TANTALUM. 237 



was ignited and weighed as Ta.^Oj. 100 parts of the salt gave the follow- 

 ing quantities of Ta^O^ and KjSO^ : 



56.50 44-37 



56.75 44-35 



56.55 4422 



56-56 . 44-24 



Mean, 56.59, =h .037 Mean, 44.295, ± .026 



From these figures, 100 parts of K.SO^ correspond to the subjoined 

 quantities of Ta^Oj : 



127.338 

 127.960 

 128.178 

 127.848 



Mean, 127.831, ±.120 



The ammonium salt, (NHJ.^TaF.. ignited with sulphuric acid, gave 

 these percentages of TajO^, The figures are corrected for a trace of K^SO^ 

 which was always present : 



63.08 



63-24 



63.27 



63.42 



Mean, 63.25, zb .047 



Hence we have four values for Ta : 



From potassium salt, per cent. Ta^Oj Ta =r 182.336 



From potassium salt, per cent. KjSO^ " = 180.496 



From potassium salt, KjSO^ : Ta^Oj " ^ 181.422 



From ammonium salt, per cent. TajOj. ....... " ^181.559 



Average Ta = 181.453 



Or, if = 16, Ta = 182.836. 



These values are computed with = 15.879, K = 38.817, S = 31.828, 

 N = 13.935, and F = 18.912. 



