Cuvier’s Historical Eloge of Werner^ 9 
succeeds gneiss, which is only a granite beginning to be slaty. 
By degrees, argil predominates. Schists of different kinds ap- 
pear ; but in proportion as the purity of the precipitations is 
changed, the distinctness of the crystalline grain is diminished. 
Serpentines, porphyries, and traps succeed, in which this grain 
is still less distinct, although the siliceous nature of these rocks 
evinces the returning purity of the deposition. Intestine agita- 
tions in the fluid destroy a part of these primary deposites : 
new rocks are formed from their debris united by a cement. It 
is amidst these eonvulsions that living nature arises. Carbon, 
the first of these products, begins to shew itself. Lime, which 
had already been associated with the primitive rocks, becomes 
more and more abundant. Rich collections of sea salt, to be 
one day explored by man, fill immense cavities. The waters, 
again tranquillised, but having their contents changed, deposite 
beds less thick, and of greater variety, in which the remains of 
living bodies are successively accumulated, in an order not less 
fixed than that of the rocks which contain them. Finally, the 
last retreat of the waters diffuses over the land immense collec- 
tions of alluvial matters, the first seats of vegetation, of cultiva- 
tion, and of social life. 
The metals, like the rocks, have had their epochs and their 
successions. The last of the primitive, and the first of the se- 
condary rocks, have received them in abundance. They be- 
come rare in countries of later formation. Commonly they are 
found in particular situations, in those veins which seem to be 
rents produced in the great rocky masses, and which have been 
filled after their formation. But they are not all of equal age. 
Those which have been last formed are easily known, because 
their veins intersect those of the more ancient, and are not 
themselves intersected. Tin is the oldest of them all ; silver 
and copper are the latest formed. Gold and iron, those two 
masters of the world, seem to have been deposited in the bowels 
of the earth, at all the different epochs of its formation ; but 
iron appears at each epoch under different forms, and we can 
assign the age of its different mines. 
The necessity of abridging obliges me thus to unite under 
one view, results which, we may easily imagine, could only 
