Oluf Borch, the Danish Scientist, visited Wookey Hole in 1663. He described the speleothems there and also noted that the villagers were not specially susceptible to developing stones in the kidney etc., although they drank water from the cave. This led him to suppose that speleothems were not due to impurities but were formed from pure water. He explained the process by saying that the particles of water, if left totally undisturbed, would bind together because they were so similar (rather as ice forms when molecular movement is reduced by low temperature).