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SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 54 



Gaiitier's determinations' were based upon analyses of four boron 

 compounds. First, boron sulphide was decomposed by caustic soda; the 

 solution was then oxidized with bromine water, and the sulphur was 

 precipitated and weighed as barium sulphate. I give the ratio SBaSO^ : 

 B0S3:: 100: a; in the third column below. The weights are all reduced 

 to a vacuum standard : 



Mean, 16.8855, ± .0033 



Hence B = 11.024. 



Secondly, boron carbide was heated in chlorine to expel the boron as 

 BCI3. The residual carbon was then burned in oxygen, and the dioxide 

 so produced was weighed. I subjoin the weights, and also the ratio CO., : 

 BgC : : 100 : x: 



B^C. CO.. Ratio. 



.2686 .1515 177.293 



.3268 .1844 177.224 



Mean, 177.258, ± .024 



Hence B = 10.999. 



Third, boron tribromide was decomposed by water, and its bromine 

 content was then determined as silver bromide. The following data 

 relate to two samples of the boron compound, with five analyses of the 

 first lot and four of the second : 



Mean, 44.512, ± .0009 

 Hence B = 11.021. 



Finally, the analysis of boron chloride was effected in the same w? 

 with the following results: 



1 Ann. Chim. Phys. (7), 18, 352. 1899. 



