MEMOIR OF WERNER. 29 



united by a cement. It is in the midst of these 

 commotions that life 6rst begins to appear. Carbon, 

 the first of these products, now shews itself. Lime, 

 which was associated with the primitive rocks, be- 

 comes more and more abundant ; and rich deposites 

 of sea-salt, one day to be explored by man, fill large 

 cavities. The waters, again becoming tranquil, but 

 having their contents changed, deposit beds less 

 thick, and more varied, in which the remains of living 

 bodies are successively accumulated, in an order not 

 less determinate than that of the rocks which con- 

 tain them. At last, the final recession of the waters 

 spreads over the continent immense alluvial collec- 

 tions of moveable substances, which form the ear- 

 liest seats of vegetation, of culture, and of social life. 

 Metals, like rocks, have had their epochs and their 

 successions. The last of the primitive, and the first of 

 the secondary rocks, have received them abundantly. 

 They become rare, however, in deposites of more 

 recent formation. They are usually distributed in 

 particular situations, in those veins which seem to 

 be produced by rents in the rocky masses, and filled 

 after their formation ; but they are by no means of 

 equal age. The last formed are known by their 

 veins intersecting those of older date, and not being 

 themselves intersected. Tin is the oldest of the 

 whole ; silver and copper the most modern. Gold 

 and iron those two masters of the world seem 

 to have been deposited in the bowels of the earth 

 at all the periods of its formation ; but at each pe- 



