of which Dr. Osty speaks.

10

I consider it necessary to declare for the last time that these
psychometric phenomena, astonishing though they appear at first,
are known, proved and certain and are no longer denied or doubted
by any of those who have studied them seriously. I could have
given full particulars of a large number of conclusive
experiments; but this seemed to me as superfluous and tedious as
would be, for instance, a string of names of the recognized
chemical reactions that can be obtained in a laboratory. Any one
who pleases is at liberty to convince himself of the reality of
the facts, provided that he applies to genuine mediums and keeps
aloof from the inferior "seers" and especially the shams and
imposters who swarm in this region more than in any other. Even
with the best of them, he will have to be careful of the
involuntary, unconscious and almost inevitable interference of
telepathy, which is also very interesting, though it is a
phenomenon of a different class, much less surprising and
debatable than pure psychometry. He must also learn the art of
interrogating the medium and refrain from asking incoherent and
random questions about casual or future events. He will not
forget that "clairvoyance is strictly limited to the perception
of human personality," according to the role so well formulated
by Dr. Osty. Experiments have been made in which a psychometer,
on touching the tooth of a prehistoric animal, saw the landscapes
and the cataclysms of the earth's earliest ages displayed before
his eyes; in which another medium, on handling a jewel, conjured
up, it would seem with marvellous exactness, the games and