102 KANT'S UNIVERSAL NATURAL HISTORY. 



has preserved from its previous proximity to the sun. For 

 it may be conjectured that a comet at the time of its for- 

 mation has passed through several revolutions with greater 

 eccentricity, and that these have been only gradually 

 diminished; but, the other planets of which the same may 

 be supposed, do not show this phenomenon. Nevertheless, 

 they would show it in themselves if the kinds of lightest 

 matter, which are included in the composition of the 

 planet, were present in it as abundantly as in the comets. 

 The earth has in it something which may be compared 

 with the expansion of the vapours of comets and their 

 tails, namely, the Northern Lights, or Aurora Borealis. 

 The finest particles which the action of the sun draws 

 from its surface, accumulate around one of the poles when 

 the sun is going through the- half of its course in the 

 opposite hemisphere. The finest and most active particles 

 which ascend in the Torrid Zone, when they have attained 

 a certain height in the atmosphere, are forced by the 

 action of the rays of the sun to retreat and to accumulate 

 in those regions which are then turned away from the 

 sun and buried in a long night ; and they make up to 

 the inhabitants of the Arctic Zone for the absence of the 

 great light which sends to them even at that distance 

 the effects of its warmth. The same force of the rays of 

 the sun, which makes the Aurora Borealis, would produce 

 a vapour head with a tail, if the finest and most volatile 

 particles were to be found as abundantly on the earth as 

 on the comets. 



