3G0 



THE GEOLOGIST, 



ancients, of some geological ideas. Tlie work is throngliout mai'lred by a 

 manly, vigorous, style of tlioiiglit, which alone would entitle the author to 

 take the prominent place amongst Europe's most philosophical thinkers 

 he has assumed. In the confidence that future researches will speedily 

 result from his prolonged attempts to pierce into the hidden fountains of 

 human thought during past ages, we cannot better express the pleasure 

 and admiration we have felt while reading the work than in this necessaril}'' 

 brief and imperfect notice of Dr. Schvarcz's volume. 



Volcanos, and the Character of their Phenomena. By Gr. Poulett 

 Scrope, Esq. London : Longman. 1862. 



There are only two ways of reviewing a book, either thoroughly or 

 briefly. To review Mr. Scrope's book properly would not only occupy the 

 space of a number, but it would be superfluous on our part ; for, as with- 

 out exception, it is the standard work on the subject, every geologist 

 who studies volcanic phenomena must have it. Mr. Scrope's views are 

 well known. He traces in all the m.ass of evidence accumulated the proof 

 of the general uniformity and simplicity of the phenomena of which vol- 

 canos and the volcanic formations are the expressions. Opposing Hum- 

 boldt's view of their " isolated, variable, and obscure character," he 

 mostly labours to show, that in every quarter of the globe the eruptions 

 that have taken place are characterized by the same repeated splitting of 

 the earth's crust in fissures, and generally accompanied by earthquakes and 

 other indications of the swelling and heaving of subterranean effervescent 

 matter, the same explosive outbursts of steam and vapours, throwing up 

 liquid drops and cellular fragments of wholly or partially fused mineral 

 substances or lava, or expelled in jets or streams, which flow or spread over 

 considerable areas, or accumulate in bulky masses about the eruptive vent 

 according to their degree of liquidity or gravity, and an examination of 

 which discloses everywhere the same basalts, greystones, or trachytes, 

 composed of the same minerals in varying proportions. He points out 

 everywhere the same composition and structure in volcanic formations, 

 from the smallest cinder-cones to the greatest and loftiest mountains, pre- 

 senting the accumulated result of a long series of successive eruptions ; 

 the same general quaquaversal dip of their component beds of lava and 

 conglomerate from the central heights, as formed by successive outpourings 

 and successive showers of ejected materials ; the same hollows drilled here 

 and there through the axes of the mountain-masses by the force of explod- 

 ing volumes of steam ; and, finally, the general parallelism over the entire 

 surface of the globe of the chief trains of volcanic vents as if the fissures 

 through which the eruptions find their way outwardly were owing to 

 the lateral drag occasioned by the upheaval of some contiguous superficial 

 portion of the earth's crust overlying a stratum of intensely heated and 

 highly elastic matter, the tension of which, through increase of tempera- 

 ture, had more or less overcome resistances exposed to its expansion. 



