Saturday 4 February 2023

Modern Psychic Mysteries and Sir Arthur Conan Doyle’s resignation from the Society for Psychical Research


1 Events at Millesimo Castle

Modern Psychic Mysteries, by Gwendolyn Kelley Hack, is a lengthy record of a series of séances which took place in Italy in 1927-8.  These were arranged by Marquis Carlo Centurione Scotto, resident at the mediaeval Millesimo Castle near Savona in northern Italy.  A medium himself, he participated in the séances in the hope of contacting his son, the Marquis Vittorio dei Principi Centurione, who had died in September 1926 while testing an aeroplane for a Schneider Cup race.  Having read an Italian translation of H Dennis Bradley’s 1924 book Towards the Stars (Verso la Stelle), he had attended séances with American medium George Valiantine at Bradley’s home in Surrey, where he received what he considered strong evidence of Vittorio’s survival.

Valiantine gave the Marquis an aluminium trumpet, suggesting he attempt direct voice mediumship at home.  This he did, and the resulting séances, with himself and Signora Fabienne Rossi acting as mediums, were extremely successful.  Modern Psychic Mysteries (1929) is a compilation of séance reports and commentary assembled by Mrs Hack, one of the sitters and herself a mental medium as well as an artist.

Hack relied heavily on others’ accounts, notably those of Professor Ernesto Bozzano, who also contributed a lengthy preface.  His favourable reports on the sittings had already appeared in the Italian periodical Luce e Ombra.  The structure of the book is chaotic and often prolix and repetitive, but cumulatively it provides a fascinating account, one that was to have far-reaching ramifications beyond the Italian borders.

An extensive range of phenomena was said to have occurred in the dark: the materialisation of hands and feet; the levitation of the Marquis to a height of six feet while sitting in a heavy chair; apports (bulky items that could not easily be concealed within the room) and asports; antique weapons engaging in a noisy battle; the movement of sometimes weighty and bulky objects; direct writing; the movement of a heavy table; thuds and bangs; the playing of musical instruments as they floated.  On one occasion the sitters were creating a favourable atmosphere by singing a fascist song when an illuminated picture of Mussolini was transported from an adjoining room through closed doors.  Curiously, although it arrived intact, a direct-voice trumpet fell on it, breaking the glass.  Perhaps someone present was not a fan of Il Duce.

A flexatone (a ‘musical’ instrument only recently patented) moved through the air while accompanying music playing on the gramophone.  The trumpet flew around, the voices emanating from it speaking a range of languages: Latin, Spanish, German plus five Italian dialects, in one of which a discarnate Eusapia Palladino (died 1918) communicated.  During a session in July, the Marquis suffered terribly from the heat, and when this problem was raised by the sitters a refreshing blast of icy air swept through the room.

An entity identifying itself as Cristo d'Angelo, claiming to have been a Sicilian shepherd, acted as control.  He possessed a range of abilities, such as reading the thoughts of people both during séances and on other occasions, answering questions put mentally, reading messages in sealed envelopes, providing a remote medical diagnosis of leukaemia, plus indicating a cure, making a prediction of death (somewhat dubious ethically), and saying what was happening to circle members when they were elsewhere.

Most famously, on 29 July 1928 the Marquis was transported, or asported, from the locked séance room, necessitating a two-and-a-half-hour search of the castle and grounds.  He was eventually found after Mrs Hack received an automatic message through her spirit guide Imperator supplying his location: he was fast asleep on a pile of hay and oats in a granary within the stables, the door locked from the outside.

Unfortunately, quite often information was withheld by Hack on account of its private nature.  This secrecy was of importance to those concerned but unhelpful to the independent observer, who was prevented from assessing it.  However, enough is presented to establish the phenomena as wide-ranging and dramatic.  Hack was clearly convinced by them, yet it is noticeable from the transcripts that despite the phenomena supporting a paranormal explanation, there were many instances where direct questions were deflected, or evasive answers provided, when there was no reason not to provide the information requested.

