Mineralogy and Geology of the White Mountains. 121 
The foundation, or mass of this mountain, as it is seen in the 
_ deep gorges cut by the slides in the western side, is granite ; and 
the top has been stated, by those who have and by others who have 
not ascended it, to be granite; and Alpine travellers, who have 
visited Mont Blanc, have thought they saw in the vast ruins sur- 
rounding the summit, the remains of lofty aiguilles, that towered 
above the present peak; but let the observer stand at the most ele- 
vated point, near the rude artificial monument, as in the centre of 
a decapitated summit, and let him critically examine the rocks in 
the whole circle about him, and he will soon discover the incor- 
rectness of these opinions. He will find the rocks stratified, layer 
upon layer, and symmetrically arranged around the center he oc- 
cupies. ‘The rock is mica slate, consisting of coarse mica and 
fine quartz, occasionally with fine grained veins of the two min- 
erals, with a little feldspar, and some considerable veins of white 
quartz. The uniformity of this surface, in level and appearance, 
is such, that a passage to the top is marked out by no ravines and 
eminences, but the path leads directly over the ruins, and the 
guide himself is directed by masses of white quartz, or collec- 
tions of stones raised at proper distances. Near the top are small 
black tourmalines, and also a small spring of water. 
The case is clear. ‘The mountain of granite was raised from 
the deep, bearing up on its Atlantean shoulders this huge cov- 
ering of mica slate, that extends a quarter of a mile below the 
summit, and by disruptive agencies has been fissured in every di- 
rection, and reduced to ruins. The granite, instead of rupturing 
the mica slate, and protruding at the centre of elevation, itself 
forming the peak, has broken it at some distance from the centre, 
and we ought to find the long line of disruption of the mica slate, 
if the rocks remain and are uncovered, very far down the moun- 
tain ; if not, in the low grounds of the valleys. 
The different zones, or belts of vegetation, are distinctly mark- 
ed on the flanks of the mountain—the lower forests with their 
varied hues—the upper belt of sombre evergree ighest 
of dwarf trees, stunted shrubs, and long grass and mosses, and 
terminates at the lower line of the rough weather-worn rocks that 
form the summit. From this height the several belts may be 
traced, with the eye, for a great distance each way. The upper 
limit of vegetation indicates very definitely the comparative ele- 
vation of the 7 peaks, according as it surmeounts or 
L. XXXIV.— 16 
