150 Rev. Mr Wheweirs Address to the Geological Society, 



England is again dmwn, there is scarcely any but microscopic 

 alterations which require to be made. No higher evidence can 

 be conceived of the vast knowledge and great sagacity of its 

 author. 



Such modifications we must ever expect to have to make of a 

 first approximation ; and I should think it a misfortune to our 

 researches if we should attempt to elude this necessity by giving 

 up the key of all our geological knowledge of our country, — 

 the doctrine that there is a fixed order of strata, characterized 

 mainly by their organic fossils. If we have not advanced so 

 far as to prove this, what have we proved ? If our terms do 

 not imply this, what is their meaning ? Is it not true, in our 

 science as in all others, that a technical phraseology is real 

 wealth, because it puts in our hands a vast treasure of foregone 

 generalizations ? And if we evade the difficulties which may 

 occur in the application of this phraseology to new cases, by 

 declaring that our terms are of little importance, is not this to 

 deprive our language of all meaning and all worth ? Do we 

 not thus refuse to recognise as valuable the tokens which we 

 ourselves circulate, and plainly declare ourselves bankrupts ia 

 knowledge ? When certain strata of Devon have thus been 

 identified with the coal-measures of other regions, can we still 

 term them grauwacke? Either this term implies members 

 having a definite place in our series of strata, or it does not. If 

 it do, it is certain that these strata have not that place. If it 

 do not, it conveys no geological knowledge at all. But if it 

 be used to imply a rejection of such series, it involves a denial 

 of all geological knowledge hitherto asserted concerning the 

 older rocks of this county. 



The transition downwards from the culmiferous beds of De- 

 von to the older strata on which they rest, is, according to al- 

 most all who have studied the subject, wrapt in great obscurity. 

 In this obscurity, if it be true that the fossil plants of the culm 

 measures are found also in the subjacent rocks, there is nothing 

 which need make us mistrust the clear and positive part of our 

 knowledge. And even if this be so, it will not be the less neces- 

 sary to separate the culmiferous from the subjacent Silurian and 

 Cambrian systems, by a different name in our lists, and by a 



