No. 50.] 
321 
of a vein of magnetic oxide in that region. This part of my district 
I hope to explore the next season. We have, as will be seen, seven dis- 
tinct mineral districts in the northern counties, each of which are capable 
of supplying a vast amount of ore. Of these ores, it is to be considered 
that they possess, in themselves, qualities which will enable a scienti- 
fic manufacturer to convert them into the best of iron and steel. Of 
this, there is no doubt. Whether it is as profitable to embark in the 
manufacture of refined iron and the best varieties of steel as to continue 
to make the ordinary bar iron, is another question ; but that the ores can 
be converted into them as economically as those of any country, (the 
value of labor being the same) we consider established. 
Jefferson County. 
The geology of Jefferson county is quite simple and free from any 
obscure points, so far, at least, as it regards the order of superposition 
of its rocks. In speaking of its geology, brevity will be consulted, for 
the reason that in my next report I shall, necessarily, give a detailed 
account of it. It will be quite unnecessary to speak of the character of 
the surface or of the soil. Few counties are better known than this. 
It is celebrated for its agricultural productions, the excellencies of which 
are owing, partly to its limestones and argillaceous slates, which under- 
go a slow decomposition and furnish the elements of a valuable soil. 
A general division of the rocks of this county may be made as fol- 
lows : 1st. The primary class. They are confined mostly to the 
eastern towns, Wilna and Antwerp ; though a portion of Alexandria, all 
of Wells island and a part of Grindstone island are also of this class. 
The primary rocks are a gray granite and gneiss, a white granular 
limestone and hornblende. They are associated together more or less, 
though there are tracts over which one or the other may extend to the 
exclusion of all the others ; thus, in Antwerp, there is an extended 
field of primary Hmestone, and in Alexandria, granite ; though Wells 
island and a large portion of the shore opposite the island is hornblende 
and gneiss, with scarcely any limestone. Besides the primitive rocks 
just noticed is one composed of a mixture of serpentine and granular 
limestone, forming what is frequently called Verd Antique. To this I 
may subjoin Rensselaerite, which frequently occurs in thick, heavy 
beds in connexion with the above. 
I am the more disposed to notice the Rensselaerite, in consequence 
of the use which has been made of it in agriculture as a substitute for 
[Assembly, No. 50.] 41 
