ANNOTATIONS AND ADDITION'S. 137 



trary to generally acknowledged physical laws. Fantastic 

 images of terrestrial youth, and unrepose associated on the 

 one hand, and on the other, those of increasing dryness, 

 and inertia in maturer age, could only have presented 

 themselves to minds more inclined to draw ingenious or 

 striking contrasts between the two hemispheres, than to 

 strive to comprehend, in one general view, the construction 

 of the entire globe. Are we to regard the south of Italy 

 as more modern than its northern portions, because the 

 former is almost incessantly disquieted by earthquakes and 

 volcanic eruptions? Besides, what small phenomena are 

 the volcanoes and earthquakes of the present day, in com- 

 parison with those revolutions of nature which the geologist 

 must suppose to have accompanied, in the chaotic state 

 of the earth, the elevation, solidification, disruptions, and 

 cleavings of the mountain masses? Diversity of causes 

 must produce diversity in the operations of natural forces, 

 in countries remote as well as near. Perhaps the volcanoes 

 of the new continent, (of which I still reckon above 28 in 

 a state of activity), have only continued to burn longer 

 than others, because the lofty mountain ridges, on which 

 they have broken forth in rows or series above long sub- 

 terranean fissures, are nearer to the sea, and because this 

 proximity seems, with a few exceptions, to affect the energy 

 of the subterranean fires in some way not yet sufficiently ex- 

 plained. Besides, both earthquakes and fire-emitting moun- 

 tains have periods of activity alternating with periods of 

 repose. "At the present moment," (I -wrote thus 42 years 

 ago !) " physical disquiet and political calm reign in the New 



