In the mineral kingdoms are intelligences that learn to communicate with human beings. They live, as they express it, in the interspaces of rock. Their higher orders are like quicksilver in their activity, but they can appear in bodies similar to ours, and by their power over mind-stuff can clothe themselves in the fashions of the people to whom they appear. As they live for many centuries they generally adopt the costumes of an old-fashioned style. People in whom the mineral properties predominate are easily impressed by their vibrations and they inspire the giants of the engineering world in their inventions. The Dayspring of Youth, by M