18 ECONOMICAL MINERALOGY. 



from these differs somewhat in its characters. In one of them it is granular, and of a blue- 

 black colour. When reduced to grains, it is strongly attracted by the magnet ; but none of 

 the masses which I have tried, possess polarity. It is free from foreign admixture, except a 

 minute portion of quartz. Its specific gravity is 4.977. The following is its composition, 

 according to my analysis : 



Protoxide of iron, 27 . 00 



Peroxide of iron, 71. 50 



Quartz (mechanically mixed) and loss, 1 .50 



The average width of tliis vein is four or five feet. It is, as well as the rest, crossed by 

 a dyke of greenstone. 



By the side of the black vein, there is a vein of light blue granular ore, and one of a grey 

 variegated colour. They are separated from each other by a few feet of rock. The blue ore is 

 almost destitute of metallic lustre, and is not magnetic, although it bears a general resemblance 

 to the magnetic ores. Its powder is red, thus indicating an ore in the highest state of oxida- 

 tion, which is also confirmed by the results of its analysis. Its composition is as follows : 



Peroxide of iron, 98. 00 



Sihca, 2.33 



Lime, traces. 



The greyish ore is easily reduced to grains, and often has spots of a green and blue colour. 

 It does not possess the least magnetic properties, and the powder has a bro^vnish red colour, 

 like the specular ores. I suppose both these last ores to have acquired their high state of 

 oxidation by some decomposition which has taken place subsequently to the original deposition 

 of the mineral. The composition of this ore is as follows : 



Peroxide of iron, 97. 00 



Insoluble matters, 2. 83 



Oxide of manganese and lime, traces. 



The width of the blue vein varies from two to eight feet, which is also about the width of 

 the grey vein. According to Dr. Emmons, calcareous spar, in opaque masses, forms a large 

 proportion of the gangue of these ores, through which also fluor spar, in green or purple 

 grains, is sparingly disseminated. 



The Finch vein is a continuation of the Arnold vein. The ore is grey and black, and has 

 been much used in the vicinity of Clintonville ; but it is not worked at present. 



About two or three miles west of the preceding, is the Palmer Mine. This was opened 

 several years since ; but, according to Dr. Emmons, the principal vein, which is thirty-five 

 feet in width, was not worked until 1839. The geological relations of this deposit are similar 

 to those of the Arnold Mine, but the accompanying rock is of a more crystalline character. 

 Large masses of feldspar and of quartz frequently occur, mica being more sparingly disse- 

 minated. The ore is black and magnetic, but so largely mixed with foreign minerals, prin- 

 cipally silica, as to render it necessary to subject it to the process of washing, or to the action 



