ATOMIC WEIGHTS 333 



Mean. 89.662, ± .0007 



Hence Bi = 208.153. 



Eejecting the work of Lagerhjelm, which has so high a probable error 

 as to count for ahnost nothing, the data for the percentage of Bi in 

 Bi^,03 combine as follows : 



Schneider, 1851 89.655, ± .0034 



Marignac 89.682, ± .0036 



Lowe 89.648, ± .0040 



Classen 89.696, ± .0009 



Schneider, 1894 89.657, ± .0015 



Birclvenbach, preliminary oxidations. . 89.651. ±.0027 



Birckenbach. final oxidations 89.656, ± .0010 



Birckenbach, preliminary reductions.. 89.660, ± .0041 



Birckenbach, final reductions 89.662, it .0007 



General mean 89.6683. ± .00044 



If we omit the high value found by Classen, the general mean becomes 

 89.6594,±. 00052. 



Mehler/ also under Gutbier's direction, studied the composition of 

 bismuth tribromide, which was prepared by direct union of the metal 

 with bromine, and afterwards sul^limed. The bromine was precipitated 

 with silver solution, and the silver bromide was weighed. The weights 

 are given as reduced to a vacuum. In the third column I give the ratio 

 3AgBr:BiBr3::100:a;; 



BiBt\. AgBr. Ratio. 



3.77071 4.74323 79.497 



4.37676 5.50932 79.443 



3.64088 4.58160 79.467 



4.57894 5.76183 79.470 



4.53204 5.70410 79.452 



2.85054 3.58682 79.473 



4.58310 5.76618 79.482 



6.47910 8.15465 79.453 



Mean, 79.467, ± .0042 

 Hence Bi = 207.92. 



^ Inaug. Diss., Erlangen, 100.5. Sitzungsb. phys. nied. Soz. Erlangen. 37, 343. 

 22 



