76 Prof. Bischof on the Natural History of 



have been felt so often in Szveden, but never" \\r Denmark. He 

 estimates, according to rough calculations, the elevation of the is- 

 land Bor7ihoIm to amount to one foot in the course of a century. 

 If elevations of countries., in which volcanic actions are felt, and 

 which are agitated by violent earthquakes, be produced, as is 

 very probable, by the same causes as these phenomena, yet it is 

 difficult to imagine these causes to operate in elevating countries 

 where no such phenomena occur, or where, at least, they take 

 place but rarely or to a small extent. The latter is the case 

 in the Scandinavian Peninsula. That region has no active 

 volcanos, no hot springs — even thermal springs bearing a tem- 

 perature of but a few degrees higher than the mean temperature 

 of the place, are considered as rarities ; whilst, in other coun- 

 tries, they are of very frequent occurrence. All this proves that 

 the crust of the earth in this country must be very soHd, and 

 traversed by comparatively few rents or fissures. 



Berzelius assigns as the cause of this rising of the Swedish 

 coast, the gradual cooling of the earth; and says: " Its diameter, 

 in this manner, decreases, and the consolidated crust leaves either 

 empty spaces between itself and the fluid mass, or sinks down- 

 wards. Being, however, of so large an extent that foldings 

 and bendings must occur, portions must rise up on one side and 

 sink on the other. This supposition seems to be supported by 

 the sinking of the western coast of Greenla7id, and of an island 

 situated in the Gulf of Youghall, a phenomenon which has 

 been recently pointed out by Ehe de Beaumont and Pingel. 

 Kloden also has recently given much probability to the sup- 

 position of a sinking of the Dalmatian coast,* 



We shall endeavour to shew in our next section what effect 

 might be expected on the surface of the earth, if its solid crust 

 should still continue to increase in thickness towards the inte- 

 rior by gradual consolidation of the fluid centre. Besides I 

 think that a sinking^ the outer crust can scarcely be supposed 

 to occur, but that it is much more probable that caverns should 

 be formed at the moment, when the fluid mass becomes sohd. 

 Al least the latter effect was seen in fusing two basalt balls 

 two feet in diameter, in which many larger and smaller cavities 



* Poggendorff's Ann., t. xliii. p. 361. 