Hack conceded that controls had been poor but, working on the assumption she would have been able to detect fraud if it occurred, defended the results on the grounds of the Marquis’s class and amateur private status as a medium, and the impossibility of carrying out the phenomena by fraudulent means in the dark.  She argued that ‘it is possible to conduct a whole series of metapsychic experiments which give solid, scientific proof, without adopting any kind of personal control of the mediums whatsoever.’  It is hardly surprising her critics disagreed.

However, while some may have thought the Marquis had nothing to gain by cheating, not everybody was convinced the séances provided reliable evidence.  Critics included Baron Albert von Schrenck-Notzing, Rudolf Lambert – and Theodore Besterman, whose blistering review of Hack’s book in the SPR’s Journal (of which he was the editor) caused veteran member Sir Arthur Conan Doyle to leave the SPR in high dudgeon.

 

2 Theodore Besterman reviews the book

Besterman dismisses Modern Psychic Mysteries as displaying ‘an almost complete lack of understanding of what constitutes good evidence and adequate recording of mediumistic sittings.’  For those readers who find the 360 pages of Hack’s volume a slog, it is heartening to find Besterman in agreement.  He states that ‘In the present review I take into account only Signor Bozzano's reports. The remainder of the book (with the exception of a few pages by Professor Castellani) is too confused and ill-arranged to be seriously considered, apart from being disfigured by scores of misprints and literal mistakes.’

He notes the lack of controls, with sitters drawn from family and friends in the Marquis’s own home, poor documentation of the séance room and progress of the sessions, doors and windows that would make it hard to secure the environment, and the frequent playing of the gramophone which could cover fraudulent activity.  Bozzano’s claim that the trumpet whirled about with precision is undermined by references to sitters being knocked on the head, and air currents can be generated by the use of balloons.  Besterman wonders how the flexatone was introduced to the circle as Bozzano says no one had heard of it before (it would perhaps be more accurate to say they claimed they had not) and it was difficult to play.

Besterman grumpily thinks that as no information is available on the instrument, and Bozzano fails to describe it adequately, what he has to say about it is hard to evaluate.  If Besterman had had access to YouTube in 1930, he would have found numerous videos describing its operation, allowing him to conclude it is not a particularly difficult instrument from which to coax sounds, though something tuneful might be more challenging.  After exhibiting irritation at the lack of measurements of apports, and pointing out that apports never occurred in the absence of one of the sitters, Signora Rossi, he adds that despite claims of size and weight, they were of sufficient dimensions to allow them to be smuggled in under a woman’s dress.

 His conclusion is devastating:

‘All groups of people have of course the unquestionable right to sit in circles for their own edification; but to put forward such a book as this as a serious contribution to psychical research, and to put it forward with such dogmatic claims of infallibility as Signor Bozzano's, is to bring our subject into contempt and disrepute.’

 

3 The fallout of Besterman’s review

The result of the Besterman review was Conan Doyle’s resignation from the SPR.  The October 2009 issue of Psypioneer reprints Besterman’s review, remarking that while resignations from psychic societies are not uncommon, this is the only known case of one resulting from a book review, though it should be added that the review was not the sole cause.  Charles Higham in his biography of Conan Doyle calls the controversy ‘one of the most tragic events’ in Conan Doyle’s life.

Conan Doyle, who knew the Marquis through his friendship with Bradley, circulated a statement to members, dated January 1930, which was printed in the March 1930 issue of the SPR’s Journal.  A reply by the SPR’s president and hon. secretaries, and another by Besterman, followed.  Conan Doyle’s circular begins by reprinting a letter he had sent to the ‘Chairman of the Council’ (i.e., the president) on 22 January 1930.

In it he attacks Besterman’s review, condemning it for flinging around ‘misrepresentations’, ‘insulting innuendoes’, ‘insolence’ and ‘gratuitous offensiveness’, contrasting Bozzano’s ‘considered opinion’ with Besterman’s general inexperience in psychical research, not to mention non-participation in the séances (though of course the same applied to Conan Doyle).  He stresses the unlikelihood of a man of the Marquis's status, socially and politically, gathering together a group merely to conduct fraud, completely fooling the company, including Bozzano.  To paint such a scenario, he concludes, is ‘the limit of puerile perversity.’

