1 832.] Progress of Geological Science. 527 



succession of phenomena, not one of which we perfectly comprehended, and under 

 the name diluvium, classed them all together. 



" To seek the light of physical truth hy reasoning of this kind, is, in the language 

 of Bacon, to seek the living among the dead, and will ever end in erroneous induc- 

 tion. Our errors were, however, natural, and of the same kind which led many ex- 

 cellent ohservers of a former century to refer all the secondary formations of geo- 

 logy to the Noachian deluge. Having been myself a believer, and, to the best of 

 my power, a propagator of what I now regard as a philosophic heresy, and having 

 more than once been quoted for opinions I do not now maintain, I think it right, 

 as one of my last acts before I quit this chair, thus publicly to read my recan- 

 tation. 



" We ought, indeed, to have paused before we first adopted the diluvian theory, 

 and referred all our old superficial gravel to the action of the Mosaic flood. For 

 of man, and the works of his hands, we have not yet found a single trace among 

 the remnants of a former world entombed in these ancient deposits. In classing 

 together distant unknown formations under one name ; in giving them a simul- 

 taneous origin, and in determining their date, not by the organic remains we had 

 discovered, but by those we expected hypothetically hereafter to discover, in them ; 

 we have given one more example of the passion with which the mind fastens upon 

 general conclusions, and of the readiness with which it leaves the consideration of 

 unconnected truths. 



" Are then the facts of our science opposed to the sacred records ? and do we deny 

 the reality of a historic deluge ? I utterly reject such an inference. Moral and 

 physical truth may partake of a common essence, but as far as we are concerned 

 their foundations are independent, and have not one common element. And in the 

 narrations of a great fatal catastrophe, handed down to us, not in our sacred books 

 only, but in the traditions of all nations, there is not a word to justify us in look- 

 ing to any mere physical monuments as the intelligible records of that event : such 

 monuments, at least, have not yet been found, and it is not perhaps intended that 

 they ever should be found. If however, we should hereafter discover the skeletons 

 of ancient tribes,, and the works of ancient art buried in the superficial detritus of 

 any large region of the earth ; then, and not till then, we may speculate about their 

 stature, and their manners, and their numbers, as we now speculate among the dis- 

 interred ruins of an ancient city*." 



After learning, that so important a change has been efFected in the nomencla- 

 ture of geological formations, we cannot conclude the present compilation better 

 than by presenting our readers with a comparative view of the classification of 

 rocks, according to all the current systems, extracted from the excellent Manual of 

 Geology recently published by Mr. De la Beche, a work which compresses into the 

 most portable form the whole data of Geological Science, and on which Mr. Mur- 

 chison passes the following encomium : 



" Nothing short of this compendious and instructive digest, in which with- 

 out losing sight of general principies the author has endeavoured to adhere to 

 the impartial rule of suum cuique was to have been expected from the pen of 

 so experienced and acute a geologist ; and so eager is the demand of the public 

 for a really good work on this subject, that a second edition has been called 

 for, and is already publishedf." 



* Rev. Prof. Sedgwick's Address, Phil. Mag. 314. 

 f Murchison's Address, Phil. Mag. lxv. 374. 



2 X 



