with the Mercury Cathode. 379 



absent. Certain it is that in the electrolysis with an anode of 

 pure silver alone — no platinum about the apparatus — in the 

 experiments recorded in Part 2 of Table V the turbidity was 

 present; showing that platinum exposed to the electrolyte is 

 not, as supposed by Goldbaum, the controlling factor. 



In general when an electrolysis of 50 cm3 of "IN salt solution 

 was conducted with a low initial amperage, "24-77, opalescence 

 made its appearance when the current fell to "02-06 amp. ; the 

 time, 28-140 minutes, varying inversely with the strength of 

 the current used. 



The liquid of the inner cells in some of these experiments 

 on settling spontaneously some weeks gave precipitates which 

 weighed '5-"8 mgrms. 



In some cases where the electrolyses were conducted for 

 long periods the opalescence came and disappeared. It is 

 assumed here that the silver chloride, the substance giving rise 

 to the opalescence, reacted with the sodium hydroxide and that 

 ' the products were electrolyzed ; the chlorine going to the 

 anode and the silver into the mercury. 



Even in the experiments recorded in Part 4 of Table V, the 

 conditions being the most ideal for quantitative work that the 

 writer was able to obtain, the liquid of the inner cell showed 

 a trace of opalescence when viewed alone in a small beaker. 



Reactions. — Some remarks, mostly theoretical, may not be 

 out of place at this point. If we assume the simultaneous 

 deposition of chlorine and oxygen on the anode, the chlorine 

 being deposited most freely at the beginning of the process and 

 the oxygen at the end, it would seem natural that the process 

 should go smoothly until the silver anode surface is covered 

 with these products. One of the natural results of crowding 

 on more oxygen and chlorine would be to cause the formation 

 of compounds of silver, oxygen and chlorine. Allowing the 

 formation of soluble silver oxygen compounds, say the hypo- 

 chlorite, either or both of the following reactions might take 

 place, according to the amounts of sodium hydroxide or chloride 

 present in the inner cell: 



AgOCl + NaOH = AgOH + NaOCl, or 

 AgOCl + NaCl = AgCl + NaOCI. 



The writer has found soluble silver oxide in the inner 

 cell ; Goldbaum,* under some conditions, also found a de- 

 posit of silver oxide. The opalescent substance occurring 

 during electrolysis one would expect to be silver chloride. 

 Gooch and Readf found hypochlorite in the inner cell using 



* Loc. cit. 42. f Loc. cit. 



