By this art, the rabbi Bar-Cacheba, in the reign of the emperor Hadrian, made the credulous Jews believe, that he was the hoped for Messias, and two centuries after, the emperor Constantius was thrown into great terror, when Valentian informed him, that he had seen one of the body guards breathing out fire and flames in the evening. It appears evident from the writings of Herodotus, that the ancients possessed a knowledge of attracting lightning, or the electric fluids with pointed instruments made of iron. He informs us, that the Thracians disarmed heaven of its thunder-bolts, by discharging arrows into the air; and the Hyperboreans by darting into the clouds, pikes headed with pieces of sharp pointed iron. Pliny speaks of a process, by which Porsena caused fire from the heavens to fall upon a monster which ravaged his country. He mentions also, that Numa Pompilius, and Tullius Hostilius practised certain mysterious rites to call down the fire from heaven. What these mysterious rites were is of no moment; the fact is sufficient. Tullius, because he omitted some prescribed ceremony, is said to have been killed by the fire. A similar accident happened in France with the electrical kite.[10] For deceptions with fire, the ancients employed a number of inflammable substances, which they dexterously used; among them, naphtha, a fine bituminous oil, which readily inflames, was principally used. (For the effect of _naphtha_, _see_ _Greek fire_.) Galen informs us, that a person excited great surprise by extinguishing a candle, and again lighting it without any other process than holding it against a wall or a stone. This, Galen observes, (_De Temperamentis_, iii. 2, p. 44.) was effected in consequence of the wall or stone being previously rubbed with sulphur, which, however, must have been something more. He also speaks of a mixture of sulphur and naphtha. If it had been phosphorus, or some of its preparations, it would appear more probable. Plutarch relates the secret effects of naphtha, and observes, that Alexander was astonished and delighted, when it was exhibited to him in Ecbatana. Medea destroyed Creusa, the daughter of Creon, with this oil. This fact is stated by Plutarch, Pliny, Galen, and others, and believed by Beckman. She sent, it appears, to the unfortunate princess, a dress covered with it, which burst into flames as soon as she approached the fire of the altar. The dress of Hercules, which also took fire, was dipped in naphtha, though said to be in the blood of Nessus. On the subject of naphtha, Beckman remarks, "that this oil must have been employed when offerings caught fire in an imperceptible manner. _In all periods of the world, priests have acted as jugglers to simple and ignorant people._"