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[Assembly 
certain sense, may be, in part, the result of galvanic agency ; but it 
must, from' the nature of the case, be confined to the separation or de- 
composition of materials already in the vein ; for instance, the salts of 
silver being in solution, may be decomposed, and pure silver may be 
deposited on the v^ood and other materials in the mine. This has oc- 
curred in gome of the abandoned pits of mines which v^^ere filled with 
water, in which ladders and other implements were left. But this is a 
result quite different from the original action, when the vein was filled; 
and in all the experiments yet published to illustrate this process by 
galvanic agency, the analogy of the two cases is quite obscure, if it 
does not totally fail, and the result amounts to but little more than the 
decomposition of some of the materials held in solution by the water 
filling the vein, and does not go so far as to explain how the materials 
got there in the first place. ' 
Magnetic Oxide of St. Lawrence and Jefferson Counties. 
In the southeastern part of St. Lawrence, the great beds of hme- 
stone disappear, and along with them, the specular oxide. In their 
places we find a granite, approaching in its character to the hypersthene 
rock, with its usual associate, the magnetic oxide. The geological 
structure of this region is much like that of the eastern part of Essex, 
and the southern part of Clinton, and the probabihty is, that when the 
country is cleared, there will be found a similar mineral district. We 
already know of several veins of the magnetic oxide. One of these 
has been noticed in one of the preceding reports. It is known as the 
Chamont bed, and was explored to some extent, twenty years ago. It 
is about 4 miles west from the point where the Albany road crosses 
the Oswegatchie. It is situated near the road, and traverses a ridge 
or hill, about 100 feet high. A portion of this hill is occupied by the 
ore mixed with flint, varying in proportions, from 50 to 80 per cent of 
iron. It is black, and resembles the Palmer ore. It is described by 
Dr. Ambler, of Rossie, who visited the locality last fall, as a complete 
"pepper and salt mixture," which we may understand as consisting of 
fine grains of gray quartz and black particles of iron. 
The direction of the ore is nearly east and west, and the richest 
portion is on the southern declivity. It is in a gneiss rock, whose stra- 
ta are nearly vertical, but whose dip is to the west. It is highly mag- 
netic. 
The quality of this ore has not been sufi&ciently tested. Nothing in 
it appears injurious, and the probability is, that it will prove valuable. 
