501 



Professors Kirchhoff and Bunsen on Chemical 



separated by boiling with water from the insoluble platinum, 



both substances weighed, and the chlorine in the chloride of 



caesium estimated with silver. 

 Experiment gave — 



Chloride of platinum and caesium employed. 8*6142 grms. 



Loss on reduction with hydrogen .... 1*8725 „ 



Platinum separated 2*6138 „ 



Chloride of caesium obtained 4*1544 „ 



Chloride of silver obtained 3*7506 „ 



Hence we obtain the following composition : — 



[ \ CI 2 ' 





Calculated. 



Found. 



9910 



3014 



30*25 



70*92 



21*57 



21*67 



123*35 



37*51 



37*35 



35*46 



10*78 



1053 



328*83 



100*00 



99*80 



Bichloride of platinum- 

 Chloride of caesium . < ™ 



It is interesting to compare the solubility of the double chlo- 

 rides of platinum, rubidium, and caesium with the potassium- 

 platinum double salt. The solubility of the latter is seen from 

 the following experiments, which were conducted with special 

 cave, the numbers being the mean of several well-agreeing deter- 

 minations. 



100 parts of water dissolve — 



at C. 0*724 chloride of platinum and potassium. 

 6*8 0*873 „ „ 



13*8 0*927 „ 



46*5 1*776 



71*0 3018 „ „ 



100*0 5-199 

 By interpolation, the solubility of the caesium, rubidium, and 

 potassium-platinum chlorides is obtained for intervals of 10° C, 

 and is found to be as follows : — 







Potassium-salt. 



Rubidium-salt. 



Caesium-salt 



oc. 



. . . . 0-74 



0184 



0*024 



10 



... 0*90 



0*154 



0050 



20 



. . . 1*12 



0141 



0*079 



30 



. . . 1-41 



0*145 



0110 



40 



. . . 1*76 



0*166 



0142 



50 



. . . 217 



0*203 



0*177 



CO 



. . . 2*64 



0*258 



0-213 



70 



. . . 3*19 



0-329 



0-251 



80 



. . . 3*79 



0*417 



0*291 



90 



. . . 4*45 



0*521 



0-332 



100 



. . . 5*18 



0*634 



0*377 