This is merely the opening salvo of a more generalised attack on the SPR’s perceived bias against Spiritualism, or as Conan Doyle puts it, ‘the Podmore, Dingwall, Besterman tradition of obtuse negation,’ which he considers to be getting worse.  He contrasts the SPR’s ‘unscientific’ and ‘anti-spiritualist’ approach with that of a ‘real psychical researcher’, Dennis Bradley.

The SPR in his view had done no positive work for a generation while hindering those who were carrying out research.  He praises the ‘accurate reporting’ of the Millesimo sittings, though as someone himself reliant on second-hand reports he was not in a position to independently gauge how accurate they were.  Having been dissatisfied with the SPR’s direction for some time, Besterman’s review was the final straw, hence his resignation and public protest.

The circular continues in an even more intemperate vein, accusing the SPR, in the hands of a ‘small central body of reactionaries,’ of being actively anti-spiritualist and having done no useful work for many years while ‘hindering and belittling’ those who are conducting ‘real active psychical research.’  Besterman’s review is not an isolated incident: ‘This latest article of Mr Besterman may be insignificant in itself, but it is a link in that long chain of prejudice which comes down from Mr Podmore, Mrs Sedgwick [sic], and Mr Dingwall, to the present day.’  To understand why he considers this episode to be critical, he continues:

‘...these Millesimo sittings are on the very highest possible level of psychical research, both from the point of view of accurate reporting, variety of phenomena, and purity of mediumship. Therefore, if they can be laughed out of court anything we can produce will be treated with similar contempt.’

He wonders whether Besterman had even read the book, enumerating what he judged a number of lapses in the review, having missed Besterman’s statement that he had not bothered, but instead had relied on Bozzano’s articles: not the best way to approach the production of a book review it must be said.  Besterman had suggested that apports could be smuggled in under clothing, but Conan Doyle points out that photographs are included, one of a lance six feet long, and another a plant four and a half feet high.

He says that while Besterman was bemoaning the lack of information on the flexatone, there is a description of it in the book.  Besterman, Conan Doyle concludes, is a ‘slovenly critic.’  Finally, having had enough and despairing of reform, he announces his departure and calls on like-minded individuals to follow his example, recommending the British College of Psychic Science (the organisation run by James Hewat McKenzie and Barbara McKenzie) as a more congenial alternative.

The reply by the president, Sir Lawrence J Jones, and the hon. secretaries, Eleanor Sidgwick and W H Salter, begins by stating a wish to avoid entering the controversy on the grounds of Conan Doyle’s lengthy membership, his eminence, and his ill health, but his circular, with its call for mass resignation, required a response.  This naturally consisted of a stout defence of the Society, reminding readers of the work done in recent years, thereby contradicting Conan Doyle’s claim that the SPR had carried out no constructive activities.  The authors also pointed out that members encompassed a broad range of views ‘from complete acceptance to total denial,’ and all contributions to its publications were the responsibility of their authors; hence Besterman’s views were his own, though they were not impressed by the claims made in the book either.

Besterman then makes his own reply, taking issue with Conan Doyle’s defence of Bozzano’s ‘considered opinion’ and stressing that what was at issue was not opinion but facts.  He picks apart Conan Doyle’s allegations, showing his review to have been misrepresented in its details, such as the size of the apports and how the air current was produced, but still focusing on Bozzano’s articles rather than Hack’s book more generally.  Whereas Conan Doyle feels the sitters were critical in their approach, Besterman believes them to have been the opposite.

The ‘Podmore, Dingwall, Besterman tradition of obtuse negation’ he considers to be Conan Doyle’s invention, though to rub salt in the wound, he adds how much he admires Frank Podmore’s methods.  Of the flexatone, he says his review stated not that it had not been described but that it had not been illustrated or adequately described.  (While an illustration of this novel instrument would have been useful, there is in fact enough description for the reader to obtain a fairly clear idea of how it worked, but probably not enough to appreciate that it was simpler to play than claimed.)  Besterman’s firm defence of his review, contradicting Sir Arthur’s condemnation point by point, was not designed to mollify his stern critic.

