ON AMMONIÅCAL PLATINUM BASES. 63 



is soluble in hot water and, on cooling the solution, it again separates in small balls, 

 which soon congregate in a serai-liquid layer at the bottom of the vessel. When per- 

 fectly cool it forms a yellow resinous matter. 



Analyses, the sulphate dried at 100°: 



0,7870 gr. gave 0,4360 gr. platinum and 0,4700 gr. sulphate of barium =0,0645 gr. 

 sulphur. 



This result, calculated in per. et., is 



Platinum 55,40 



Sulphur 8,19 



The formula requires: 



Platinum 54,68 



Sulphur 8,84 



The resinous sulphate is easily soluble in diluted sulphuric acid, and the solution, 

 when concentrated, deposits small whitish granules, which are perhaps the neutral sid- 



f° 



lo 

 phuric acid. 



S0 2 , but I did not obtain the matter free from excess of sul- 



All the known compounds of platinsemidiammine are as follow 

 I. Chloro-compound R=Pt{^» 



1. Chloride RC1 



{.; V i r 

 3Br 3 



2. Bromide RBr . 



III. lodo-compound R=Pt{g* Hs 



3. lodide Ii I 



IV. Hydroxylo-compound R=Pt{JjjJj, 



4. Nit råte R . N0 3 



f2NH 3 



V. Chloro-nitrito-compound R=Pt{c] 2 



|o . NO 



5. Nitrite R.N0 2 



f2NH 3 



VI. Bromo-nitrito-compound R=Pt<Br 2 



(O . NO 



6. Nitrite R . N0 2 



f2NH, 



I Cl 



VII. Chloro-hydroxylo-nitrito-compound R=Pt N0 



loH 



7. Nitrite Ii . X0 2 



