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



ro-platinate of potassium thus precipitated was collected on a weighed filter, 

 and washed with moderately concentrated alcohol, dried at 212° Farhenheit, 

 and its weight ascertained. The 1.701 grammes thus obtained is equivalent 

 to 0.6875 grammes of platinum, giving 41.08 per cent, of metallic platinum in 

 the salt. 



12. Another quantity, 1.502 grammes of the dried salt was next decomposed 

 by water, evaporated to dryness, and ignited in a porcelain crucible. This 

 j\e\diedi platinum 0.603, or 4:0.19 per cent. 



13. Another portion, 1.580 grammes of the salt was introduced into a small 

 glass tube, sealed at its lower end, and heated over a spirit lamp (Berzelius's) 

 until it became brightly red hot, and all volatile matters were effectually driven 

 out of the tube. This left, of platinum, 0.655 grammes, or 41.51 per cent. 



14. In order to estimate the quantity of nitric oxide, a graduated tube was 

 filled with mercury and inverted over the mercurial cistern. A small quantity 

 of the salt was then weighed and promptly enveloped, as tightly as possible, in 

 blotting-paper. This was then passed up, by aid of a fine copper wire, into 

 the tube, and a small portion of water, previously deprived of air, was also 

 introduced. A little care in the manipulation enabled the pellet containing the 

 salt to be kept in contact with the water. The quantity of gas thus extricated 

 was shown upon the graduation of the tube, care being taken to preserve the 

 mercury at the same level inside and outside. 



15. Adopting this method, 0.7875 grammes of the salt gave 33.2 cubic cen- 

 timetres of nitric oxide gas, at 82.25° Far. The barometric pressure being 

 29.46 inches at 80° Far. Applying the proper reductions for pressure, tem- 

 perature, and moisture, this gives 28.37 cubic centimetres, equivalent, in weight, 

 to 0.0382 grammes, or 4.86 per cent, of nitric oxide gas. 



16. By another experiment, 1.028 grammes yielded 44.5 cubic centimetres 

 of nitric oxide gas, at a temperature of 79° Far., and barometric pressure of 

 29.81 inches at 81° Far. The proper reductions for pressure, temperature, and 

 moisture being made, there resulted 38.81 cubic centimetres of the gas, equiva- 

 lent, in weight, to 0.0524 grammes, or 5.09 per cent. 



17. With a view to estimate, in the next place, the quantity of the chlorine, 

 1.5275 grammes of the salt were introduced into a platinum crucible, and a 

 sufficient proportion of carbonate of potassa and water added. It was then 

 carefully evaporated to dryness, and ignited; after which it was repeatedly 



