SILLIMAN'S INTRODUCTION. 21 



hurried from that which is stupendous and vast, to that which is 

 inconceivably minute. The extremes of creation meet in the mineral 

 kingdom. In the solid rocks are found both the colossal reptiles, 

 and the microscopic infusorial animalcules. Ehrenberg has dis- 

 covered that polishing slate is made up of the cases or shells of 

 animalcules so minute, that forty-one thousand millions of them are 

 required to fill a cubic inch, and these siliceous shields are the 

 cause of the well-known effect of the tripoli, or rotten stone, in 

 polishing steel, &c. An analogous constitution has been discovered 

 in certain flint, opal, and bog iron ; and extensive deposits of marl, 

 &c, in this country, are composed of similar remains, figures of 

 many of which have been given by Professor Bailey, in the 

 American Journal of Science. Even the soft parts of the foramini- 

 fera have been detected in the chalk and flint of England by our 

 Author* 



10. General Remarks. — Such is a very general and imperfect 

 sketch of the progressive groups of animals and plants, that have 

 inhabited our world, have become extinct, and are, in countless 

 myriads, entombed in the strata, and in the solid rocks. It is only 

 on the upper surface that we discover loose and scattered boulders 

 and fragments of rocks, and beds of gravel, sand, and detritus, 

 the ruins of more ancient strata; in short, such accumulations 

 of drifted and alluvial materials as we could with reason attribute 

 to catastrophes of rising and rushing water, the deluges cf geo- 

 logists, or the deluge of the Scriptures; the latter, almost alone, 

 being admitted to the contemplations of those who are uninstructed 

 in our science. Now, it is a matter of physical demonstration, 

 that the earth existed for many ages before Man was created ; the 

 whole course of geological investigation proves this view to be the 

 only one that is consistent with the facts. To be convinced of its 

 truth, it is only necessary to become thoroughly acquainted with 

 the innumerable records of a progressive creation and destruction 

 which the earth contains, inscribed on medals, more replete with 

 historical truth, and more worthy of confidence, than those that 

 have been formed by man; as much more as nature exceeds in 

 veracity, the erring, or mendacious records of the human race. 



11. Consistency of Geology with the Scripture History.— 

 Hardly two centuries have passed since the astronomical doctrines 



* See Philosophical Transactions, for 1846. 



