instruction, a certain grade of skill as muscle-readers, provided, of course, good subjects were experimented with. It is estimated that about one in five or ten persons can be put into the mesmeric trance by the ordinary processes; and, under extraordinary circumstances, while under great excitement, and by different causes, every one is liable to be thrown into certain stages or forms of trance; the capacity for the trance-state is not exceptional; it is not the peculiar property of a few individuals—it belongs to the human race; similarly with the capacity for muscle-reading. The age at which this delicacy of touch is most marked is an inquiry of interest; experience, up to date, would show that the very young or the very old are not good muscle-readers. I have never known of one under fifteen years of age to study this subject; although it is conceivable that bright children, younger than that age, might have sufficient power of attention to acquire the art, certainly if they had good instruction in it.
In these mind-reading experiments, as indeed in all similar or allied experiments with living human beings, there are six sources of error, all of which must be absolutely guarded against if the results are to have any precise and authoritative value in science.
1. The involuntary and unconscious action of brain and muscle, including trance, in which the subject becomes a pure automaton. I have used the phrase "involuntary life" to cover all these phenomena of the system that appear independently of the will. The majority of those who studied the subject of mind-reading—even physicians and physiologists—failed through want of a proper understanding or appreciation of this side of physiology.
2. Chance and coincidences. Neglect of this source of error was the main cause of the unfortunate results of the wire and chain experiments with mind-readers.
3. Intentional deception on the part of the subject.
4. Unintentional deception on the part of the subject.
5. Collusion of confederates. To guard against all the above sources of error it is necessary for the experimenter himself to use deception.
6. Unintentional assistance of audience or bystanders.
When the muscle-reader performs before an enthusiastic audience, he is likely to be loudly applauded after each success; and, if the excitement be great, the applause, with shuffling and rustling, may begin before he reaches the right locality, while he is approaching it; when, on the other hand, he is far away from the locality, the audience will inform him by ominous silence. The performance thus becomes like the hide-and-seek games of children, where they cry "Warm!" as the blindfolded operator approaches the hidden object; "Hot!" as he comes close to it; and "Cold!" when he wanders far from it. Some of the apparent successes with the wire-test may be thus explained.
In regard to all the public exhibitions of muscle-readers, it should