Extract from The Changing Face Of Warminster by Wilfred Middlebrook, published in 1971:
Hog’s Well is at Bugley. This was a spring that was once noted for healing weak eyes. It is joined by a brook from Cley Hill, and by other streams before it enters the town of Warminster at the Obelisk to join the Swan River. It is a fact that many mothers have taken their children to Hog’s Well to bathe their eyes, and farmers with a weak pig in a litter, would let the piglet stand in the spring for fifteen minutes; this may well be the origin of the name Hog’s Well. Victor Manley relates a fantastic story of the Hog’s Well demons, who would rise out of the ground and seize anyone found wandering near the well. The unfortunate yokel would then be dragged underground, forced to repeat certain unspecified words, before being given money and released.