Stone Barometer.
Reading edition
A Finland newspaper mentions a stone in the northern part of Finland which serves the inhabitants instead of a barometer. This stone, which they call Tlmakiur, turns black, or blackish gray, when it is going to rain; but on the approach of fine weather it is covered with white spots. Probably it is a fossil mixed with clay, and containing rock-salt, nitre or ammonia, which, according to the degree of dampness in the atmosphere, attracts it, or otherwise. In the latter case the salt appears, forming the white spots.