In spite of this extraordinarily independent behaviour, lightning has not so much liberty of action as we might be tempted to believe; it obeys certain laws which are not yet defined, and its gestures, although apparently wild and capricious, are not the result of fortuitous circumstances. To allude to it as chance may serve as a refuge from ignorance, but it does not, any more than we can, explain the extraordinary phenomena. Why are certain organic or non-organic bodies visited repeatedly by lightning? We need not have recourse to magic to explain. It is simply because they serve as favourable conductors for the fluid. One of the best-known examples of this kind is that of the church of Antrasme. It was struck by lightning in 1752. It melted the gold of the picture frames adorning the sanctuary, blackened the edges of the niches in which the images stood, scorched the pewter vases enclosed in a press in the sacristy; then, lastly, it made two very neat holes at the end of a side chapel, by which it took its departure. The traces of this disaster were removed with all haste, but twelve years later, on June 20, 1764, the lightning returned to the charge. It penetrated the church for the second time, but the most remarkable fact is, that it worked havoc similar to that done on its first visit. Again the sacred picture-frames were despoiled of their gilding, the niches of the saints blackened, the pewter vases scorched, and the two holes in the chapel reopened. What demon guided the lightning in these scenes of pillage? The end of the story gives us the clue. Soon after the catastrophe the use of the lightning-conductor became general throughout the whole world. The church was put under the protection of a rod of iron, after the principles of Franklin, and ever since lightning allows the faithful to pray in peace within the sanctuary, and has never returned to profane the church at Antrasme. Such incidents are of fairly frequent occurrence; they give us a chance of understanding the supposed preferences of lightning. In the last chapter we shall see curious cases of "galvanoplasty," of the nature of the following: amongst others, that of a piece of gold in a purse, which was silvered over with silver taken out of another part of the purse, through the leather of the compartment. What a trick of prestidigitation! On our music-hall stages this turn would have a great success. But our last word has not been said about lightning. Just a few more. One of the most curious effects produced on metals, is the magnetic polarity communicated to objects in steel and iron, no matter what they be. We have already quoted a remarkable case, that of the ascending lightning. A tailor was slightly touched by the spark; the day after the accident he found his needles were magnetized: they clung closely to each other as they were taken out of the case.