ANNIVERSARY ADDRESS OF THE PRESIDENT. XXXlll 



Internal Heat of the Globe.' There has been no field hitherto more 

 in want of able cultivators than that of Chemistry applied to the 

 elucidation of geological phsenomena, one which my able and lament- 

 ed friend, our former Secretar}'^, Professor Edward Turner, had just 

 entered upon with so much success, when he was taken away from 

 us in the prime of life. We ought therefore to hail with satisfaction 

 the appearance of this work by Professor Bischof. " The earth," 

 he says, " so far as we are acquainted with it, is a great laboratory, 

 wherein, since the creation, chemical processes have been uninter- 

 ruptedly going forward, and will go on, bo long as the earth continues 

 in its orbit round the sun. If we seek to investigate the structure 

 of the earth, if we endeavour to explain the phaenomena it presentSj 

 and the changes which are unceasingly taking place upon it, we must 

 enter the domains of Chemistry and Natural Philosophy." The first 

 part, that recently published, treats of the aqueous phsenomena within 

 and upon the earth ; " a knowledge of them," he observes. " of the 

 substances which waters take up, and of the processes to which they 

 mutually give rise, leads us to an explanation of the most important 

 and mighty changes M^iich the earth has undergone^ and is still sub» 

 ject to, and to the origin of the sedimentary formations." The 

 second part will treat of the origin of the materials of which these 

 formations are composed, of the crystalline rocks, their constituent 

 parts and their decompositions ; of the substances filling the cavities 

 in amygdoloids, of pseudomorphisms, &c. ; and a particular attention 

 will be devoted to a subject hitherto little attended to, the lithological 

 differences between primary and secondary formations. 



In my Address to you last year, I dwelt so much upon the older 

 series of rocks that I was unable to offer more than a few observa- 

 tions on the recent additions to our knowledge of the tertiary and 

 more modern formations, and on terrestrial changes now in pro* 

 gress. I entered; it is true, at some length upon the subject of 

 boulder formations and erratic blocks, and on some recent discoveries 

 of changes in the relative levels of sea and land, but I did not touch 

 upon the many valuable observations, communicated to us within a 

 short time, on the alterations which the surface of the earth has under- 

 gone subsequently to the deposit of the more modern tertiary beds, 

 in the period which approaches historical times, as well as on the 

 terrestrial changes which have since occurred and are now in pro- 

 gress. On the present occasion, I shall confine my review almost 

 exclusively to those contributions received in the last two years, which 

 have enlarged our knowledge of the more modern periods of geolo- 

 gical chronology, and even to a small number of these ; for I believe 

 that it will be more agreeable to you that I should dwell upon some 

 of the great questions opened up by the authors of the works to which 

 I refer, than that I should occupy your time by brief outlines of the 

 general contents of many works. I will also, in the present as in 

 my last year's Address, abstain from reference to the papers read in 

 this room ; not from any want of a due appreciation of their value, 

 but because I deem it superfluous. You heard them read and dis* 



