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we know not how it is to perform, andin which we have no experience of itspower. Mr. Murray* attempts to get overthis objection by an appeal to facts ; andpointing out the analogy which subsistsbetween the contorsions of entire strata,and the wavings which, on the small scaleare seen in alabaster and stalactite, (wav-ings which Count Bournon b ascribes toa change in the direction of the consti-tuent crystals,) infers that as crystallizationhas produced these appearances in the onecase, it may be presumed to have done soin the other. I apprehend it has not pro-duced them in either, and that in rea-soning on this subject Mr. Murray has notguarded himself sufficiently against an errorto which we are always liable, that of con-founding co-existent phenomena with causeand effect. That alternate beds of differentsubstances, such as limestone, sandstone, andslate, should be all curved, as we find themon the coast of Devonshire, and in many
• Comparative View of the Huttonian and Neptu-nian Systems of Geology, p. 109.