60 UPON A NEW COMPOUND OF THE DEUTO-CHLORIDE OF PLATINUM, 



der, sometimes possessing a crystalline texture, is seen to precipitate.* Should 

 the solution, when transferred to the glass vessel, show a tendency to pass too 

 rapidly to the solid state, the best remedy is to heat it again on the sand bath, 

 when it will be again liquefied. 



3. When the powder has separated, and is fully settled, the liquor is to be 

 decanted and again evaporated nearly to dryness, and the other steps of the 

 process just described repeated. The several parcels of the precipitate thus . 

 procured are added together, and the mass filtered and pressed between bibu- 

 lous paper, to free it as completely as possible from the mother liquid. Still 

 more effectually to dry it, it is exposed, under an exhausted receiver, to the 

 desiccating agency of sulphuric acid. 



Description and Properties of the Salt. 



4. When prepared according to the process above described, the precipitate 

 has the form of a yellow pov/der, often minutely crystalline, and has a consi- 

 derable resemblance to the chloro-platinates of potassium and ammonium. It 

 absorbs water quickly from the atmosphere with deliquescence, undergoing 

 decomposition at the same time. In a close vessel it may be preserved for any 

 length of time without decomposition. 



5. When water is added, an active effervescence takes place, with disen- 

 gagement of nitric oxide gas. That the gas thus extricated is pure nitric oxide 

 is proved by its giving no precipitate with a solution of nitrate of silver, and by 

 its being entirely absorbed by a solution of sulphate of protoxide of iron. The 

 solution which remains after the disengagement of the nitric oxide gas is acid ; 

 it does not smell of chlorine, and gives copious precipitates with nitrate of silver 

 and chloride of potassium. 



6. Alcohol, hydro-chloric acid, and a solution of chloride of sodium, when 

 added to the salt, act upon it as pure water does, extricating the nitric oxide 

 and dissolving the chloride of platinum. A saturated solution of chloride of 

 platinum has no action on it. 



7. Before we had estimated the quantity of chlorine in the salt, we did not 

 suppose any hydro-chloric acid essential to its constitution, attributing the acid 



* An addition of too much water will redissolve it. 



