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T1IE GEOLOGIST. 



ing to the authors, none at all in the great beds of red sandstone ; hence 

 the question, are all these beds Jurassic, or does the red sandstone repre- 

 sent an island of the Trias? The authors incline to the opinion that all 

 the rocks between the dolomite and the Dobra are jurassic, including 

 the Dobra limestone itself. If the Dobra limestone be jurassic, the authors 

 contend that the eastern part, if not the whole of the Cantabrian chain, 

 which reach 2600 feet, are likewise jurassic; and that the conclusion then 

 is inevitable, that the jurassic formation extends into the province of the 

 Asturias, and that the whole of the geology of the eastern part of that 

 province requires rectification. 



After the geology, the third part of the book is devoted to the geognos- 

 tical relations of the more important metalliferous deposits, and the fourth 

 to the mineralogical structure and chemical composition of the ores, with 

 some remarks upon their mode of production ; and finally, we have chap- 

 ters on the deposit of sulphate of the soda in the valley of «j arama, near 

 Aranjuez ; on the chemical composition of a lacustrine dolomitic lime- 

 stone in the neighbourhood of Madrid ; and on some curious molecular 

 changes produced in disiiicate of zinc and some of its compounds with 

 carbonates by the action of heat. This work is well worthy of the attention 

 of geologists. 



Geological Essays, and Sketch of the Geology of Manchester and the 

 Neiglibourhood. By John Taylor. London : Simpkin, Marshall, and 

 Co. 1864, 



It is refreshing to take up a book on Geology in which we find ourselves 

 free from the set phrases and pratings of the old school of geologists, or 

 the hackneyed and tiresome inveighings against the hard words of science, 

 so common in the multitude of works on so-called popular science. Of 

 geological nomenclature, at least, Mr. Taylor takes a more sensible view 

 than most of his "popular " contemporaries, and he at least considers geo- 

 logical classification as the grammar of geology, without which — 



" The student could no more make headway than he could read Horace or Virgil 

 without having first learned to construe in Latin." "Nomenclature," continues Mr. 

 Taylor, Ci is the ' slough of despond/ through which every man must wade ere he can 

 cultivate the acquaintance of any science whatever. It is the Cerberus which guards the 

 gates of its under-mysteries, the cipher whose knowledge unfolds the gathered wisdom 

 of centuries; aft r this difficulty has been overcome, no man will stand up more for its 

 utility or find it more serviceable than he who at first sight was about to turn away with 

 mingled feelings of disgust and despair ; and although such a classification is anything 

 but perfect, and by no means to be relied upon as infallible, it serves as a clue to the 

 mode of natural operations in bygone epochs. In short, its utility may be seen by the 

 fact that it has been originated by those very men who wandered for years amid the com- 

 plexities of geology, often without so much as an idea of their labours ; and these tech- 

 nological terms are the results of their patient investigations and long years of experi- 

 ence." 



We cannot always agree with the author however, who, it is only just 

 to say, follows closely to received opinions, some of which, it is well known, 

 we have long been disposed to contest. One of these points to which he 

 adheres is the old igneous origin of certain crystalline rocks : — 



"We may learn from this," he says, "that the various rocks of igneous origin owe 

 their numerous modifications to the circumstances under which they have solidified, not 

 to any difference in iheir origin ; the on'y changes being what they have lost or what 



