The flame test refers to the phenomenon in which the flame color changes when certain element or compound is introduced to a hot and non-luminous flame. This phenomenon has always fascinated me. The flame test appears in both ancient Eastern and Western occult books. Tao Hongjing, a famous Chinese alchemist of the 5th century, recorded in his Collected Commentaries on the Materia Medica the "purple and green smoke" of potassium nitrate when exposed to fire, as a way of identifying the material. The Alchemist Discovering Phosphorous by the English painter Joseph Wright of Derby depicts the marvelous moment when the German alchemist Henning Brand discovered the bright bluish green flame of phosphorus in his laboratory, thinking that he had found the philosopher’s stone. Modern science tells us that the reason for the fire color change in a flame test is the emission of photons when excited electrons return to ground state. The integration and disintegration of various elements create all forms of materials that make up the world we live in. As those worldly materials are engulfed by fire, infinitesimal particles become activated, emitting bright and mysterious flames— same as they were centuries ago—like a fissure of this world, emanating lights from another dimension, calling people to explore their secrets.