554 Notices respecting Neio Boohs. 



of chemistry. The work is divided into two sections, Section I. 

 dealing with stereoisomerism, and Section II. with stereochemical 

 problems into which isomerism does not enter. Section I. is 

 subdivided into two parts, Part I being devoted to optical activity, 

 and Part II. to stereoisomerism without optical activity. The 

 subjects dealt- with in Part I. include a general account of the 

 asymmetric carbon atom, of optically inactive and active com- 

 pounds, the determination of configuration, the asymmetric carbon 

 atom as a ring-member, some exceptional cases of optical activity, 

 the quantitative relations between activity and the nature of the 

 asymmetric carbon atom, various active elements other than 

 carbon, and the factors determining the amount of rotation. 

 Part II. deals with cis-trans isomerism in cyclic compounds, geo- 

 metrical isomerism in the ethylene series and in carbon-nitrogen 

 compounds, and stereoisomerism in the compounds of nitrogen, 

 cobalt, platinum, and chromium. Section II. deals with the 

 phenomena of steric hindrance, the relation between the space 

 formula and the chemical properties, the effects of substitution 

 upon the formation and stability of cyclic compounds, the con- 

 figuration of optically inactive carbon compounds, and the space 

 formula of benzene. There are two appendices, in one of which 

 the author discusses the relations of stereochemistry to physiology, 

 while in the other he gives directions for the construction of 

 stereochemical models. Enough has been said to give our readers 

 some idea of what they may expect to find in this book. Numerous 

 references are given to original sources oi information, and name 

 and subject indexes are provided at the end of the book, which 

 fully maintains the high standard set by its predecessors in the 

 same series. 

 Notions Generates sur La Telegraphie Sans Fit. Par E. De 



Valbkeuze. Paris: edite par "l'Eclairage Elect rique." 1907. 



Pp. vi + 170. 

 Numerous books have been published from time to time dealing 

 with the principles of wireless telegraphy, some intended for 

 specialists, others for " the man in the street." Of books of the 

 latter type there has been great profusion, and unfortunately the 

 desire to popularise science has not infrequently led their authors 

 to modes of expression which are neither scientific nor particularly 

 illuminating even from the " popular " standpoint. The art of 

 presenting the facts and theories of physical science in a manner 

 which, while perfectly intelligible to the average well-educated 

 person, retains all the precision characteristic of genuine scientific 

 work, is one possessed by comparatively few writers. To steer a 

 middle course between the technicalities of applied science and the 

 laxity of common parlance is, indeed, no easy matter. We there- 

 fore heartily congratulate the author of the volume under review 

 on having accomplished this extremely difficult task in a manner 

 which commands admiration. While writing in a way calculated 

 to arouse the interest of the reader, the author never allows himself 

 to depart from those strictly scientific modes of expression without 

 which no really accurate presentation of facts is possible. The 



