48 r. T. CLEVE, 



Hydrochloric acid searcely attacks the nitrite witnout heating, but when heated 

 it soon yields a green solution, which evolves red vapours and deposits a yellow pre- 

 cipitate of well developed, microscopical scales, of hexagonal form. 



Xitric acid, (concentrated), decomposes the nitrite 011 heating, evolving red va- 

 pours, and by evaporation a thick sirupy liquid is obtained. It did not deposit cry- 

 stals. 



Bromine and chlorine are directly united with the nitrite and produce the bromo- 

 or chloro-nitrite of platinsemidiammine. 



Sulphurous acid led through the boiling solution of the nitrite first conimunicates 

 a brownish colour to it; then the solution löses its transparency from the formation of 

 a yellowish-brown precipitate, which afterwards dissolves to a yellow liquid. By con- 

 tinued treating with sulphurous acid the liquid assumes a beautiful green colour, re- 

 sembling the solution of soine salt of nickel. If the green solution is evaporated in 

 the water bath, and alcohol is added to it, an olive-green plastic matter is separated. 

 The green precipitate Avas dissolved in a small quantity of water and again precipita- 

 ted with alcohol, and dissolved in water, when the green solution was left to evapo- 

 rate in a warm place. It was then dried up to a green, transparent gum-like mäss. 



This matter dried at 100° gave by the analysis: 



Platinum 58,25 



Sulphur 14,2j 



The matter is easily dissolved in water, giving it a green colour; its solution co- 

 lours litmus red, it evolves carbonic acid with carbonate of sodiuin and gives a preci- 

 pitate with baryta. Hydrochloric acid does not give sulphurous acid with the green 

 matter. From its solution chloroplatinate of ammonium is precipitated by adding te- 

 trachloride of platinum. If the matter is boiled with nitromuriatic acid, a violent re- 

 action takes place and yellow, microscopical octahedrons of chloroplatinate of ammo- 

 nium are deposited. These reactions make it seem very probable, that the matter is a 

 kind of double sulphite of platinum and ammonium. 



9. Sulphate, R0 2 . S0 2 , was obtained from the chloride by boiling it with sulphate 

 of silver. If, after being separated from chloride of silver, the solution is left in a 

 warm place to evaporate, härd yellowish crystalline crusts are obtained. The sulphate 

 is commonly impregnated with a small quantity of purple matter, from which it may 

 be purified by washing with boiling water, in which the sulphate is very slowly soluble. 



Analysis: the sulphate dried at 100°. 



a. O,C080 gr. gave 0,3ö3ö gr. platinum and 0,«7o gr. sulphate of barium ^=0,06ii gr. 

 sulphur. 



b. 0,25i5 gr. gave 0,1525 gr. platinum. 



The formula requires: 



