Geological Society. 44<9 



or through a new alkaline or acid, or saturated saline solu- 

 tion. 



I cannot help thinking that the theory of secondary piles, 

 of which the functions seem to depend on chemical changes 

 so very minute, will, when rightly understood, afford the best 

 refutation of the doctrines of the clcctromotists. The beauti- 

 ful experiments of Schcenbein and Matteucci have surely 

 prepax'ed the way for the establishment of such a theory ! 

 I remain. Gentlemen, yours, &c, 



J. B. 



LXVIII. Proceedings of Learned Societies. ' 



GEOLOGICAL SOCIETY. 

 President s Anniversarj/ Address: continued from p. 387. 



IN attempting a sketch of the subjects which have occupied the 

 attention of the Society during the year, I should wish to retain 

 that distribution of the science of geology according to which I ar- 

 ranged my remarks in the Address which I had last year the honour 

 of reading to the Society ; I mean the primary division into Descrip- 

 tive Geology and Geological Dynamics ; the former implying a de- 

 scription of the rocks of the earth's surface according to an esta- 

 blished classification of strata and formations ; and the latter dealing 

 with the study of those general laws and causes of change by which 

 we hope to understand and account for the facts which Descrip- 

 tive Geology brings before us ; — in short, the jjresent condition and 

 the past history of the earth's crust. But as the laws of permanence 

 and change, with regard to organized beings, differ very widely from 

 the dynamics of brute matter, we may conveniently make a separate 

 study of the relations of organic life to which geology conducts us, 

 and may mark it by the name Palaontology, by which it is com- 

 monly known. I will add, that it still appears to me convenient, for 

 the present, to divide Descriptive Geology into two portions, — the 

 Home circuit, in which the order of superposition has already been 

 established with great continuity and detail ; and the Foreign region, 

 in which we are only just beginning to trace such an order. I shall 

 also, as before, take the ascending order of strata. According to 

 this arrangement of the science, I shall venture to bring to your re- 

 collection a few of the points to which our attention has mainly been 

 called during the past year. 



DESCRIPTIVE GEOLOGY. 



1. Home {North European) Geology When I stated that De- 

 scriptive Geology lias for its task the reference of the rocks of some 

 portion of the eartli's surface to an established classification into 

 strata and formations, it was implied, that the more common employ- 

 ment of the descriptive; geologist must l)e to refer the rocks whicii 

 he examines to some classes already Jixed and recognized ; but it 

 could hardly fail to occur to you, that from time to time the leaders 



Phil. Mag. S. 3. Vol. 14. No. 91. June 1839. 2 G 



