A REVISION OF THE ATOMIC WEIGHT OF IODINE. 



97 



sticks were used in an elongated form of pycnometer for solids.^ The average 

 of the last two experiments is undoubtedly more accurate than that of the first 

 three, since it was extremely difficult to pump out the air from the more porous 

 material used in the first experiments. 



The vacuimi correction for silver iodide, when weighed with brass weights, 

 calculated from this value for its specific gravity, is +0.000067 8°^- for every 

 apparent gram of salt.^ A vacuiun correction of —0.000031 gm. was applied 

 to every apparent gram of silver. 



The Atomic Weight of Iodine. 



Series I. Ag: Agl. 



No. 

 of 

 anal- 

 ysis. 



Sam 

 pleof 



io- 

 dine 



Weight of 

 silver in 

 vacuum. 



gm. 



5-23123 



3-57039 

 4.60798 



4.52467 

 4.66256 



Weight of 



silver 

 iodide in 



gm. 

 11.38074 



7.77023 

 10.02747 



9.84834 

 IO.14601 



Loss 



on 



fusion. 



gm. 

 0.00030 

 not fused 

 0.00047 

 0.00036 

 0.00062 



Weight of 



silver 



from 



filtrate. 



gm 



Weight of 



silver 



iodideand 



asbestos 



fr. filtrate. 



gm. 

 0.00482 

 0.00007 

 o.ooioo 

 0.00020 

 0.00048 



Corrected 



weight 



of silver 



iodide in 



gm. 

 11.38526 



7.77030 

 10.02800 



9.84818 

 10.14587 



Ratio 

 AgrAgI 



0.459474 

 0.459492 

 0.459511 

 0.459448 

 0.459552 



Atomic 



weight of 



iodine. 



Ag = 



107.880. 



126.910 

 126.QOI 

 126.891 

 126.925 

 126.870 



Average 0.459495 126.899 



Series II. Ag: Agl. 



126.915 



126.917 



126.887 

 126.934 



126.912 

 126.907 



126.881 



126.909 

 126.926 

 126.914 

 126.913 



Average ■ ■ ■ 0.459473 



Average, rejecting Analysis 12 0.459468 



Average of analyses with Sample I 0.45946a 



Average of analyses with Sample II, Fraction i . . . 0.459473 



" 2 . . . 0.45947S 



" " " " 3 . . . 0.459460 



" « " 4 . . . 0.459468 



126.910 

 126.913 

 126.916 

 126.911 

 126.911 

 126.918 

 126.914 



• Baxter and Hines: Amer. Chem. Jour., 31, 222 (1904). 



2 In the original publication of this paper a slightly higher vacuum correction was em- 

 ployed owing to an incorrect assumption as to the specific gravity of the weights, which are 

 here taken at 8.3. 



