This fire magic trick is really a simple trick of science! Blow out a candle and relight it by passing a flame through the trail of smoke.
A candle burns wax vapor into carbon dioxide and water. When you blow out a candle there is still some wax vapor in the air, which you can heat to relight the candle. In order for this to work you want to relight the candle as quickly as possible. Also, it helps if the air is calm so that the smoke doesn't dissipate. I used a lighter to relight the candle, but you could just as easily use another candle or even a match.