CONDUCTIVITY AND LUMINOSITY OF FLAMES COXTAIXIXO VAPORISED SALTS. 105 



The foregoing tubles show 



I. That at small concentrations equivalent solutions of all salts of the 



metal impart the same conducting jxtwer to the flame. 



II. That at higher concentrations the equality mentioned in I no longer holds 

 good, the oxysalts showing a greater conducting power than the haloid 

 ^.ilts. This ditt'erence increases with increasing concentration, and with 

 increasing electromotive force. 



A clearer conception of the relations which hold is obtained by expressing the 

 conducting power in terms of molecular conductivities. It is impossible to give abso- 

 lute molecular conductivities, as this would require an exact knowledge of the concen- 

 tration of suit vapour between the electrodes and of the cajMicity of the electrode 

 system. In the following table the numbers, which are proportional to the molecular 

 conductivities, have been obtained by dividing the numbers of the preceding table by 

 the concentration of the solution, taking -fa normal solutions as of unit concentration. 



The values all refer to an E.M.F. of '227 volt. At this E.M.F. Ohm's law is 

 obeyed with close approximation in our experiments, so that the conditions correspond 

 in this respect with those of conduction in aqueous solution, from which the idea of 

 molecular conductivity is drawn. 



\ul.. i \i III. A. 



