84 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



III. 0.2302 gram of the substance required 20.36 cubic centimeters of 



acid, and gave 0.2872 gram of argentic iodide. 



IV. 0.2307 gram of the substance required 20.35 cubic centimeters of 



acid. 

 V. 0.2150 gram of the substance on electrolysis gave 0.0367 gram 

 of copper. 



100.00 



99.65 



(4.) Ammonic Dicupric Acetate, NH4Cu2(C2H;,02)5- HoO. 



Since compounds containing three molecules of ammonia, one of 

 acetic acid, and one atom of chlorine, bromine, or iodine had been 

 proved to exist, it became a matter of interest to discover if it were 

 possible to prepare Cu(NH3)3(C2H.^02)2, in which the halogen is re- 

 placed by acetic acid. Many unsuccessful attempts were made to 

 obtain this compound. In the course of these experiments, however, 

 a new double salt of cupric and ammonic acetates was discovered. 

 Four grams of cupric acetate, six grams of glacial acetic acid, and 

 twenty cubic centimeters of alcohol were mixed together, and ammonia 

 gas was passed into the mixture until the green color just turns into 

 blue. The solution became hot from the absorption of the ammonia, 

 and the cupric acetate dissolved readily. After standin-z; a few hours 

 many small bluish green crystals were deposited, which have the com- 



