232 THE ATOMIC WEIGHTS. 



These results are best used by taking the ratio between 

 the BaS04, put at 100, and the LajOg. The figures are 



then as follows: 



46.489 

 46.652 

 46.873 



Mean, 46.671, ± .075 



In the analyses of the iodate the lanthanum was thrown 

 down as oxalate, as before. The iodic acid was also esti- 

 mated volumetrically, but the figures are hardly available 

 for present discussion. The following percentages of LeoO^ 



were found : 



23.454 

 23.419 

 23.468 



Mean, 23.447, d= .0216 



The formula of this salt is La2(I03)e.3H20. 



The double nitrate, La2(N03)6.3Mg(N03)2.24H20, gave 

 the following analytical data : 



SalL H^O. MgO. La^Oy 



.5327 gim. .1569 grm. .0417 grm. .1131 grm. 



•5931 " -1734 " -0467 " .1262 " 



.5662 " -1647 " .0442 " -1197 " 



.3757 " — — -0297 " .0813 '• 



.3263 " _ .0256 " .0693 " 



These weighings give the subjoined percentages of La^Og : 



21.231 

 21.278 

 21. 141 

 21.640 

 21.238 



Mean, 21.3056, ± .058 



These data of Holzmann give values for the molecular 

 weight of LasOj as follows: 



From sulphate \.^f).^ = 325.674, ± .522 



" iodate " =322.419,^.113 



" magnesian nitrate_. " = 324.355, d= .923 



