RICHARDS AND WHITRIDGE. — CUPRIAMMONIUM SALTS. 459 



The following procedure was found to be the most successful, but 

 great care was needed to carry it out. Three grams of crystallized 

 cupric formiate were dissolved in just enough warm alcohol to effect 

 solution, and two grams of animonic chloride were added to the mix- 

 ture. The whole was then heated to boiling, and dry ammonia was 

 passed in until a very slight excess was present. Upon cooling and 

 evaporation in the air, fine blue prismatic crystals separated, which 

 were fairly pure, as the analyses show. The salt resembles in its 

 properties the formiobromide, being permanent in dry air, but at once 

 decomposed by water. In color it is a purer blue than the formi- 

 bromide, having much less of the greenish tinge. 



In the analysis of the compound the copper was determined electro- 

 lytically after the substance had been evaporated with sulphuric and 

 nitric acids. The chlorine from a new portion was weighed as argen- 

 tic chloride, and the ammonia was distilled after the addition of pot- 

 ash. The formic acid was determined by combustion. 



Analyses of Cu(NH3)2ClCH02. 



I. 0.0862 gram of the substance gave on electrolysis 0.0305 gram 



of copper. 

 II. 0.0997 gram of the substance gave on electrolysis 0.0356 gram 



of copper. 

 III. 0.1258 gram of the substance yielded 0.0994 gram of argentic 



chloride. 

 IV. 0.1285 gram of the substance yielded 0.1008 gram of argentic 



chloride. 

 V. 0.1060 gram of the substance distilled with caustic potash re- 

 quired 11.75 cubic centimeters of a decinormal solution for 



neutralization. 

 VI. 0.0984 gram of the substance yielded on combustion 0.0241 gram 



of carbon dioxide. 



Analyses III. and IV. were made from different samples; hence 

 they prove the definiteness of the compound. 



