80 PROCEEDINGS OF THE AMERICAN ACADEMY. 



Cu(NH3)3ClC2H302.H20 and Cu(NH3)3BrC2H302. H.O. The rea- 

 son for this anomaly remains obscure. 



The ammonia present in the compound was determined by distilla- 

 tion with pure potash or soda, the distillate being titrated with stan- 

 dard acid. It is convenient to prepare the alkali for this purpose 

 directly from metallic sodium or from sodium amalgam, thus avoiding 

 the complications in the subsequent proceedings introduced by the 

 usual impurity of chlorine in commercial potash and soda. The res- 

 idue in the distilling flask after the ammonia had been expelled was 

 filtered, and to the filtrate was added a little sulphurous acid to reduce 

 any iodate which might have been formed. Argentic nitrate was then 

 added, and subsequently the argentic oxide and sulphite were dissolved 

 by nitric acid, the argentic iodide being collected and weighed upon a 

 Gooch crucible. In Analysis IV. the alkali was nearly neutralized, 

 and in Analysis V. the solution was just acidified by pure nitric acid 

 before the precipitation. In every case enough nitric acid was added 

 after the precipitation to insure the solution of all but argentic iodide, 

 and the agreement of the results is sufficiently satisfactory. The cop- 

 per was determined by the electrolysis of the cupric sulphate obtained 

 from the precipitated cupric oxide, which contained no trace of iodine; 

 and the acetic acid was determined by combustion. 



Analyses of Cu(NH3)3lC2H302. 



I. 0.2591 gram of the substance on distillation with potash re- 

 quired 25.34 cubic centimeters of decinormal acid for neutrali- 

 zation, gave on electrolysis 0.0545 gram of cojiper, and yielded 

 0.2042 gram of argentic iodide. 

 II. 0.2524 gram of the substance required 25.05 cubic centimeters 

 of decinormal acid and gave 0.0527 gram of copper. 



III. 0.2322 gram of the substance required 23.25 cubic centimeters 



of decinormal acid. 



IV. 0.3960 gram of the substance gave 0.3109 gram of argentic 



iodide. 

 V. 0.2559 gram of the substance gave 0.2004 gram of argentic 

 iodide. 

 (VI.) 0.3211 gram of the substance gave on combustion 0.0939 gram 



of carbon dioxide. 

 VII. 0.2946 gram of the substance gave on combustion 0.0864 gram 

 of carbon dioxide. 

 VIII. 0.3062 gram of the substance gave on combustion 0.0907 gram 

 of carbon dioxide. 



