541 B. An exhaustive and impartial survey of the existing evidence for the faculty of "dowsing" is given in Professor W. F. Barrett's two articles "On the So-called Divining Rod" in the Proceedings S.P.R., vol. xiii. pp. 2 - 282, and vol. xv. pp. 130-383. From the latter I quote the general conclusions at which Professor Barrett has arrived (p. 313).

(1) For some centuries past certain individuals locally known as dowsers have declared that they can discover the presence of underground water, mineral lodes, coal, building stone, or other buried objects which may be sought for by the apparently spontaneous motion of the so-called divining rod; when their pretensions have been tested, the result, though by no means uniformly in their favour, has been so remarkable that chance coincidence appears a wholly inadequate explanation.

(2) Any explanation based upon trickery or unconscious hints from bystanders, or the detection of faint surface indications of the concealed object, or other known cause, is insufficient to cover all the facts.

(3) The movement of the rod or forked twig is only a special case of motor automatism exhibited by a large number of individuals, and arises from a subconscious and involuntary "suggestion " impressed on the mind of the dowser.

(4) Accompanying the involuntary and usually unconscious muscular contraction which causes the motion of the forked twig or rod, many dowsers experience a peculiar malaise and some a violent convulsive spasm. This is a psycho-physiological effect, akin to emotion. Moreover, the state of mono-ideism of the dowser creates a condition of partial catalepsy when some suggestion causes the idea to culminate.

(5) This subconscious suggestion may arise from a variety of causes; sometimes it is merely an auto-suggestion, at others it is unconsciously derived through the senses from the environment, but in a certain number of those who exhibit motor automatism the suggestion appears to be due to some kind of transcendental perceptive power.

(6) Such persons appear only able to exercise this transcendental faculty when their normal self-consciousness is more or less in abeyance, or when it is completely submerged, as in profound hypnosis.

(7) This subconscious perceptive power, commonly called "clairvoyance," may provisionally be taken as the explanation of those successes of the dowser which are inexplicable on any grounds at present known to science.

The malaise mentioned above as a frequent accompaniment of the exercise of their art by dowsers is thus described in an earlier part of the same paper (p. 299).

Nearly all dowsers assert that when the rod moves in their hands, or when they believe that underground water is beneath them, they experience a peculiar sensation, which some describe as felt in the limbs like the tingling of an electric shock, others as a shivering or trembling, and others as an unpleasant sensation in the epigastric region. With all there is more or less of a convulsive spasm, sometimes of a violent character. This malaise is very marked in some cases, but not experienced in others. That these physiological disturbances have a purely psychological origin is obvious - (1) from the fact that they are not experienced when the dowser is off duty, that is, when he has no suspicion that he is in the neighbourhood of underground water, and (2) that like effects are not produced by the much greater masses of visible water in rivers, lakes, or the sea. The interesting point is that these psycho-physiological phenomena have a real existence; they exist among dowsers in all countries, and can be traced back, as historical investigation shows, for upwards of two centuries.

In the preceding Report I devoted an Appendix to this subject.... [Proceedings S.P.R., vol. xiii. pp. 272 et seq].

The writer proceeds to give further cases - ancient and modern - of the malaise associated with dowsing, and shows its analogy with the physiological disturbances, arising from psychological causes, that sometimes accompany other phases of automatism.

541 C. I next take the case of metallæsthesia, - that alleged reaction to special metals which has often been asserted both in hypnotic and in hysterical cases. As a definite instance I will take the statement made by certain physicians attending Louis Vive (see 233 A) that while they supported him during a hysterical attack a gold ring on the finger of one of them touched him for some time and left a red mark, as of a burn, of whose origin the patient knew nothing. It is further alleged - and this is a quite separate point, although often confused with the first - that gold is distinguished by some subjects under conditions where no degree of sensitiveness to weight or temperature could have shown them that gold was near.

Now as to the first point, e.g. the Louis Vivé incident, I can readily believe that the touch of gold, unknown to the subject's supraliminal consciousness, may produce a redness, subsequent pain, etc. All that is needed for this is a capricious self-suggestion, like any other hysterical idea. This self-suggestion might remain completely unknown to the waking self, which might be puzzled as to the cause of the redness and pain. And observe that such a result might even deserve the name of heteræsthesia. There might be a whole complex range of specific reactions to substances chemically inert paralleling our reactions to drugs which chemically affect our tissues. The second claim, however, involves much more than this. If gold is recognised through a covering, for instance, or heated to the same point as other metals, so that no sensation of weight or temperature can help observation, this might possibly be by virtue of some sensibility more resembling the attraction of low organisms to specific substances whose chemical action on them we cannot determine, or to particular rays in the spectrum. I am not convinced that this has yet been proved; but I should not regard it as a priori impossible.

I think it probable that our central sensorium may have the capacity of discriminating many sensations which it does not habitually discriminate, and that dermal end-organs may transmit messages which are not habitually interpreted in all their fulness. It is with central rather than with peripheral capacities that such a problem is ultimately concerned.