results of his own enquiries, on which he was anxious for my opinion. My reply was simply, "Shut your 'eyes, or turn them away; let some one else watch the "oscillations under the conditions you have specified, "and record their results; and you will find, if I do not "mistake, that they will then show an entire want of "the constancy you have hitherto observed." His next letter informed me that such proved to be the case; so that he came entirely to agree with me as to the dependence of the previous uniformity of his results on his own expectancy.'

A curious variation of the 'Odometer' was introduced by Mr. Rutter, then manager of the gas-works at Brighton, under the name of Magnetometer;' which was simply a gallows-shaped frame, mounted on a solid base, and having a metallic ball suspended from its free extremity. When the finger was kept for a short time in contact with this frame, the ball began to oscillate, usually in some definite direction; changing that direction with any change of circumstances, after the manner of Dr. Mayo's 'odometer.' To many persons, as to Mr. Rutter himself, it appeared impossible that these oscillations could have their origin in any movement of the operator; but everyone who knew how difficult it is to prevent vibrations in the supporting frame-work of a Microscope or a Telescope, and who recognised in the construction of the 'Magnetometer' exactly such an arrangement as enabled the smallest amount of imparted motion to produce the greatest sensible effect, was prepared to anticipate that the oscillations of the suspended ball would be

as much maintained and guided by the expectancy" of the operator, as they are when it is hung directly from his own finger. Experiment soon proved this to be the case; for it was found that the constancy of the vibrations entirely depended upon the operator's watching their direction, either by his own eyes or by those of some one else; and further, that when such a change was made without his knowledge in the conditions of the experiment, as ought, theoretically, to alter the direction of the oscillations, no such alteration took place.

A very amusing exposé of the mystery of the 'Magnetometer' resulted from its application by Dr. Madden, a Homœopathic physician at Brighton, to test the virtues of his 'globules,' as to which he had, of course, some pre-formed conclusions of his own. The results of his first experiments entirely corresponded with his ideas of what they ought to be; for when a globule of one medicine was taken into his disengaged hand, the suspended ball oscillated longitudinally; and when this globule was changed for another of (supposed) opposite virtues, the direction of the oscillations became transverse. Another Homcopathic physician, however, was going through a similar course of experiments; and his results, while conformable to his own notions of the virtues of the globules, were by no means accordant with those of Dr. Madden. The latter was thus led to re-investigate the matter with a precaution he had omitted in the first instance; -namely, that the globules should be placed in his hand by another person, without any hint being given

him of their nature. From the moment he began to work upon this plan, the whole aspect of the subject was changed; globules that produced longitudinal oscillations at one time, gave transverse at another; whilst globules of the most opposite remedial virtues gave no sign of difference. And thus he was soon led to the conviction, which he avowed with a candour very creditable to him, that the system he had built up had no better foundation than his own 'expectancy' of what the results of each experiment should be; that anticipation expressing itself unconsciously in involuntary and imperceptible movements of his finger, which communicated a rhythmical vibration to the framework when the oscillations of the ball suspended from it were watched.

Thus, by the investigations of scientific experts who were alive to the sources of fallacy which the introduction of the human element always brings into play, the hypothesis of Odylic force was proved to be completely baseless ;• the phenomena which were supposed to indicate its existence being traceable to the Physiological conditions of the Human organisms through whose instrumentality they were manifested. The principle that the state of 'expectant attention' is capable of giving rise either to sensations or to involuntary movements, according to the nature of the expectancy, had been previously recognised in Physiological science, and was not invented for the occasion; but the phenomena I have been describing to you are among its most 'pregnant instances.'

DIVINING ROD.

The same principle furnishes what I believe to be the true scientific explanation of the supposed mystery of the Divining Rod, often used where water is scarce for the discovery of springs, and in mining districts for the detection of metallic veins. This rod is a forked twig, shaped like the letter Y, hazel being usually preferred; and the diviner walks over the ground to be explored, firmly grasping its two prongs with his hands, in such a position that its stem points forwards. After a time the end of the stem points. downwards, often, it is said, with a sort of writhing or struggling motion, especially when the fork is tightly grasped; and sometimes it even turns backwards, so as to point towards, instead of away from, the body of the diviner. Now there is a very large body of apparently reliable testimony, that when the ground has been opened in situations thus indicated, either watersprings or metallic veins have been found beneath; and it is quite certain that the existence of such a power is a matter of unquestioning faith on the part of large numbers of intelligent persons, who have witnessed what they believed to be its genuine manifestations. This subject, however, was carefully enquired into more than forty years ago by MM. Chevreul and Biot; and their experimental conclusions anticipated

1

I have lately received a pamphlet from an Engineer in the United States, giving most circumstantial details of successes thus obtained within his own experience.

those to which I was myself led, in ignorance of them, by Physiological reasoning. They found that the forked twig cannot be firmly grasped for a quarter of an hour or more in the regular position, without the induction of a state of muscular tension which at last discharges itself in movement; and this acts on the prongs of the fork in such a manner, as to cause its stem to point either upwards or downwards or to one side.

The occasion of this discharge, and the direction of the movement, are greatly influenced-like the oscillations of bodies suspended from the finger-by the expectancy of the operator; so that if he has any suspicion or surmise as to the 'whereabouts' of the object of his search, an involuntary and unconscious action of his muscles causes the point of the rod to dip over it. This was admitted even by Dr. H. Mayo, a believer in the existence of an 'Od-force' governing the movements of the rod; for he found that when his diviner' knew which way the fork was expected to move, it invariably answered his expectations; whilst, when he had the man blindfolded, the results were uncertain and contradictory. Hence he came to the conclusion that several of those in whose hands the Divining Rod moves, set it in motion, and direct its motion (however unintentionally and unconsciously) by the pressure of their fingers, and by carrying their hands near-to or apart-from one another.'

Again, since not one individual in forty, in the localities in which the virtues of the Divining Rod are still held as an article of faith, is found to obtain any On the Truths contained in Popular Superstitions, Letter I., p. 19.