50 



THE GEOLOGIST. 



very easy to smelt. However frequent copper may be, tin is of rare 

 occurrence. Thus the only mines in Europe which produce tin at 

 the present day are those of Cornwall, in England, and of the Erzge- 

 birge and Fichtelgebirge, in Germany. 



But the question arises whether previous to the discovery of 

 bronze, man, owing to the great rarity of tin, may not have begnn 

 by using copper in a pure state. If so, there would have been a 

 copper-age between the stone- and bronze-ages. 



In America this has really been the case. When they were dis- 

 covered by the Spaniards, both the two centres of civihzation, Mexico 

 and Peru, had bronze composed of copper and tin, which was used 

 for manufacturing arms and cutting-instruments, in the absence of 

 iron and steel, which were unknown in the New World ; but the 

 admirable researches of Messrs. Squier and Davis on the antiqui- 

 ties of the Mississippi valley* have brought to light an ancient civi- 

 lization of a remarkable nature, and distinguished by the use of raw 

 virgin copper, worked in a cold state by hammering without the aid 

 of fire. The reason of its being so worked lies in the nature of pure 

 copper, which, when melted, flows sluggishly, and is not very fit for 

 casting. A peculiar characteristic of the metal, that of occasionally 

 containing crystals of virgin silver, betrays its origin, and shows that 

 it was brought from the neighbourhood of Lake Superior. This 

 region is still rich in metallic copper, of which single blocks attaining 

 a weight of fifty tons have lately been discovered. There was even 

 found at the bottom of an old mine a great mass of copper, which 

 the ancients had evidently been unable to raise, and which they had 

 abandoned, after having cut off the projecting parts with stone 

 hatchets, t 



The date of this American age is unknown : all we know is that 

 it must reach as far back as ten centuries at least, that space of time 

 being deemed necessary for the growth of the vii'gin forests, now 

 flourishing upon the remains of that antique civilization of which the 

 modern Indians have not even retained a tradition. 



* Sqiiier and Davis. — " Ancient Monuments of the Mississippi Yalley." 

 Smithsonian Contributions to Knowledge. Wasliington, 1848. It is one of the 

 most splendid archreological works ever pubhshed. 



t Lapham. — " The Antiquities of Wisconsin." Smithsonian Contributions to 

 Knowledge, p. 76, 1855. 



