Geology of Massachusetts. 25 
The limestone quarries in Smithfield, Rhode Island, are so situa- 
ted as to be of great importance to Massachusetts, being accessible 
to a large portion of the southeastern part of our State, and lying 
close to the Blackstone canal. -The limestone here is white and gran- 
ular ; very much resembling that in the towns northwest of Boston,— 
especially that in Stoneham. It occurs in two principal beds, about 
two miles apart. I was told by an agent of one of the companies, 
which own this limestone, that not far from twenty thousand casks of 
lime, containing from thirty eight to forty gallons each, and worth 
nearly two dollars each, were annually prepared in the whole town. 
Several beds of limestone may be seen on the Map in the eastern 
part of the range of mica slate in Franklin county, west side of the 
Connecticut, in the towns of Whately, Conway, Ashfield, Colerain, 
&c. But this limestone is quite impure, and is not generally distin- 
guished, by the inhabitants of those towns, from the mica slate. It 
becomes an interesting inquiry, to those residing in the valley of the 
Connecticut, where quick lime is more expensive than in any other 
part of the State, whether this stone can be profitably converted into 
mortar. Very few attempts have yet been made to burn it, and 
those obviously quite unsatisfactory. ‘Those who made these attempts 
probably thought that the stone, after burning, would slack with as 
much energy and readiness as pure quick lime; and because the 
process went on slowly and feebly, they have inferred that the lime 
would be of no value. At least, I know this to have been the con- 
clusion in one instance, in which I had procured the burning of a 
considerable quantity of this limestone, in a regular lime kiln. But 
the mason, not seeing it slack briskly, did not think it necessary to 
apprise me of what he was doing, and mixed it with other lime, and 
defeated the whole experiment. I have, however, burnt a few 
pounds of this stone in a common chemical furnace, and found it 
to form a very excellent mortar; although requiring less sand than 
pure lime. Bricks cemented with it two or three years since, still 
remain as firmly united as ever. 
This limestone contains a large proportion of silex, which, on 
burning, becomes a harsh sand. Wishing to know how much of pure 
carbonate of lime was contained in it, I powdered and dissolved por- 
tions of it, from different localities, in muriatic acid; and the results 
were as follows : 
1. Purest variety from Whately ; 100 parts contain carbonate of 
lime 78; residuum (chiefly sand) 22 parts 
Vou. XXII.—No. 1. 4 
