Let us now turn to another bright and classical page in the history of Spiritualism: the experiments of Professor Zöllner with the medium Slade. Sir A. C. Doyle granted in the Debate, with an air of generosity, that Slade "cheated occasionally," but he insisted that Slade's phenomena in the house of Professor Zöllner were genuine. Now, as long as Sir A. C. Doyle does this kind of thing, as long as he assures his readers that he will not build on any medium who has been convicted of fraud and then builds on such a medium, as long as he tells his readers (who will not check the facts) that a medium who was exposed over and over again merely "cheated occasionally," it is no use for him to assert that he is trying to purge Spiritualism of fraud. Slade was a cynical impostor from beginning to end of his career. I will show in the next chapter but one how Slade confessed his habitual fraud as early as 1872, how he was exposed and arrested in London in 1876, and how he was exposed again in Canada in 1882 and in the United States in 1884. A word about the last occasion will suffice for my purpose here. Henry Seybert, a Spiritualist, left a large sum of money to the University of Pennsylvania on the condition that the University authorities would appoint a commission to examine into (among other things) the claims of Spiritualism. They did; and it was the most unlucky inspiration the ghosts of the dead ever conveyed. Very few mediums would face the professors, and those who did were shown to be all frauds. Slade was one of these, and the Pennsylvania professors, wondering how any trained man could be taken in by so palpable a fraud, sent a representative to Leipsic to investigate the experiences of Professor Zöllner and the three other German professors who had endorsed Slade. The gist of his report was that of the four professors one (Zöllner) was in an early stage of insanity (he died shortly afterwards), one (Fechner) was nearly blind, the third (Weber) was seventy-four years old, and the fourth (Scheibner) was very short-sighted, yet did _not_ (as Sir A. C. Doyle says) entirely endorse the phenomena!