454 SMITHSONIAN .MISCELLANEOUS COLLECTIONS VOL. 54 



PALLADIUM. 



The first work upon the atomic weight of palladium seems to have 

 been done by Berzelius. In an early paper' he states that 100 parts of 

 the metal united with 28.15 of sulphur. Hence Pd = 113.91, a result 

 which is clearly of no present value. 



In a later paper" Berzelius published two analyses of potassium pal- 

 ladiochloride, K2PdCl4. The salt was decomposed by ignition in liydro- 

 gen, as was the case with the double chlorides of potassium with platinum, 

 osmium and iridium. Reducing his results to percentages, we get the 

 following composition for the substance in question : 



Pd. 2KCI. Ch. 



32.726 46.044 21.229 



32.655 45.741 21.604 



Mean, 32.690 Mean, 45.892 Mean, 21.416 



From these percentages, calculating directly, very discordant results 

 are obtained : 



From percentage of metal Pd ^ 106.86 



From percentage of KCl " = 104.90 



From percentage of CI2 (loss) " ^ 111.11 



Obviously, the only way to get satisfactory figures is to calculate from 

 the ratio between the Pd and 2KC1, eliminating thus the influence of 

 water in the salt. The two experiments give, as proportional to 100 

 parts of KCl, the following of Pd : 



71.075 

 71.391 



Mean, 71.233, ± .1066 



Hence Pd = 106.22. 



In 1847 Quintus Icilius " published a determination, which need be 

 given only for the sake of completeness. He ignited potassium palladio- 

 chloride in hydrogen, and found the following amounts of residue. His 

 weights are here recalculated into percentages : 



^ Poggend. Annalen, 8, 177. 1826. 

 = Poggend. Annalen, 13, 454. 1828. 



^ " Die Atomgewichte vom Pd, K, CI, Ag, C, und H, nach der Methode der kleinslen Quadrate 

 borechnet." Inaug. Diss. GSttingen, 1847. Contains no ether original analyses. 



