TELLURIUM. 273 



Te. TeO. 2 . Percent. Te. 



2.3092 2.9001 79.625' 



2-8153 3-533 2 79-68i 



4.0176 5-347 79-798 



3.1613 3-9 6 85 79.660 



.8399 1.0526 79-793 



Mean, 79.711, .0239 



Hence Te = 124.709. 



In a single analysis of the dioxide, by reduction with S0 2 , 2.5489 

 grammes Te0 2 gave 2.0374 of metal. If we give this experiment the 

 weight of one observation in the synthetic series, the percentage of tel- 

 lurium found by it becomes 



79.93 2 , -0534. 

 Hence Te = 126.494. 



Brauner's best results were obtained from analyses of tellurium tetra- 

 bromide, prepared from pure tellurium and pure bromine, and after- 

 wards sublimed in a vacuum. This compound was titrated with standard 

 solutions of silver, and three series of experiments, made with samples 

 of bromide of different origin, gave results as follows. The TeBr 4 equiva- 

 lent to 100 parts of silver appears in the third column : 



First Series. 



TeBr^. Ag. Ratio. 



2.14365 2.06844 103.636 



1.76744 1.70531 103.643 



1.47655 1.42477 103.634 



1.23354 1.19019 103.642 



Second Series. 



TeBr. Ag. Ratio. 



3.07912 2.97064 103.651 



5.47446 5- 2 8i57 103.652 



3-30927 3.I93I3 103.637 



7.26981 7.01414 103.645 



3.52077 3-39667 103.654 



Third Series. 

 TeBr. Ag. Ratio. 



2.35650 2.27363 103.645 



1.51931 1.46564 103.662 



1.43985 1.38942 103.630 



Mean of all as one series, 103.644, .0018 

 18 



