Experimental glass blowing for boys

by Carleton John Lynde

FIG. 96
WATER FROM FLAME

The water vapor (H₂O) condenses to water on cooling and takes up very little space. The carbon dioxide remains a gas and occupies space, but this is offset by the volume of the air which escaped at first. The result is that the volume of gas at the end is about ⅕ less, and the atmospheric pressure on the water in the pan lifts water into the bottle.

The candle goes out because it must have oxygen to burn and the oxygen is used up.

Experiment 72. Water produced by fire.

It is certainly magic to produce water from fire, but you can do it easily as follows: Hold a clean, dry, cold tumbler over your alcohol lamp flame (Fig. 96). Does water deposit in the form of mist on the inside of the tumbler?

FIG. 97
ATMOSPHERIC PRESSURE

Repeat with fresh tumblers with the flame of a kerosene lamp and of a candle. Are the results similar?

Direct the blowpipe flame into the end of a piece of No. 2 or 4 tubing. Does water deposit in drops inside the tube about 1 inch above the end?