352 M. De Charpen tier’s Conjectures regarding 
between the disposition of the rocks and the external form of 
die chain which they compose, furnish the geologist with ample 
materials for establishing interesting conjectures regarding the 
original form of these mountains, and the revolutions which, by 
modifying and breaking down this form, have successively given 
rise to that under which they now present themselves. 
We shall attempt briefly to point out these conjectures ; and, 
for this purpose, we shall recapitulate the principal facts which 
the arrangement and disposition of the rocks have exhibited in 
the Pyrenees. 
We have seen, that the different formations are disposed 
in bands parallel to each other, and parallel to the general 
direction of the Pyrenees ; that the granite forms only a single 
band, or, speaking more correctly, a chain or series of protube- 
rances ; that each of the other formations constitutes in general 
two bands, one of which is situated to the north, the other to 
the south of the granitic chain, resting upon it in the order of 
their relative antiquity ; that many of these granitic protube- 
rances are separated from one another by valleys, while others, 
on the contrary, are, as it were, agglutinated by rocks of later 
origin, which have filled up the spaces or vacuities by which 
they were formerly separated ; and, lastly, that it is commonly 
in the spaces which exist between two great protuberances that 
we observe the bands that occur to the south of the granitic 
chain, touching and mingling with those which occur to the north. 
These facts entitle us to presume, that the granitic formation, 
comprising that of mica-slate and primitive limestone, form- 
ed originally an uninterrupted chain, or rather an elongated 
line, having a direction from south-east to north-west, and being 
of a height, whether absolute or relative, much greater than at 
the present day; that at a period anterior to the formation of 
the other rocks which recline upon it, this granitic chain has un- 
dergone degradations caused by a power (perhaps currents of 
water) which, acting horizontally from south to north, or from 
north to south, has broken its ridge in many parts, scooped it 
out to a great depth, and changed it into a series of more or less 
isolated eminences ; that the rocks formed after this revolution 
have been applied on each side against this central granitic chain, 
have filled up its deepest hollows, and have even covered its 
