WORK OF ROUILLER. 



OBJECT OF THIS INVESTIGATION. 



This work is a direct continuation of the investigation carried out in Johns 

 Hopkins University two years earlier by Jones and Bassett. 1 They wished, if 

 possible, to trace a connection between the phenomena of minimum conduc- 

 tivity, first observed by Zelinsky and Krapiwin 2 and later extensively studied 

 by Jones and Lindsay, 3 which solutions in certain mixtures of alcohol and water 

 exhibit. Jones 4 and his students have extended the investigation of this 

 problem to mixtures of other solvents, including acetone, and have obtained 

 interesting results. It \vas, therefore, thought desirable to extend also 

 the work of Jones and Bassett. The conductivity of silver nitrate and the 

 transport number of its anion in binary mixtures of water, methyl alco- 

 hol, ethyl alcohol, and acetone have been determined at two temperatures, 

 and 25. 



SOLVENTS. 

 WATER. 



The water used in preparing the solutions was purified essentially by the 

 method of Jones and Mackay. 5 Ordinary distilled water w r as twice redistilled 

 from an acidified solution of potassium dichromate, and the stream from the 

 second distillation passed through a boiling solution of barium hydroxide. 

 It had, at 0, a conductivity of about 1.0 X 10~ 6 . 



4 



METHYL ALCOHOL. 



The purest obtainable product was boiled 1 to 2 days with lime, distilled, 

 and allowed to stand over anhydrous copper sulphate till needed. All dis- 

 tillations were made through a Singer fractionating head and a block-tin 

 condenser, and the liquid was protected during distillation from the moisture 

 in the air by means of a soda lime U-tube. To prevent any possibility of 

 soda-lime dust being drawn back into the liquid, the end of the tube nearest 

 to the bottle was covered with filter paper. The first and last portions of the 

 distillate were always discarded. The mean conductivity at = 0.8 X 10" 



1-6 



1 Amer. Chem. Journ., 32, 409 (1904). 4 Ibid., 32, 521 (1904); 34, 481 (1905). 



2 Ztschr. phys. Chem., 21, 35 (1896). 5 Ibid., 19, 83. 

 9 Amer. Chem. Journ., 28, 329 (1902). 



115 



