From The Arthur Conan Doyle Encyclopedia
Sir, I understand from your columns that Mr. Magee has challenged me to produce Mr. Forbes Winslow's letter in which he disclaimed his previous views upon spiritualism, especially as regards lunacy.
I therefore enclose the essential part of the letter, written in 1912. The allegations quoted by Mr. Magee were made in 1877. The original can be seen at the office of "Two Worlds," 18, Corporation-street, Manchester. It was written in answer to a direct question on the subject from the late J. J. Morse.
I trust that Mr. Magee will apologise, and that he will forward the address of the priest who is alleged to have offered £50 for the production of this document. We may hope that we have now heard the last of the mythical 10,000 lunatics.
ARTHUR CONAN DOYLE