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?
The “why” of it
One of the chief constituents of alcohol, kerosene, and candle wax is hydrogen (H), and when this burns in the oxygen (O) of the air, it produces water (H2O). It is this water which condenses on the cold glass.