Charm-stones were sometimes kept on the altars of ancient churches, as in the case of St. Ronan's Chapel, and the church in Iona already referred to. At other times they were associated with crosses. Sir Arthur Mitchell tells of an Irish curing-stone in shape like a dumb-bell, preserved in Killaghtee parish, County Donegal. "There is," he says, "a fragment of a stone cross on the top of a small cairn. In a cleft or hollow of this cross is kept a famous healing stone, in whose virtues there is still a belief. It is frequently removed to houses in which sickness exists, but it is invariably brought back, and those living near the cross can always tell where it is to be found, if it has been so removed." Pennant, in connection with his visit to Iona, speaks of certain stones lying in the pedestal of a cross to the north-west of St. Oran's Chapel. "Numbers who visit this island," he remarks, "think it incumbent on them to turn each of these thrice round, according to the course of the sun. They are called Clach-a-brath--for it is thought that the brath, or 'end of the world,' will not arrive till the stone on which they stand is worn through." Pennant thought that these stones were the successors of "three noble globes of white marble," which, according to Sacheverel, at one time lay in three stone basins, and were turned round in the manner described, but were afterwards thrown into the sea by the order of the ecclesiastical authorities. MacCulloch says that, in his day, the superstition connected with the Clach-a-brath had died out in Iona. We do not think that this was likely. Anyhow he mentions that "the boys of the village still supply a stone for every visitor to turn round on its bed; and thus, in the wearing of this typical globe, to contribute his share to the final dissolution of all things." MacCulloch alludes to the same superstition as then existing on one of the Garveloch Isles. Sometimes hollows were made on the pedestals of crosses, not for the reception of stone-balls, but to supply occupation to persons undergoing penance. A sculptured cross at Kilberry, in Argyllshire, has a cavity of this kind in its pedestal. In connection with his visit to Kilberry, Captain White was told that "one of the prescribed acts of penance in connection with many of the ancient Irish crosses required the individual under discipline, while kneeling before the cross, to scoop out a cavity in the pedestal, pestle-and-mortar fashion; and that such cavities, where now to be seen, show in this way, varying stages of the process."