According to Pausanias, Callimachus made a golden lamp for the Temple of Minerva at Athens, with a wick composed of asbestos, which burned day and night for a year without trimming or replenishing with oil. If this was true, the font of the lamp must have been large enough to have contained a year's supply of oil; for, though some profess that the economical inventions of the ancients have been forgotten, the least knowledge in chemistry proves that oil in burning must be consumed. The perpetual lamps, so much celebrated among the learned of former times, said to have been found burning after many centuries, on opening tombs, are nothing more than fables, arising perhaps from phosphorescent appearances, caused by decomposition in confined places, which vanished as soon as fresh air was admitted. Such phenomena have frequently been observed in opening sepulchres.