356 Analysis of Scientific Books. 



volume before us, our limits prevent any more extended notice 

 than that already given in our abstract of the proceedings of the 

 Royal Society, (Vol. xix. p. 277.) 



II. Considerations on Volcanoes; the probable Causes of their Phe- 

 nomena, the Laws which determine^ their march, the Disposition 

 of their Products, and their connexion ivith the present State of, 

 and past History of the Globe ; leading to the establishment of a 

 Neio Theory of the Earth. By G. Poulett Scrope, Esq., Sec. 

 Geol. Soc. London, 18.25. Phillips. 



This work forms what is commonly called a complete treatise, 

 though the author has given it a more moderate title ; and al- 

 though, like every work on geology, it cannot fail to contain dis- 

 puted points and controversial matter, we do not know that any 

 thing new can now be said on these subjects, and shall not there- 

 fore indulge ourselves in discussing them. Thinking it equally 

 unnecessary to enter into any discussion on the merits of the 

 work, as such, since, on all subjects which, like this, may be called 

 technical, the particular readers into whose hands it must fall, are 

 fully as competent to judge of it as ourselves, we shall be content 

 with giving such an analysis of it as is practicable, conceiving, 

 that in so doing, we shall be best able to gratify and interest our 

 readers. 



Describing generally what is meant by volcano, and by lava, in 

 which the author properly includes all volcanic rocky erupted 

 matter, under whatever form it may be disposed on the surface, 

 Mr. S. proceeds to state the known volcanoes at 200; afterwards 

 showing reason to think this to be much less than the number 

 probably existing in the world. The arguments for this opinion 

 consist in our ignorance of the interior of great continents, in the 

 probability of unknown marine volcanoes, and in the fact that, for 

 want of observers and records, many which have broken out at 

 distant times, are unknown or forgotten. 



To the terrestrial volcanoes he has given the term subaerial, 

 and to the marine the appellation of subaqueous. 



In the first class, the character of the appearances vary accord- 

 ing to the incidental fact of the volcano being new, or appearing 

 through an ancient vent. But it is not very certain that we know 

 of any rigidly new ; as even the eruptions of Yorullo are con- 

 sidered as coming from vents subsidiary to former ones. Au- 

 vergne, however, and the well-known country connected with it, 

 in this respect, as well as the volcanic territory of the Rhine, 

 preserve the records of volcanoes which have been once of this 

 character, and where therefore the circumstances can be studied 

 with facility. 



