530 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 54 



GADOLINIUM. 



]\Iarignac/ the discoverer of gadolinium, assigned to its oxide the 

 '"equivalent" 120.5, whence Gd= 156.75. Boisbaudran ^ found Gd = 

 155.33, 156.06, 155.76 and 15G.12, with preference for the last figure. 

 Cleve, quoted by Boisbaudran, found Gd=: 154.15, 155.38, 155.1 and 

 154.77. For these determinations there are no details, and all, pri)b- 

 ably, are referred to 863 = 80. 



The first chemist to publish his determinations with individual data 

 was Bettendorff.^ He effected the synthesis of the sulphate from the 

 oxide, and his weights were as follows. The percentage of Gd.,03 in 

 Gd2(S04)3 is given in the third column: 



Mean, 60.080, ± .0013 

 Hence Gd = 156.75. 



Benedicks' * series of determinations were also by the synthetic process, 

 as follows : 



Gd^O^. Gd^SO,),. Per cent. Gd.O,. 



.4308 .7171 60.075 



.5675 .9451 60.047 



.5726 .9534 60.059 



.6785 1.1301 60.039 



.7399 1.2329 60.013 



1.3253 2.2063 60.069 



Mean, 60.050, ± .0020 

 Hence Gd= 156.52. 



The two determinations by Marc ^ are unimportant, l)ut cannot be 

 overlooked. The data are — 



GdM^. Gd.iSO^),. Per cent. Gd:0,. 



.2201 .3666 60.014 



.2444 .4070 60.049 



Mean, 60.032, rh .0120 



Hence Gd= 156.39. 



' Oeuvres Completes, 2, "04. 

 ^Conipt. Rend., Ill, 409. ISOJ. 

 3 Ann. Chem. Pharm., 270, 376. 1S92. 

 *Zeitsch. anorg. Chem., 22, 393. 1S99. 

 ' Zeitsch. anorg. Chem., 38, 121. 1904. 



