98 Mr WhewelPs Address to the British Association 



shell of the earth, as the geologist has done of its solid crust, 

 this would be a vast step for meteorology. This, however, must 

 needs be a difficult task : in addition to the complexity of these 

 superincumbent masses, time enters here as a new element of 

 variety : the strata of the geologist continue fixed and perma- 

 nent ; those of the meteorologist change from one moment to 

 another. Another difficulty is this ; that while we want to de- 

 termine what takes place in the whole depth of the aerial ocean ^ 

 our observations are necessarily made almost solely at its bot- 

 tom. Our access to the heights of the atmosphere is more li- 

 mited, in comparison with what we wish to observe, than our 

 access to the depths of the earth. 



Geology, — Geology, indeed, is a most signal and animating in- 

 stance of what may -be effected by continued labours governed by 

 common views. Mr Coneybeare's Report upon this science gives 

 you a view of what has been done in it during the last twenty 

 years ; and his Section of Europe from the North of Scotland 

 to the Adriatic, which is annexed to the Report, conveys the 

 general views with regard to the structure of Central Europe, 

 at which geologists have now arrived. To point out any more 

 recent additions to its progress or its prospects is an undertak- 

 ing more suitable to the geologists by profession, than to the 

 present sketch. And all who take an interest in the subject will 

 rejoice that the constitution and practice of the Geological So- 

 ciety very happily provide, by the annual addresses of its presi- 

 dents, against any arrear in the incorporation of fresh acquisi- 

 tions with its accumulated treasures. 



Miner ahgy.-'^l^he science of Mineralogy, on which I had the 

 honour of offering a Report to the Association, was formerly look- 

 ed upon as a subordinate portion of Geology. It may, however, 

 now be most usefully considered as a science co-ordinate and close- 

 ly allied with Chemistry, and the most important questions for 

 examination in the one science belong almost equally to the 

 other. Mr Johnston, in his Report on Chemical Science, has, 

 as the subject required, dwelt upon the questions of isomorphism 

 and plesimorphism, which I had noticed as of great importance 

 to Mineralogy. Dr Turner and Professor Miller, who at the 

 last meeting undertook to inquire into this subject, have exa- 

 mined a number of cases, and obtained some valuable facts ; 



