110 Volcanos. 



"In the night this current is luminous; but in the clay, it is 

 generally obscured by vapors, or loses its light by the cooling 

 and blackening of the surface. There are cases, however, in 

 which no torrent of lava occurs, and where no other rocks than 

 scoriae are erupted. The greatest period of violence is generally 

 over when the lava has flowed for a little while, or this is the 

 crisis of the volcano. But commonly, the explosions of fragments 

 and dust continue for some time, gradually diminishing, till the 

 whole falls into a state of quiescence, and is finally extinguished. 

 Lastly, it must be noticed, that from the action of the volcano on 

 the atmosphere, clouds are generally formed in it, which produce 

 falls of rain, often causing torrents, or even inundations. 



" We must refer to the work itself, pp. 13, 14, for a catalogue 

 of eruptions which we could not conveniently introduce. But the 

 intervals of repose are various, reaching in some cases as far as 

 to many centuries; so that cultivation and population are renewed, 

 to be dispersed again at some future day. In these intervals of 

 repose, however, it is common for vapors to continue to be pro- 

 duced, either from the craters, or in the course of the currents of 

 lava; and when these are sulphureous, they deposit sulphur ; and 

 in other cases, from their acid nature, they corrode and decom- 

 pose the rocks through which they find a vent. What are called 

 solfataras and souffrieres are the result." 



Journal of Science of the R. Inst. JVb. 40, p. 356. 



The above citation contains a concise, but clear and in- 

 teresting account, of the principal phenomena which attend 

 volcanic eruptions. We now proceed to quote the Edinburgh 



Analysis. 



" The work of which we propose at present to give a copious 

 analysis, is one of those excellent productions which appear at 

 very distant intervals, and give a new tone to scientific inquiry. 

 Mr. Poulett Scrope has not only enjoyed numerous opportuni- 

 ties of studying many of the grand, operations which he de- 

 scribes, but he has exercised unusual diligence in making him- 

 self acquainted with the facts and reasonings of our most emi- 

 nent geological travellers. When we say, that this work was writ- 

 ten after visiting the active volcanos of iEtna, Vesuvius, and 

 Stromboli, and exploring the extinct craters of Auvergne, of 

 Italy, of the Rhine, and of the jiorth of Germany, we offer 

 our readers some pledge for the accuracy of its facts, and the 

 soundness of its reasonings. 



" The work commences with a descriptive account of the 

 Volcanic Phenomena, in which the author treats of the num- 

 ber and dispersion of volcanic vents on the surface of the globe, 

 a detailed catalogue of which is given in an appendix. The 



