C. A. Peters — Reactions in a System of Chloride. 387 



Two days later another piece of red litmus was added, and this, 

 in three minutes, was blue on the edges. After standing 

 several mouths a piece of red litmus turned blue instantly upon 

 introduction into the liquid over the mercury. It is evident 

 that the amount of sodium hydroxide produced in a few day- 

 is extremely small and inappreciable in analysis. 



In other experiments platinum wires were substituted for 

 nickel. A scum formed slowly as before and under the micro- 

 scope was found to be composed of coarse white crystals with 

 numerous small globules of mercury between them. The crys- 

 tals contained mercury and chlorine, and were very insoluble 

 in water. Small amounts crystallized from boiling water had 

 the characteristic " silky " appearance of calomel. The crys- 

 tals consequently were identified as mercurous chloride. The 

 platinum showed uo erosion. 



The liquid over the mercury showed the same tendency, in 

 about the same degree as when the nickel was present, to 

 develop alkalinity. A few cubic centimeters from one of the 

 platinum-mercury-salt systems which had been standing several 

 days developed only the faintest pink coloration with phenol- 

 phthalein. 



Summary. 



From the work described in this paper it is seen that when 

 a solution of sodium chloride is allowed to stand over mercury 

 with a nickel wire connecting both liquids, crystalline nickelous 

 hydroxide is formed very slowly, sodium hydroxide being pro- 

 duced at the same time. When platinum is substituted for 

 nickel, mercuroTis chloride is formed, sodium hydroxide being 

 likewise produced. 



