Examination of Ores of Iron. 379 



grains, and left ten grains of earthy matter like sand. This 

 earthy substance was examined with the microscope, and ap- 

 peared to be fragments of hornblende, coccolite, with a small 

 portion of the ingredients of granite. 



Pure potash in solution was now added in excess to the 

 solution of muriate of iron, to precipitate the iron and retain 

 the alumine if any was present. 



The precipitate of oxide of iron was washed, dried, and 

 heated to a low red ; it then weighed eighty-nine grains. 

 In adding pure potash to the solution of muriate of iron, 

 there was an oxide of iron with muriate of potash, the oxide 

 of iron precipitating, and the muriate of potash holding in so- 

 lution alumine if any was present. In order to determine this 

 I added pure water of ammonia ; it let fall a precipi- 

 tate, which was examined in the following manner after wash- 

 ing and drying it : it was then cooled and moistened with a 

 solution of nitrate of cobalt, which gave a slight blue color ; 

 the best test of the presence of alumine. The eighty-nine grains 

 of oxide were now dissolved again in muriatic acid ; pure water 

 of ammonia was added to neutralize the solution, then benzo- 

 ate of ammonia to separate the iron, leaving the manganese 

 in the solution of muriate of ammonia. The compound mu- 

 riate was sublimed, and left the oxide of manganese at the 

 bottom of the subliming vessel in the form of a white powder, 

 which turned black on being exposed to the air. The pow- 

 der was then collected, washed, dried, and then weighed one 

 and a half grains. Fused with borax and a small quantity 

 of nitrate of potash, it gave a faint rose color. 



Hence it will appear that this ore is composed of 

 Black oxide of iron, - - 87 00 

 Earthy admixture, - - 11 00 



Manganese, - 1 50 



99 50 loss 50 = 100 



No. 2. Iron ore from West-port, Essex County, New- 

 York. 



