Supplement to "Nature" February 5, 1903. 



the book deals with the compressibility of liquids and 

 gases, and the phenomena of capillarity, diffusion and 

 viscosity. In discussing these subjects, the molecular 

 theory of matter has of necessity been very freely intro- 

 duced, but the detailed account of the theory has been 

 reserved for the volume on heat. Among the subjects 

 incidentally discussed in the present volume are Van 

 der Waals's equation for the relation between the pressure 

 and the volume of a gas, reversible thermal effects 

 accompanying alterations in strains, effect of tempera- 

 ture on surface tension, change of vapour-pressure under 

 stress, osmotic pressure, vapour-pressure of solutions, 

 lowering 1 of the boiling point of solutions, lowering of 

 the freezing point of solutions, variation of viscosity with 

 temperature, and explanation of viscosity and diffusion 

 on the kinetic theory. An elementary knowledge of heat 

 may reasonably be expected of the student, but it would 

 seem preferable to have reserved some of these subjects 

 until the kinetic theory and the second law of thermo- 

 dynamics had been discussed. 



It is hardly necessary to say that the book is of a 

 thoroughly practical character, and will commend itsel 

 both to the teacher and the student. The book is 

 written from the point of view of the experimental 

 physicist, and the subjects selected for illustration are 

 those most useful and instructive to the student. The 

 mathematical methods employed are generally of a 

 simple character. In many cases, these may appear 

 cumbrous and difficult to the student who possesses a 

 knowledge of more advanced mathematical methods. 

 But even for such fortunate students, there is some com- 

 pensation in the fact that the more elementary method 

 compels attention to the physical meaning of the 

 processes employed. In the case of many of the subjects 

 discussed, it would be difficult for the student to find an 

 equally concise and clear account of the theory and the 

 experimental methods in any other book at present 

 accessible, and we are confident that the present volume 

 will be found to be a useful addition to the text-books 

 available for advanced students of physics. 



H. L. C. 



ZITTEL'S TEXT- BOOK OF PALAEONTOLOGY, 



Text-book of Palaeontology. By Karl A. von Zittel. 

 Translated and edited by Charles R. Eastman. 

 Vol. ii. Pp. viii + 283. (London : Macmillan and 

 Co., Ltd., 1902.) Price \os. net. 



NEARLY three years have elapsed since we received 

 the first volume of the English edition of Prof. 

 Karl A. von Zittel's well-known " Grundzuge der PaUeon- 

 tologie." We therefore open the newly published second 

 volume with some fear lest the long delay in its pro- 

 duction be due to a complete remodelling, such as that 

 which we criticised on the last occasion. This new 

 nstalment, however, is a welcome surprise ; for, while 

 the sections with which it deals have been judiciously 

 edited and somewhat brought up to date, the author's 

 original plan is strictly followed, and it still remains 

 essentially the work of the Munich professor. 



1 This is evidently a misprint for " raising of the boiling point," which is 

 the ttrm used near the end of the section, but the sign of the change is not 

 clearly brought out in the analysis. 



NO. 1736, VOL. 67] 



The present volume deals with Pisces, Amphibia, 

 Reptilia and Aves, and extends only to 278 pages— a 

 slight increase on the original text from which it is 

 translated. The Mammalia will form a third and con- 

 cluding volume, to be issued later. This plan of sub- 

 dividing the text-book into instalments of convenient 

 size for ready reference will be appreciated by all who 

 have been compelled to use the ponderous German 

 edition, which is a volume much too bulky for comfort- 

 able handling. 



The section on Pisces, occupying 114 pages, has been 

 translated and revised by Dr. Smith Woodward. The 

 author's original classification has only been slightly 

 modified to incorporate Dr. Traquair's recent descrip- 

 tions of Upper Silurian and Lower Devonian fishes, and 

 the translator's own observations on the Pycnodonts and 

 some of the Teleosteans. These changes are evidently 

 approved by Dr. von Zittel himself. Traquair's figures 

 of Drepanaspis, Birkenia and Lasanius appear for the 

 first time in a text-book and his remarkable discoveries 

 are now made accessible to an elementary student. The 

 revised account of the Teleostei is also the first condensed 

 synopsis of recent discoveries which has been published 

 in a general treatise. 



The section on Amphibia, occupying twenty-five 

 pages, has been translated and revised by Dr. E. C. 

 Case. There are no new figures, and the changes consist 

 merely in a few allusions to recent discoveries. 



The revision of the section on Reptilia, now occupying 

 116 pages, was begun by the late George Baur, whose 

 untimely death prevented his accomplishing more than 

 part of the chapter on Chelonia. Most of the present 

 translation has been done by Dr. E. C. Case. The 

 chapters on Squamata and Pterosauria have been revised 

 and extended by Prof. S. W. Williston, who has also 

 contributed notes on Plesiosauria and Chelonia. The 

 chapter on Dinosauria has been brought up to date by 

 Prof. H. F. Osborn, Dr. O. P. Hay and Mr. J. B. 

 Hatcher. Dr. Case himself appears to be responsible for 

 the removal of the Clepsydropid;e from the Theromorpha 

 to the Rhynchocephalia. The revision, on the whole, is a 

 distinct improvement on the original work. The supple- 

 mentary details concerning the fossil reptiles, especially 

 of North America, will prove very useful for reference ; 

 while a few new figures of restorations by Williston, 

 Smith Woodward and Hatcher add to the educational 

 value of the book. 



The section on Aves has been doubled in extent by 

 Mr. F. A. Lucas and now occupies twenty-three pages. 

 No new figures are given, but the text is well up to date, 

 and it is especially valuable as being a critical summary 

 combined with original observations. 



The volume concludes with a good index to the names 

 of genera, and forms the most exhaustive work of refer- 

 ence on the extinct cold-blooded vertebrates and birds 

 which has hitherto been published in the English 

 language. Dr. Eastman and his colleagues are, indeed, 

 to be congratulated on the successful completion of this 

 new instalment of their undertaking, which will prove of 

 the greatest service to all -English- speaking students 

 both of geology and zoology. 



