220 Dr Daubeny on the DUtrJial Thcoiy, 



selves aulhorized to refer the latter to that principle, which em- 

 braces both cases, rather than adopt two explanations for pK^-" 

 nomena in other respects so analogous. ^ '^-■r^.'An. oi ab^tiWijJk 

 ^T have hitherto been arguing on the assumption that the va!J- 

 l^kin Auvergne are really destitute of debris derived from a 

 distant quarter ; and that the negative evidence adduced to 

 ^eW' the total absence ttf-^iifch^'pi^bbles; resting as it does on au- 

 thority, which, however fes^ec^table, ' is that of foreigners, such 

 as Messrs Scrope, Murchison and Lyeli (to which I ought in 

 candour to add that of niy own ciirsory ^xiamination this sum- 

 mer), is to be regarded as absolutely decisive. * ' ./ rt.iKKj 



Other observers, however, resident in the counti'yj'keefln'lo 

 have arrived at an opposite conclusion ; for Messrs Deveze 

 and Bouillet* are stated to have discovered, in various parts of 

 the arrondissement of Issoire, fragments of Jura limestone, 

 which, occurring in such a spot, furnish precisely the sairi^ 

 proof of the action of a distant current, as the Leckie pebbles 

 afford, when observed in the valley of Oxford. 



To assert, therefore, in the present state of our knowledge^ ¥!ie 

 absence of all proofs of diluvial action throughout Auvergne, 

 wotild at least be hazardous ; but, were the fact ever so well esta- 

 blished, I still think that those geologists who contend against 

 IfeiKih'd supposition, not on general grounds, but by evidence de- 

 duced from this particular district, should be required to prove, 

 not only that the valleys in that country may have been pro- 

 ducted By rivers, but likewise that the phenomena they exhibit 

 "are such as a deluge could not have given rise to. " 



Now, I apprehend the arguments adduced by the opponents 

 'rif this theory belong sometimes to the former and sometimes to 

 the latter of these heads ; and that, by keeping in view this dis- 

 tinction between their real drift, we shall simplify considerably 

 the question at issue, and be able more clearly to shew how far 

 th6y may have succeeded in deciding it. 



'' ' In referring to the facts which are adduced to prove that ex- 

 isting causes are competent to have occasioned the valleys in 

 ^A^^Ve^ghe, it is no more thian justice in the 'first place to rS- 



* See the work by Messrs Croizet and Jobert on the Fossil Bones found 



