« 



i 



of Boston and its Vicinity 



131 



iSpecies XIII. 



Asbestus. 



t j Silica^ Magnesia^ Miimine and Lime, 



XIV.— Hornblende* 



Subspecies I. Common Hornblende 



11. Basaltic Hornblende- 



in. Actynolite. 



tj Silica^ Alumine and Magnesia* 



XV. 



Steatite. 



XVL— Chlorite. 



Subspecies I. Common Chlorite 



n. Chlorite Earth. 



t| Silica and Mumine. 



XVIL— Finite. 

 XVIIL — Argillaceous Slate 



Variety 1. Argillite. 



2. Novacuiite. 



Clay. 



Variety 1. Potter's clay. 



CLASS Ih—SdLIJ^'E FOSSILS, 



.^ 



These are composed of an acid united with an alkali^ earthy 

 or a metallick oxide, or two of these ; they are eapid^ and soluble 



^ 



■ r 



in water. The genera are founded on the peculiar alkali, earth 

 or metal, and the species on the predominant acid. 



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GENUS I.—JROJ^- 



Species I.— Sulpliate of Iron. 



t 



CLASS llh-^LJ^FLAMMABLE SUBSTAJ^CES. 



These are either solid, fluid or gasseous ; they possess a low 

 specifick gravity ; when solid, they are seldom crystalized, gen 



erally yield with ease to the knife, and are brittle. 



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