.8^. SOME NEW BOOKS. 467 



ing of obsidian passing into trachyte: on page 119 the hornblende 

 andesite of tlie Wolkenburg is styled trachyte, and the same term 

 does duty for the tephrite of Niedermendig : on page 234 granophyre 

 is said to be a variety of andesite ! And this is Contemporary 

 Science ! 



The greater part of the work is a compilation of descriptions of 

 volcanoes and volcanic areas, and is certainly not salted with the 

 salt of modern science. Before commenting on the grave errors that 

 render this part of the work really misleading, let us point out a few 

 of those small blemishes which may serve like a rash to diagnose the 

 disease within. On p. 63 we read " Val del Bove (Valle del Bue) " ; 

 little pedanticisms like these may be an adornment when correct 

 — but when they are wrong ! Let us have it Valle del Bove (Val di 

 Bue). On page 198 the discovery of the volcanic nature of the rocks 

 of Llyn Padarn is attributed to the Rev. J. F. Blake, though Pro- 

 fessor Bonney had preceded him in this matter by some ten years 

 (Bonney, On the Quartz-felsite and Associated Rocks at the Base 

 of the Cambrian Series in N.W. Carnarvonshire, Quart. Journ. Geol. 

 Soc, vol. XXXV., p. 309, 1879). On page 68 we are led to understand 

 that we owe our knowledge of the chemical and microscopical 

 characters of the lavas of Vesuvius to Haughton and Hull. The 

 chemical analyses of the first-named author are of undoubted value : 

 they are cited in standard works, but the microscopical investigations 

 of Hull do not seem to have obtained, owing to some reprehensible 

 oversight, the same recognition. Errors are so congenial to our 

 author that he actually goes out of his way to make them. There 

 was no pressing necessity to explain the sky-effects following the 

 eruption of Krakatoa ; the author says as much, yet on this difficult 

 problem he cannot be silent. After reading his explanation on page 

 214, let the reader turn to the elaborate discussion on sky-glows in 

 the Report of the Royal Society — verily a little knowledge is a 

 dangerous thing ! To account for the order of emission of the 

 different kinds of igneous rocks from a volcano the early crude form 

 of Durocher's hypothesis published in 1857 is resuscitated, and no 

 mention is made of Richthofen's results (1868) and the explanations 

 of Teall and others. And this is Contemporary Science! On the 

 hypotheses of volcanic activity ventilated by our author we cannot 

 afford to dwell, they are expressed in such loose and unscientific 

 language that it is difficult to get at their meaning with any approach 

 to precision. To anyone who thinks it worth while to consider them 

 we will utter onl}' one caution, let him first make himself acquainted 

 with the strength of materials under pressure and tension, and he 

 will be proof against many of the fallacies of this part of the work. 



Where the author is describing things immediate to the senses, 

 he wields, not unskilfully, a fluent pen, which might not discredit 

 G. A. Sala, but directly phenomena involving exact observation, or 

 depending on inductive reasoning for their explanation, are concerned, 

 his efforts are painful. Let us take, for instance, his account of 

 volcanic eruptions. An unscientific writer might be pardoned for an 

 impressionist description of phenomena, and we do not greatly blame 

 a newspaper writer for colouring his accounts of " burning mountains " 

 with "fires" and "flames," but this is not science, and the work 

 before us claims to describe phenomena "which have been most 

 carefully observed and recorded under the light of modern geological 

 science." Just, therefore, is our indignation when we find our author 

 ignoring the true cause of the volcanic glow, and indulging in all the 



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