Returning to Myreside, we continue our walk due east, along a road bordered by villas, till we find ourselves passing on the left the narrow postern door, guarded by the lions _couchant_ that surmount the pillars on either side. Behind it stands Merchiston. This very ancient castle, built no one knows when or by whom, has for centuries belonged to the illustrious family of Napier, they having acquired it in 1438. Their most famous son, John Napier, the inventor of logarithms, was born here in 1550. His father, Sir Alexander, who was only sixteen years old at the time of his birth, was later Master of the Mint to James VI. His mother was Janet, only daughter of Sir Francis Bothwell, and sister to Adam, Bishop of Orkney. John Napier pursued his studies and researches at Merchiston. He was supposed by the vulgar to be deeply versed in magic, and to possess a familiar spirit in the shape of a jet-black cock. The story goes that once, when some petty thefts had been committed in the castle, of which one of the servants was suspected, Napier brought them all up the winding stair into a darkened room, where the cock was placed. He commanded them to stroke its back, declaring it would crow at the touch of the guilty person. During the whole ceremony the cock remained silent, but afterwards the hand of the culprit was found to be free from the soot with which the bird's feathers had been liberally sprinkled. Napier was also believed to possess the power of discovering hidden treasure. Among the Merchiston papers still exists a curious contract, dated July 1594, between him and Robert Logan of Restalrig, which sets forth: "Forasmuch as there were old reports and appearances that a sum of money was hid within Logan's house of Fast Castle, John Napier should do his utmost diligence to work and seek out the same." For his reward he was to have a third of the discovered treasure. "This singular contract," says Wilson, "acquires a peculiar interest when we remember the reported discovery of hidden treasure, with which the preliminary steps of the Gowrie conspiracy were effected;" Logan of Restalrig being deeply implicated in that plot, though nothing of his share in it was known at the time.