The auditory cases are even plainer. For here the hypothesis of points de repere seems quite out of the question. It has never been observed that the hallucinations occur when the attention is being fixed on particular external sounds, or begin or cease synchronously with the beginning or cessation of such sounds; in fact silence seems to be a specially favourable condition for them. The only alternative, therefore, to supposing them to be centrally initiated, is to suppose some abnormality in the external organ itself. Such an abnormality has often been detected; and even when not absolutely detected, it may sometimes be inferred from other symptoms. Thus, an enlarged carotid canal, or a stoppage which produces an unwonted pressure on the vessels, will first make itself felt by hummings and buzzings; hallucination then sets in, and imaginary voices are heard which we should naturally trace to the local irritation that produced the former sounds.2 But the analogy is not obvious.

2The abnormality may be of the most transient kind. Thus on one occasion I myself distinctly traced the illusion of hearing steps accompanying my own to the recurrent variations in the blood-flow of the ear, caused by the very act of stepping. But I may add that hummings are sometimes experienced where no cause whatever can be discovered in the condition of the ear; and thus may possibly themselves be centrally initiated. (See Koppe, Op. cit., p. 50).

In two of the three cases the figure thus seen had peculiarities which made it quite unmistakable, and was observed in the same place more than once during the service, just as any real member of the congregation might have been. The third case is this: between these cases and those where there are no hummings and turnings, and no grounds for supposing that there is a stoppage or lesion of any sort. Among a numerous, though much neglected, class of phenomena - the casual hallucinations of the sane - the commonest form by very far is for persons to hear their name called when no one is by. The experience is often remarkably distinct, causing the hearer to start and turn round. It is not at all connected with conditions that produce blood-pressure, such as lying with one ear closely pressed on the pillow; it comes in a sudden and detached way, and apparently at quite accidental moments. Another experience, which I have myself occasionally had when going to sleep, but without any external pressure on the ear, is for sentences which are floating in one's head to take on a slightly externalised form - a central "illusion hypnagogique," in contrast to the visual sort which are due to the Licht-staub of the retina.

And when we come to insane cases, we find a more positive refutation of peripheral origin. A well-known form of hallucination occurs in the form of dialogue; the patient returns answers to the voices that haunt him, and is answered in turn. He can regulate the course of his own delusion. Dr. V. Parant has recently reported the case of an asylum-patient who, when thwarted or annoyed, would go to special spots to consult imaginary advisers; the replies that she received - it need hardly be said - always corresponded with her own desires and prejudices. Another insane woman used to play "odd and even" with an imaginary prefect of police, whose guesses were always wrong.1 We clearly cannot suppose here an intermittent abnormality of the ear, which always sets in by chance at the very moment when the imaginary speaker's replies fall due. It may be added that even where a distinct morbid cause can be traced, it is as often as not a central cause. After a long course of alcohol a man begins to hear voices; but alcohol, while admittedly affecting brain-tissue, has no recognised tendency to affect the ear.

"I went, as usual, to the school, about a quarter of an hour before service, and either spoke or nodded to all the teachers present. I particularly noticed one in whom I am much interested, sitting with her class, nodded to her, and she smiled back again. Subsequently, in church, I noticed her again, and counted her (I always count my congregations) twice over; once when I counted the entire number present; once when I counted children and adults separately. It turned out, however, that the girl had not been present. I think I was never so surprised in my life. I made several inquiries, but there was no mistake. She had been detained at home, much to her vexation and annoyance, during the whole afternoon on which I had seen her in two different places, and had had my eye upon her, practically, the whole time.'*

Again, we have to remember the clear relation which often exists between sensory hallucinations and more general ideas and delusions.2 This remark, which is a commonplace of alienists, applies far beyond the limits of insanity. One of the commonest incidents of the witch-cases is the apparition of the supposed witch to the victim. The explanation of this phenomenon must surely be sought in the preoccupation of feeble and excitable minds with a particular terrifying subject. And these cases present a further feature, the importance of which has, I think, escaped notice, and which points still more decisively to a purely cerebral origin. They comprise the most remarkable examples on record of hallucinations of pain. The verdict of the victims' senses often was that the witch was not only visibly present, but was torturing them.3 The pains were often distinctly localised, and were specifically described - as beating, scratching, pinching, biting; while the parts affected were, of course, not being externally excited more than any other part of the body.

1Ann. Medico-psych., 6th series, vol. vii., p. 379; Ball, Maladies Mentales, p. 98. See also Kahlbaum, Op. cit., p. 10; the cases described by Michea in the Ann, Medico-psych. for 1856, p. 389; and M. Sandras' own experience in the same journal for 1855, p. 542.

2Ielut,L'Amulette de Pascal, p. 101; Krafft-Ebing,0p.,c#.p. 19; Griesinger, Op. cit., pp. 97-8; Wundt, Op. cit., vol. ii., p. 356; Dagonet, Les Maladies Mentales, p. 94.

3Mather, Wonders of the Invisible World (Boston, 1693), p. 105; Magnolia Christi Americana (London, 1702), pp. 68, 69, 72, 75; Deodat Lawson, Further Account of Tryals of the New England Witches (London, 1693), p. 2; Sadducismus Triumphatus.