"I have sometimes thought that this theory was in part occasioned by the spectacle of the sun and other heavenly bodies unceasingly emitting heat and light. I have found, however, no reference to this striking phenomenon in the writings of the phlogistians; and however much the unbroken radiance of the sun might justify a popular belief in the power of combustibles simply to emit light, it could never justify the assertion of this even as a probable truth, for this would have been to explain one mystery by another."