- ^ Dionysius Lardner. Treatise on Heat. Longman, Rees, Orme, Brown, Green & Longman. 1833. "The state in which a heated body, naturally incapable of emitting light, becomes luminous, is called a state of incandescence."
- ^ John E. Bowman. An Introduction to Practical Chemistry, Including Analysis Second American. Philadelphia: Blanchard and Lea. 1856.