42 PHILOSOPHICAL TRANSACTIONS. [aNNO ISQS. 



such as marble, stone, coal, chalk, sand, gravel, clay, marl, and other sorts 

 of earth. Among other things, he observes that there are lodged vast numbers 

 of sea-shells, and other marine bodies, in these terrestrial strata, as well as in 

 the more solid ones, as stone and marble, wherewith they are incorporated, 

 being lodged among the matter they consist of, and found in the midst of the 

 stone of rocks and quarries, -as in those that are not so hard, such as chalk, 

 clay, and the like ; and this in the most midland countries as well as in those 

 which are nearer to the sea. He observes, that these shells are thus found in- 

 closed in this terrestrial matter fiom the surface of the earth down to the very 

 bottom of the deepest quarries and mines ; ; that they lie according to the order 

 of their specific gravity, the heavier kinds deeper, the lighter nearer the surface 

 of the earth, and both among terrestrial matter, that is of the same specific 

 gravity that they are of ; and this not only in England, but in other parts of 

 Europe, Asia, Africa, and America, or in short, all over the world. But be- 

 cause many learned men of late have doubted whether these were truly shells or 

 not, he removes that doubt, and answers their objections, proving these to be 

 the real shells of once living shell-fish, and that they were originally generated 

 in the sea. 



He then proceeds to the body of the work, which is divided into 6 parts. In 

 the 1st of which he examines the ways whereby other authors have thought 

 these shells were brought to land ; and particularly those who suppose that there 

 happen great changes of sea and land. E. gr. That there have been many and 

 great islands raised from the bottom of the sea by earthquakes, such as Rhodes 

 and others ; that the centre of gravity in the terraqueous globe shifts and moves, 

 and consequently the water of the sea moves also : so that it deserts those tracts 

 of land which it formerly covered, and betakes itself to others which were till 

 then dry land. That the mud which is carried down into the sea by rivers, and 

 precipitated at their ostia, makes daily additions to the earth, which therefore 

 encroaches and gains upon the sea, as the sea in other places does upoi the 

 earth ; that the sea by these means being forced off, and having left many parts 

 of the globe, it also left there behind it shells and other sea productions. 



But to these opinions our author replies, that they are destitute of all true 

 foundation, and repugnant to observation ; that on them can never possibly be 

 accounted for the circumstances of these marine bodies, as t^eir being lodged 

 in the middle of the rocks, their numbers, order, variety, depth in the earth, 

 distance from any sea, and the like. So that though such changes as they sup- 

 pose had really happened, yet these shells, &c. could never by them have been put 

 into the condition wherein they are now found ; but he further adds, that there 

 is not any reason to believe that such changes did ever happen, having not the 



