184 Mr Whewell's Address to the 



■which occur in the chalk and chalk flints, and have been termed Spiro- 

 linites. And, finally, under this head I must mention Mr Alfred Smee's 

 paper on the state in -which animal matter is usually found in fossils. 



" Mr Austen's hypothesis of the origin of the limestone of Devon, 

 though belonging in some measure to Geological Djmamics, may perhaps 

 be nrentioned here, since he explains the position of those beds by refe- 

 rence to the habits of the coral animal. Mr Austen has already shevm 

 himself to us as an excellent observer; and in constructing geological 

 maps, a task requiring no ordinary talents and temper, he has earned our 

 admiration. We shall therefore not be thought, I trust, to depreciate his 

 labours if we receive with less confidence speculations in their nature 

 more doubtful. As we can hardly suppose the calcareous beds of Devon 

 to have had an origin difierent from those of other countries, we cannot 

 help receiving with some suspicion a doctrine which would subvert al- 

 most the whole of our existing knowledge of the relations of fossiliferous 

 beds of limestone. 



Geological Dijnamici. 

 " In that part of geology which I have termed Geological Dynamics, 

 and which investigates and applies those causes of change by which we 

 may hope to explain geological phenomena, we may still observe that 

 fundamental antithesis of opinion which has so long existed on the sub- 

 ject : — the division of our geological speculators into Catasfrophists and 

 Uniformitarians ; — into those who read in the rocks of the globe the evi- 

 dence of vast revolutions, of an order different from any Mhich those of 

 man has^survived : — and those who^see in the condition of the earth the 

 result of a series of changes which are still going on without decay, the 

 same powers which produced the existing valleys and mountains being 

 3'et at work about us. Both these opinions have received their contri- 

 butions during the preceding year : Mr Darwin having laid before us his 

 views of the formation of mountain-chains and volcanos, which he con- 

 ceives to be the effect of a gradual, small, and occasional elevation of con- 

 tinental masses of the earth's crust ; while Mr Murchison gathers from 

 the researches in which he has been engaged, the belief of a former state 

 of paroxysmal turbulence, of much deeper rooted intensity and wider 

 range than any that are to be found in our own period ; and M. de Beau- 

 mont in France, has endeavoured to prove that Etna and many other 

 mountains must have been produced by some gigantic and extraordinary 

 convulsion of the earth. Both Mr Darwin and M. de Beaumont refer to 

 the same examples ; and while M. de Beaumont conceives that the cones 

 of the Andes must have been formed by an abrupt elevation, caused by 

 subterranean force, Mr Darwin has maintained the opinion, that these 

 lofty summits have been gradually thrust into the place which they oc- 

 cupy by a series of successive injections of molten matter from below, 

 each intruded portion of fluid having time to harden into rock before it 

 was burst and again injected by the next molten mass. For how other- 



