upon the skin are more satisfactory than those on other parts of the body, partly because their results are more manifest and partly because they are attended with less discomfort to the patient. They belong to two types: (1) those in which the modifications induced are chiefly vasomotor—redness, swelling, exudation of blood, etc.—but greater than one can usually produce by an act of will; and (2) those in which there is visible change in the tissue. It is quite possible that the latter are due in large part to vasomotor modifications, but we can not at present prove that such is the case. In connection with these experimental cases I shall introduce a few parallels derived from other sources to show their absolute identity of type.
The first case which I shall quote is reported by Dr. Biggs, of Lima, and is recorded by Mr. F. W. H. Myers in the Proceedings of the Society for Psychical Research, vol. vii, page 339. In three cases Dr. Biggs produced a red cross upon the skin by suggestion. His own account of the first of these cases, slightly abbreviated, is given as follows in a letter dated October 18, 1885:
"I put her into a magnetic or mesmeric sleep by laying my hand on her head for about a minute. I then said, 'Maria, do you hear me?' 'Yes.' 'Are you thoroughly magnetized?' 'Yes.' 'Now listen attentively: a cross is going to appear on your right forearm and remain there until I tell it to go away. Here is where it is to appear.'(I then described a cross with my forefinger on the inner side of her right forearm.)' Have you understood what I have said to you?' 'Yes.' I then awakened her by two or three up-passes; for the next two or three days she seemed sulky and out of sorts, would now and then rub her right arm, over the place where the cross was to appear; when asked why she did this, she said there was an itching and she could not help scratching the place, although there was nothing to be seen that could cause the irritation. I then magnetized her as before, and asked, 'Do you recollect what I told you the other day about the cross that is to appear upon your arm?' 'Yes.' 'Will it appear?' 'Yes.' 'When?' 'In a few days.' 'Well, it must come out in three days; do you understand?' 'Yes.' By the time appointed a dusky red cross, four or five inches long and about three inches wide, made its appearance. At first we pretended not to notice this, although we could often see the lower part of it when her sleeve was partly rolled up in some of her duties in and about the house; she was our housemaid. It was only at intervals, when thrown into the magnetic sleep, that we could get a full view of the cross; never a word had been said to her about the cross in her waking moments, for some time, several weeks, until one day I pretended to have caught sight of the strange mark on her arm, and said:
