236 Dependence of the Geographical Relations of Countries 



explosions, as the latter are the most essential phenomena of eruptions ; 

 we may perceive in them the most direct external manifestation of the 

 origin of the internal commotion. It is for this reason that I consider 

 my observations on the flames of Vesuvius as tending to assist in explain- 

 ing the cause of volcanic phenomena. 



Reviewing what has been stated, I think the following conclusions may 

 be drawn from it : — 



1. Flames never appear in Vesuvius but when the volcanic action is 

 energetic, and is accompanied with a development of gaseous substances 

 in a state of great tension ; they do not appear when the actions are 

 feeble. 



2. Their appearance always accompanies explosions from the principal 

 mouth ; only they cannot be observed but in favourable circumstances. 



3. They likewise shew themselves in the small cones in action, which 

 are formed in the interior of the crater, or at the foot of the volcano. 



4. Finally, they are not visible except in the openings which are 

 directly in communication with the volcanic fire, and never on the 

 moving lavas which are at a distance from their source. 



After this exposition, it is natural to enquire, what is the gas which 

 produces these flames in Vesuvius }* 



Dependence of the Geographical Belations of Countries and 

 Nations, on the extent and situation of Forests. 



The rapid progress of all the material interests of nations 

 during the general peace, which has liberated the German 

 tribes, in particular, from the foreign yoke imposed on them 

 from the West, was not without considerable influence upon 

 the theoretical and practical turn of those sciences, which 

 principally forward those interests, and are essential to their 

 promotion. Among these sciences. Geography, which has 

 for its object all the measurable, physical and political rela- 

 tions of the earth, holds no trifling, but rather a highly im- 

 portant place, because it off'ers various scientific, historical, 

 and philosophical data, and considers them in their imposing 

 details, in reference to the character of countries, nations, 

 and empires. Its object is, harmoniously to connect the end- 

 less variety of the phenomena of our globe, to subordinate the 

 accidental to what is regulated by laws, to establish an uni- 



* From Comptes Rendus, 1843, No. 17, p. 889. 



