26 P. T. (LEVE, 



The formula requires. 



Theory Found 



Platinum 197,88—31,02 32,55 



Silver 215,94—34,50 34,17 



Sulphur 64,(io — 10, 23 10,21 



Nitrogen 28,oo 



Hydrogen 8,oo 



Oxygen 112, oo 



625,82 



The formula requires that, by heating with sulphuric acid, the sulphite shall give 

 81,46 per. et. of platinum and sulphate of silver. 



18. Sulphite of barium and platosammine R{ ()SOO ('Ba+3H i O. If a solution of the 



nitrate of barium is added to a solution of the ammonio-sulphite of platosammine, a 

 snow-white precipitate is immediately thrown down. Examined with the microscope it 

 seems composed of colourless, stellated needles. 



Analysis: the compound dried över sulphuric acid. 



a. 0,r>930 gr. were melted with carbonate of sodiuni and soine nitre. The 

 mäss was then exhausted with water and from the solution w T ere obtained 

 with chloride of barium 0,5620 grms sulphate of barium =0,0772 grms sulphur; 

 the residuum, insoluble in water, was treated with hydrochloric acid, when 

 0,2240 gr. platinum were left, and from the hydrochloric solution were ob- 

 tained 0,284 gr. sulphate of barium =0,1661 gr. barium. 



b. 0,3340 gr. were mixed with sulphuric acid and ignited, when 0,2470 gr. plati- 

 num and sulphate of barium were obtained. 



The formula requires. 



Calculated Found 



Platinum 197,88 — 33,95 32,33 



Baryum 137,oo — ,23,50 23,97 



Sulphur 64,00 — 10,98 11,14 



Nitrogen 28,oo 



Hydrogen 12, oo 



Oxygen 144,oo 



582,88 



When the result is calculated in per. et. the an. b. gives 73,95 platinum and sul- 

 phate of barium, and the formula requires 73,92 per. et. 



19. Sulphite of manganese and platosammine R ' g0 ' | Mn+4HjjO. By mixing the 



concentrated solution of the sulphite of ammonium (N:o 16) with a concentrated solu- 

 tion of the chloride of manganese, the compound is easily obtained in the form of a 

 heavy and whitish crystalline powder, rather difficult to dissolve, and which, when exa- 



