

 markable mountain, of the form of its crater, and of the 

 changes which it undergoes. The recollection was still fresh 

 of one of the greatest eruptions which Vesuvius ever exhi- 

 bited, that of 1794, which destroyed Torre del Greco ; and his 

 account of the phenomena that accompanied it is a masterly 

 delineation of a sublime natural event. Vesuvius then pre- 

 sented no eruptive appearances, for though the bocche of 

 1794 were still smoking, the large crater was emptied, and 

 there was a funnel 400 feet deep, whose interior was inacces- 

 sible. It was not till the year 1804 that the mountain, ex- 

 hausted by its excessive efforts, again began to be disturbed, 

 and on the 12th August 1805, there was a remarkable erup- 

 tion, at which, Buch, Humboldt, and Gay- Lussac were together 

 present. This he also described, and we in this way possess 

 the first regular description of the phenomena which take 

 place during the eruption of a volcano, and the first attempt 

 to bring them into connection with one another ; even at the 