The Daily Express picked up on the controversy and published an article on 19 March 1930.  The journalist sought a comment from Besterman who said that just six members had followed Sir Arthur’s exit, and only two of them had specifically referred to the dispute.  After reprinting extracts from Conan Doyle’s letter and the SPR response, Conan Doyle tells the journalist that he is ‘not at all bitter about the matter,’ though he clearly was, concluding ‘We want more experiments and knowledge, and to secure that I think it is necessary for the society to have more sympathetic people in the seats of the governors.’  In other words, people with views similar to his own.

Elizabeth Savage, in a blog post on the Cambridge University Library Special Collections website concerning Conan Doyle’s resignation, alludes to the private debate the letter generated between the SPR’s officers.  In public they tried to make light of the affair by calling it ‘a very trivial matter,’ expressing confidence in the management of the SPR and noting the differing views on Spiritualism within the Society but an atmosphere of tolerance.  While trying to minimise the impact, they were right to be wary of the negative publicity the controversy would generate.

The May 1930 number of the Spiritualist International Psychic Gazette blared: ‘’The Crisis in the Society for Psychical Research. Hearty Support for Sir A. Conan Doyle.’  Salter had the task of defending the Society, and he claimed the SPR had in fact received a number of letters from ‘prominent Spiritualists’ disapproving of Sir Arthur’s action and defending the SPR’s methods.  If the claim was true, they were doubtless outweighed by the volume of criticism, which the International Psychic Gazette was happy to share.  It was clear the dissatisfaction ran deeper than anger at Besterman, as a number of other comments critical of the SPR were made by correspondents.  Added to the members who resigned in support of Conan Doyle, a number said they had either resigned some time earlier, or did not intend to renew their membership, thus leaving without submitting a resignation.

Conan Doyle includes the teleportation in The Edge of the Unknown (1930), in which he compares the Marquis’s passage through solid objects and reassembly on the other side to Houdini’s abilities as an escapologist, not though because he saw the Marquis as fraudulent but because he considered Houdini to possess psychic abilities.  He calls the witnesses to the teleportation ‘first-class’, and continues to take Hack’s description at face value; he does not consider that ‘several locked doors’ might present little difficulty to the building’s owner.  Nandor Fodor in the Encyclopaedia of Psychic Science (1933) dedicates a column to the Marquis, beginning by calling him ‘a medium of the Italian nobility’ and referring to his ancient lineage, thereby hinting he is above reproach.  In the lengthy section devoted to transportation, Fodor describes the Marquis’s as ‘the best authenticated recent case.’

 

4 Later discussion

The SPR found an ally in Harry Price, who covers what he calls ‘The Conan Doyle uproar’ in his Fifty Years of Psychical Research (1939).  Though he does not name Besterman, his sympathies, he says, are entirely with the SPR, and the book ‘deserved all that was said about it.'  He adds he had taken a similar stance in a review he had written for an American monthly, ‘but in more polite language.’  By ‘American monthly’ Price presumably meant the ‘International Notes’ he contributed to the American Society for Psychical Research’s Journal, of which he was the Foreign Research Officer.  In the January 1930 issue he spends a couple of paragraphs on the book, criticising it for lacking an index (a significant issue given the unhelpful manner of the book’s organisation), adding ‘the book is full of errors of description and of fact,’ though he does not delve into details.  He concludes that ‘the method of presenting that information to the reader leaves much to be desired.’

Fodor’s Encyclopedia of Psychic Science puts the number of resignations following Conan Doyle’s at 84. The figure is repeated in a potted biography taken from the encyclopaedia included in a 1948 Lily Dale reprint of Conan Doyle’s What Does Spiritualism Actually Teach and Stand For?  Mauskopf & McVaugh (1980) put the figure at 77.  That both might actually be an underestimate (and Besterman’s six simply a number he plucked out of the air to demonstrate the futility of Conan Doyle’s act) can be gauged by figures provided by Price in Fifty Years showing, whether or not directly attributable to Conan Doyle’s actions, the period saw a dramatic decline in SPR membership, though this had begun prior to his resignation.  As Price put it in 1939:

‘The Doyle resignation was rather in the nature of a test as to whether members approved of the way in which the Society was managed. There were resignations. In 1920, there were 1,305 members and associates; in 1931, the number had fallen to 954. In 1932, the number was 809. The latest figures, just published, show a grand total of 699 members and associates. Excluding subscribing libraries, the number is 636.’

