46 P. T. CLEVE, 



The sulphocyanate of platosemidiammine is easily soluble in warm water, hut the 

 solution soon deeoinposes and deposits a yellow or brownish uncrystalline powder. 

 When heated with nitroinuriatic acid the result is a yellow solution, which soon depo- 

 sits a yellow powder, probably consisting of several different compounds. Examined 

 with the microscope it seems to contain yellow globules, octahedrons with rhombic ba- 

 ses and some hexagonal scales. 



Analysis: the sulphocyanate dried över sulphuric acid. 

 0,2io gr. gave 0,1255 gr. metallic platinum and 0,20?o gr. sulphate of barium = 

 0,0408 gr. sulphur. 



The formula requires: 



Calculated Found 



Platinum 56,88 57, 3i 



Sulphur 18,40 18,63 



With nitrate of silver the solution yields a yellow precipitate contain ing silver 

 and platinum. 



7. Nitrate, R . 2 . 2N0 2 , is obtained by double decomposition of the chloride 

 and nitrate of silver. The solution has a påle yellow colour and yields by evaporation 

 the nitrate in the form of dirty whitish crusts, consisting of densely crowded rhombi- 

 cal tablets or needles. 



Analysis: the nitrate dried at 100°. 



a. 0,2585 gr. gave 0,i 437 gr. platinum. 



b. 0,3385 gr. gave 46 C. C. nitrogen (temp. of the water 15°. Bar. 758 t° 20) 

 0,0535 gr. nitrogen. 



The formula requires: 



Theory Experiment 



Platinum 197,88 — 55, oo 55,59 (a) 



Nitrogen' 56, do — 1 5,7 i 15,80 (b) 



Hydrogen 6,oo( 28,61 (loss) 



Oxygen 96,ooj ' 



355,88 100,oo 100,oo 



The reaction of the nitrate are as follows: 



Chlorine led through the solution produces the chloride of platinsemidiammine. 

 The solution treated with chlorine gave by evaporation yellow rhombic scales, which 

 were subjected to the following analysis: 



0,1200 gr. gave 0,0635 gr. metallic platinum and 0,i8is gr. chloride of silver =0,0449 

 gr. chlorine. 



[a 

 The formula Pt<2NH s .Cl requires: 

 ci, 



