ATOMIC WEIGHTS 



399 



puted. The determinations by this method may be arranged in three 

 principal series, representing differences in the source of the initial sub- 

 stance, as follows : 1. Fractional crystallization of telluric acid from 

 barium tellurate. 2. Fractional crystallization of telluric acid produced 

 by oxidation of the element. 3. Tellurium dioxide prepared from tel- 

 lurium hydride. 



Mean of all as one series, 40.136, it .0028 



Hence Te= 137.62. Several other determinations, concordant with 

 these, are cited, but without the detailed weighings. 



Baker and Bennett also determined the atomic weight of tellurium by 

 synthesis of the tetrabromide. Tellurium and bromine were directly 

 combined in an atmosphere of nitrogen, and the excess of bromine was 

 expelled by a current of nitrogen at a temperature of 50°. The deter- 



