IF a strong magnet, capable of supporting about ten pounds, be drawn downward over the bodies of fifteen or twenty persons, without actually touching them, some among them will always be found to be excited by it in a peculiar manner. The number of people who are sensitive in this way is greater than is generally imagined : sometimes three or four are met with in such a number as above mentioned : indeed, I know an establishment where the experiment was tried, and of twenty-two young ladies who were collected there, no less than eighteen felt more or less distinctly the passage of the magnet. The kind of impression produced on these excitable people, who otherwise may be. regarded as in perfect health,1 is scarcely describable; it is rather disagreeable than pleasant, and combined with a slight sensation either of cold or warmth, resembling a cool or gently warm breath of air, which the patients imagine to blow softly upon them. Sometimes they feel sensations of drawing, pricking, or creeping; some complain of sudden attacks of headache. Not only women, but men in the very prime of life, are found distinctly susceptible of this influence; in children it is sometimes very active.
To produce this effect, it is essentially indifferent whether we use a horse-shoe magnet or a straight iron bar, with either pole, if it be but strong enough and possess something like the sustaining power above mentioned. The passes must be made from head to foot, and not with too great rapidity. The magnet must be carried as near the body as possible without actually touching the clothes; and to ensure the absence of deception on either side, the pass may be made downward from the back of the head over the neck and hack. The person magnetized is then unaware of the passage of the magnet, and his movement must be unconstrained.
Vigorous men and healthy strong women usually feel nothing of these sensations. Nevertheless, I have met with individuals who have been distinctly affected by the passage of the magnet when in the full enjoyment of health, and these, active light-hearted men and women. But the excitability presents itself more frequently in people of sedentary habits, who may otherwise be considered as healthy, especially in men who are occupied continuously in writing, or girls who pass the greater part of their time at needle-work; moreover, in those who are depressed by secret troubles, anxiety respecting their means of support, neglect, or the loss of relatives. Next to these imperfectly healthy, the slightly diseased are very frequently the most sensitive to the magnet, especially those persons of whom it is commonly said they suffer from weak nerves, who are readily frightened, or have received a shock from some fright they have experienced; besides these, the truly sick in innumerable cases, especially in those whose complaints are accompanied by local or general cramps; during abnormal developments of puberty; many hypochondriacs, valetudinarians as they are called; persons who are very disagreeably affected by odours; but above all, those suffering from catalepsy, St. Vitus's dance, palsy, many of the hysterical, and lastly, those who walk in their sleep, and the true somnambulists without exception. Thus from the healthy person to the sleep-walker a chain is formed, at one end of which stands a powerful man, and at the other a weak somnambulist. Any one may readily convince himself of those facts in every large hospital.
The magnet thus declares itself as a general agent upon the vital principle; a property of it which individual physicians have indeed endeavoured, though as yet without solid results, to bring into more extensive application, in reference to the possibility of deriving from it a curative treatment in cases of disease,—which, however, has not yet been received by natural philosophers into the realm of physics; and from the uncertainty of the observations, hitherto, has been altogether passed over by natural science generally. Nevertheless, magnetism, when more closely examined, presents an infinitely varied and exalted interest on this side. If a portion of the phenomena here assert an influence upon life, this occurs exactly and especially at the point where the boundaries of the organic and inorganic are intermingled. Since a doubt exists whether it shall be attributed to the domain of physiology or of physics, it is neglected on both sides. Thus it is left over to medicine, and has not always fallen into the best hands there. I hope, in the following pages, to disentangle some of the threads of this knot, and to combine a number of phenomena under a common point of view, at the same time arranging them under fixed physical laws.