208 Professor HoflPmann on (he Geological Investigations 



bourhood so extremely rich in natural beauties and splendid 

 geognostical displays, lie met Von Humboldt. He has given 

 so correct and attractive a representation of the environs of 

 Salzburg, that we can still advantageously make use of it as 

 an unsurpassed model of the description of a magnificent 

 mountainous tract ; the course of the mountains, the nature 

 of the Alpine lakes, the forms of the valleys (more especially 

 that of Gastein), with their basins and burstings, are delineat- 

 ed with the most striking fidelity and elegance. The state of 

 geognostical knowledge at that period did not admit of the 

 determination of the part of the Wernerian series to which 

 the rocks predominating in the outer parts of the Alps are to 

 be referred ; but nevertheless we find the first hints of the 

 fact recently so remarkably established, that the prevalent 

 rock of the calcareous Alps, contrary to the generally received 

 opinion, is comparatively of very modern formation. 



The two naturalists passed the winter of 1797-8 at Salz- 

 burg, and this residence was rendered very important by the 

 meteorological and eudiometrical investigations instituted by 

 Humboldt. The next spring Buch continued his journey 

 across the Alps to Italy, and as he made a careful exa- 

 mination of the central chain of the Alps through the Tyrol, 

 we have to thank him for the first minute geognostical section 

 of that range of mountains, and which he afterwards admirably 

 combined and compared with a similar section of Mont Cenis, 

 This comparative section formed the germ of the important 

 scientific investigations of Ebel. At this time he stopped but 

 a short period in northern Italy, and was there occupied with 

 the volcanic Euganean hills near Padua ; for, his eagerness to 

 study the phenomena of active volcanos, urged him to the 

 south. 



We owe to him an excellent and skilfully combined account 

 of the tract on which Rome is built, where he triumphantly 

 opposes the views of the Italian geologist Breislak, who 

 brought forward the opinion that Rome is built on the craters 

 of extinct volcanos, of which the chief was the ancient Forum 

 J^omanumj the present Campo vaccina. 



In the Albanian hills he met with a variety of phenomena, 

 which disturbed the ideas that he had brought with him from 



