Still more ingenious was the "clairvoyance" of the famous American medium Foster, one of the impostors who duped Robert Dale Owen and for years held a high position in the movement. While he was out of the room you wrote on bits of paper the names of your dead relatives or friends, and you then screwed up the bits of paper into pellets. Foster then came in, and sat near you. He dreamily took the pellets in his hand, pressed them against his forehead, and then let them fall again upon the table. Slowly and gradually, as he puffed at his everlasting cigar, the spirits communicated all the names to him. Such tricks can be fathomed only by an expert, and they ought to warn Spiritualists of the folly of thinking that "fraud was excluded." Truesdell, the great medium hunter, the terror of the American Spiritualist world in the seventies, had a sitting with Foster and paid the usual five dollars. He was puzzled, and consented to come again. On the second occasion Foster could tell him, clairvoyantly, the name of his hotel and other details. He had had Truesdell watched in the usual way. At last the detective got his clue. Foster's cigar was continually going out, and in constantly re-lighting it he sheltered the match in the hollow of his hands. Truesdell concluded that he was then reading the slips of paper, and the rest was easy. In pressing the pellets to his forehead Foster substituted blank pellets for them and kept the written papers in his hand. So the next time Truesdell went, and Foster had touched one of the six pellets and read it, Truesdell snatched up the other five pellets and found them blank. Foster genially acknowledged that it was conjuring, but he continued as a priest of the Spiritualist movement for a long time afterwards. Another clairvoyant feat is to read the contents of a sealed envelope, provided the contents are not a folded letter. We shall see in the next chapter how the contents of a folded and sealed letter are learned. I speak here of the simple clairvoyant practice of taking a sealed envelope which contains only a strip of written paper, pressing it to the forehead and reading the contents. You need not pay half-a-guinea to a Bond Street clairvoyante for this. Sponge your envelope with alcohol (which will soon evaporate and leave no trace) and you can "see through it."