BISMUTH. 229 



BISMUTH. 



Early in the century the combining weight of bismuth was approxi- 

 mately fixed through the experiments of Lagerhjelm.* Effecting the 

 direct union of bismuth and sulphur, he found that ten parts of the metal 

 yield the following quantities of trisulphide : 



12.2520 

 12.2065 

 12.2230 

 12.2465 



Mean, 12.2320 



Hence Bi = 215 in round numbers, a value now known to be much too 

 high. Lagerhjelm also oxidized bismuth with nitric acid, and, after igni- 

 tion, weighed the trioxide thus formed. Ten parts of metal gave the 

 following quantities of Bi 2 3 : 



11.1382 

 11.1275 



Mean, 11.13285 



Hence, if = 16, Bi = 211.85, a figure still too high. 



In 1851 the subject of the atomic weight of bismuth was taken up by 

 Schneider,f who, like Lagerhjelm, studied the oxidation of the metal 

 with nitric acid. The work was executed with a variety of experimental 

 refinements, by means of which every error due to possible loss of mate- 

 rial was carefully avoided. For full details the original paper must be 

 consulted ; there is only room in these pages for the actual results, as 

 follows. The figures represent the percentages of Bi in Bi 2 O 3 : 



89.652 

 89.682 

 89.644 

 89.634 

 89.656 

 89.666 

 89-655 

 89-653 



Mean, 89.6552, .0034 



Hence, if = 16, Bi = 208.05. 



Next in order are the results obtained by Dumas. J Bismuth tri- 



* Annals of Philosophy, 4, 358. 1814. Adopted by Berzelius. 

 t Poggend. Annalen, 82, 303. 1851. 

 I Ann. Chitn. Phys. (3), 55, 176. 1859. 



