3G PROCEEDINGS OF THE AMERICAN ACADEMY. 



In an investigation which I am now making on cells of the above tvj>o 

 I have attempted a verification of these equation! in the following way. 



('hoo.-ini: two solvents in which the value of In- maybe neglected. 



r 



nanu'lv, water and a mixture <>f alcohol ami water, then if /•._. be made 



equal to Pj, '., should equal zero. Unfortunately the dissociation in 



alcohol-water mixtures of the salt9 that are available for our purp 

 has not hitherto been determined. If the two solutions are made up 

 with equivalent amounts of the original salt, then the concentration of 

 the ions in the alcohol-water solution will he less than that in the water 

 solution on account of the greater dissociative power of water. In the 

 following cell-, made up in tin- way. we should expect, therefore, a -mall 

 temperature coefficient, and moreover, since the electrode in contact with 

 the water solution is found to he negative, this temperature coefficient 

 Bhould he negative. 



The following tahle gives the results ohtained for the cells : — 

 (1) Zinc; zinc sulphate, tenth normal, in water and fifty per cent ethyl 

 alcohol. (2) Zinc: zinc sulphate, tenth normal, in water and fifty per 

 cent methyl alcohol. (3) Cadmium; cadmium sulphate, tenth normal, 

 in water and sixty per cent ethyl alcohol. (4) Thallium; thallium 

 sulphate, hundredth normal, in water and twenty-seven per cent ethyl 

 alcohol. (5) Thallium; thallium sulphate, hundredth normal, in water 

 and forty per cent methyl alcohol. 



