458 



THE CANADIAN NATURALIST. 



[Dec. 



necessary. Blades of copper must be placed in tlie metallic solu- 

 tions, to throw down the silver in a metallic form, then blades of 

 iron to throw down the copper, the gold being then extracted as 

 previously directed. I think the advantages of this process are, 

 1st, cheapness ; 2nd, absence of injury to the health of the persons 

 employed ; 3rd, that not only is the metahic gold in the ore ex- 

 tracted (as is done by mercury), but it attacks and dissolves all 

 gold which may be present in a combined state, besides enabling 

 the miner also to extract what silver and copper the ore may con- 

 tain. I cannot, however, conclude without reminding you of what 

 is generally underrated ; that is, the heavy expenses which attend 

 the bringing of the ore to the surface of the ground, and crushing 

 and preparing it for being acted upon by mercury or by any other 

 agents. 



MISCELLANEOUS. 



ILLUSTRATION TO DR. DAWSON S ARTICLE ON THE GENUS 



RUSOPHYCUS. 



RUSICHNITES ACADICUS. 



For description, see a7ite, page 367. 



