FOSSIL-SHELLS, ETC. 351 



when cleaned, they appeared of the color of bezoar, and ot 

 the same polish. After boiling in water they become 

 whitish, and left a chalkiness upon the fingers." 



In several parts of Asia and Africa, travellers have ob- 

 served these shells in great abundance. In the mountains 

 of Castravan, which lie above the city Barut, they quarry 

 out a white stone, every part of which contains petrified 

 fishes in great numbers, and of surprising diversity. They 

 also seem to continue in such preservation, that their fins, 

 scales, and all the minutest distinctions of their make, can 

 be perfectly discerned. 



From all these instances we may conclude, that fossils 

 are very numerous; and, indeed, independent of their 

 situation, they afford no small entertainment to observe 

 them as preserved in the cabinets of the curious. The 

 varieties of their kinds are astonishing. Most of the sea- 

 shells which are known, and many others to which we are 

 entirely strangers, are to be seen either in their natural 

 state, or in various degrees of petrifaction. In the place 

 of some we have mere spar, or stone, exactly expressing 

 all the lineaments of animals, as having been wholly 

 formed from them. For it has happened, that the shells 

 dissolving by very slow degrees, and the matter having 

 nicely and exactly filled all the cavities within, this matter, 

 after the shells have perished, has preserved exactly and 

 regularly the whole print of their internal surface. Of 

 these there are various kinds found in our pits ; many of 

 them resembling those of our own shores ; and many 

 others that are only to be found on the coasts of other coun- 

 tries. There are some shells resembling those that are 

 never stranded upon our coasts ; but always remain in the 

 deep : and many more there are which we can assimilate 

 with no shells that are known amongst us. But we find 

 not only shells in our pits, but also fishes and corals in 

 great abundance; together with almost every sort of 

 marine production. 



