1 }H S1CAL PROPERTIES AND STATES OF MATTER 17 



,des of the bottle. The burning of the candle has resulted in 

 the formation of a new form of matter. 



EXPT. 24.- Allow the candle to burn in a similar bottle 

 placed on the table. After a time the candle ceases to burn, 

 and when this has happened take the candle out and cover the 

 bottle over with a glass plate. Notice that no change seems 

 to have taken place in the gas which filled the bottle. Now 

 pbur some clear lime-water into another clean bottle and shake 

 it up t the lime-water remains clear. 1 Lift off the glass plate 

 and do the same with the bottle in which the candle has been 

 burnt, the lime-water turns milky. The burning of the candle 

 has also resulted in the formation of a new kind of matter, viz.) 

 a gas which turns clear lime-water cloudy. 



Evidently, then, when a candle burns it ceases to exist as 

 tallow or wax, or whatever the candle is made of, and assumes 

 new forms, still material, one liquid, the other a gas which turns 

 lime-water milky. If we were to weigh all the liquid formed 

 and all the gas which turns lime-water milky, we should find 

 that these two things together 

 actually weigh more than the part 

 of the candle which has disap- 

 peared did. The reason why 

 there is an increase of weight 

 will be explained later. The 

 arrangement for performing this 

 experiment is shown in Fig. 11. 

 The candle is burned in a wide 

 tube, A, fitted with a cork at 

 the bottom with holes in it to 

 allow the air, which is neces- 

 sary to help the candle to burn, 

 to pass in as shown by a bent 

 arrow. The tube B is filled with 



a substance which has the power FlG - ii.-Apmratus to show that no 

 ^ matter is destroyed when a candle 



of arresting the products ot the burns. 



burning. Such a substance is 



caustic soda, which is used in the form of lumps. Air is drawn 



through the apparatus as shown by the arrows. 



1 There may be a slight milkiness owing to the presence in the air of the gas 

 which is formed. If so the experiment must be made comparative. 



