334 Notices respecting New Books. 



PhysiTcalisches PraTctilcum, mit besonderer Berilcksichtigung der 

 physikaliscli-chemisclien Metlioden. (Practical Physics, with 

 special reference to physico-chemical methods.) By E. Wiede- 

 maidst and H. Ebert. Second Edition, 1893. Vieweg und 

 Sohn, Brunswick. 



During the past year the subject of practical physics seems to 

 have received an unusual amount of attention both in Germany 

 and England. Some months ago we bad occasion to notice 

 a new work by Traube dealing with the methods of practical 

 cbemical physics, and the present volume bears a very similar title. 

 Until quite recently Kohlrausch's classical text-book was almost 

 universally adopted in German laboratories, but alterations in 

 design of apparatus, changes in methods of teaching, and a 

 necessity for the measurement of constants the importance of 

 which was formerly unrecognized, have combined to make the 

 work appear antiquated in a modern laboratory. The authors 

 have treated the subject in a comprehensive manner as far as 

 description of experiments is concerned ; each section is introduced 

 by an epitome of the theory of the experiments to be performed ; 

 this is followed by accounts of the experiments, apparatus and 

 requisite manipulation, and when necessary the method of 

 calculating results is indicated. The data of actual experiments 

 are given as examples, and these show the degree of accuracy 

 attainable. It would be an improvement if these data were stated 

 in the way in which a student would be expected to write them 

 down in his note-book, the method of entering results being one 

 of the greatest difficulties experienced by the younger students in 

 a laboratory. As they stand the quantities are merely designated by 

 letters, of which the meanings can only be found b} r reference 

 to the context. 



As the work was written more especially for chemical students, 

 the sections devoted to Electricity and Magnetism are not so 

 complete as the rest of the book; for example the methods of 

 measuring induction-coefficients and the capacity of a condenser 

 are omitted. The rough determination of the specific inductive 

 capacity of a dielectric, and of the resistance of a badly conducting 

 liquid might, however, have been included with advantage. 



The lists of apparatus required for each experiment form an 

 excellent feature of the book, and will be of great service to the 

 laboratory assistant. The illustrations are likewise good, especially 

 those in colours, representing the solar spectrum, chromatic 

 aberration, and grating spectra respectively. Indeed, the volume 

 quite maintains the high standard which physicists have previously 

 ascribed to the scientific work of its two authors. 



James L. Howard, 



