Life and Chemistry 181 



The doctrine of residual affinity has been 

 long advocated by Armstrong ; and the 

 present writer has recently shown that it is 

 a necessary consequence of the electrical 

 theory of chemical affinity, 1 and that the 

 structure of the resulting groupings, or 

 compound aggregates, may be partially 

 studied by means of floating magnets, some- 

 what after the manner of Alfred Mayer. 2 



It may be well here to explain to students 

 that one of the lines of argument which lead 

 to the conclusion that the water molecule, 

 as it ordinarily exists, is really complex and 

 massive, is based upon measurements of the 

 Faraday dielectric constant for water ; for 

 this constant, or "specific inductive capacity," 

 is found to be very large, something like 

 50 times that of air or free ether ; whereas 

 for glass it is only 5 or 6 times that of 

 free space. The dielectric constant of a 

 substance generally increases with the 



1 See Nature^ vol. 70, p. 176, June 23, 1904. 



* See an article on " Modern Views of Chemical Affinity " 

 by the present writer in a magazine called Technics^ for 

 September 1904. 



