408 Miscellanies. 



ingly low and the work performed by laborers who live on little. 

 This secondary may be considered as a proof if ever the veins were 

 filled, that they must have been filled from the surface, for it is difH- 

 cult to conceive how, in a primitive range, the secondary could be 

 ejected from below ; it has been considered as a geological fact, that 

 metallic veins can have no dependence or connection with volcanos, 

 yet our total ignorance of many original natural methods of opera- 

 tion, ought to make us cautious in restricting nature to any exclusive 

 mode of acting. Our primitive mountains in the north have iron in 

 abundance, but the precious metals have, as yet, been rarely found ; 

 nor are there any modern volcanic rocks- The same may be ob- 

 served in the north of Europe. Sweden, and the north of Ger- 

 many, have rarely silver and gold, and no modern volcanic rocks, 

 whereas, in Saxony and Hungary and Spain, there are both precious 

 metals and volcanic rocks — and on the southern continent of Amer- 

 ica, there seems to be a proportion between the gigantic volcanic 

 formation and the abundance of the precious metals. If we sup- 

 pose the convulsions and earthquakes that might precede the erup- 

 tion of lava to the surface, to have rent and cracked the shell so as 

 to give space to the formation of these veins, and the precious metals 

 if converted into vapor, would penetrate through chinks that would 

 not permit lava to pass ; this vapor meeting with the secondary that 

 was filling the vein from the surface, might form a mixture such as 

 we find in most of the veinstones ; this conjecture will not support 

 the fashionable theory of the central fire, for there would be no good 

 reason why the cracks in our northern mountains were not as near 

 the melted mass, and therefore as liable to be filled with the vapor 

 of the precious metals as the rocks of the inter-tropical countries. 



5. Aluminium and magnesium. — Lieut. W. W. Mather, of the 

 Military Academy, West Point, has succeeded in obtaining the chlo- 

 rides of aluminium and magnesium, and in decomposing them by po- 

 tassium, so as to obtain the metallic base both of alumina and of mag- 

 nesia. The magnesium that he obtained, had not a distinct metallic 

 appearance until it was burnished, but both it and the aluminium were 

 combustible when heated in the air. 



Lieut. Mather was so good as to enclose to us a portion both of the 

 aluminium and magnesium, whose metallic appearance is quite dis- 

 tinct; the color -of the aluminium is light grey and in spots tin white. 

 The chloride of magnesium obtained by him has exactly the appear- 