The comments in the International Psychic Gazette expressed by members supporting Conan Doyle alluded to a dissatisfaction with the direction the SPR had taken, and it appears this unhappiness was shared, for whatever reason, by other members; such certainly is the implication of Price’s figures.  It should be borne in mind, however. that the economic situation in the 1930s was not favourable, and many may have left for financial reasons rather than because they disliked what they read in the Journal and Proceedings.  While it is clear Conan Doyle’s resignation acted as a catalyst, it is not possible to put a figure on the number who followed his example as a direct result of his act.

Following the Psypioneer reprint of Besterman’s review is an article on the Marquis’s transportation by Masimo Biondi (2009).  An editorial note prefacing Biondi’s article states there had been no further discussion of the matter in the SPR publications since 1930.  For some reason, Biondi gets the date of the Marquis’s famous transportation wrong, giving it as 18 July 1929 instead of 29 July 1928.

After noting Bozzano’s exaggerated claim for the flexatone’s difficulty, Biondi draws attention to a letter written in 1945 by Count Piero Bon – who was present at a number of the séances, including the one in which the Marquis asported – to leading Spiritualist Gastone De Boni.  De Boni (whom Luca Gasperini (2011) calls Bozzano’s ‘disciple’) had inherited Bozzano’s library and papers on the latter’s death in 1943.

According to this letter, Bon and Mrs Hack visited the castle the day after the Marquis’s disappearance and were shown into the séance room to wait for him.  Bon spotted a patch of light shining through a tapestry from a concealed door which had been left open, and when the Marquis came into the room he was furious about it.  Bon says the sitters were unaware of the door’s existence behind the wall covering.

Crucially, the door led to the dining room and was close to the sofa on which the Marquis had been sitting.  Bon later checked the tapestry and found the door could easily be opened, and a table by the sofa had been moved as if it had been pushed by someone (i.e., the Marquis) moving past it in the dark.  The Marquis was wearing felt slippers, a detail not in Hack's book.  Thus, Bon concluded, not only could the Marquis have left the room unnoticed, but apports could easily be introduced and removed later, constituting ‘a vile deception.’

Biondi comes down on Besterman’s side in the dispute with Conan Doyle over Bozzano’s reports, concluding the Marquis’s vanishing was merely a deception.  Biondi adds that Bon did not make this information public; neither did De Boni, a curious omission, especially as he wrote a book which discussed events at the castle.  Biondi shows a photograph of the outside of Millesimo Castle, taken probably in the 1970s but showing a structure little changed since the 1920s.  It is striking how close the séance room and the room where the sleeping Marquis was found are.  Once away from the other sitters, he could have crept down to his hiding place quickly and with little fear of detection.

It is surprising the hidden door was not known about by sitters, as a cursory inspection of the room should have revealed it.  Perhaps such an inspection would have been considered impolite.  Bozzano was supposed to check the room before each séance, but he may not have thought to look behind the hangings, though a failure to do so makes one wonder what else he might have failed to observe.

Hack does not refer to the discovery in Modern Psychic Mysteries, though according to Bon she was present, and neither of them seems to have told Bozzano this key piece of information, or if they did he suppressed it.  On the other hand, Besterman deduces in his review that the room had doors on three sides and a window on the fourth, already offering plentiful possibilities for cheating, so it is possible other sitters, including Hack, did know about the door but assumed the Marquis would not lower himself to use it.  Hack’s mediumistic information providing the information that the Marquis was asleep in the granary may perhaps indicate she was conspiring with him, in which case she would already have known about the door when she and Bon saw the light through the tapestry.

