24 GEOLOGY OF THE SECOND DISTRICT. 



which crosses the Oswegatchie a few rods to tlie west, or northwest of the village, and spreads 

 out extensively into the adjacent fields. At the bridge over the river at this place, the gi-anite 

 partakes of the character of sienitc ; and in and beneath it, near the water's edge, is a con- 

 tinuation probably of this bed of limestone. It is an important locality for studying the rela- 

 tions of the two rocks ; setting at rest, as an impartial observer would expect, the question of 

 the origin of limestone. 



At Gouverneiu: there are several beds of granite ; one of which is about two miles on the 

 road to Fowler, and is a fine variety of graphic granite. Another is about one mile south of 

 tlie village, at the locality of phosphate of lime ; it is a coarse gi-anite, and is traversed by 

 veins of limestone. It appears to extend south to the village of Antwerp. At some places 

 in this small range of primary, it is difficult to determine what rock predominates, the granite 

 or limestone. 



The granite at Gouvcrneur contains albite, and it appears to be of that variety which is 

 sometimes called albitic granite* It contains, also, large crystals of feldspar, usually at the 

 junction of the two rocks. Pyroxene, scapolite, hornblende and phosphate of lime are abun- 

 dant, and frequently so crowded as to injure materially the perfection of their forms. The 

 crystals at this place are imperfect and rough also, from another cause ; and to account satis- 

 factorily for it, wc are obliged to go back to that state when they were in the process of form- 

 ing. Thus, it is not mifrequent to find crystals of pyroxene enclosing a multitude of smaller 

 crystals of hornblende. The entire form is that of pyroxene, or the form of that mineral is 

 predominant ; but on inspecting these crystals, however, we find as much of their surfaces 

 composed of' hornblende as of pyroxene, the former standing out slightly in relief, or suffi- 

 ciently so as to disclose two of the sides of the prism. If the pyroxene were removed by a 

 corroding substance, its form would still remain, but the material would be that of hornblende. 

 The materials, therefore, mutually penetrate each other, but the crystals pass for pjTOxene. 

 It is certainly a curious kind of isomorphism, and well worthy of remembrance ; and it may 

 serve to explain some of the discordant results in the analyses of minerals, or to put chemists 

 on their guard in the selection of subjects for chemical examination. 



Another bed of granite appears at Alexandria Bay, and extends down to Hammond Landing. 

 It is a mi.\ture of the grey and flesh-colored varieties. In the neighborhood of the ba}^ small 

 veins of the magnetic oxide of iron occur in it. At Hammond Landing the bed is quite nar- 

 row, and is immediately succeeded by the Potsdam sandstone, which may be seen almost in 

 contact with it. At the landing, there is not sufficient space for any other mass to be inter- 

 posed between the two rocks, and the precise line of junction is concealed by earth. 



Granite appears, also, in the south part of Canton, at Potsdam village, and at Parrishville. 

 At neither of these places docs it present any thing worthy of notice. At Malone, between 

 three and four miles west of the village, there is another district of granite. It is in this place 

 traversed by veins of magnetic iron ore, which have been explored. An unimportant vein of 



♦ Albite in small hemitropes occurs in the cavities of the granite ; tliey are similar in form and appearance to those which are 

 found in the magncsian limestone at WilliamstowTi in Massachusetts. 



