328 THE ATOMIC WEIGHTS. 



In 1881 Seubert* published his determinations, basing them upon 

 very pure chloroplatinates of potassium and ammonium. The ammo- 

 nium salt, (NH 4 ) 2 PtCl 6 . was analyzed by heating in a.stream of hydrogen, 

 expelling that gas by a current of carbon dioxide, and weighing the 

 residual metal. In three experiments the hydrochloric acid formed 

 during such a reduction was collected in an absorption apparatus, and 

 estimated by precipitation as silver chloride. Three series of experi- 

 ments are given, representing three distinct preparations, as follows : 



Series I. 

 Am. 2 PtCl 6 . Pt. Percent. Pt, 



2.1266 .9348 43-957 



1.7880 .7858 43.948 



1.8057 .7938 43-960 



2.6876 1.1811 43-946 



4 7^74 2.0959 43-963 



2.0325 .8935 43.961 



Mean, 43.956, =b .002 



Series II. 

 Am^PtCl^. Pt. Per cent. Pt. 



3- 46o .3363 43-87 1 



2.6584 .1663 43-876 



2.3334 .0238 43-872 



1,9031 .8351 43-88: 



3.1476 .3810 43.875 



2.7054 .1871 43-889 



Mean, 43.876, .001 



Another portion of this preparation, recrystallized from water, of 1,4358 

 grm. gave 0.6311 of platinum, or 43.955 per cent. 



*Ber. Deufcsch. Chem. Gesell., 14, 865. 



