MM. Godon’s mineralogical observations. 151 
ry soil. Besides, its bordering upon rocks considered as primordial, 
to which it unites by insensible transitions, and which it sometimes 
includes, confirms that it has a common origin with them. 
If permitted to venture an opinion on the mode of its formation, 
we may suppose, that, as we find in it specimens of almost all the 
rocks, which predominate in the country, it originated from a motion, 
which disturbed and divided the vast deposits of felspathic, porphyrit- 
ic, petrosiliceous, &c. rocks, while they were passing from the state of 
fluidity to that of solidity. This motion ought to be supposed as 
having taken place, before the complete solidification of these rocks ; 
since the compactness of the wacke indicates that its elements were 
in astate of softness, which permitted the union of these heterogene- 
ous bodies to form a solid mass. Moreover this aggregation cannot 
be supposed to have been formed after the last cast of the primordial 
deposit, because the rents, which took place in its mass, have been fill- 
ed by veins or rather strata of amphiboloid and felsparoid (some spe- 
cimens 2 this a entirely see ne granite), which demonstrates, 
p> age es F 4°T} i 7 
the formation of the wacke. OK er all, I give to this explanation res- 
pecting the formation of this rock, only the value it will receive from 
-haturalists themselves ; persuaded, that the destiny of all theories res- 
pecting geological facts is to remain hypothetical, until the surface of 
the earth shall be more attentively and more generally observed. 
3, at a period later than 
Amygdaloid. 
38. This rock is the least abundant. I had an opportunity of ex- 
amining it only in one place [Brighton o]; but several fragments, 
Scattered in many parts, indicate that it exists in other spots. — 
