IOWA ACADEMY OF SCIENCES. 



133 



The molecular conductivity of ammonium bromide was 

 determined with a specimen which had been repeatedly 

 crystallized, starting with a large quantity of fairly pure 

 salt. 



Molecular Conductivity of NH^Br (98.02) . 



The conductivity of zinc bromide in water could not be 

 determined directly, since the bromide is so readily decom- 

 posed by water. By comparing a number of chlorides and 

 bromides we find the conductivity of the latter to be about 

 two units greater than the former for equal concentrations. 

 To obtain the conductivity of zinc bromide at any dilution, 

 we have taken the conductivity of zinc chloride at that 

 dilution and added two units. This is, of course, only 

 approximate, but it seems the best that can be done under 

 the conditions. 



Comparison for SNH^Br. ZnBr^, 



