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SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 54 



Berzelius/ treating barium cliloride with sulphuric acid, obtained 

 the following results in BaSOi for 100 parts of BaCl., : 



112.17 

 112.18 



Mean, 112.175 



Hence Ba = 135.653. 



Struve/ in two experiments, found : 



112.0912 

 112.0964 



Mean, 112.0938 



Hence Ba = 137.037. 



Marignac's ^ three results are as follows : 



8.520 grm. BaCls gave 9.543 BaSO^. 



8.519 " 9.544 " 



8.520 " 9.542 " 



Ratio, 112.007 

 112.032 

 111.995 



Mean, 112.011, ± .0071 

 Hence Ba= 138.473. 



Richards, in his work on this ratio, regards the results as of slight 

 value, because of the occlusion of the chloride by the sulphate. This 

 source of error he was never able to avoid entirely. Another error in 

 the opposite direction is found in the retention of sulphuric acid by the 

 precipitated sulphate. Eight experiments were made in two series, one 

 set by adding sulphuric acid to a strong solution of barium chloride in a 

 platinum crucible, the other by precipitation in the usual way. Rich- 

 ards gives in his published paper only the end results and the mean of 

 his determinations; the details cited below I owe to his personal kind- 

 ness. The weights are reduced to a vacuum standard : 



Ratio. 

 112.086 

 112.072 

 112.064 

 112.076 

 112.080 

 112.080 

 112.076 

 112.085 



First 



Second 



Mean, 112.077, ± .0017 



Hence Ba= 137.398. 



1 Poggend. Annalen, 8, 177. 



2 Ann. Cliem. Pharm., SO, 204. 1851. 



3 Arch. Sci. Phys. Nat., 1, 209. 1858. Jouin. piakt. Chem., 74, 212. Oeuvres Completes, 1, 559. 



