The phlogiston was believed to be a substance contained within combustible bodies, released to the ambient during the combustion phase.

The title for this piece, "Flogisto", came to mind right away as by staring at it I get a feeling of uncanny fascination, an ominous circle of fire spontaneously burning from the inside out.

Part of my physarum polycephalum experiments, entirely made with code (Processing and GLSL), 2900x2900.