Wells and springs, like lakes, seem to have appealed to the imagination of men at all times, and the description of their peculiarities occupied disproportionate space in medieval books of marvels. Giraldus Cambrensis mentions wells with petrifying properties in Ulster, Norway, Britain, and Cappadocia;[915] and Saxo Grammaticus expresses great wonder at a spring in Iceland the exhalation or foam of which is capable of turning the softest substances almost instantaneously into the hardest stone.[916] Gervase of Tilbury describes a salt well in the diocese of Worcester.[917] Though these are reasonable enough, it is a little more difficult to explain Giraldus’ belief in wells which ebb and flow like the tides,[918] especially when he insists that some of them are situated far from the sea. Giraldus describes an absolutely miraculous spring in the province of Munster in Ireland.[919] When touched or even looked at by a man, this spring will proceed to inundate the entire province with rain. The rain does not stop until a priest, virgin from birth and especially deputed for the purpose, celebrates mass in a chapel not far away and, having blessed the waters, conciliates the spring by sprinkling into it the milk of a one-colored cow. Giraldus remarked parenthetically that this was a barbaric ceremony and quite lacking in reason. Gervase of Tilbury tells of a lake in Great Britain which would produce a storm when certain words were chanted over it and of a fountain in the Kingdom of Arles which would cause rain if a stick or stone were thrown into it.[920] These tales, indeed, are but examples of a widespread belief among primitive and ignorant folk that man can attain the secret of the magical control of the elements. Sir James G. Frazer cites them with similar examples from other peoples and ages as illustrations of the doctrine that a “way of constraining the rain-god is to disturb him in his haunts. This seems to be the reason why rain is supposed to follow the troubling of a sacred spring.”[921]