Australian runner Ron Clarke serves as the final torch bearer for the 1956 Melbourne Olympics—at a high price.

Packed with added magnesium and aluminum flakes to burn extra brightly as it approached the Olympic cauldron, Clarke's torch spat hot sparks onto his hand and arm.

Though magnesium was never again used in an Olympic torch, other solid fuels took over, including gunpowder in 1960 and 1964. In 1972 the Munich Olympics ushered in hydrocarbon fuels—such as propane and butane—which have been the standard ever since.

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