42 Mr. W. R. Bousfield and Dr. T. M. Lowry. [June 19, 



was very small, but. as in the ease of nickel, exhibited a change of 

 sign, the reversal taking place in a field of 9500 c.g.s. (See fig. 7.) 



The highest field obtained was only 11.000 c.g.s.. and as the self- 

 demagnetising force must be very great in this case, it is possible that 

 with much stronger fields the effect may increase rapidly. The same 

 specimen of iron was used as in the experiments with ordinary fields. 



All the experiments described above were carried out in the Physi- 

 cal Laboratory of the University College of North "Wales ; and. in 

 conclusion. I desire to acknowledge my great obligation to Professor 

 E. Taylor Jones for the interest he has taken in the work, and also for 

 much valuable help and advice. 



" Influence of Temperature on the Conductivity of Electrolytic 

 Solutions. 5 ' By W. E. Bousfield,. M.A., K.C., M.P., and T. 

 Maetix Lowey, D.Sc. Communicated by Professor H. E. 

 Armstrong, F.E.S. Received and read June 19, .1902. 



The phenomenon of electrolysis is characteristic mainly of the liquid 

 state, a liquid electrolyte usually ceasing to conduct when it passes 

 into the gaseous or into the crystalline state. The influence of tem- 

 perature on the conductivity of a liquid such as an aqueous solution of 

 hydrogen chloride is. however, of such a character as to indicate that 

 an upper and a lower limit of conductivity may exist apart altogether 

 from the boiling point and freezing point of the solution. The pre- 

 sent communication contains a summary of the evidence for the 

 existence of these limits of conductivity, a brief discussion of their 

 probable position on the scale of temperature in the case of some 

 aqueous and other electrolytes, and a review of the influence of tem- 

 perature on conductivity over the whole range of temperature within 

 which electrolysis can take place. 



Whatever view be taken of the nature of the process by which a 

 conducting solution is formed on dissolving a -alt. acid, or base, in an 



ionising solvent.'" there is every reason to believe that the process is 

 only complete in presence of a very large excess of solvent, and that 

 usually only a part of the solute is concerned in carrying the current. 

 The proportion of the solute that is thus rendered active in electro- 

 lysis is represented by a coefficient of ionization/'' and two general 

 methods are in use for determining its magnitude. In the first method, 

 the •■ equivalent conductivity," X, of the solute is determined for a 

 series of dilutions., and the ratio Xv X x of this constant at a dilution 

 of v litres per equivalent to that at infinite dilution is taken to repre- 

 sent the coefficient of ionisation at volume c. This method is based on 



