[2] The first synthesis of mercury thiocyanate was probably completed in 1821 by Jöns Jacob Berzelius: Evidence for the first pure sample was presented in 1866 prepared by a chemist named Otto Hermes.

When heated, mercury(II) thiocyanate decomposes in an exothermic reaction that can produce a large mass of coiling, serpent-like solid.

An inconspicuous flame, which is usually the blue color of burning carbon disulfide but which can be yellow from impurities or incidental combustion of flammable materials on the surface it is ignited on.

[10] The number of resonance structures of heptazine and triazine, varying molecular weights of samples, and the fluorescense of the product made acquiring spectra difficult even by relatively exotic methods of NMR (with one spectrum acquisition being run for 12 days straight to get a mostly clean reading).

Because of this, a heptazine-based structure similar to Liebig's melon, a compound initially prepared around the same time that the pharoah's snake reaction was discovered, was not ruled out by the authors as a partial component of the solid material.

Cyanogen is generally only produced when Hg(CN)2 or similar is heated to decomposition, and early attempts to form (SCN)2 via the same route starting at this compound failed and only generated SO2, CO2 and N2.