NATURE 



[August 21, igi, 



physics and chemistry. In the course of his intro- 

 duction M. Ed. Bouty pays high tribute to the 

 author's skill as an exponent of popular science, 

 and it must be admitted that the anticipations so 

 raised are not disappointed, for the explanations 

 are clear, the analogies happily chosen, and the 

 whole is written, in a bright and interesting 

 fashion. 



Among the subjects dealt with are " L'ultra- 

 microscopie " and " Le Mouvement Browien," 

 "L'etat colloidal et la vie," " Le cycle de l'azote," 

 and " Les Terres Rares." This last includes an 

 interesting- account of the applications of the so- 

 called rare elements, and justifies to a considerable 

 extent the dictum that "the only really rare bodies 

 are those for which no practical applications are 

 known." 



(4) Prof. Goldhammer chooses as the basis of 

 his treatment of dispersion that particular form 

 of the theory first advanced in 1902 by M. Planck. 

 In this book the theory is generalised and ex- 

 tended to conducting" media with more than one 

 absorption band. An investigation, in vectorial 

 notation, of the vibration of Planck's resonator — 

 the " Electrische Dipole " — is followed by the 

 development of the theory in terms of this body. 

 The theoretical results are then compared with the 

 experimental data : gases and vapours, solutions, 

 metals and various compounds all being con- 

 sidered. This portion of the book is especially 

 commendable, being fully illustrated with tables 

 of data and curves. 



In the las f chapter dispersion is considered 

 from the point of view of the electron theory, the 

 author, following J. J. Thomson, making no dis- 

 tinction between the bound and free electrons. 

 It is concluded finally that, so far, this generalisa- 

 tion of Planck's theory is nowhere in antagonism 

 with the results obtained by experiment. An ex 

 cellent little treatise, being a notable addition to 

 the literature of the subject. 



(5) This is the second volume of a complete 

 course of physics based on the notes of lectures 

 delivered at the University of Lille. The work i-^ 

 to be completed in three volumes, of which the 

 first and third are still in the press. 



The thermodynamics is treated mathematically 

 on the usual lines, a knowledge of partial differ- 

 ential coefficients being assumed. The ground 

 covered is extensive, and the treatment rather un- 

 even. For example, thermodynamic potential is 

 dismissed in a single page, and the study of the 

 solid state in a chapter of three pages, while, on 

 the other hand, the section on univa riant 

 systems is particularly good. Interspersed in 

 the text are a number of worked numerical 

 examples. 



V '. 2286, VOL. 91] 



Radiation is treated descriptively on modern 

 lines, mathematical formula; only being given. 

 Nearly a third of this part of the book is devoted 

 to the astrophysical aspects of the subject : an 

 interesting section, but only inserted at the 

 expense of the rest of the subject. 



OUR BOOKSHELF. 



Les Pyrdndes Mdditerraneennes, Etude tic geo- 

 graphie biologique. By Prof. M. Sorre. Pp. 

 508 + xi plates, 41 figures and a map. (Paris: 

 Armand Colin. 1913.) Price 12 francs. 

 This book is not the outcome of a wholly new 

 method of inquiry, but it is a more complete ex- 

 amination of local influences, past and present, 

 acting in a defined area, than most works of a 

 similar nature. 1 he subject is treated historically, 

 especially in relation to man's activity, from the 

 earliest times, in altering or modifying the aspects 

 and composition 1 I the vegetation and in the 

 development of animal life, in relation to advanc- 

 ing- civilisation. It is a consolidation of knowledge 

 obtained by workers in the various branches of 

 research connected with lite, animal and vegetable, 

 and physical conditions. 



The area under consideration comprises the 

 eastern part of the Pyrenees from Andorra in the 

 west and the whole of the low mountains, hills 

 and plains falling therefrom to the east and to the 

 south, to the sea. There are altitudes of nearly 

 10,000 feet, and the essentially alpine vegetation 

 begins at about Sooo feet. Phvtogeographv plays 

 an important part in the history of the human 

 race and naturally occupies a large place in this 

 book, where the results of Prof. Ch. Flahaut's 

 investigations are largely drawn upon. The map 

 shows the distribution of the characteristic trees 

 of the successive zones, beginning- with the purely 

 littoral vegetation and followed by the evergreen 

 oak and olive, the stone pine, the cork oak, hairy 

 oak, beech, silver fir, Scotch pine, mountain pine, 

 and the alpine zone. 



The plates mostly illustrate paysages or scenery, 

 and the figures physical conditions and pheno- 

 mena. An idea of the arrangement of the matter 

 may be obtained from the headings of the chap- 

 ters : — I. Les Pa\ sages. II. Le sol et les formes 

 du Relief. III. Climat. IV. Les Eaux. Y. Les 

 formes de la Vegetation Spontanee ; and VI. to 

 VII. Les Genres de Vie of the different regions, 

 with 1 final chapter on La Vie de relations, son 

 influence sur la Vie locale. W. B. H. 



Travers' Golj Ben];. By Jerome D. Tracers 



Pp. xi -I- 242 4- xlvi plates. (New York: The 



Macmillan Co.; London: Macmillan and Co., 



Ltd., 1913.) Price 85. 6d. net. 



This book will prove interesting" reading to all 



golfers, and especially to those who aim at being 



champions. Mr. Tracers tells how he attained 



his expertness — simply by thoughtful, deliberate 



practice. He gives many valuable hints on stance 



and grip, and elucidates these by means of photo 



g-raphs of himself in all sorts of positions, am: 



