172 THE ATOMIC WEIGHTS. 



by Weselsky which was published by him in a paper pres- 

 ently to be cited : 



.4360 gmi. nickel precipitated .9648 grm. gold. 45.191 



.4367 " .9666 " 45-179 



.5189 " I. 1457 " 45-291 



.6002 " 1.3286 " 45-175 



3147 

 5829 

 5"i 



5821 



559 



Mean, 45.151, ± .025 



Weselsky 's paper,* already cited, relates only to cobalt. 

 He ignited the cobalticyanides of ammonium and of phe- 

 nylammonium in hydrogen, and from the determinations 

 of cobalt thus made deduced its atomic weight. His results 

 are as follows : 



-7575 C"''- (NH^)gCo2Cyj2 gave .166 grm. Co. 21.914 per cent. 

 .5143 " .113 " 21.972 " 



Mean, 21.943, ± .029 



.8529 grm. (C5HgN)5Co2Cyi2 gfive .1010 grm. Co. 11.842 per cent. 



.6112 " -0723 " 11.829 " 



.7140 " .0850 " 11-905 " 



.9420 " .1120 " 11.890 " 



Mean, 11.8665, zt .0124 



Finally, we come to the work done by Leef in the labora- 

 tory of Wolcott Gibbs. Like Weselsky, Lee ignited certain 

 cobalticyanides and nickelocyanides in hydrogen and deter- 

 mined the residual metal. The double cyanides chosen 

 were those of strychnia and brucia ; salts of very high mo- 

 lecular weight, in which the percentages of metal arc rela- 

 tively low. A series of experiments with purpureo-cobalt 



*Ber. d. Deutsch. Chem. Gcsell., 2, 592. 1868. 

 f Am. Journ. Sci. and Arts, (3,) 2, 44. 1871. 



