6 



But in order to make the physical and phytological character 

 of this Alpine region more intelligible to you, and to enable you 

 to understand more easily our subsequent remarks upon the Geo- 

 logical relations of its flora, let me carry you in imagination to 

 the summit of one of our loftiest mountains, and point out as we 

 descend what is most noteworthy in its natural features and vege- 

 tation. For this purpose I shall not choose Ben Nevis, which, 

 as already stated, is the loftiest mountain of our island, but one 

 which in several respects is better adapted to illustrate what I 

 have in view, viz. — Ben-na Macdhui, the second highest, which 

 attains an elevation of 4,296 feet, according to the Ordnance 

 Survey. This constitutes one of a series of very lofty moun- 

 tains in the northern Grampians of Scotland, in the district of 

 Braemar, and is surrounded, amongst many lower hills, by about 

 a dozen neighbours, but slightly inferior in elevation to itself. 

 In the same district, also, there are numerous other mountains, 

 attaining an altitude of not less than 3,000 feet ; so that we have 

 here the most elevated ground of similar extent in Great Britain. 

 Transported to the summit of this mountain, which is entirely 

 composed of reddish granite, varied only by veins of quartz, and 

 commencing our inspection from the highest point, which is 

 marked by a large cairn of stones, we make the following obser- 

 vations. The summit, about three miles in circuit, is broad and 

 rounded, gradually sloping down on all sides into deep glens and 

 corries, except on the N.W. and S.E., where it is coterminous 

 with two other lofty mountains. In one part it is covered with 

 masses of broken granite and quartz, generally of considerable size, 

 interspersed here and there with larger boulders, and having the 

 appearance of being more or less water-worn, which are evidently 

 fragments of rock that once stood in situ, as may still be seen on 

 some of the neighbouring mountains, where, at a distance, they 

 appear like large protuberances upon their bare brows. In 

 another part, again, we perceive extensive tracts of coarse detri- 