Besterman highlights the presence of Signora Rossi coinciding with the occurrence of apports, meaning she could be responsible for their introduction, while Conan Doyle in turn dismisses the idea of bulky objects being smuggled in under a modern short dress (a reasonable defence, even if it was a longer evening dress), but there was no need to secrete them under clothing if they could be brought in through a door.  Either way, she may have been assisting the Marquis in fraud.  And it is worth bearing in mind that just before the Marquis’s disappearance he was holding Signora Rossi’s hand before – he said – he lost consciousness.  She could have told the company she was still holding his hand while he was making his way to the granary.

It is worth remembering when assessing his accusation of fraud that Bon, a political opponent of the Marquis (who was active in fascist politics), was privately reporting an event which had occurred 16 years earlier.  His claim should consequently be treated with caution, but the passing of objects through it into and out of the séance room by ordinary means, however achieved, seems a more parsimonious explanation than their paranormal materialisation and dematerialisation.

Biondi surmises that Besterman did not touch on the Marquis’s vanishing because he did not consider anything Bozzano said to have any value (his review merely picked out a few incidents at random), but Biondi adds: ‘However, generations of spiritualists, in Italy and abroad, judged the “Centurione’s vanishing” as a wonderful and beautiful mediumistic phenomenon, one of the most important ones of the whole history of mediumship.’

Yet Gasperini in his biographical sketch of Bozzano indicates his unscientific approach, because when he attended the séances he was ‘already profoundly convinced of the reality of the facts to which he would have attested, and of the authenticity of the mediums.’  Further, the participants’ class told in their favour, Hack and Bozzano assuming that members of the aristocracy and their guests would not fabricate evidence.

The Marquis clearly considered that as an aristocrat and gentleman, his word was effectively his bond.  With his public profile as a senator, he would have had much to lose by being exposed as a fraud.  On the other hand, this assumption militated against the imposition of rigorous controls, and the temptation to allow the benefit of the doubt in questionable situations, which would have worked in his favour and minimised the risk of exposure.

In a review of Brian Inglis’s 1984 survey Science and Parascience in the SPR Journal, Carlos Alvarado (1985) says that Besterman’s review of Hack’s book ‘presents several good criticisms, although it can be said that Besterman overdoes his points and presents them in too harsh a style.’  It should be added that while it may be thought Besterman’s criticisms had some merit, they would have carried greater weight not only if he had tempered his language, but had actually read the book.  Inglis in Science and Parascience accurately describes Besterman as belonging to the ‘High-and-Dry’ element of the SPR, impatient with those who did not share his views.

The controversy, and resulting publicity, did Modern Psychic Mysteries no harm.  In the August 1930 issue of the American Society for Psychical Research’s Psychic Research, Price mentions in passing the controversy within the SPR, but mainly focuses on the claim that the book had brought latent interest in psychic research in Italy into the open.  John Lewis, the editor of the International Psychic Gazette was invited to visit Hack in Italy in 1934, and calls Modern Psychic Mysteries ‘Mrs Hack’s famous book.’  This was surely a degree of fame it would not have achieved without the fallout from Besterman’s review.  (Incidentally, Besterman’s Polish origin is referred to more than once in the Gazette, injecting a racist element into the defence of the sittings he critiqued.)

As for Sir Arthur, after he died the brief notice in the October 1930 issue of the SPR’s Journal was as generous as could be expected in the circumstances:

‘We regret to record the death on 7 July (after the July issue of the Journal had gone to Press) of Sir Arthur Conan Doyle, who became a Member of the Society in 1893. Sir Arthur resigned his membership a few months ago in circumstances known to our readers; at this time we wish only to pay a tribute to the manifest sincerity and enthusiasm invariably shown by him in respect of any cause that he had at heart.’

 

References

Alvarado, Carlos. Review of Science and Parascience: A History of the Paranormal, by Brian Inglis, Journal of the Society for Psychical Research, Vol 53, June 1985, pp. 100-108.

