Notices respecting New Books. 391 



The general course of the changes referred to is best seen 

 from the annexed figure, which corresponds to the last series 

 of observations. The ordinates are distances of the inserted 

 condenser from an arbitrary origin near the end of the wires, 

 the abscissas of the points on the two curves are the distances 

 of nodes B and A from the same origin on twice the scale, 

 the crosses between the curves showing the position of the 

 condenser. It will be seen that the apparent half wave-length, 

 or distance AB, is least when the condenser bisects the 

 distance. When the condenser coincides with either node, 

 A B is the full half- wave. When the condenser passes out- 

 side A B, the curve of A turns in again. 



I have to express my thanks to Prof. Ebert of Kiel, in 

 whose laboratory and under whose kind direction the expe- 

 riments were carried out of which these observations form 

 part. 



Queen's College, Belfast, 

 27th February, 1897. 



LIII. Notices respecting New Books. 



Grundzuge einer thermodynamischen Theorie elelctrochemischer 

 Kriifte. Dr. Alfred H. Bucherer. Freiberg in Saxony: 

 Craz and Gerlach, 1897. 

 'TVHE dissociation theory of electrolytes has received so much 

 -*- attention during recent years, and the case in its favour has 

 been so ably stated by Arrhenius, Nernst, and Ostwald, that we need 

 to be reminded of the existence of the older chemical or association 

 theory of solution. The author of the present volume expresses 

 his objections to the newer theory, and especially to the way in 

 which it sets aside previously established ideas coucerning chemical 

 combination. He indicates how the laws of thermodynamics, so 

 freely used by the founders of the dissociation theory, can be 

 applied with equal success in the development of the older ideas. 

 According to his view, an electrolyte consists of molecules of salt, 

 molecules of solvent, and complex molecules containing both salt 

 and solvent ; the relative proportion of the complex molecules 

 increases with increasing dilution and the conductivity of the 

 solution depends upon their presence. The aim of the treatise 

 seems, however, to be destructive criticism of the views of the new 

 school, rather than the construction of a theory in accordance 

 with the requirements of the chemist. J. L. H. 



