Dr. Kilner conceived the idea that the aura might be made visible to normally-sighted people if viewed through a suitable substance, and he experimented with dicyanin, a remarkable coal-tar dye. This dye appears to have an unusual effect upon eyesight, making the observer more readily able to perceive radiation in the ultra-violet band. The introduction by Leslie Shepard indicates the present status of work on the human aura. Illustrated. Index.