The needle literally ran after his hand. On using the fingers of his left hand the needle was deflected to the left. But since Breitung himself states that he cannot deflect the needle of a compass by means of his finger-tips, it would be as well to find out whether there was not some source of error in his experiments with the knitting-needle, such as draughts, etc.

It has also occasionally been pointed out that there are some people who are so electric that they may even emit sparks. Du Bois-Reymond doubted these statements and thought, moreover, that the whole question was of but little interest. It has also been stated that steel becomes magnetic in certain persons' hands. Eisenstein relates of his subject Leopoldine R., who was chief subject in the Viennese experiments mentioned on Page 13, that she could turn ordinary steel needles into magnets simply by touching them. She told the audience and Dr. Hummel, who was controlling the experiments, that she only possessed this power when she was tired and worn out, but not when she felt quite well. But when the experiments were more carefully controlled, her assertions were not substantiated. The magnetizer Lafontaine also stated that he could render iron magnetic, and could produce a north or south pole at will, according to the passes he made; he further stated that he was able to deprive a steel magnet of its magnetism by a proper process of magnetizing.

He also further asserted that he could render water so magnetic that it would cause a galvanometer to show a deflection of from 10° to 20o With one of his patients, Thilorier, he approached the Acadimie des Sciences with a request that this fact might be tested. On June 10, 1844, the Academy appointed a commission consisting of Pouillet, Dutrochet, Becquerel, Chevreul, Regnault, and Magendie. The experiments proved unsuccessful. Lafontaine blamed Thilorier on the ground that the latter did not understand the business; but he refused to make any further experiments, asserting that the commission was prejudiced.

Certain experiments that have recently attracted attention are of a somewhat different nature. Erich Harnack, for instance, is convinced that he can deflect the compass-needle by rubbing the glass-plate with his finger. Harnack assumes that the friction produces statical electricity, that we have to deal with a process that is not merely mechanico-physical, but with one that is distinct and peculiar to certain individuals. He came to this conclusion, because (1) apparently stronger currents of frictional electricity did not deflect the needle, (2) the finger-tips of numerous individuals did not possess this faculty, (3) he only possessed it at times. Harnack thought he refuted the objection that the process was only mechanico-physical, because he tested the tension and found it over 1000 volts. This assumption has been disputed, notably by Betbe, who experimented with his own finger and also on the corpse of a man sixty-nine years of age. Bethe was able to get a tension of 1000 volts with the finger of the dead man when it had been dried in the exsiccator.

But in spite of these objections, Harnack's experiments seem to me to be of such great importance, and so interesting, that we cannot but earnestly desire that they should be put to a further objective and scientific test. But the question whether the processes were physiological or merely mechanical does not seem to me solved. The rapidity with which Harnack obtained such a high tension - 600 volts with one pass - is certainly extremely remarkable. Experts must examine this question further, and objectively. This is particularly necessary so as to prevent occultists and magnetopaths making an unscientific use of Harnack's experiments, as they might otherwise do.

Of course, experiments, the results of which can be made use of, should only be carried out under the strictest conditions. I think I may assume from Harnack's own publications, that he was not invariably as careful as he might have been. He speaks of cases in which people were supposed to cause deflection of the magnetic needle by merely approaching it, though he himself had to rub the glass-plate. He was able to experiment with two people who were said to possess this power. With one of them the experiment failed - he assumed the subject was only a magnetopath in her leisure hours. Harnack writes, "I obtained better results in the second case, that of a woman of the educated classes. It was only by accident that she became aware that she possessed this peculiar power. She told me at once that she did not always succeed in deflecting the needle by approaching and withdrawing her finger (she never rubbed the glass-face)." In his experiments with this lady, Harnack used a rather large, but simply constructed compass, with a glass-face; the needle was about 4 inches long, and very sensitive.

When the experiment had been going on for about ten minutes, the needle suddenly deflected in the direction of the subject's finger-tips. The deflection gradually increased to from 200 to 250. Harnack considers this experiment, which he often repeated, thoroughly convincing. During the experiments "the lady wore nothing that was made of steel, and no stays," and Harnack thinks that this excluded all possibility of fraud, because if the subject had had anything made of steel about her, the needle must have been affected directly she approached the compass, but nothing of the kind ever happened Harnack further thinks that the lady and her husband took no special interest in the matter, but were solely concerned in serving the cause of truth.

But the experiments Harnack made with this lady are not convincing. His assumption that if she had had anything steel about her it would have caused the needle to deflect directly she approached the compass, is incorrect. That would depend upon whether the steel object were freely movable, so that she might weaken its action when she wished. At all events, I have not been able to discover anything in Harnack's publications showing that those precautions were taken which are absolutely necessary, if the possibility of some steel object being concealed about the subject is to be precluded. It would have been all the better if the proper precautions had been taken in this case, as it is the only one in which Harnack saw the needle deflected without the glass plate being rubbed; i.e.., supposing the observation was free from error, we have here a proof that friction is unnecessary. Unfortunately, Harnack did not take the necessary precautions in the case of this lady; perhaps he was unable to do so, for it is especially difficult to get any one, particularly a lady, to observe all the necessary conditions of a scientifically controlled experiment.