Borlase was less impressed. But he was the reverend at Ludgvan. So he probably couldn’t be officially doing with too much superstitious behaviour.
The soil round Madern Well, in the parish of Madern, is black, boggy, and light, but the stratum through which the Spring rises, is a grey moorstone gravel, called, by the Cornish, Grouan. Here people who labour under pains, aches, and stiffness of limbs, come and wash, and many cures are said to have been performed, although the Water can only act by its cold and limpid nature, forasmuch as it has no perceivable mineral impregnation. Hither also upon much less justifiable errands come the uneasy, impatient, and superstitious, and by dropping pins or pebbles into the Water, and by shaking the ground round the Spring, so as to raise bubbles from the bottom, at a certain time of the year, Moon, and day, endeavour to settle such doubts and enquiries as will not let the idle and anxious rest. Here therefore they come, and, instead of allaying, deservedly feed their uneasiness; the supposed responses serving equally to increase the gloom of the melancholy, the suspicions of the jealous, and the passion of the enamoured. As great a piece of folly as this is, ‘tis a very ancient one. The Castalian Fountain, and many others among the Grecians, was supposed to be of a prophetic nature.
From The Natural History of Cornwall by William Borlase (1758).