This is a phenomenon which has for several years excited the attention of travellers, under the name of a burning spring: it exists in one of the principal forks of Licking river in Kentucky. It is situated, about three-fourths of a mile from the banks of the river, and about eighty miles above its junction with Ohio, opposite Cincinnati. A spring here breaks out at the foot of a hill, forming a basin of water about six feet in diameter and two feet deep, at the bottom of which issues a stream of gas, which in volume and force is about equal to the blast forced from a common smith's bellows; but there is no cessation of its force, which is such as to create a violent ebullition in the water. Being heavier than common atmospheric air, the gas, on passing up through the water, constantly occupies the surface, which is still the lower part of an indenture in the earth at that place. On presenting a taper, this gas instantly takes fire, and burns with great brilliancy. There is no absorption of it by the water, which possesses the purity of common spring water, neither is any offensive odour thrown off. This spring has been known to dry up entirely in the summer, when the air rushes out with increased force, accompanied by a hissing noise. There is nothing like smoke emitted. - Schoolcroft, on the Lead Mines of Missouri, p. 216.