56 Mr. Smithson on Mr. Penns Theory concerning [July, 



bv every wave ; and sand wetted with ordinary sea water and 

 dried is not converted into millstone. The great hardness is 

 due to the silicious part. 



I brought a mass of sand from the sea at Dumbarton, inclos- 

 ing a recent razor shell with its epidermis on it, and fragments of 

 coal, cemented to stone by carbonate of lime, so that the cala- 

 brain process takes place on that coast. 



In limestones consisting of considerable-sized fragments of 

 shells, the sparry cement which connects them is perfectly evi- 

 dent. It is this cement which appears as regular crystals where 

 cavities occur in the mass too large to have been filled by it. 



Beds of sediment can by this means become rock at the 

 utmost depths of the ocean, and it is in all probability there that 

 most of them have done so. The workings of contiguous volca- 

 nos have supplied the carbonic acid. 



Oolites have been evidently formed in a sea much loaded 

 with dissolved carbonate of lime, and which on the escape of 

 the dissolving acid has crystallized round floating particles. 

 When the weight of the grains has become such as to occasion 

 their subsidence, they have been cemented together, every 

 thino- taking place in all respects as in the case of the pisolites of 

 Carlsbaden. The Kirkdale rock being composed of oolites ttiust 

 have had this origin. 



Such a formation cannot be assigned to the time of the deluge. 

 Besides the violence of bringing within the compass of a few 

 months, operations whose accomplishment seems to have 

 required centuries of centuries, the necessary conditions must 

 have been wanting. Had not all the volcanos become extin- 

 guished, they could not, and in such a time, have poured forth 

 carbonic acid to saturate the immensity of its waters ; and it is 

 also utterly impossible to believe that the beings in the ark, 

 already not a little inconvenienced for respiration, could with- 

 stand the suffocating effluvium. 



Coming of the Animals by Sea. 



Of the animals having been tropical ones no testimony is 

 offered. The elephant of Siberia being now ascertained to have 

 been a very hairy animal may be supposed to have been a 

 northern one, and if there were formerly northern elephants, 

 there may have been northern hyaenas and northern tigers. 



If the bodies were brought by water, no reason appears why 

 they are, with the exception of a few birds, exclusively those of 

 quadrupeds. Reptiles, insects, trees, even fish, for all of them 

 must have perished from the mixture of salt and fresh water, 

 must have entangled in the clusters. 



As the bodies must have been macerated for about a year in 

 the tropical seas, before the retreat of, the waters transported 



