250 Dependence of the Geographical 'Relations of Countries 



considerable than in the plains of Champagne, which are desti- 

 tute of wood ; and why the productions of the former are not 

 80 numerous as those of the latter. This fact throws a new 

 iight on the nature of the influence which forests exert on 

 the physical character of countries, and on the geographical 

 relations of the population. 



Atmospheric humidity is one of the most powerful agents 

 in the formation of climate, and leads to the most remarkable 

 changes in the physical aspect of countries. Observe, for in- 

 stance, the great contrast between the savannahs of Ame- 

 rica and the sandy deserts of Africa, and between the north 

 and south of Germany, as also between the geographical con- 

 dition of the respective populations ; for the highly sensible 

 effects of moisture greatly favour the growth of plants and 

 •the breeding of insects, but they are exceedingly prejudicial 

 to the animal functions of the mammalia, and, in particular, 

 of the human race. A very moderate degree of humidity, 

 or a very dry condition of the atmosphere and of the ground, 

 produce contrary results, because they are incompatible with 

 the life of insects, and constantly lessening the number of cul- 

 tivated plants, thereby circumscribing, in the same proportion, 

 the means of support of the human species. 



Comparative geography proves to us, that, on the one hand, 

 a damp atmosphere produces a damp country ; that the latter, 

 though unwholesome, is in a state of productiveness, and cap- 

 able of increasing the products of agriculture, as also, by judi- 

 cious management, capable of tendering the most precious 

 gifts, and that it has entered the period of youthful develop- 

 inent ; of which we have a striking example in the United 

 States of North America. On the other hand, a dry atmo- 

 sphere produces a dry country, which, though wholesome, 

 assumes a more and more barren aspect, until it refuses to 

 supply its inhabitants with the necessary nourishment ; as an 

 instance, we may mention the deserts of Asia and Africa. 

 These deserts are plains destitute of water, plants, and ani- 

 mals ; they present the causes and effects of the last degree of 

 dryness, and exhibit nature as it were in old age, a melancholy 

 picture of its decrepitude. The geography of Asia, America, 

 Africa, and Australia, in contrast with that of Europe, exhi- 



