Browning and Flint — Complexity of Tellurium. 351 



Summary of Analyses. 



Process Alpha Beta 



Basic nitrate 126-53 128*97 



Permanganate _ 126*64 128*77 



Ammonia — acetic acid 126*31 128*81 



Mean.. _ 12649 12885 



It is seen that an atomic weight of 126*5 gives more satis- 

 factory results for alpha, while neither 126*5 nor 127'5 will 

 answer for beta. 



Besides the experiments with the basic nitrate, just 

 described, the following experiments upon the dioxide are to be 

 noted. Two portions of tellurium dioxide from each fraction, 

 prepared by the ignition of the basic nitrates, were dissolved 

 in equal amounts of hydrochloric acid and treated with equal 

 amounts of boiling distilled water. The results given in 

 Table IV indicate different degrees of hydrolytic susceptibility 

 on the part of the tetrachloride prepared from these fractions. 



Table IV. 



Te0 2 taken Te0 2 found Percentage 



grm. grm. precipitated 



(1) 0-3000 0*2521 84*. # 



(2) 0*3000 0-2602 86*7$ 



(3) 0*3000 0*2772 92*4^ 



(4) 0*3000 0*2806 93*5^ 



(1) and (2) were obtained from one fraction and (3) and (4) 

 from the other. (1) and (3) stood 22 hours before filtration, 

 (2) 26 hours, and (4) 18 hours. 



A sample of tellurium dioxide obtained from the tellurium 

 tetrachloride by several hot water precipitations, according to 

 the procedure for the preparation of the alpha fraction, was 

 analyzed by the permanganate process already described. The 

 results of the analysis of this specially prepared dioxide, as 

 given in Table V, show a close agreement with the analyses of 

 the basic nitrate prepared from the alpha fraction and recorded 

 in Table II. 



Table V. 



TeOo taken Te0 2 found Error Te0 2 found Error 



grm. grm. grm. grm. grm. 



Te=126-5 Te=127*5 



(1) 0*3066 0*3064 —0*0002 0*3076 +0*0010 



(2) 0*2723 0*2719 —0*0004 0*2729 +0*0006 



(3) 0*2229 0*2228 —0*0001 0*2243 +0*0014 



(4) 0*2220 0*2220 0*0000 0*2235 +0*0015 



