1894.] Thermo-electric Properties of Salt Solutions. 



Fio. 4. 



365 



60 80 100 



WWatetAQ 60 40 ZQWater 



and considerable alteration in bulk, so that we might expect to find 

 a change in any physical property disproportionate to that usual in a 

 case of simple mixture. 



The variations in the value of 5 for these two pairs are very like 

 those in the conductivity of different pairs of metals, for here again 

 we have in some cases the conductivity of the mixture nearly equal 

 to the mean conductivity of the components, while for other pairs the 

 conductivity of a mixture is far lower than that of either component. 



Besides the above sets of experiments, observations on a constant 

 strength of a stock solution of zinc sulphate mixed down to a con- 

 stant bulk per 5 c.c. of stock with various substances, gave the fol- 

 lowing results. 



Water only 5 = 8'15 



10 per cent, alcohol 5 = 7'628 



20 5 = 7-22 



30 5 = 6-883 



40 5 = 6-66 



10 grams sugar per 100 c.c 5 = 8'127 



45 , 5 = 8-04 



10 c.c. of a sodic sulphate solution per 100 c.c. 5 = 7' 764 



20 5 = 7-7 



30 5 = 7-67 



20 + 10 c.c. 



alcohol per 100 c.c 5 = 7'436 



