Leslie Kean writes in Surviving Death: “Trance medium Leonora E. Piper (1857-1950) of Boston was studied so extensively that the few volumes of case records are still unsurpassed in quantity and detail. She is also one of the very few mediums whose trance speech and writings have been subjected to a serious and extensive psychological analysis.
“Mrs. Piper was ‘discovered’ for psychical research by William James of Harvard University, arguably the greatest psychologist of that or perhaps any time. James was sufficiently impressed by his sittings to send some twenty-five other persons to her under pseudonyms. In the spring of 1886, he wrote an account of the results and stated, ‘I am persuaded of the medium’s honesty, and of the genuineness of her trance. I now believe her to be in possession of a power as yet unexplained.’
“The general procedure at a sitting would be this: Mrs. Piper would pass into a trance. There was never the least doubt that the trance state was, in some sense, ‘genuine’—William James and G. Stanley Hall, another well-known American psychologist, demonstrated that Mrs. Piper could be cut, blistered, pricked, and undisturbed by a bottle of strong ammonia held under her nose. (The test were so stringent that Mrs. P. complained bitterly about their painful aftereffects.)
"After a few minutes, Mrs. Piper would begin to speak with the voice of her control, who gave the name of ‘Dr. Phinuit.’ A soi-distant French doctor with scanty knowledge of the French language, Phinuit spoke in a gruff, male voice and made use of Frenchisms, slang, and swearwords, in a manner quite unlike that of the awake Mrs. Piper. Phinuit would give sitters accounts of the appearances and activities of deceased (and sometimes also of living) friends and relations, and would transmit message from them, often with appropriate gestures.
"On an off day, Phinuit would ramble, flounder hopelessly, and fish for information, and if given any, would blatantly serve it up again as though it had been his own discovery. But when he was on form he could, with hardly any hesitation, relay copious communications from the deceased friends and relatives of sitters, communications that would turn out to be very accurate even in tiny details, and far too accurate for the hypothesis of chance or of guesswork based simply on the appearance of the unnamed sitters, to seem in the remotest degree plausible.
"As a result of a report by William James, a leading member of the British Society for Psychical Research (SPR) and an expert in the unmasking of fraud, Richard Hodgson (1855-1905), went to Boston in 1887 and assumed charge of the investigation of Mrs. Piper. He arranged for the careful recording of all sittings and took the most extensive precautions against trickery. Sitters were introduced anonymously or under false names and were drawn from as wide a range of persons as possible. For some weeks Mrs. Piper was shadowed by detectives to ascertain whether she made inquiries in the affairs of possible sitters, or employed agents to do so. She was brought to England where she knew no one and could have had no established agents; her sittings were arranged and supervised by leading members of the SPR. Sitters were for the most part introduced anonymously, and comprehensive records were kept. And still Mrs. Piper continued to get results.
"The thought of fraud was never far from Mrs. Piper’s early investigators. The case against it was powerfully summarized in 1889 by Frank Podmore, a highly skeptical writer, who points out that despite careful overseeing amounting at times to invasion of privacy, Mrs. Piper had never once been detected being dishonest. Yet successful communicators often addressed sitters in exactly the right tone and might unmistakably refer to trivialities of a wholly private significance. The charge of credulity, said Podmore, rested with those who, without consideration and without inquiry, could lightly attribute all the results to imposture."
Leslie Kean, Surviving Death: A Journalist Investigates Evidence for an Afterlife (Three Rivers Press, 2017).