32 



CONDUCTIVITY AND VISCOSITY IN MIXED SOLVENTS. 



STRONTIUM IODIDE. 



The strontium iodide used in this work was a sample of Bender and Ho- 

 bein's best material. It was freed from all impurities. The material was 

 dried as follows : It was carefully heated with a little ammonium iodide in a 

 current of pure, dry hydrogen, until all the water and ammonium iodide 

 had been driven off. After cooling in the stream of hydrogen it was at once 

 dissolved. The solutions were perfectly neutral and showed not the slight- 

 est coloration with a starch solution. No trace of ammonium salts could be 

 detected. The solutions were preserved in the dark in tightly stoppered 

 bottles. 



TABLE 13. Molecular conductivity of strontium iodide. 



TABLE 14. Temperature coefficients of conductivity of strontium iodide. 



Some of the results in table 13 are plotted in fig. 4. It is seen that the 

 curve is of the same form as that for potassium iodide at the same tempera- 

 ture. The minimum point is reached with an alcohol of about 50 per cent. 



