January 13, 19 10] 



NA 7 URE 



303 



shifting from place to place under changes of geo- 

 graphical conditions. Twenty years ago many of us 

 may have said the same, particularly if we lived where 

 glacial relics were not abundant. Travel and confer- 

 ence with others have wrought a great change in this 

 respect, and we may venture to think that Prof. 

 Meunier still prefers to remain a critic rather than a 

 field-observer. His volume is a pleasure to read, for 

 he has the happy manner of an essayist ; but it is full 

 of pitfalls for the beginner. It contains, moreover, too 

 many misprints, and is not provided with an index. 



M. Cels, fortified in his geology by long and numer- 

 ous quotations from De Launay's "La Science geo- 

 logiquc," rejoices as a giant to run his course. He 

 reminds us at all points of the sailor who, hearing 

 for the first time of an essential fact of sacred history, 

 left the meeting-house and knocked down an un- 

 offending Jew. M. Cels has discovered the Huttonian 

 doctrine ; for him, as for Prof. Meunier, the world 

 Jives and is subject to evolution (p. 29) ; but he looks 

 in vain (p. 247) for the traces of a beginning or of an 

 end. Consequently, in the light of this great truth, 

 .-ill geologists, and notably the late M. de Lapparent, 

 seem to him but as blind guides. Lamarck and 

 Darwin (p. 39) have deceived enthusiastic men of 

 science by presuming a beginning of life, from which 

 our existing organic structures spread. 



The author's devotion to causes now in action (p. 

 46) is that of a convert won by faith. With the earlier 

 and not the later Lyell, he would lay enormous stress 

 on the imperfection of the record, and would trace man 

 back beyond the "eoliths" of early Eocene times (pp. 

 202 and 219). With the early Huxley, he would urge 

 that strata containing the same fossil types in different 

 parts of the globe may be separated by great inter- 

 vals, even of geological time ; and he further believes 

 that the similarity of faunas is due to similarity of 

 conditions of environment rather than to any contem- 

 poraneity in time. Prof. Meunier dislikes the idea of 

 a general glacial epoch, on the ground that the earth's 

 climates have got steadily colder; how then, he asks, 

 shall we account for the disappearance of an epoch 

 colder than that in which we now live? M. Cels dis- 

 likes it because he believes in the shifting of our polar 

 axis (p. 107) and in the sufficiency of this vital earth 

 to manage all its own affairs. Yet it is interesting to 

 find Prof. Meunier employing the same arguments 

 lax demolishing the glacial epoch (p. 274 of his work) 

 as i\L Cels employs against the idea of successive 

 ^geological periods marked by faunas in course of 

 evolution. 



M. Cels, during his recent reading, has discoverc-d 

 many valuable things, such as the occurrence of true 

 sediments among archaean masses, and the difficulty 

 of finding any relics of the primordial crust — facts 

 pointed out long ago by Sir A. Geikie, but which are 

 here dated back only to 1905. His studies among the 

 modernists throw him, however, more and more to- 

 wards Hutton, and even towards Pythagoras (p. 232), 

 and his hope is to reform geology altogether. Both 

 these books are out of the common ; but neither is 

 quite so stimulating as Reyer's " Prinzipienfragen," 

 which was reviewed in these columns in 1908. 



Grenville a. J. Cole. 

 NO. 2098, VOL. 82] 



CHEMICAL PHILOSOPHY. 

 The Fundamental Principles of Chemistry. An Intro- 

 duction to all Text-books of Chemistry. By Prof. 

 W. Ostwald. Authorised translation by Harry W. 

 Morse. Pp. xii + 34g. (London : Longmans, Green 

 and Co., 1909.) Price 7s. 6d. net. 



SINCE the retirement of Prof. Ostwald from the 

 directorship of the Institute of Physical 

 Chemistry in Leipzig, his literary activity appears to 

 have increased, although for many years his output 

 has been phenomenally great. With his departure 

 from the atmosphere of the laboratory, from the 

 sphere of attraction of experimental problems, the 

 philosophic, pedagogic and historical aspects of chem- 

 ical science have claimed his attention more closely 

 than was possible heretofore. 



The present work is essentially philosophical in 

 character. In a sense it is an attempt to work out 

 a system of chemistry without reference to the pro- 

 perties of individual substances, and its chief char- 

 acteristic consists in a minute analysis of various 

 chemical conceptions, and of the facts of experience 

 from which they are derived. 



The range of analysis is indicated by the titles of 

 the separate sections : — Bodies, substances and pro- 

 perties ; the thr^e states; mixtures, solutions, and 

 pure substances; change of state and equilibrium; 

 solutions; elements and compounds; the law of com- 

 bining weights; colligative properties; reaction 

 velocity and equilibrium ; isomerism ; and, finally, the 

 ions. 



At the outset the author takes the view that the 

 conception of matter is unnecessary, and this term 

 is not made use of in the text. The idea that matter 

 is something originally existing, something which is 

 at the basis of all phenomena, and in a sense inde- 

 pendent of them, is very widely spread, and any 

 attempt to get rid of the conception will have to show 

 a clear gain in simplicity, so far as derived concepts 

 are concerned, before chemists agree to discard this 

 particular conception. Such gain is not demonstrated, 

 and the author's assertion that matter can be shown 

 to be made up of the simpler concepts weight, mass 

 and volume will doubtless be objected to on the 

 ground that weight is not a conception of a simpler 

 order than matter. 



About half the book is taken up by the chapters 

 on solutions and elements and compounds. A good 

 deal seems to be made of the fact that pure sub- 

 stances can be regarded as limiting cases of solutions. 

 Two component systems are subjected to a somewhat 

 laborious analysis, and numerous diagrams are given 

 to illustrate the various types of possible phase com- 

 binations. Chief interest attaches, however, to the 

 demonstration that there are two component mixtures 

 and solutions— viz. those which admit of hylotropic 

 transformation— which behave exactly like pure sub- 

 stances in respect of such change. These solutions 

 can, however, be readily differentiated from pure sub- 

 stances, for the hylotropy of the former is limited to 

 certain definite temperatures and pressures, whereas 

 that of the latter extends over considerable ranges of 

 these variables. 



The relationships involved in hylotropy are made 



