It ought to be understood that the sanction given by the spirits whose names are attached to the preceding certificate, was obtained under test conditions, as explained in paragraph bb., dd., in the description of Plate iv. Moreover, I placed my hand on the instrument illustrated by Fig. 2 in same plate, so as to question the spirits directly as to the reliability of the affirmation, previously given to me, and the fidelity of the medium generally. In both cases the index moved so as to give an affirmative reply. SUPPLEMENTAL PREFACE. The most precise and laborious experiments which I have made in my investigation of Spiritualism, have been assailed by the most disparaging suggestions, as respects my capacity to avoid being the dupe of any medium employed. Had my conclusions been of the opposite kind, how much fulsome exaggeration had there been, founded on my experience as an investigator of science for more than half a century! And now, in a case when my own direct evidence is adduced, the most ridiculous surmises as to my probable oversight or indiscretion are suggested, as the means of escape from the only fair conclusion. Having despatched a spirit friend from Cape Island, at one o’clock on the third of July, to request Mrs. Gourlay, in Philadelphia, to send her husband to the bank to make an inquiry, and to report the result to me at half-past 3 o’clock, the report was made to me as desired. The subject was not mentioned until after my return to Philadelphia, when, being at the residence of Mrs. Gourlay, I inquired of her, whether she had received any message from me during my absence? In reply, it was stated that while a communication from her spirit mother was being made to her brother, who was present, my spirit messenger interrupted it to request her to send her husband to the bank to make the desired inquiry: that, in consequence, the application was made at the bank. The note-clerk recollected the application to him, but appeared to have considered it as too irregular to merit much attention. Hence the impression _received_ by the applicants, and communicated to me, was not correct. But as it did not accord with that existing in my memory, it could not have been learned from MY mind. Wishing to make this transaction a test, I was particularly careful to manage so that I might honourably insist upon it as a test; and, until I learned the fact from Mrs. Gourlay and from the note-clerk that the inquiry was made, it did not amount to a test manifestation. But, if I had been ever so indiscreet, would it not be absurd to imagine a conspiracy between any person at Cape Island with Dr. and Mrs. Gourlay, her brother, and the note-clerk at the bank, to deceive me on my return by concurrent falsehoods?