July 17, 1890] 



NA TURE 



26: 



first time with the means of judging of the real nature of 

 the processes going on in the pit-craters of non-explosive 

 volcanoes. A similar discussion of the records concern- 

 ing Mokuaweoweo, the summit-crater of Mount Loa^ 

 enables the author to furnish an interesting, but neces- 

 sarily less complete, narrative of the operations going on 

 there during the same period. The want of anything 

 like synchronous action between these two great craters 

 in the same mountain-mass, one of which is at an eleva- 

 tion of 10,000 feet above the other, has often been re- 

 marked upon ; and the truth of the conclusion — one 

 which must always be taken account of in attempts to 

 explain volcanic phenomena — is fully established in the 

 work before us. 



Prof. Dana forcibly illustrates the remarkable contrast 

 between the effusive eruptions of the Hawaiian volcanoes 

 with their extremely liquid and perfectly fused basaltic 

 avas, and the explosive outbursts of Vesuvius, Krakatab, 

 and Tarawera. He describes the characters and limited 

 distribution of the curious glassy lavas, and their deriva- 

 tives — the curious Pele's hair and the beautiful " thread- 

 lace scoria;"; and he points out the inaccuracy of the 

 early chemical analyses of the Hawaiian lavas, which 

 have misled so many subsequent writers. His remarks 

 on the characteristics and origin of the chief varieties of 

 the lava, and especially of the pseudo-bombs — vast pillow- 

 like masses of lava covered with a thin vitreous crust — are 

 remarkably interesting and suggestive. 



One of the most valuable chapters in the book is that 

 on the petrographical characters of the Hawaiian lavas, 

 supplied by the author's son. Prof. E. S. Dana. The 

 singular fissile basalts of the higher cone, which resemble 

 phonolite, and several other remarkable types are here 

 described for the first time. Very noteworthy are the curious 

 feathery forms of augite which occur in some lavas, and 

 the strangely-elongated crystals of olivine which are 

 found in others. But the part of the chapter which will 

 unquestionably awaken the greatest amount of interest 

 in the minds both of mineralogists and geologists is that 

 which deals with the curious stalactites found in certain 

 caverns in the lavas. That these stalactites are formed by 

 aqueous action there cannot, as Prof. E. S. Dana shows, be 

 any reasonable doubt. Yet the stalactites are built up of 

 crystals of felspar, augite, and magnetite, all the consti- 

 tuents formed by igneous action in the lavas themselves, 

 being present, with the exception of olivine ! All students 

 of mineral synthesis are acquainted with the fact that the 

 same species can often be formed by several, and some- 

 times by very diverse, methods. Mr. Sorby has even 

 shown how fragments of quartz-crystals, originally formed 

 in a granite or other igneous rock, may after enormous 

 intervals renew their growth and become complete 

 crystals again under purely aqueous conditions ; so that 

 the same crystal may in different parts be the result of 

 totally different kinds of action. In spite of these facts, 

 liowever, few petrographers would be prepared to find 

 that, from aqueous solutions, rocks made up of felspar, 

 augite, and magnetite could be formed in the way de- 

 scribed in this interesting essay. Prof. E. S. Dana not 

 unnaturally announces these remarkable conclusions with 

 some diffidence and reserve ; yet it is impossible to find 

 any flaw whatever in the line of argument by which he 

 seeks to establish their truth. 

 NO. 1 08 I, VOL. 42] 



Prof. J. D. Dana has prefaced his description of the 

 Hawaiian Islands by a sketch to which the title of 

 " Characteristics of Volcanoes " is more directly applic- 

 able. In this introduction, which only extends to some 

 27 pages, many of the great problems of vulcanologfv are 

 discussed with singular clearness and freedom from bias. 



The work concludes with two interesting appendices, 

 the first on " Volcanoes and Deep-sea Topography," and 

 the second on "Denudation of Volcanic Islands; its 

 Amount a Mark of Age." The book is well illustrated 

 with maps and sketches, and some plates reproducing 

 photographs will serve to give a just idea of the peculiar 

 lava cascades and fountains of Hawaii — phenomena 

 which have not unnaturally excited the imagination of 

 untrained observers, and given rise to startling drawings 

 and florid descriptions in popular works of travel. But 

 the sober truth is, that the wonders of Hawaii stand in no 

 need either of exaggeration or embellishment from the 

 writer or the artist. 



We heartily welcome the volume as the crowning 

 labour of the greatest of America's men of science — the 

 latest, and not by any means the least important, of a 

 long series of contributions to science on very diverse 

 subjects, but of unvarying excellence. J. W. J. 



A POLYGLOT MEDICAL VOCABULARY. 

 Terminologia Medica Polyglotta : a Concise International 



Dictionary of Medical Terms. Compiled by Theodore 



Maxwell, M.D. Cantab. (London: Churchill, 1890.) 

 'HP HE current literature of medical subjects is extensive 

 and polyglot, and those who endeavour to keep 

 themselves abreast of the most recent research in any 

 branch require to dip into works in many languages, and 

 need to have at hand some such aid as the present vocabu- 

 lary, wherein they can seek for the several vernacular 

 synonyms of those newer technicalities which modern 

 developments of science have produced, and which are not 

 to be found in the ordinary dictionaries. Moreover^ 

 it is often necessary that the special senses in which some 

 of the older and more general words are used by medical 

 writers should be defined. One may be very well ac- 

 quainted with the anatomy of the brain as described in 

 the English standard works, and yet have much difficulty 

 in following the descriptions in German or French books 

 on cerebral pathology, when vernacular names are used for 

 the several parts ; and one longs for some international 

 agreement as to a uniform system of scientific terminology 

 like the Latin generic and specific names of the Linnaean 

 nomenclature. 



The compilation of a new dictionary is a task involving 

 an enormous amount of labour, and when, as in the work 

 under notice, the synonyms of each term in seven lan- 

 guages have to be sought and tabulated, the difficulties of 

 the undertaking are seriously increased. The compiler 

 has evidently expended great care, and exercised much 

 judgment in his toilsome task, and doubtless this voca- 

 bulary will prove of much help and be highly appre- 

 ciated by students of foreign medical literature. The 

 typography is excellent and clear, and the work is singu- 

 larly free from errors of the press. 



It is questionable whether the selection of French as 

 the fundamental language was a wise choice. There are 



