10 Geology of Massachusetts. 
to furnish a soil of good quality, and sometimes of superior fertility. 
The island of Rhode Island exhibits the superiority of the soil of this 
formation, to that of several other islands that surround it. As we pro- 
ceed northerly, the great quantities of diluvium spread over the sur- 
face, obliterate, or greatly modify the soil peculiar to the formation. 
But in Dorchester, Roxbury, Brooklyn, Brighton, and Newton, it is 
exhibited to great advantage ; presenting the finest examples of ex- 
uberant farms and gardens in the Commonwealth; although we must 
not forget the very superior cultivation that has been bestowed upon 
that part of the State.. Still, such luxuriance as we there witness— 
such fine fruit especially—could not be produced without a soil nat- 
urally excellent. 
Tron Ore. 
No ore except iron occurs in sufficient quantity in the State to de- 
serve notice in an agricultural point of view. In the west part of 
Worcester County, the soil for a width of several miles across the 
whole State, is so highly impregnated with the oxide of iron, as to 
receive from it a very deep tinge of what is called iron rust. This is 
particularly the case in the low grounds; where are frequently found 
beds of bog ore. I do not know very definitely the effect of this iron 
upon vegetation; but judging from the general excellence of the 
farms in the Brookfields, Sturbridge, Hardwick, New Braintree, 
Barre, Hubbardston, &c., I should presume it to be good. Certain- 
ly it cannot be injurious; for no part of the County exceeds the 
towns just named in the appearance of its farming interest; and 
nearly all the County, as may be seen by the map, is of one forma- 
tion. It would be an interesting problem, which in that county can 
be solved, to determine the precise influence of a soil highly ferru- 
ginous upon vegetation. 
Steatite, Serpentine, Scapolite Rock, Limestone. 
The next rocks, in an ascending order upon the tablets attached to 
the map, are steatite or soapstone, serpentine and scapolite rock. 
But they are of such limited extent as to deserve no notice in this 
connection. ‘The next rock, namely limestone, is found only in Berk- 
shire County, in quantities sufficient to modify the soil over much extent 
of surface. But in that county it occupies most of the vallies; while 
the mountains are chiefly mica slate. And the fertility of these val- 
lies is a striking evidence of the good influence of disintegrated and 
