16 M. R amon d on the Vegetation [Appendix:, 



in full force, germination, florescence, and fructification, take 

 place almost simultaneously. Sometimes, with a wind blowing 

 from the south, with a heavy shower, or with a scorching sun, 

 the face of the meadows, downs, and forests, in a moment 

 changes, and the whole of a particular species seems to vanish : 

 in fact, there, every fine day is a spring to some particular assem- 

 blage of vegetables, or to some of the inaccessible heights in 

 which they grow. 



To this picture, another succeeds. If we examine the moun- 

 tains, and vallies, every place has its peculiar soil, every differ- 

 ent elevation its peculiar climate, and each of them its charac- 

 teristic vegetables. In the plains, these vegetable assemblages 

 occupy vast spaces, the limits of which are too extensive, and 

 indeterminate, to be easily perceived. On the contrary, in the 

 mountains, they are confined to narrow limits, which the 

 eye often takes in at one view. In a gentle rising extended 

 between two dales, in a pile of rocks, or in a cliff, which the 

 traveller ascends in a few moments, he finds the perpetual 

 barriers of those productions, which nature has been pleased to 

 separate. 



Among the various causes of these separations, one seems to 

 reign predominant over all others; this is elevation above the 

 level of the sea. In every 100 inches in height, the temperature 

 falls about half a degree of our thermometers. Afrer that de- 

 gree of cold, which generally puts a stop to all vegetation, an 

 eternal frost prevails on the summit of these Alps, as at the 

 poles, and every 100 metres of vertical elevation corresponds 

 nearly to one degree of the distance, at which the mountain is 

 placed from the pole. 



By this scale, the various phenomena of different climates in 

 our globe may be easily understood ; circumstances may differ, 

 but the general results will be nearly the same. While the in- 

 crease of cold is accompanied by a diminution of the column of 