Besterman, Theodore. Review of Modern Psychic Mysteries, Millesimo Castle, Italy, by Gwendolyn Kelley Hack, Journal of the Society for Psychical Research, Vol. 26, January 1930, pp. 10-14. Reprinted in Psypioneer, Vol. 5, No. 10, October 2009, pp. 324-328.

Besterman, Theodore. ‘Reply by Mr Besterman’, Journal of the Society for Psychical Research, Vol. 26, March 1930 (dated 14 February 1930), pp. 50-52. Reprinted in Psypioneer, Vol. 5, No. 8, August 2009, pp. 268-69.

Biondi, Massimo. ‘The Strange Case of the Marquis’ Transportation’, Psypioneer, Vo. 5, No. 10, October 2009, pp. 328-333.

‘Conan Doyle’s “Spirit” Protest’, The Daily Express, 19 March 1930.

‘The Crisis in the Society for Psychical Research. Hearty Support for Sir A. Conan Doyle.’  The International Psychic Gazette, vo. 18 no. 200, May 1930, p. 1. Reprinted in Psypioneer, Vol. 5, No. 8, August 2009, pp. 258-263.

Doyle, Arthur Conan. ‘Sir Arthur Conan Doyle’s Circular’, Journal of the Society for Psychical Research, Vol. 26, March 1930 (dated January 1930), pp. 45-48. (Includes letter from Sir Arthur Conan Doyle to the president of the SPR, dated 22 January 1930.) Reprinted in Psypioneer, Vol. 5, No. 8, August 2009, pp. 264-66.

Doyle, Arthur Conan. The Edge of the Unknown. London: John Murray, 1930.

Doyle, Arthur Conan. What Does Spiritualism Actually Teach and Stand For? Lily Dale, New York: Dale News, 1948.

Fodor, Nandor. Encyclopaedia of Psychic Science, London: Arthurs Press, 1933.

Gasperini, Luca. ‘Ernesto Bozzano: An Italian Spiritualist and Psychical Researcher’, Journal of Scientific Exploration, Vol. 25, No. 4, 2011, pp. 755-773.

Hack, Gwendolyn Kelley. Modern Psychic Mysteries: Millesimo Castle, Italy, London: Rider & Co., 1929.

Higham, Charles. The Adventures of Conan Doyle: The Life of the Creator of Sherlock Holmes, London: Hamish Hamilton, 1976.

Inglis, Brian. Science and Parascience: A History of the Paranormal, 1914-1939, London: Hodder and Stoughton, 1984.

Jones, Lawrence J., Sidgwick, Eleanor and Salter, W. H. ‘Reply by the president and hon. Secretaries’, Journal of the Society for Psychical Research, Vol. 26, March 1930 (dated 14 February 1930), pp. 48-50. Reprinted in Psypioneer, Vol. 5, No. 8, August 2009, pp. 266-268.

Lewis, John. ‘Our Italian Notebook’, The International Psychic Gazette, vol. 22, no. 249, June 1934, pp. 129-130.

Mauskopf, Seymour H., McVaugh, Michael R. The Elusive Science. Origins of Experimental Psychical Research. Baltimore: John Hopkins University Press, 1980.

‘Obituaries’. Journal of the Society for Psychical Research, Vol. 26, October 1930, p. 116.

Price, Harry, ‘International Notes’, Psychic Research (Journal of the American Society for Psychical Research), Vol. 24, No. 1, January 1930, pp. 39-44.

Price, Harry, ‘International Notes’, Psychic Research (Journal of the American Society for Psychical Research), Vol. 24, No. 8, August 1930, pp. 377-84.

Price, Harry, Fifty Years of Psychical Research: A Critical Survey, London: Longmans, Green and Co., 1939.

Savage, Elizabeth, ‘Challenging Challenger: The Fallout between Sir Arthur Conan Doyle and the Society for Psychical Research’, Cambridge University Library Special Collections, 4 April 2019 (retrieved 12 December 2022).

‘Sir Arthur Conan Doyle’s resignation’, Journal of the Society for Psychical Research, Vol. 26, March 1930, p. 45.  Reprinted in Psypioneer, Vol. 5, No. 8, August 2009, pp. 263-64.