70 



Mineralogy and Geology, 



ments showing that the shells, in some cases, attained to considerable di- 

 mensions. Others are not more i 

 than a fourth of the size figured, 

 and, from the circumstance of 



being commonly found in ^.-—t^"-:^ ^0 



groups, show the gregarious 

 habits of the fish in their ori- 

 ginal state. In the diluvium 

 of Norfolk and Suffolk, they 

 rarely occur in any other form 

 than as casts in flint, or hard 

 chalk, or occasionally with a 

 fragment of the shell only ad- 

 hering to the chalk nodules. 

 These are dispersed in every 

 part of this district, being found 

 equally on the highest eminences 

 and on the margins of the val- 

 leys. We give ready insertion to the communication of Mr. Stock, not 

 because we attach an unnecessary importance to the present article, but 

 from the desire to encourage local contributions, and notices of occasional 

 discoveries in this or in any other department of natural science. The 

 fossil elephant's tooth, and, judging from its locality, the Inoceramus also, 

 are derived from the diluvial valley of the Waveney, which has afforded 

 numerous specimens of the remains of animals, particularly in the higher 

 parts, in the neighbourhood of Eye, Hoxne, Diss, Roydon, &c., and there 

 is little doubt that similar relics exist, but have attracted little observation, 

 in every portion of this valley. Agricultural and domestic operations, such 

 as digging drains in meadows and marshes, sinking wells, and excavating 

 gravel-pits, are favourable to such discoveries ; and the communication of 

 the circumstances, from local observers, leads to a useful concentration of 

 geological facts. Our correspondent will oblige us by continuing his observ- 

 ations. We would suggest his endeavouring to trace the crag-beds in this 

 direction. They seem to exist without the shells, or with slight indications 

 of them, in the vicinity of Beccles and more westerly, and have been met 

 with in the diluvium of the gravel-pits much higher up. Mr. R. C. Taylor 

 has sketched the geological character of the Waveney valley, in his work 

 on the geology of East Norfolk, with reference to the hypothesis of Mr. 

 Robherds, on the supposed gradual sinking in the level of the German 

 ocean. 



Temperature of the Interior of the Earth. — A very interesting paper on 

 this subject, by M. L. Cordier, Professor of Geology in the Garden of 

 Plants at Paris, vi^ill be found in Professor Jameson's Journal for April. 

 From numerous experiments made by himself and others in mines, M. Cor- 

 dier concludes, — 1. that there is a subterraneous heat peculiar to the terres- 

 trial globe, which does not depend on the solar rays, and which increases 

 rapidly with the depth ; 2. the increase of this heat does not follow the 

 same law all over the earth, it may be twice or three times as much in one 

 country as in another ; 3. these differences are not in constant relation with 

 longitudes and latitudes j and, 4, the increase is more rapid than has been 

 supposed. 



It is proper to state that the opinions maintained by the author are not 

 new. The value of the memoir lies in its placing on a firm scientific basis 

 what was formerly a mere hypothesis. M. Cordier, after much research, 

 holds that an intense heat exists in the interior of the earth, that the ex- 

 ternal crust upon which we stand may be from 50 to 100 miles in thickness, 

 that beyond this all within is occupied by a molten mass ; he infers further, 

 that the entire globe consisted originally of such a molten mass, the outer 



