OF THE FRENCH GEOLOGICAL SOCIETY. 419 
very brittle stone, I have never seen. After this the valley widens 
for a short distance, and is then almost closed in by two walls of rock, 
projecting to meet each other on the opposite side of the river. 
These walls are, perhaps, eighteen or twenty feet thick, and three or 
four hundred high, and they project not less than twenty yards 
from the general line of the rock on each side. Not far off there 
is a considerable spring of petrifying water, whose source is hidden 
among the luxurious vegetation and the water drops from the 
leaves and the extremities of the branches in a constant stream, en- 
crusting with stone every substance upon which it falls. So large 
a quantity of calcareous matter is thus deposited, that the petrifac- 
tions are actually dug out and carried to a distance, to be used as a 
building stone after time has hardened the composition. Soon after 
leaving these weeping trees, and on coming out of the gorge towards 
Montier, the tertiary sandstone called molasse is seen on the road- 
side, and continues southward. Our course, however, lay rather to 
the east, and we reached the Weissenstein the same evening, just in 
time to be witness of a most magnificient storm, but too late to en- 
joy the very extensive prospect which, in fine weather, makes this 
place so much resorted to by all travellers in Switzerland. 
The next morning we left our elevated quarters on this moun- 
tain rather early, though without seeing more than some very pretty 
clouds far below us. Going first to an adjacent mountain, rather 
higher, we almost directly descended upon a remarkably interesting 
secondary valley, in which might be observed the whole series of 
the Jura oolites, down to the muschelkalk. I may remark here, 
especially to those who have not visited Switzerland with geologi- 
cal eyes, that no where can the effects of the various causes in ope- 
ration be so well observed—no where are they exposed in so unal- 
tered a way to observation—as in the valleys of the Jura, the eastern 
ones more particularly. All seems as fresh as if the disturbances 
had taken place yesterday, and one can see the jagged and naked 
rock at the head of a valley, melting quietly down into a regular 
hill-side, and terminating in merely undulating ground at the open- 
ing of the valley, with all the simplicity and clearness of a work of 
yesterday. It need not be pointed out how much the interest of 
geology is increased in such a district, and how many difficulties, or 
things which seem to be difficulties, are here cleared up before the 
light of nature and truth. 
Working our way now towards Solothurn, or Soleure, we come 
into the valley of the Aar, and the geology met with is entirely 
secondary. ‘The city of Soleure stands upon the Aar ; and although 
