I had no way of learning the truth or falsity of this theory.
Thought Photography.
These Ploidites have distanced us in the study of the nervous system, including the intricate problems of the cerebrum and cerebellum. They have ascertained, by long ages of observation and experimenting, the exact effect of every kind of impulse on the brain matter. The experts are able to tell, at a post-mortem examination, what kinds of thinking were most prevalent during the subject's life, just as easily as we can judge the great or little use of the arm by an examination of its muscles.
But more wonderful, a thousand fold, is their ability to follow the course of thought in a living cerebrum after the brain has been made visible by a light more potent than the X ray. After this exposure the operator, with his wizard magnifying lens, watches the tiny tremulous brain cells in their infinitesimal quivering, as they carry messages from the soul to the world of sense and being.
The voluntary nerve action is distin-
