Many strange things are done by these Jumpers. One of those with whom I experimented came very near cutting his throat the day before I reached the lake. He was shaving, and the door slammed suddenly behind him; he jumped, and, had the razor been held in a different way, he might have inflicted a severe wound. One of these Jumpers being surprised by an order to "strike," while standing before a window, struck his fist right through the glass, cutting it severely. These Jumpers have been known to strike their fists against a red-hot stove; they have been known to jump into the fire, as well as into water; indeed, no painfulness or peril of position has any effect on them; they are as powerless as apoplectics or hysterics, if not more so; the absolute victims of the orders that are given them, or of the surprises that are played upon them; they must do as they are told, though it kill them, or though it kill others. I can find no evidence that the presence of water or of fire will interfere, even in the slightest degree, with the motions which they are compelled to make. As has been made apparent by the above description, it is not necessary that the surprises should come from any human being; it is not necessary that they should be ordered to strike or to jump; any sound, from any source, that comes upon them with sufficient severity and suddenness, for which they are not forewarned and forearmed, may cause them to jump and to cry. One of those on whom I experimented told me that the falling of a tree in the woods, when unexpected, would have the same effect upon him. He said that one time he was so alarmed by the sudden crash of a tree that he not only jumped, but was perfectly entranced, so that he could not move, although the tree did not fall upon him. The explosion of a gun or pistol is almost sure to excite these Jumpers. The screech of a steam whistle is especially obnoxious to them, few of them, so far as I have been able to learn, having been able to withstand it. On one of the lake-steamers in which I returned from the hotel, there was a Jumper who, when the screech was heard, jumped right up, so that he nearly hit his head on the upper deck. As the steamer neared the landing and came to a place where he knew the whistle would sound again, he was warned to prepare himself, and he did so with such success, that on the first screech he jumped scarcely any; on the second, however, despite his care, he raised his shoulders perceptibly, but did not jump. In many of these cases, it may be observed, a simple raising of the shoulders, a sudden impulsive movement, is all that is done, there being no cry and no movement of the hands to throw or to strike.
the part of the subject experimented on 3. Intentional collusion of other parties; 4. Unintentional collusion of other parties; 5. Chances and coincidences; 6. Phenomena of the involuntary life. In experimenting with the Jumpers the nature of the phenomena made it easy to eliminate the main element of error, intentional deception on the part of the subject—since, unless the subject is deceived or at least surprised, the phenomena do not appear.