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SMITIISOXIAX MISCELLANEOUS COLLECTIONS 



VOL. 5-1 



with Miss Mary B. Breed/ repeated his former work, with some varia- 

 tions, and added precautions to ensure accuracy. His general method 

 was the same as before, namely, the reduction of palladiamnioniuin 

 cliloride by a stream of hydrogen. First, palladium was purified by 

 distillatio;! as PdCl, at low red heat in a current of chlorine. From this 

 chloride the palladiammonium salt was then prepared. Upon heating 

 the compound gently in a stream of hydrogen, decomposition ensued 

 absolutely without decrepitation or loss of palladium by volatilization. 

 Neitlier source of error existed. The results obtained were these : 



Hence Pd = 106.46. 



In a second series of experiments, palladium was purified as in the 

 earlier investigation, but with special care to eliminate rhodium, iron, 

 copper, gold, mercury, etc. The palladiammonium salt prepared from 

 this material gave as follows : 



Hence Pd = 106.47. 



Here, again, no loss from decrepitation or volatilization occurred, 

 although evidence of such loss was carefully sought for. 



Hardin," in 1899, made three series of determinations of the atomic 

 weight of palladium, by reduction of three palladium salts in hydrogen. 

 His results, with weights reduced to a. vacuum, are as follows: 



lAm. Chem. Journ., 16, 20. 1894. 

 * Journ. Amer. Chem. Soc, 21, 947. 



