Make a fire using a LEMON!? -- Yes, here's how!
Although in the wilderness is easier to carry a lighter rather than a lemon and some zinc nails, it could still be interesting to know and learn this trick which is based on an elementary chemical reaction that has a very surprising result.
To perform this trick you need a lemon, some brass round head fasteners, zinc nails, metal wire, and a ball of steel wool. Carefully push the brass fasteners and the zinc nails into the lemon fruit about one centimeter apart on the appropriate sides of the lemon, and then connect these with the metal wire as shown. This connection will create an electric circuit which when placed in the steel wool will be powerful enough to make sparks and then a flame to start a fire. Fantastic!