For Christmas dinner that year, he started to electrocute another turkey, but inadvertently gave himself the shock intended for the fowl: “The company present ... say that the flash was very great and the crack as loud as a pistol.... I neither saw the one nor heard the other.... I then felt ... a universal blow throughout my whole body from head to foot.... That part of my hand and fingers which held the chain was left white, as though the blood had been driven out, and remained so eight or ten minutes after, feeling like dead flesh; and I had a numbness in my arms and the back of my neck which continued till the next morning but wore off.” He was apologetic rather than frightened by the near catastrophe, comparing himself to the Irishman “who, being about to steal powder, made a hole in the cask with a hot iron.” This was soon after he had come to the conclusion that what he now called “electrical fluid” had much in common with lightning—that indeed they might be one and the same thing. He was not the first to propose this theory but no one before him had been able to suggest how it might be tested. Thunder and lightning had mystified humanity since the beginning of recorded history. The Greeks had held that thunderbolts were launched by the god Jupiter. (One Greek philosopher, Empedocles, thought that lightning was caused by the rays of the sun striking the clouds.) Hunters of primitive tribes prayed to the god of lightning, who was a killer, as they wished to be. Certain medicine men were said to be endowed with the gift of summoning lightning at will. Since biblical days, lightning was assumed to be an act of heavenly vengeance, but no one could explain the paradox that it struck church steeples more frequently than other buildings. In medieval times, people believed that ringing church bells would keep lightning away, a belief that survived the death of countless unfortunate bell ringers. About 1718, an English scientist, Jonathan Edwards, suggested that thunder and lightning might be produced by a “mighty fermentation, that is some way promoted by the cool moisture, and perhaps attraction of the clouds.” There had been very few other attempts to give a scientific explanation of the phenomenon, and even in Franklin’s time many preachers considered lightning a manifestation of the Divine Will. “Electrical fluid” and lightning had in common, Franklin wrote in his notes on November 7, 1749, that they both gave light, had a crooked direction and swift motion, and were conducted by metals. Both melted metals and could destroy animals. Since they were similar in so many respects, would it not follow that lightning, like “electrical fluid” would be attracted by pointed rods? “Let the experiment be made.” By May 1750, he was sure enough of his hypothesis that he elaborated to Peter Collinson the advantages to humanity of what later were called lightning rods: