Fierce and rude attacks were made in the columns of _The Boston Courier_, _by these professors_, upon mediums, Spiritualists, and all who had any faith in the phenomena; insinuating at the time that, "If mediums believed in themselves, they would only be too eager to exhibit their powers before those who are most sceptical." In reply to these attacks Dr. Gardner made the following proposition, viz., That a committee of twelve disinterested men shall be selected by the principal editors of _The Boston Journal_, _The Boston Courier_, and _The Daily Traveller_, which committee shall arrange all the preliminaries of the discussion, and decide upon the strength of the arguments, adduced for and against the Spiritual origin of the various forms of manifestations of the present day, usually denominated Spiritual. The challenge to a public discussion was declined, but in lieu of it the following statement appeared in _The Courier_, which was well understood to have proceeded from Professor Felton, of Harvard: "We will pay $500 to Dr. Gardner, to Mrs. Henderson, to Mrs. Hatch, or to Mr. or Mrs. anybody else who will communicate a single word imparted to the 'Spirits' by us, in an adjoining room; who will read a single word, in English, written inside a book, or sheet of paper, folded in such a manner as we may choose; who will answer, with the aid of all the higher intelligences he or she can invoke from the other world, _three questions_--which the superior intelligences must be able to answer, if what they said in _The Melodeon_ was true; and we will not require Dr. Gardner or the mediums to risk a single cent on the experiment. If one or all of them can do one of these things, the five hundred dollars shall be paid on the spot. If they fail, they shall pay nothing; not even the expense incident to trying the experiment." Immediately on receipt of this challenge from the professors, Dr. Gardner replied, "Now, Mr. Editor, I accept the offer, as I do also the distinguished gentlemen named as the committee, provided the person or persons making the offer will agree to let all of the conditions of the arrangement come within the scope of those natural laws within which we believe Spirits are confined in producing the manifestations above referred to; and I will meet the person or persons making the offer at any time and place, after next Sabbath, which he or they may name, to make such arrangements as are necessary to a thorough and scientific test of this great subject. "H. F. GARDNER. "May 27, 1857." The committee named in the _Courier_ was George Lunt (editor of that paper), Prof. Benjamin Pierce, chairman, Prof. Agassiz, Prof. Horsford, and Dr. A. B. Gould. The place of meeting was in the upper room of the Albion Building, corner of Tremont and Beacon Streets, Boston.