1850.] 



MURCHISON VENTS OF HOT VAPOUR IN TUSCANY. 



383 



range of the Swiss and Austrian Alps, the greatest changes of me- 

 tamorphism, elevation, depression, and contortion have been deter- 

 mined upon lines having on the whole an east-north-east and west- 

 south-west direction ; whilst in the Apennines the same changes have 

 occurred at the same periods on linear bands trending generally from 

 N.W. to S.E., and even veering round to a meridian strike as they 

 approach the direction of the ancient and palaeozoic rocks of Corsica 

 and Sardinia. Notwithstanding, however, their great diversity of 

 direction, the Alpine and the Sardinian lines of active disturbance have 



Fig. 6. 



Vesuvius. 



each been manifested along primaeval coasts, the strata formed upon 

 which contain palaeozoic fossils. When, however, we pass from the 

 consideration of events so long past to the contemplation of those 

 agents of terrestrial change which have been most active in com- 

 paratively recent times, the Apennines are at once distinguished from 

 the Alps in possessing those truly volcanic phaenomena which 

 connect geology and existing history. With the most frequent evi- 



