Ref inactivities of Air , Oxygen, Nitrogen, Argon, fyc. 227 



with a Topler's pump ; and before admission of gas each tube was 

 pumped empty, so that in an attached Pliicker's tube there was 

 brilliant phosphorescence. The tubes were then washed out with 

 the gases to be admitted, the apparatus again evacuated, and the 

 final quantity of gas allowed to enter by a contrivance a description 

 of which is to be found in the ' Trans. Chem. Soc.,' vol. 67, p. 686. 



Purity of the Gases. Hydrogen. — The hydrogen was made by 

 warming a tube containing palladium-hydrogen which had been pre- 

 pared by admitting hydrogen made from pure zinc and sulphuric 

 acid into contact with spongy palladium. The tube was pumped 

 empty in the cold, and then gently warmed ; it was again allowed to 

 cool and again pumped empty. The hydrogen was then collected, 

 passing slowly through a tube, filled with phosphoric anhydride, into 

 the experimental tube. 



Oxygen. — The oxygen was prepared by heating a small tube con- 

 taining potassium permanganate ; a large quantity of gas was allowed 

 to escape, and a portion was collected finally which served for the 

 experiments. 



Nitrogen. — The nitrogen was prepared from a mixture of am- 

 monium chloride and sodium nitrite, to which a little copper 

 sulphate had been added. The apparatus was exhausted before 

 admission of either of the solutions, and before allowing the solu- 

 tions to enter they were boiled, and the flasks corked while boiling. 

 The gas was passed over red-hot copper ; the ammonia liberated by 

 the alkalinity of the nitrite thus reacted with any oxides of nitrogen 

 possibly present to form water. The gas was collected, after rejec- 

 tion of a considerable portion, in a tube containing oil of vitriol ; it 

 was then transferred to a fresh tube, treated with a very strong solu- 

 tion of caustic potash, and finally admitted to the apparatus. 



Air. — The air was left standing for some hours in a tube con- 

 taining sticks of caustic potash, and was then admitted to the appa- 

 ratus through a tube of phosphoric anhydride. 



Experimental Data. — Each gas was compared with air and with 

 the other two. Air is in each case taken as unity. 



Hydrogen. — Hydrogen/air 0*4730 



Mean . . 0-4733 



0-4737 



Hydrogen/oxygen ... 0'5125 



05125 



0-5125 



Hydrogen/nitrogen . . 0*4654 

 0-4654 



0-4654 



Oxygen. — Oxygen/air 



0-9237 

 0-9262 

 0-9230 



„ . . 0-9243 



