OHEMISTET OF THE WASHOE PEOOESS. 277 



tightly-fitting stopper, to prevent access of air. It was exposed for twenty- 

 four hours to a temperature of 90° centigrade. Sulphuric acid and sub- 

 chloride of copper were found in the solution. Chloride of silver was pre- 

 cipitated. After removing the soluble salts, by washing, the chloride of sil- 

 ver was dissolved out, by digesting it with ammonia. The residue gave, by 

 assay, .099 grammes of silver. Two grammes of the mineral produced .1705 

 of pure metal; showing that, under the most favorable conditions, but little 

 over one-half of the silver was chloridized. The application of heat greatly 

 facilitated the decomposition. 



Polybasite, after being subjected to the chloride of copper solution, at 

 the ordinary temperature of air, also yielded a small quantity of the chlorid- 

 ized silver. 



Argentite was exposed to the same treatment, with sub-chloride of cop- 

 per, as in the last experiments. In the cold, decomposition ensued after stand- 

 ing several days. The residue from two grammes of the mineral, subjected 

 to the action of heat at 90° centigrade, without access of air, gave .1655 

 of a gramme of silver, showing that only .006 had been chloridized. 



Galena, in a pulverized condition, was digested with a strong mixture of 

 salt and sulphate of copper, and after standing three or four weeks, at the 

 ordinary temperature, was filtered. The residue exhibited, besides the unde- 

 composed mineral, a light green oxychloride of copper, and a large quantity 

 of sulphate of lead incrusting the galena. 



Blende was also subjected to a similar treatment. The solution was 

 found to contain a considerable quantity of oxide of zinc, and but little cop- 

 per. The residual blende was coated with the same oxychloride of copper 

 already noted in the case of the galena. 



Two grammes of the powdered mineral were placed in a flask, a solu- 

 tion of five grammes of salt and seven of sulphate of copper added, and ex- 

 posed for two days to a temperature of 90° centigrade. After remaining 

 three days longer in the cold the amount of oxide of zinc found to have 

 been dissolved was .2785 of a gramme. The same experiment was repeated 

 with the addition of one gramme of iron filings. The latter rapidly disap- 

 peared ; metallic copper was precipitated, but was redissolved, probably by 

 the chloride of copper present, the sub-chloride being produced. Later, 



