NATURE 



409 



THURSDAY, MARCH 3, 1892. 



DEEP-SEA DEPOSITS. 

 Report on the Scientific Results of the Voyage of H.M.S. 

 '•'^ Challenger" during the Years 1873-76, under the 

 command of Captain George S. Nares, R.N., F.R.S., 

 and the late Captain Frank Tourle Thomson, R.N. 

 Prepared under the Superintendence of the late Sir C. 

 Wyville Thomson, F.R.S., and now of John Murray, 

 LL.D., Ph.D., &c., one of the Naturalists of the Ex- 

 pedition. Report on Deep-Sea Deposits, based on the 

 Specimens collected during the Voyage. By John 

 Murray, LL.D., Ph.D., and the Rev. A. F. Renard, 

 LL.D., Ph.D., Professor of Geology and Mineralogy in 

 the University of Ghent. Pp. xxix. and 496 ; with 43 

 Charts, 22 Diagrams, and 29 Lithographic Plates. 

 (London : Published by Order of Her Majesty's Govern- 

 ment, 1 891.) 

 GEOLOGISTS have had to wait long for this very 

 important work, but now that it lies before them, 

 we believe that the general verdict will be that it was 

 worth while to wait even sixteen years for a monograph 

 so excellent in design and so complete in execution. It 

 must not be forgotten, too, that much of the information 

 contained in this volume has been already given to the 

 scientific world — first in Mr. Murray's Preliminary Report 

 on the subject, published in the Proceedings of the Royal 

 Society ; and secondly in a series of papers written by 

 him in conjunction with Prof. Renard, and published in 

 the Proceedings of the Royal Society of Edinburgh. 



It is a most fortunate circumstance that the naturalist 

 on board the Challenger, who had charge of the collection, 

 examination, and preservation of the samples of the de- 

 posits collected by the sounding-apparatus and the dredge, 

 as well as of those obtained by means of the tow-nets 

 and tangles, has been able during the long period that 

 has elapsed since the return of the vessel to England, to 

 devote his attention to their careful study and description. 

 In the work of dealing with this vast mass of materials, 

 as the preface informs us, Mr. Murray has had the co- 

 operation of Mr. Frederick Pearcey, who accompanied 

 the Expedition, and was afterwards assistant in the 

 Challenger Office, and also of Mr. James Chumley. 

 Especially fortunate has been the circumstance that Sir 

 Wyville Thomson and Mr. Murray were, in 1878, able 

 to secure the aid of the eminent Belgian petrographer. 

 Prof. Renard, who is so great a master of those micro- 

 scopic methods of research which have played no unim- 

 portant part in the development of geological science 

 during recent years. In the exact determination of the 

 minute fragments of minerals which occur in these de- 

 osits, Prof. Renard's knowledge of the optical and 

 chemical methods of microscopic research has proved 

 of especial value ; and the assurance that, during several 

 months in the years 1881 and 1882, the Belgian petro- 

 grapher was able to devote himself to the work of in- 

 vestigating these deposits will invest the mineralogical 

 determinations with an authority which they could not 

 otherwise possess. 



The introduction to the work consists of an excellent 

 summary of the references contained in various authors, 

 NO. I 166, VOL. 45] 



beginning with Herodotus, Plato, and Skylax, to the 

 supposed nature of the sea-bottom. The sagacious re- 

 marks on the subject by the Italian naturalists, who were 

 the real founders of the science of geology in the fifteenth 

 century, receive appreciative notice ; and the earliest 

 attempts to deal with the deposits of the deep seas, espe- 

 cially those of Soldani, Ehrenberg, Sir Joseph Hooker, 

 Edward Forbes, and Prof. J. W. Bailey, have full re- 

 cognition. The important memoir of Prof. W. C. 

 Williamson on the mud of the Levant is noticed ; but 

 the authors seem to be scarcely aware how many of the 

 later discoveries in this branch of science were fore- 

 shadowed in the remarkable monograph of the Man- 

 chester Professor. A general account ' of the results 

 obtained by the chief expeditions fitted out for the study of 

 the deep ocean and its deposits — expeditions which 'pre- 

 ceded and followed that of the Challenger — leads up to 

 a division of marine deposits into " Terrigenous " and 

 " Pelagic," a classification which, if not too rigidly 

 applied, appears to be serviceable and even necessary. 



The first chapter is devoted to the various methods of 

 obtaining, examining, and describing deep-sea deposits, 

 and here the general arrangements made on board the 

 Challenger, which are familiar to most readers from the 

 description given by Sir Wyville Thomson in his " Voyage 

 of the Challenger," and the narrative volumes of the Re- 

 port, receive very full and exhaustive treatment. The 

 precise account of the apparatus, illustrated as it is by 

 numerous woodcuts, cannot fail to be of great value to 

 those engaged in fitting out similar expeditions. The 

 study of the methods employed in the sifting, fractional 

 decantation, and chemical examination of the several 

 deposits is essential to the proper understanding of the 

 results detailed in succeeding chapters of the work. 

 The methods of analysis employed by Prof. Brazier at 

 Aberdeen, and by MM. Renard, Sipocz, Hornung, and 

 Klement, in the laboratory of Prof. Ludwig, of Vienna, 

 and in M. Renard's laboratory at Brussels, are given in 

 full detail, and will prove of great service when the 

 results described in the present volume come to be 

 compared with those of future investigators. 



The second chapter consists of a series of synoptical 

 tables, occupying 114 pages, in which the nature and 

 composition of every deep-sea deposit collected during 

 the voyage of the Challenger is described. In each case 

 the number of the station, the date, the latitude and 

 longitude, the depth in fathoms, the temperature at the 

 surface and the bottom are given ; and these particulars 

 are followed by (i) a general description of the material 

 brought up ; (2) the percentage of calcium carbonate ; 

 (3) a list of the chief Foraminifera present ; (4) an enu- 

 meration of the other calcareous organisms ; (5) the per- 

 centage of insoluble residue ; (6) a list of the siliceous 

 organisms ; (7) of the minerals ; (8) a description of the 

 fine washings ; the last column being devoted to addi- 

 tional observations. These synoptical tables are followed 

 by a discussion of the variation of the deposits with 

 change of conditions along the different lines of soundings 

 and dredgings. This general summary of the results, 

 which occupies 36 pages of the work, constitutes an 

 admirable rhumc of the information contained in the 

 tables. 



Chapter iii. is devoted to the description of recent 



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