A New Theory of Human Combustion Explained by John Emsley

Phosphorus was the thirteenth element to be isolated in its pure form. It's highly flammable and bursts into flame in an oxygen atmosphere. Scientists discovered that microbes in our guts convert some of it to a compound named diphosphane, which will ignite in air. Emsley proposes that in some cases, a person's gut bacteria might make enough di phosphane, and it might come into contact with the right gases.