6i6 



NATURE 



[February 6, 19 13 



for augmenting- its food supply. Political dis- 

 orders and difficulty of access, which have given 

 these republics a bad name, no longer apply to 

 its temperate regions. The future of these States 

 is assured so far as the gifts of nature can assure 

 it. The world will always want what they produce. 

 The reclaiming of the tropical parts and their 

 future is not yet a practical question. Such and 

 similar topics are dealt with in the last chapter, 

 entitled "Some Reflections and Forecasts." Here 

 once more it is the experienced statesman who 

 takes his survey from a lofty point of vantage, and 

 for obvious reasons we have now and then to read 

 between the lines, in contrast with the interesting 

 " South America To-day," by G. Clemenceau, the 

 former Prime Minister of France, who, likewise 

 on a rapid trip, lectured the Argentinos on their 

 own social problems. Mr. Bryce's work, although 

 not embellished with pictures, contains several 

 large-scale maps, notably of the Panama Canal 

 and the Straits of Magellan, to which hitherto 

 little-described region is devoted a charming 

 chapter from the historic and scenic points of view. 



THE BEGINNING OF A NEW ERA 

 IN MINERALOGY. 

 U ntersuchitngen iiher die Bildungsverhdltnisse der 

 oseanischen Salaahlagerungen insbesondere des 

 Stassfurter Salzlagers. By J. H. van't Hoff 

 and others. Herausgegebcn von Prof. H. 

 Precht und Prof. Ernst Cohen. Pp. xx-i-374 

 + 8 plates. (Leipzig : Akademische Verlags- 

 gesellschaft m.b.h., 1912.) Price i6 marks. 



VAN'T HOFF'S researches on the formation 

 of oceanic salt deposits were originally pub- 

 lished in the Sitsungsberichte of the Royal Prus- 

 sian Academy of Sciences. As this periodical is 

 unfortunately inaccessible to the vast majority of 

 scientific workers, the need for a re-publication 

 of the whole series of papers (fifty-two in all) has 

 been keenly felt for a considerable time. Although 

 summaries of the work, or portions of it, have been 

 published from time to time in various readily 

 accessible scientific journals, and although van't 

 Hoff himself published a very concise account of 

 his work (" Zur Bildung der ozeanischen Salzabla- 

 gerungen," 2 vols., 1905 and 1909, Vieweg und 

 Sohn), those acquainted at first hand with the 

 researches in question have realised that nothing 

 short of a re-publication in extcnso of the whole 

 series could give that detailed and intimate ac- 

 quaintance which is necessary for the advance of 

 science. We therefore owe Profs. Cohen and 

 Precht and the Akademische Verlagsgesellschaft 

 in Leipzig a deep debt of gratitude for the publica- 

 tion of this splendid volume. 

 NO. 2258, VOL. 90] 



.A.S all the world knows to-day, van't Hoff's 

 work on the oceanic salt deposits deals in the 

 main with a systematic study of the conditions 

 affecting the formation, decomposition, and co- 

 existence of all the single and double salts, and 

 all the various combinations of these which can 

 appear in the system Na-K-Mg-Ca-Cl-SO^-HjO. 

 Borates are also considered and dealt with in a 

 number of interesting papers. 



Owing to the enormous labour and time in- 

 volved, van't Hoff confined his attention in the 

 main to working out the isotherms at 25° and 83°. 

 But the gap between these temperatures was, at 

 any rate as regards the appearance and disappear- 

 ance of the chief minerals, very largely bridged 

 over by many determinations of vapour-pressures 

 and transition-points. So much so that van't Hoff 

 was enabled to construct what he called a "geo- 

 logical thermometer " ; that is to say, he could 

 state at what temperatures various minerals or 

 groups of minerals had in long past ages been 

 deposited. The thirty-sixth paper of the series 

 gives an account of the temperature-limits deter- 

 mining the coexistence, between 25° and 83°, of 

 the various groups of minerals (parageneses). 

 These paragenetic tables might indeed be regarded 

 as the crowning glory of the whole series of 

 researches. 



The remark has been sometimes made that van't 

 Hoff's work on the oceanic salt deposits cannot 

 be regarded as equal to his earlier achievements 

 in point of originality and genius. Such remarks 

 arise from that striving after sensationalism and 

 notoriety which is apt to infect science, just as 

 it has infected and corrupted many other depart- 

 ments of life at the present day. In originality 

 of design and method, grandeur of scope and 

 conception, and intellectual power and insight in 

 development, van't Hoff's work on the oceanic 

 salt deposits bears the stamp of sovereign genius. 

 Like every other work of genius, it has had and 

 will have far-reaching results. Not only is it a 

 model for all time of how problems in inorganic 

 chemistry and its technical applications should be 

 studied, but it points the way towards the crea- 

 tion of the mineralogy and geology of the future. 

 Already the Verband fur die wissenschaftliche 

 Erforschung der deutschen Kalisalzlagerstatten 

 and the Geophysical Laboratory of the Carnegie 

 Institution at Washington are actively following 

 in van't Hoff's footsteps, so that on the one hand 

 the particular problem he attacked is being com- 

 pleted in its details, whilst on the other the new 

 experimental mineralogy of the future is making 

 rapid progress. 



The present volume of collected researches will 



