Mud volcanoes or boiling springs, while not common, are to be met with in New York and Pennsylvania. The writer recently visited a large one in New York State, near Lake Ontario. It was around Christmas, and a cold blustering day, yet the water from the spring was quite warm, and had melted the snow for quite a distance in all directions. The water was impregnated with sulphur and salt, and though there was not an eruption when the writer was present, there were marks on surrounding trees showing where mud had been hurled to a height of thirty or forty feet.