476 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 54 



in this case) lost -upon ignition in hj^drogen. In the fourtli eohiinn I 

 add the amount of KoPtClt; corresponding to 100 parts of AgCi : 



Mean, 84.809, ± .071 

 Hence Pt= 195.31. 



Halberstadt/ like Seubert, studied the chloroplatinates of potassium 

 and ammonium, and also the corresponding double bromides and platinic 

 bromide as well. The metal was estimated partly by reduction in hy- 

 drogen, as usual, and partly by electrolysis. Platinic bromide gave the 

 following results : 



/. By reduction in H. 



Mean of all ten experiments, 37.847, ± .0033 



Hence Pt = 194.66. 



The ammonium platinbromide, (NH4)oPtBrg, was prepared in two 

 ways, and five distinct lots were studied. With this salt, as well as with 

 those which follow, the data are given in distinct series, with from one 

 to several experiments in each group, but for present purposes it seems 

 best to consolidate the material and so put it in more manageable form. 

 The percentages of platinum and weights found axe as follows : 



' Ber. Deutsch. chem. Gesell., 17, 2962. 1SS4. 



