The two holed-stones exhibited are from the collection of Sir F. Tress Barry, and were dug out of brochs, popularly called "Picts' houses," in the neighbourhood of Keiss Castle, Caithness.
They measure on and three-sixteenths and one and seven-sixteenths of an inch respectively in diameter. The smallest is from one-eighth to a quarter of an inch in thickness, whilst the larger and less perfect specimen has a thickness of three-eighths of an inch on one side, but on the opposite is chipped away to little more than one-sixteenth of an inch. The perforation of the first is a clean cut circle not quite a quarter of an inch in diameter. The hole of the larger stone is rougher, and has a diameter of three-eighths of an inch. Sometimes these stones are found decorated with small patterns of scratched lines. They are, in fact, ancient spindle whorls.
A few people in Caithness still attribute some superstitious power to these stones, and on the first night of the "quarter" they tie one of them between the horns of each of their cows and oxen, to frighten away the fairies and ill-luck. There is a tradition that the magic stones were made by seven vipers, who worked them into shape with their teeth, and that as they were finished the king of the vipers carried them off up on his tail ! *
When cattle sickened it used to be the custom in the old days - and, indeed, until quite recently - to call in a man with "charm stones" to conjure out the evil spirit. The grandfather of a middle-aged man now living in Caithness was celebrated for his wonderful cures, and declared that he had often seen the "fairy darts" sticking in the sick oxen when called in to doctor them.
He had to be left quite alone when practising his magic arts, but one day a neighbour - being very curious to see what he did - hid in a stable where he had shut himself up, and saw him rub the sick animal with the charm-stones, while at intervals he turned the stones over in the basket he had brought them in, saying "Swate ye! Swate ye!" He then administered a "drink of silver" (a bucket of water with a piece of silver money in it), and the animal was cured. The "silver drink" is still believed to be very effective in many parts of Caithness, and certainly it is a simple remedy, not likely to do any mischief.
*In the Hebrides these stone whorls are known as adder-stones.
Edward Lovett; F. Barry; J. G. Frazer; F. N. Webb
Folklore, Vol. 16, No. 3. (Sep. 29, 1905), pp. 334-337.