432 Reviews, and Notices respecting New Books. 



likely to throw illustration on this subject, and which I yet almost 

 hesitate to allude to, lest I should incur the charge of indulging spe- 

 culations altogether rash and visionary. However, I would premise 

 the observation, that we must surely in no respect consider our planet 

 as an isolated body in nature ; it is one only of the general planetary 

 system, and every fair presumption of analogy favours the supposi- 

 tion, that similar general causes have acted in all the members of that 

 system. Now one of these members, our own satellite, is placed suf- 

 ficiently near us to enable our telescopic observations to distinguish 

 accurately the general outlines of its mountain chains, and other si- 

 milar features of its physical geography. We have been able to 

 discern even the eruption of volcanoes; and any one who has viewed 

 its surface through a telescope, must be struck with the exact iden- 

 tity of the forms which he there contemplates with the maps and de- 

 scriptions of the volcanic districts of our own globe. If we recall 

 Von Buch's account, already referred to, of crateriform amphitheatres 

 of many leagues in diameter, encircling central conical craters j of 

 lines of these generally disposed in a linear direction ; of such linear 

 trains often radiating from a central focus of principal disturbance ; 

 we may almost fancy that this description was intended as an exact 

 portrait of what we observe on the lunar surface. Is it, then, 

 altogether unfounded, to believe that by more carefully observing 

 these phenomena, where we have a whole hemisphere of a planet 

 at once open to our inspection, — by comparing the best of the 

 early delineations of its telescopic appearance, with its exact actual 

 forms, and watching diligently those forms, so that we may be able 

 to detect any changes in them, — is it too much to hope that we may 

 thus effectually extend our knowledge of the general laws of the vol- 

 canic forces, which should appear to be among the general planetary 

 phaenomena ?" 



The discussion of the remaining subject cannot be abbreviated 

 without injury, and we therefore give it entire. 



" The great branches of the comparative geology, and comparative 

 palaeontology (or study of fossil remains) of distant countries, much 

 as they have recently advanced, have as yet even a still wider interval 

 to pass over than that which they may have already accomplished, 

 before they shall have obtained that degree of completeness which 

 alone can qualify them to serve as sound bases in any geological 

 theory. First, as to comparative geology. The very introductory 

 question is yet inadequately answered, Is there or is there not any- 

 thing like such a general uniformity of type in the series of rock for- 

 mations in distant countries, that we must conceive them to have re- 

 sulted from general causes, of almost universal prevalence at the 

 same geological aeras ? Now it is clear that this question, if intelli- 

 gently proposed, does not require, for its affirmative solution, anything 

 like an exact identity of formations in remote localities. It does not 

 require any one to be able to take to Australia a detailed list of En- 

 glish strata, and to be able at once to lay his hands on the exact 

 equivalents of our lias, oolites and chalk. Such an idea would be 

 almost to caricature the Wernerian dogma of universal formations. 



