Limestone. 



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 

 apprize 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 

 portions of it* from different localities, in muriatic acid ; and the re- 

 sults were as follows : 



1. Purest variety from Whately ; 100 parts contain carbonate of 

 lime 78 ; residuum (chiefly sand) 22 parts. 



2. Compact variety from Conway ; carbonate of lime 58 parts ; 

 siliceous residuum 42 parts. 



3. Poorest from Whately ; carbonate of lime 67 parts ; siliceous 

 residuum 33 parts. 



I tried some specimens of our best limestones in the same manner, 

 with the following results : 



t. Gray limestone from New Marlborough ; carbonate of lime, 98 

 parts ; residuum (chiefly mica) 2 parts. 



2. Gray limestone from Walpole ; carbonate, of lime 92 parts - f 

 residuum 8 parts. 



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