OF COMMON MATTER. 153 



rature perpetually decreases to such a degree, 

 that the climate is altogether unfit for animal or 

 vegetable life, and the intensity of it can only be 

 apprehended, by the vast coverings of snow and 

 of ice with which the summits of the most lofty 

 mountains, in all parts of the world, whether 

 situated at the polar or meridional regions, are 

 everlastingly coated. That this is the fact, will 

 appear, if the temperature of different latitudes, 

 at the same degree of altitude, be compared with 

 each other. Although the highest mountains of 

 this island may be considered as mere dwarfs, 

 when compared to those of the continent, in point 

 of density and elevation, the decrease of tempe- 

 rature is, nevertheless, very perceptible with the 

 increase of elevation ; while the thermometer 

 was at 63. last August, at the base of Skiddaw, 

 the mercury gradually fell, in ascending towards 

 the summit of that mountain, as low as 34*. 

 This great diminution of temperature from the 

 base to the summit, is more especially found to 

 subsist in Mount ^Etna Vesuvius and Olym- 

 pus the peak of Teneriffe the Alps and Ap- 

 penines the Andes and Cordilleras those 

 gigantic mountains that are surrounded by 

 burning sands, and situated at the equator ; 

 whose position, with respect to the incident solar 

 ray, is vertical ; whose elevation is so high, that 

 the rarity of the atmospheric medium, through 

 which the rays are transmitted, is, in a great 



