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d/ Boston and its Vicinit I/. i33 



GENERAL SYNOPSIS 



CLASS I.— EARTHY FOSSILS. 



J- 



Division i. — ^Infusible before the blowpipe. 



t Soluble ivith ej'ervescence in A''itrick and Muriatick acids. 

 tj. Field to the knife^ do not effervesce. 

 fit Scratch glass^ do not yield to the knife. 



Division ii. — Fusible before the blowpipe 



§ Hardness equal or superior to that of common ivindow g 



yield slightly to the knife. 

 § Field to the knife^ sometimes feebly scratch glass. 

 § Field easily to the knife, and sometimes to the nail. 

 § Very softy yield to the nail. 



^ 



CLASS II.— S^LIJVE FOSSILS, 



r 



t Precipitated from their solution in water by carbonated alkali 



CLASS lil-^.ZJ^FLMIMABLE SUBST^jyCES. 



t Combustible imtJijlayney leave no residuum. 



t| Combustible ivithflamgy yield a large bulky ash, and a pungent odour 



CLASS TV.^METALLICK FOSSILS. 



§ Assume a metallick form after roasting on charcoal tvhile any thin^ is 

 dissipated^ and subsequent fusion with bora^r. 



t Lustre metallick. 



n 



t| Lustre non metallick. 



§ JK^ot reducible to the metallick state before the blowpipe on charcoal, eitlier 



With or ivithout borax. 



t JIagnetick after roasting. 



t4. jybt magnet ick after roasting 



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