CHEMICAL ACTION. 35 



Q. What is NITROGEN ? 



A. Nitrogen is another invisible gas. 

 It will not burn, like hydrogen; and 



iron bottle, furnished with a bent tube ; set the bottle on a 

 fire till it becomes red hot, and put the end of the tube into 

 a pan of water. In a few minutes, bubbles will rise through 

 the water; these bubbles are oxygen gas. 



These bubbles may be collected thus : Fill a common 

 bottle with water; hold it topsy-turvy over the bubbles 

 which rise through the pan, but be sure the mouth of the 

 bottle be held in the water. As the bubbles rise into the 

 bottle, the water will run out; and when all the water has 

 run out, the bottle is full of gas. Cork the bottle while the 

 mouth remains under water; set the bottle on its base ; 

 cover the cork with lard or wax, and the gas will keep till it 

 be wanted. 



N. B. The quickest way of making oxygen gas, is to rub 

 together in a mortar half an ounce of oxide of copper, and 

 half an ounce of chlorate of potassa. Put the mixture into 

 a common oil flask, furnished with a cork which has a bent 

 tube thrust through it. Heat the bottom of the flask over 

 a candle or lamp ; and when the mixture is red hot, oxygen 

 gas will be given off. Note the tube must be immersed in 

 a pan of water, and the gas collected as before. 



(Chlorate of potassa may be bought at any chemist's; 

 and oxide of copper may be procured by heating a sheet of 

 copper red hot, and when cool, striking it with a hammer : 

 the scales that peel off, are oxide of copper.) 



EXP. Put a piece of red hot charcoal, (fixed to a bit of 

 wire,) into your bottle of oxygen gas ; and it will throw out 

 most dazzling sparks of light. 



Blow a candle out; and while the wick is still red, hold 

 the candle (by a piece of wire, ) in the bottle of oxygen gas ; 

 the wick will instantly ignite, and burn brilliantly. 



(Burning sulphur emits a blue flame, when immersed in 

 oxygen gas.) 



