380 Browning and Palme?' — Estimation of Thallium. 





T1,0 taken 



T1 2 



Error 





as the 



found 







nitrate 









grm. 



grm. 



grm. 



(1) 



0-0809 



0-0809 



+ 0-0000 



(2) 



0-0809 



0-0808 



—o-oooi 



(3) 



0-0809 



0-0809 



±0-0000 



(4) 



0-1213 



0-1212 



— 0-0001 



(5) 



0-1213 



0-1216 



+ 0-0003 



(6) 



0-1213 



0-1218 



+ 0-0005 



0) 



0-1213 



0-1218 



+ 0-0005 



(8) 



0-1213 



0-1212 



— 0-0001 



(9) 



0-1213 



0-1207 



— 0-0006 



(10) 



0-1618 



0-1614 



— 0-0004 



(H) 



0-1618 



0-1613 



-0-0005 



(12) 



0*1618 



0-1616 



— 0-0002 



Gravimetric. — The satisfactory character of the precipitate 

 of thallic hydroxide obtained by this process suggested the 

 possibility of applying it to a gravimetric estimation of thal- 

 lium. Several precipitations were made according to the 

 method described and the precipitate contained in a perforated 

 platinum crucible upon an asbestos felt was dried over a 

 low flame at about 200° C. to constant weight. The results 

 follow in the table : 





T1 2 3 



T1 2 3 



Error 





taken 



found 







as the 









nitrate 









grm. 



grm. 



grm. 



(1) 



0-1305 



0:1309 



0-0004 + 



(2) 



0-1305 



0-1314 



0-0009 + 



(3) 



0-1305 



0*1308 



0*0003 + 



« 



0-0870 



0-0872 



0-0002 + 



(*) 



0-1740 



0-1741 



0-0001 + 



(6) 



0-1740 



0-1739 



o-oooi — 



(?) 



0-1740 



0*1742 



0-0002 + 



(8) 



0-1305 



0-1307 



0-0002 + 



(9) 



0-1305 



0-1309 



0-0004 + 



(10) 



01305 



0-1308 



0-0003 + 



(11) 



0-0870 



0-0872 



0-0002 + 



(12) 



0-0870 



0-0874 



0-0004 + 



In experiments (5) to (12) the precipitated thallic hydroxide 

 was washed with hot water, a procedure to be recommended 

 when large amounts are present. 



