Mr Rowell on the Electricity of Steam. 347 



habit them were the direct descendants of the fossils of Oenin- 

 gen and Menat, it would follow that we ought no longer to 

 meet with species peculiar to them either in the basin of the 

 Rhone or in that of the Rhine. Now, every thing leads us to 

 believe that the lake of Constance, as well as the greater part 

 of the Swiss lakes, were produced by dislocations posterior to 

 the deposition of the tertiary formations ; and that being the 

 case, how could the fishes of Oeningen survive catastrophes 

 which have produced such modifications in the form of the sur- 

 face of Switzerland 1 The consequence of these facts is obvious. 

 If we succeed in demonstrating that certain basins, like certain 

 terrestrial regions, are inhabited by peculiar species not found 

 elsewhere in contemporaneous deposits, we must thence con- 

 clude that the creation has been not only renewed at difierent 

 geological epochs, but also that the successive creations have 

 been more or less local ; that is to say, the species have been 

 created in the places which they inhabit, and that a limit has 

 been assigned to each which it does not overpass, as long as it 

 remains in its natural conditions. It is only man, and a small 

 number of species he has associated with him, that are not sub- 

 ject to this general law. And as the migrations of these same 

 species have taken place under the direct influence of man, we 

 may thence conclude that they did not take place in the ante- 

 rior ages.* 



On the Cause of the Electricity of Steam, By G. A. Rowell, 

 Esq. Communicated by the Author. t 



The cause of rain, evaporation, and atmospheric electricity, 

 having engaged my attention for many years, I endeavoured, 

 in two papers read before the Ashmolean Society, 1839i and 

 1841,§ to shew that evaporation is caused by the increase of 

 the surface of particles of water by expansion, and that thus 



* From BibliotliequG Universelle de Geneve, No. 100, p. 334-356. 

 t Read before the Ashmolean Society, February 26. 1844. 

 X Vide Report of the British Association, Glasgow Meeting. 

 § London and Edinburgh Philosophical Magazine, vol. xx., p. 45. 



