Abstract. The combustion of mercury(II) thiocyanate to form "Pharaoh's serpents" is a spectacular reaction first described nearly two centuries ago. The large volume of distinctive yellow branches that grow from a tiny quantity of flaming reactants makes this an enchanting demonstration, often used to depict the magic of chemistry. In recent years several videos of this bizarre process have "gone viral" online. Formally, the reaction should yield a carbon nitride with the ideal formula C 3 N 4 along with HgS. However, since early characterization attempts there has been little further study of the materials pro-