The people of these causses have a supernatural explanation for everything that they cannot account for by the light of reason and observation.  They have their legend with regard to the Puit de Padirac, and it is as follows:  St. Martin, before he became Bishop of Tours, was crossing one day this stony region of the Dordogne to visit a religious community on the banks of the Solane, whither he had been despatched by St. Hilary.  He was mounted on a mule, and was ambling along over the desert plunged in pious contemplation, when he heard a little noise behind, and, looking round, he was surprised to see a gentleman close to him, who was also riding a mule.  The stranger was richly dressed, and was altogether a very distinguished-looking person, but the excessive brilliancy of his eyes was a disfigurement.  They shone in his head like two bits of burning charcoal.  ’What do you want, cruel beast?’ said St. Martin.  This would scarcely have been saintly language had he not known with whom he had to deal.  The gentleman thus impolitely addressed returned a soft answer, and forced his company upon the saint, who wished him—­at home.  Presently Lucifer, for it was he, began to ‘dare’ St. Martin, after the manner of boys to-day.  ’If I kick a hole in the ground I dare you to jump over it,’ was the sort of language employed by the gentleman with the too-expressive eyes.  ‘Done!’ said St. Martin, or something equivalent.  ‘Digging pits is quite in my line of business!’ exclaimed the devil, in so disagreeable a voice that the saint’s mule would have bolted had the holy rider not kept a tight rein upon her.  At the same moment the ground over which the infernal mule had just passed fell in with a mighty rumble and crash, leaving a yawning gulf.  ‘Now,’ said Lucifer, ‘let me see you jump over that!’ Whereupon, the bold St. Martin drove his spurs into his mule and lightly leapt over the abyss.  And this was how the Puit de Padirac was made.  The peasants believe that they can still see on a stone the imprint left by the hoof of St. Martin’s mule.  This adventure did not cause the saint and the devil to part company.  They rode on together as far as the valley of Medorium (Miers).  ‘Now,’ said St. Martin, ‘you jump over that!’ pointing to a little stream that was seen to flow suddenly and miraculously out of the earth.  Before challenging the arch enemy he had, however, taken the precaution to lay two small boughs in the form of a cross on the brink of the water.  In vain the devil spurred his mule and used the worst language that he could think of to induce the beast to jump.  The animal would not; but, as the spurring and swearing were continued, it at length went down on its knees before the cross.  But this did not suit the devil’s turn.  On the contrary, the proximity of that emblem which St. Martin had placed unobserved on the ground made him writhe as though he had fallen into a font.  Then with the speed of a lightning flash he returned to his own kingdom—­possibly by the Puit de Padirac.  A church dedicated to the saint was afterwards built near the scene of his triumph, and the healing spring where it comes out of the earth is still known by the name of Lou Fount Sen Morti—­St. Martin’s Fountain.