158 Scientific Intelligence. 



8. Tables of Physical and Chemical Constants and some 

 Mathematical Functions ; by G. W. C. Kate and T. H. Laby. 

 Pp. vi, 153. London, 1911 (Longmans, Green, & Co.). — The 

 need of a comparatively small volume of up-to-date tables of 

 physical and chemical constants has been felt for some time, not 

 only by the authors but also by the writer of this notice. Hence 

 it seems fair to assume that this volume will appeal strongly to 

 others who are engaged either in giving instruction to laboratory 

 classes or in original investigations. 



The material has been wisely selected and the manner of pre- 

 sentation is excellent. Thus, in addition to the data incorporated 

 in the older reference books of this type, fifteen pages are devoted 

 to ionization and radio-activity. Also a table of e~ x is appended. 

 The utility of the volume is enhanced by the insertion, in the 

 case of many of the sections, of a brief resume containing refer- 

 ences to such books and original papers as may be profitably 

 consulted. The authors say in their preface : " Every effort has 

 been made to keep the material up to date ; ." 



All numbers, units, etc., deserving special emphasis are printed 

 in bold-faced type and an index to the pages is given. The book 

 is bound in a flexible cover, so that it will lie open flat or lend 

 itself to any other convenient position of holding. 



In conclusion, the present writer desires to state explicitly that 

 the book appeals very strongly to him and he hopes that many 

 other instructors and investigators will not only give the tables 

 practical trial, but will also take advantage of the prefatory 



invitation of the authors, namely, " we shall be very glad 



to receive suggestions and to be informed of any mistakes which, 

 despite every care, have eluded us." If this is done, a very 

 valuable set of convenient and reliable tables may be produced 

 in the course of a few years. h. s. u. 



9. Elektrochemische Umformer [ Galvanische Elemente] ; 

 von Johannes Zacharias. Pp. xii, 262 ; 122 figures. Vienna and 

 Leipzig, 1911 (A. Hartleben). — The author considers the custo- 

 mary classification of cells, as primary and secondary elements, to 

 be unsatisfactory and illogical, and hence he bases all of his 

 discussions on the use, performance and manner of working or 

 discharging cells. Consequently the title, " Electrochemical 

 Transformers," has been selected "to comprise all devices which 

 serve to transform chemical energy into electrical work by the 

 wet process." 



Special attention is given to batteries for furnishing strong- 

 currents and to the so-called " earth cells." Also, a special section 

 is devoted to a detailed account of pocket lamps. Accumulators 

 or secondary batteries are not given prominence. Numerous 

 tables and curves are distributed throughout the text to illustrate 

 the behavior of different types of cells under almost every con- 

 ceivable condition of activity. 



The author maintains a practical point of view, so that the 

 book should appeal primarily to those who desire to select a bat- 

 tery which is most suitable for fulfilling specified working condi- 

 tions, h. s. u. 



