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[Assembly 
cretions likewise of the shale of Chenango and Broome counties, 
and the concretions and septaria of the shore of Lake Erie. 
A further proof of the influence of crystallization is derived from 
the stony materials which form the predominant portion of all 
metallic veins. These minerals form the gangue or matrix of the 
ores; being those which commonly present crystalline forms, or a 
crystalline arrrangement of their particles. They are quartz, car- 
bonate of lime, fluate of lime, and sulphate of barytes — all which 
minerals are foreign to known volcanic products. Quartz and car- 
bonate of lime enter largely into the composition of rocks; and the 
two latter minerals are as often found in the interior of rocks, 
though not in the same abundance as in the veins. The same 
proof is also exhibited in the ores of veins, all of them presenting 
Jthe crystalline state. 
Finally, the fact that the fracture of a rock, be it of what kind 
it may, from the granite upwards, exhibits moisture when just de- 
tached from its position in the quarry, shows that the mineral par- 
ticles of rock are not in contact with each other, having an inter- 
posed fluid.* It is even so with common gun-flint, compact as it 
is; this substaince when recently dug being brittle, but acquiring 
toughness by exposure to the air, which dissipates its moisture. 
This condition of the particles of rocks, aided by the degree of 
heat to which all the older rocks have been subjected, and which 
tended to a greater separation, and greater mobility of particles, 
highly favors the theory of segregation, giving a vehicle for the 
action of crystallization, without which, like life in like circumstan- 
ces, it is equally passive. 
Moreover, from the knowledge acquired from the myriads of 
veins in Mexico, there appears to be no necessary connexion be- 
tween the richness of a vein and its depth, depending, as it must, 
upon the regular or irregular distribution of its metallic mineral 
matter in the rock; this mineral matter being subjected to crystal- 
lization, gravitation, as in the case with life, would to a certain 
degree, be counteracted by that force. 
It may not be irrelevant here to remark, from having, in part, 
adverted to it in the beginning of this report, and from its impor- 
tance to science; that in no country of the world, so far as observa- 
tion has been made, has the student of geology so many advanta- 
* Called in analysis, hygrometric moisture. 
