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SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 54 



In order to render " assurance doubly sure," Professor Cooke also 

 undertook the analysis of the bromide and the iodide of antimony. The 

 bromide, SbBrj, was prepared by adding the finely powdered metal to a 

 solution of bromine in carbon disulphide. It was purified by repeated 

 distillation over pulverized antimony, and by several recrystallizations 

 from bisulphide of carbon. The bromine determinations resemble those 

 of chlorine. Eeduced to a common standard, the fifteen analyses give 

 the subjoined quantities of SbBrg proportional to 100 parts of silver 

 bromide : 



.008 



Hence Sb = 119.86. 



The iodide of antimony was prepared like the bromide, and analyzed 

 in the same way. At first, discordant results were obtained, due to the 

 presence of oxyiodide in the iodide studied. The impurity, however, 

 was removed by subliming the iodide in an atmosphere of dry carbon 

 .dioxide. With this purer material, seven estimations of iodine were 

 made. Eeduced to a uniform standard, Cooke's weighings give the fol- 

 lowing quantities of Sblg proportional to 100 parts of silver iodide : 



Hence Sb = 119.79. 



Mean, 71.060, ± .023 



