576 Notices of Scientific Works. [Oct., 



many an ancient sea-worn cave and hollow now far removed above 

 the roar and turmoil of its surging billows. 



We are glad to find that, although Mr. Mackintosh advocates 

 the sea as an efficient a-gent to produce geological changes, yet he 

 does not ignore the action of other causes in modifying the earth's 

 surface — as Ice, Snow, Frost, Kain and Elvers, Nature's untiring 

 agents, slowly — maybe secretly — yet surely modifying the surface 

 of our island, as certainly as the sea is ever changing the contour 

 of our coasts. 



Mr. Mackintosh's previous articles elicited rejoinders from 

 many of our leading geologists, and no doubt his book wiU have 

 a similar effect. 



Some of the woodcuts to this work are very excellent; e.(ji. 

 Wallow Crags ; * Sea-worn Chink, Pendower Point ; t the Peak of 

 Snowdon (Fig. 31) ; Cheddar Clifis, &c. ; t others owe their merit 

 to their utility as diagrams; a few might be better drawn, the 

 subjects being really fine, if well treated. 



In a future edition we would suggest the elision of several 

 pages in Book III. (" Excursions "), which are merely irrelevant §, 

 and the substitution of a short " Itinerary," giving plain direc- 

 tions how best to reach the many places of geological interest 

 mentioned by the author. 



It is almost too late this year for the home tourist to avail 

 himself of Mr. Mackintosh's guidance to the Welsh Mountains, or 

 Coniston Crags, but no doubt next year he will find many of our 

 readers who will gladly take a walk with him " over Malvern 

 Wych at midnight" (although, as keen geologists, they might 

 prefer the early dawn), or, knapsack on back, to start " from 

 Llanberis to Snowdon, through the Pass, and by Llyn Llydaw," 

 — or, indeed, along any of the twenty routes he has laid down 

 for their acceptance — sure of finding fresh air, hard walking, 

 capital scenery, good appetites, and some very hard geological nuts 

 to crack afterwards. 



Spectrum Analysis. — Six Lectures dehvered in 1868 before the 

 Society of Apothecaries of London. By H. E. Eoscoe, B.A., 

 F.R.S. Macmillan and Co., 1869. 



This is the most complete work on spectrum analysis which has 

 yet appeared in the English language ; and the author being one 

 of the first popularizers of this branch of experimental analysis, is 

 thoroughly competent to deal with all the varied ramifications into 

 which it has branched of late years. Little was heard of spectro- 



* P. 382. t P. 55. t P- 111. 



§ e. g. pp. 303-4, " An episode," &c. ; p. 299, " Uufouuded Suspicions," and one 

 or two other passages. 



