78 The Limeatones, and Lime. [Feb., 



Taconic Limestones of JVew York. — Sing Sing marble. 



Analysis. 



Carbonate of lime, _ - _ 53.34 



" magnesia, - - 45.89 



Silica and alumina, _ _ - 0.87 



Oxide of iron, - - - - trace 



100.10 



Per centage of caustic lime, 30.04. 

 do do pure magnesia, 22.23. 



This rock is regarded as a dolomite; it does not resist the ac- 

 tion of the atmosphere of this climate very well, and for heavy 

 structures it is not the best material which can be employed. 



Limestones of Dover and Dutchess county. Color, white, 

 bluish white, fine granular. 



Carbonate of lime, _ _ _ 60.50 

 " magnesia, - - 39.50 



100. 

 Per cent of pure lime, 34.14. 

 do. magnesia, 19.12. 



Sparry limestone of Hoosick Falls. Color; bluish white; and 

 it is usually traversed by short white crystalline veins. It is west 

 of the Stockbridge limestone, and is not magnesian properly 

 speaking. 



Jinalysis. 

 Insoluble matter, silica, &c., - 7.40 



Alumina and peroxide of iron, - 1.60 

 Carbonate of lime, - - - 91.00 



2. Taconic Limestones in Massachusetts. The beds are prolong- 

 ed from New York, the Westchester limestones being identical with 

 those of Stockbridge and Adams. The range is still prolonged 

 into Vermont. 



Stockbridge limestone of Great Barrington. Color, white, 

 and clouded, forming a clouded marble. 



Analysis. 



Carbonate of lime, - - - 60.30 



" magnesia, - - 38.09 



Peroxide of iron, _ _ _ 0.65 



Silica and alumina, - - - 0.96 



Specific gravity 2.84. Per cent of lime 33.77. 



