ON AMMONIACAL PLATINUM BASES. 59 



Analysis : 



a. 0,4450 gr. gave 0,2340 gr. metallic platinum and 0,6770 gr. chloride of silver = 

 0,1674 gr. chlorine. 



b. 0,594 gr. gave 0,3230 gr. platinum. 



c. 0,2920 gr. gave 20,5 C. C. nitrogen (temp. of water 17°. Bar. 748 m. m. t. 18°) 

 ==0,0233 gr. nitrogen. 



The formula requires: 



Calculated Found 



a b c 



Platinum 197,88 — 52,95 52,48 52,31 — 



Chlorine 141,84—37,96 37,62 — 



Nitrogen 28, oo — 7,49 — — ■ 7,96 



Hydrogen 6,oo — 1,60 — — 2,0i (loss) 



373,72 100,00 



The chloride is not decomposed by concentrated sulphuric acid. Caustic alka- 

 lies dissolve it to a clear yellow liquid without any noteworthy evolution of ammonia. 

 Sulphurous acid, led throught its boiling solution, changes it to the acid chlorosulphite 

 of platosemidiammine, before described. 



[Br 2 



2. Bromide, Pt <nh 3 ""~nH3. Br, is obtained by adding bromine to the bromide of 



(Bv 



platosemidiammine suspended in water. It forms an orange-coloured, crystalline, pow- 

 der, which is dissolved by boiling water, and recrystallises, on cooling the solu- 

 tion, into well developed, glittering dark-red scales, which, examined with the micros- 

 cope, seem to be flat prisms, or thin rhombic and hexagonal tablets. The bromide 

 is soluble in cold water, but with difficulty, and the solution has an intensely yellow 

 colour. 



Analysis, the bromide dried at 100°: 

 0,56oo gr. gave 0,2005 gr. platinum and 0,7630 gr. bromide of silver =0,3247 gr. 

 bromine. 



The formula requires: 



Theory Experiment 



Platinum 197,88 — 35,85 35,80 



Bromine 320,oo — 57,98 57,98 



Ammonia 34,oo — 6,17 6,22 (loss) 



551,88 100,oo 100,oo 



3. Polyiodide, Pt {NHy-NH 3 i.~L, is formed on adding iodine, dissolved in hot alco- 



hol to the iodide of platosemidiammine. A black crystalline powder in then obtained. 

 Under the microscope it seems composed of small hexagonal tablets almost black or of 



