324 THE CANADIAN NATURALIST. [Sept. 



an exception to this, being, as the professor believes, a part of an 

 immense trap uplift of the same age as the trap dike at White 

 Head Island, and other places further north. 



He spoke also of the markings on a rock on Monomah Island, 

 which lies by the side of Monhegan. These markings, he was 

 disposed to consider not artificial characters, but as produced by 

 the action of the atmosphere upon the partially crystalline rock. 



Prof. Agassiz made a few remarks at the close of Prof. John- 

 son's paper, after which an essay " on Norite or Labradorite 

 Rocks," was read by Dr. T. Sterry Hunt, F.R.S. 



SOME NOTES ON THE CHEMISTRY OF COPPER. 



By T. Sterry Hunt, L.L.D., F.R.S. 



Copper in its cupreous form presents some relations to silver 

 which were pointed, out. Cupreous oxyd, like oxyd of silver, 

 decomposes many protochlorids, as those of magnesium, zinc, 

 manganese, cobalt, and iron, forming cupreous chlorid. This, 

 though insoluble in water, is readily soluble in solutions of 

 chlorids, as of sodium and magnesium, especially if hot and con- 

 centrated, but is in large part separated by cooling, and by 

 dilution. From solutions of chlorids of zinc and manganese the 

 red oxyd of copper precipitates insoluble oxychlorids of these 

 metals. From chlorid of magnesium pure hydrated magnesia 

 separates. With ferrous chlorid the reaction is more complex, 

 since ferrous oxyd reduces cupreous chlorid, giving metallic 

 copper, so that the iron separates as ferric oxyd, together with 

 one-third of the copper in the metallic state. In presence of 

 an excess of ferrous oxyd the whole of the copper is reduced to 

 the metallic state. Cupric oxyd, in like manner, decomposes 

 ferrous chlorid with production of ferric oxyd, while two-thirds 

 of the copper are obtained as cupreous, and one-third as cupric 

 chlorid. These results are best obtained in presence of strong 

 hot solutions of chlorid of sodium, which dissolve the cupreous 

 chlorid. The relations, both geological and economical, of these 

 reactions, were then alluded to. 



TRICHINA SPIRALIS. 



Dr. J. Baker Edwards read a paper with the above title, 

 which appeared in the last number of this journal. 



