62 Contributions towards Establishing the General Character 



water ; they divested themselves of their burden, depositing the 

 stones in localities where they are now found under the name 

 of erratic blocks, consisting chiefly of large pieces of granite, 

 porphyry, &c., and employed for decorating the bridges and 

 museums of Berlin, as also for paving the highways and public 

 roads of Brandenburg. Our countrymen on the Baltic enjoy 

 the possession of these stones merely because ice is lighter than 

 water. 



You will remember that I stated before, that the expansive 

 power of water, when in the act of freezing, is irresistible. 

 Nature possesses no gunpowder, for this is altogether an arti- 

 ficial product; but she accomplishes by water what we obtain 

 by fire. I have already brought to your notice, how the rocks 

 of the Faulhorn are broken to pieces by the action of freezing 

 water. Nature purposed to convert steril rocks and stones 

 into a fruitful mould. She employed the simple means of ad- 

 mitting water into the crevices, and of causing it to freeze. 

 The ice, in severing the rocks, acts on the principle of a wedge. 

 When it begins to melt, it assists in loosening the rocks, and 

 in accelerating their dilapidation. This process is repeated 

 until the stone is completely reduced to clay. 



I have now endeavoured to shew, that Nature is able to ac- 

 complish great things by small means ; and I trust you will 

 not depreciate the small means I have employed in order to 

 amuse you, and to direct your attention to a class of phenomena 

 on which you have had perhaps little occasion to reflect. It 

 has fallen to the share of very few individuals to perform great 

 things by small means ; an ordinary mortal frequently accom- 

 plishing but little by great means. But he is contented with 

 the testimony, that his labours have not been thrown away. 



Contributions towards Establishing the General Character of 

 the Fossil Plants of the genus Sigillaria. By "William King, 

 Esq., Curator of the Museum of the Natural History So- 

 ciety of Newcastle-on-Tyne, &c. (Communicated by the 

 Author.) 



(Continued from page 290 of vol. xxxvi. 



Hitherto no specimens of the genus Sigillaria have been made known, 

 possessing clear evidence as to the nature of its root. In a few instances, 



