Gooch and Perkins — Determination of Free Iodine. 39 



mixture of silver and iodine was made alkaline by adding 

 about 10 cm3 of a saturated solution of sodium bicarbonate. 

 The results of the experiments in Table IY, which show 

 irregularities when made in air and a very high degree of 

 accuracy when the shaking was done under hydrogen, prove 

 the absorption of iodine to be equally as exact in the alkaline as 

 the neutral solution. 



The process described, in which free iodine is absorbed by 

 electrolytic silver under hydrogen, either in neutral solution or 

 in a solution made alkaline with an acid carbonate, should be 

 applicable in many analytical operations, as well as in the 

 gravimetric standardization of the usual iodine solution of 

 volumetric analysis. 



