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LXVIL Electrical Conductivity produced by Heating Salts. 

 By A. E. Garrett *. 



rf^HE experiments described in the following paper form a 

 _L continuation of those conducted by Dr. R. S. Willows 

 and myself which were published in the Phil. Mag. for 

 October 1904. 



The experiments there described showed that increased 

 electrical conductivity took place when the halogen com- 

 pounds of zinc were heated to a temperature o£ about 360° C. 

 This led us to think that other inorganic chemical compounds 

 might possibly behave in a similar manner, so, in the first 

 series of the present experiments, I tested a number of 

 compounds to see if they increased the electrical conductivity 

 when their temperatures were raised to about 360° 0. In 

 the second series of experiments I have confined my attention 

 to a few special cases in which increased conductivity had 

 been found to occur, in order to find out what are the causes 

 of increased conductivity (more particularly so in the cases 

 where the presence of the positive ions could be detected), 

 and to find out the nature of the positive ions. 



First Series. 



For these preliminary experiments the apparatus used is 

 shown in figure 1. 



A 



I 



To £/)/?TH 



A is an iron cylinder about 12 cms. in length and 5 cms. 

 in diameter ; caps of the same material partially close its 

 ends. is a platinum wire, connected to a wire passing 

 through the centre of the metal tube J, and carefully 

 insulated by means of ebonite pings passed through the 

 corks N and M. F is a quadrant electrometer ; both pairs 



* Communicated by the Physical Society : read April 26, 1907. 



