ELECTROCHEMICAL INVESTIGATION OF LIQUID AMALGAMS 



The saturated amalgam was then weighed, and the mercury driven off, 

 at first by distillation in hydrogen, and the last traces by heating to a red 

 heat in a crucible. The cupric oxide left was then either directly weighed, 

 or it was dissolved in nitric acid, neutralized with ammonia and the con- 

 centration of the solution approximately estimated by colorimetric com- 

 parison with the color of a standard solution of ammoniacal cupric nitrate. 

 The results are given in table 14. 



TABLE 14. Solubility of Copper in Mercury at 20. 



Thus the solubility of copper in mercury at room temperature seems to 

 be very small indeed, about 0.0024 per cent, or about I milligram in 40 

 grams of mercury. This agrees well with the observations of Sir W. 

 Ramsay, 40 but is somewhat higher than a result of Gouy.* 1 



It was then decided to measure electrically a series in which the start- 

 ing point should be undoubtedly a real solution. An amalgam containing 

 about i per cent of copper was made electrolytically. It was then filtered 

 three times through leather, the last filtration leaving no solid residue. 

 153 grams of this amalgam were then diluted with 26 grams of mercury 

 in order to make quite certain that no solid was present. This amalgam 

 was bottled in the usual way. It was estimated to contain about 0.0020 

 per cent of copper. 



TABLE 15. 



40 Journ. Chem. Soc., 1889, Trans, n, 532. 



tt Gouy, Ann. der Phys. Beiblatter, 19, 758. He found o.ooi per cent of copper, 

 1.8 per cent of zinc, and 1.3 of lead in their respective liquid amalgams. 



