THE EARTH. 



13 



fore, from these considerations, given back 

 to the sea; but the wonder was, how to ac- 

 count for their coining so far from their own 

 natural element upon land." 



As this naturally gave rise to many conjec- 

 tures, it is not to be wondered that some 

 among them have been very extraordinary. 

 An Italian, quoted by Mr. Buffbn, supposes 

 them to have been deposited in the earth at 

 the time of the crusades, by the pilgrims who 

 returned from Jerusalem; who gathering them 

 upon the sea-shore, in their return carried 

 them to their different places of habitation. 

 But this conji-cturer seems to have but a very 

 inadequate idea of their numbers. At Tou- 

 raine, in France, more than a hundred miles 

 from the sea, there is a plain of about nine 

 leagues long, and as many broad, whence the 

 peasants of the country supply themselves 

 with marl for manuring their lands. They 

 seldom dig deeper than twenty feet ; and the 

 whole plain is composed of the same mate- 

 rials, which are shells of various kinds, with- 

 out the smallest portion of earth between 

 them. Here then is a large space, in which 

 are deposited millions of tons of shells, that 

 pilgrims could not have collected, though their 

 whole employment had been nothing else. 

 England is furnished with its beds, which, 

 though not quite so extensive, yet are equally 

 wonderful. " Near Reading, in Berkshire, for 

 many succeeding generations, a continued 

 body of oyster-shells has been found through 

 the whole circumference of five or six acres 

 of ground. The foundation of these shells is 

 a hard rocky chalk ; and above this chalk, 

 the oyster-shells lie in a bed of green sand, 

 upon a level,as nigh as can possibly be judged, 

 and about two feet thickness." b These shells 

 are in their natural state, but they were found 

 also petrified, and almost in equal abundance 8 

 in all the Alpine rocks, in the Pyrenees, on 

 the hills of France, England, and Flanders. 

 Even in all quarries from whence marble is 

 dug, if the rocks be split perpendicularly 

 downwards, petrified shells and other marine 

 substances will be plainly discerned. 



" About a quarter of a mile from the river 

 Medway, in the county of Kent, after the 



Woodward, p. 43. 



* Phil. Trans, vol. ii. p. 427- 



c Button, vol. i. p. 40". 



taking off" the coping of a piece of ground 

 there, the workmen came to a blue marble, 

 which continued for three feet and a half 

 deep, or more, and then beneath appeared a 

 hard iloor, or pavement, composed of petrified 

 shells crowded closely together. This layer 

 was about an inch deep, and several yards 

 over; and it could be walked upon as upon a 

 beach. These stones, of which it was com- 

 posed, (the describer supposes them to have 

 always been stones,) were either wreathed 

 as snails, or bivalvular like cockles. The 

 wreathed kinds were about the size of a 

 hazel-nut, and were filled with a stony sub- 

 stance of the colour of marl ; and they them- 

 selves, also, till they were washed, were of 

 the same colour; but when cleaned, they ap- 

 peared of the colour of bezoar, and of the 

 same polish. After boiling in w ater they be- 

 came whitish, and left a chalkiness upon the 

 fingers."" 



In several parts of Asia and Africa, travel- 

 lers have observed these shells in great abun- 

 dance. In the mountains of Castravan, which 

 lie above the city Barut, they quarry out a 

 white stone, every part of which contains pe- 

 trified fishes in great numbers, and of sur- 

 prising 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 pre- 

 served 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 



rt Phil. Trans, p. 426. 

 e Buflbn, vol. i. p. 408. 



Hill, p. 646. 



