#84 Preface to ** The Natural History 
‘body and composition of our rocks and strata, is a clear proof, 
that those strata were formed by water,—which isso far true, I 
also assert, that these exuvie, and all the other remains of plants 
and animals found in the body and composition cf our strata, is 
a decisive proof that the strata were formed by the agency of 
water; at the same time, I positively deny that our strata were 
formed beneath the waters of the ocean, 
The natural history of the formation of our strata is fully ex 
plained in the second volume of my Essays upon rational aud 
mechanical principles, to which I refer for satisfaction on this 
topic. In my opinion, our author’s s philosophy is not more ex- 
‘ceptionable in any part of his Theory than in treating of marine 
testaceous animals, as he makes these in effect to be very €X- 
tensive creators of matter, which is exalting them much too high 
in our system of things, 
The Doctor says, that one-fourth part of the solid bulk of our 
globe is’ composed of limestone, marble, and other ¢aleareous 
matter, which I think is giving it too great a proportion, My 
general observations have beeu pretty extensive ; and, as far as 
I can judge, all our limestones, marbles, chalk- -stdite find clay- 
marl, which is soft limestone, and all other caicareous fossil sub- 
stances, may amount to about a seventh or eighth part of the solid 
bulk of the superficies of the globe, which is a great deal indeed. 
Now our author asserts, in plain terms, and in several parts 
of his Theory, that this immense bulk of solid caleareous fossil 
matter was all of it produced from the remains of the testaceous 
tribes of the ocean. In my opinion, the proposition may be re- 
versed ; and we may with more truth assert, that the calcareous 
matter produced them, than that they produced it. 
Snail-shells are found in great numbers near old stene and 
lime walls; yet we never imagine that these walls were pro- 
duced by snails. It is almost evident to our senses, that these 
animals find the calcareous matter in a fluid state mixed in the 
waters of the ocean and the land, which they collect and use to 
make shells, coral, &c. To say that they produce this matter, 
js much the same as to say that they create it. 
Matter is only changed from one form of existence to another 
$n the reproduction and growth of animal and vegetable bodies, 
but they really produce no part of matter that did not exist be- 
fore in another form. 
I grant, that the exuvie of testaceous animals are found in 
great abundance in many of our limestones and marbles, but not 
in all of them. There are very extensive rocks and strata of 
the mountain-limestones, and marbles of various colours, tex- 
“ture, and degrees of hardness, in which not the least particle of 
shell or coral is to be found. 
These 
