Gilles de la Tourette has given a number of details concerning the treatment of the sick through the agency of Parisian somnambulists in his work on the forensic importance of hypnotism. However, it is not to be imagined that such things only occur in Paris. Hirschlaff tells of a magnetopath in Berlin, who employed a somnambulist, and I have not the least doubt that the same thing is done in many other German towns. A Bavarian medical official, Wetzler, who thought he was suffering from rheumatism, treated himself with medicines ordered by a somnambulist. A man named Jost, who had formerly been a tailor, while in a state of assumed hypnosis prescribed cures for hundreds of sick people. On the testimony of the medical expert, Fiirstner, he was tried and condemned for fraud and simulated hypnosis.

Somnambulists are, moreover, also made use of to diagnose their own disease, predict its course, and indicate the necessary remedies. When a somnambulist describes the appearance of his own internal organs, he usually does so in such vague, general terms, that his statements are not worth the trouble it would take one to substantiate or disprove them. But the foretold onset of morbid symptoms occurs with extreme punctuality. I remember being called to a lady who often suffered from attacks of hysteria. When I visited her, she declared that a voice had told her that the last attack would occur the following night. A colleague and I advised her to refrain from taking any further measures to combat the attacks, as the prophecy would possibly be fulfilled; and it was. The most natural explanation - and one based on our present-day knowledge - is, that the patient caused the onset or cessation of certain morbid symptoms by auto-suggestion, in consequence of which the prophecy proved correct. Here there are, perhaps, other circumstances to be taken into consideration as well. F. Myers pointed out the importance of the secondary ego.

He thought that the latter obviously possessed a profound knowledge of the organism, and could consequently make a more reliable diagnosis than the primary ego. He also thought that auto-suggestion would account for the prediction of the course of a disease; indeed, he even considered that death might be caused by auto-suggestion, the patient becoming so anxious and depressed from the auto-suggestion of approaching death as to cause his vitality to fail gradually. But in his opinion real cognition of the secondary ego was of far greater importance. We know of something analogous in dreams. As far back as 1866, Liebeault pointed out that many morbid symptoms give warning of their approach in dreams. I will give a few instances of this from my own practice. A lady dreamed she was suffering from severe toothache. In the daytime she was free from pain, and nothing could be discovered the matter with her teeth. A few days later one of her teeth was found to be diseased. Again, a gentleman of my acquaintance frequently complained of dreams in which he suffered from pains on the right side of his chest. On one occasion he dreamed be was fighting with burglars, one of whom struck him on the chest with a hammer. During this period he also dreamed of inflammation of the lungs.

A good many days later he had symptoms of inflammation of the pleura on the right side. Ribot has reported similar cases.

Those diagnoses which are made from objects belonging to sick persons or, more especially, from their hair, also belong to the domain of clairvoyance. Many years ago, in conjunction with Max Dessoir, I made a whole series of experiments with a woman who at the time had a great reputation in Berlin for making such diagnoses by means of patients' hair. The investigation proved a complete failure. Not one single disease was correctly diagnosed, and the number of cases in which such details as age, sex, etc., were correctly given did not exceed the numerical value of the probability of chance success. I have given the results of these experiments in my work, Uber den Rapport in der Hypnose. In a number of other cases in which I succeeded in getting to the bottom of the matter the diagnosis invariably turned out to be incorrect. A Dutch woman also, who was said to be able to diagnose diseases from patients' hair, made a wrong diagnosis in a case that was carefully controlled. I observed the same thing in the case of a man in Germany, who had a reputation for diagnosing diseases from objects belonging to patients.

He also failed utterly in his attempts.

There are various sources of error to be reckoned with where such diagnoses are concerned. In the first place there are vague diagnoses, such as nervousness, a weak stomach, headache at times, occasional sleeplessness, that would apply to any number of cases. In addition to this, the diagnosis often includes a number of morbid symptoms - I came across one in which nearly a dozen were given, such as headache, weakness, bad digestion, weak kidneys, excitability, weakness of the stomach, etc. - some one or other of which would most probably be present. Most people, but more especially uncritical individuals and marvel-mongers - and these form the bulk of the people who consult clairvoyantes - are much more impressed by one success than by many failures. Any one who knows how to criticize can correct these errors, but not so a person in whom that faculty is wanting. Consequently, even when the clairvoyante is only right as to one of ten symptoms that she has described, but is wrong as to the other nine, many people think that on the whole the case is a proof of clairvoyance.

Another important point is, that as a rule such patients subsequently ponder long over the question whether they did not at some time suffer from one or other of the complaints mentioned to them; and with a little reflection any one complaining of sleeplessness will soon discover that they once suffered from some gastric affection. Finally, much is straightway accepted as true without any investigation. For example, suppose a woman who is suffering from pains in her back is told by a clairvoyante that she has a uterine complaint, she will take the assertion for an established fact, and when a doctor tells her later on that her womb is perfectly healthy, she will in all probability put her trust in the clairvoyante. Many of the diagnoses made by clairvoyantes are of such a nature that it is almost impossible to submit them to revision. Thus, stagnation of the blood, impurity of the lymph, etc., play an important part in such diagnoses. At all events, I have gone through the literature of the subject carefully, but nowhere have I found a series of experiments that would bear triticism, and would prove that a number of correct diagnoses had been made by means of clairvoyance in excess of the numerical value of the probability of chance success.