The secrets of escamoters and wizards of old times
You can do this magic for your audience. Put dish with water infront of the audience and tell them that there will be a fire once you put hand inside. In this hand you will have egg which you prepared as follows: empty the egg and insert inside burnt lime with sulphur. Block the hole properly. When putting it inside the water, be carefull and do it quickly. You can be burnt. So be careful!