"Fuse" is the device which lights a flammable material. Fuses come in many different types and sizes, from chemical fuses (normally a piece of cotton string covered in a oxidiser and reducer) to electronic fuses which use a high current-low voltage to heat a thin piece of nichrome wire to a point where it ignites the flammable substance. Fuses are used to give you time to get away from the mixture before it ignites.

Sulphur Fuse - Slow burning but very hard to put out!