Slade, Henry (d. 1905)
Controversial American medium, best known for his slatewriting
phenomena. He was familiar to the American public
The Skeptic Encyclopedia of Occultism & Parapsychology 5th Ed.
for 15 years when the choice fell on him to demonstrate paranormal
phenomena in St. Petersburg, Russia, before the investigators
of the university of that city. Helena Petrovna Blavatsky
and Henry S. Olcott, cofounders of the Theosophical
Society, were asked to find a suitable medium and sit with him
for weeks. They testified to messages inside double slates,
sometimes tied and sealed together, while they either lay upon
the table in full view of all, or were laid upon the heads of members
of the committee, or held flat against the under surface of
the table-top, or held in a committee mans hand without the
medium touching it.
En route to Russia, Slade arrived in England on July 13,
1876. He gave many sittings in London and was examined by
both Spiritualists and non-Spiritualists. Besides slate writing he
produced partial materializations and strong telekinesis phenomena.
Observers reported seeing tables being moved, matter
passing through matter, levitation, and musical instruments
played by invisible hands. For six weeks all went well, his
fame spread, and J. Enmore Jones, the editor of The Spiritual
Magazine, declared that he was taking the place vacated by the
great medium D. D. Home. The World wrote in a long article
on August 30, 1876
Then came more and violent knockings at the table, a chair
at the farthest corner from Dr. Slade was lifted rapidly in the
air and hurled to the ground without visible agency. My coat
and trousers were plucked violently, and I was pinched and patted,
all with great rapidity, and in quarters which it seemed absolutely
impossible Dr. Slade could reach. A hand appeared
and disappeared fitfully, but with unmistakable reality, close to
me; and when the slate was produced with a similar crumb of
pencil, once on it when it was held under the table, and once
under it when it was placed on the table, messages of various
kinds were inscribed rapidly and in different handwritings.
One, the longest, was of a religious character, and inculcated
the usual religious lessons. Others were in reply to questions in
which I pressed hard for a communication on some subject
which could be only known to myself.
The article on the séance at which the reporter was alone
with Slade and, presumably from the context, in daylight, concluded
I had not, and have not, a glimmering of an idea how
the effects described had been produced, and I came away inexpressibly
puzzled and perplexed.
Slade was visited by men of science who were unable to explain
what they saw. Lord Rayleigh stated at a meeting of the
British Association for the Advancement of Science in September
1876 that he had attended a séance with Slade in the company
of a professional conjurer, who admitted that he was completely
puzzled. Slade convinced Alfred Russel Wallace of his
genuine powers and finally solved the doubts of skeptic
Frank Podmore as to the truth of Spiritualism.
Podmore, author of the skeptical work Modern Spiritualism
(1902), preserved silence in his later writings over this stage of
his beliefs, but he frankly admitted that he was profoundly impressed
by Slades performance.
Then, early in September 1876, at the peak of his fame,
Slade was entangled in a serious controversy with accusations
of fraud. Ray Lankester, who was outvoted as a member of the
Selecting Committee of the British Association for the Advancement
of Science when William F. Barretts paper on Spiritualism
was admitted, intended to strike a deadly blow at this
new superstition and when Edward William Cox told him of
the puzzling slate-writing demonstrations of Slade, he went to
Slade with his friend Dr. Donkin determined to unmask the
medium at whatever cost.
He paid the usual fee of a pound, and in the second sitting
he suddenly seized the slate before the writing was supposed to
have taken place. He found a message ready, published his exposure
on September 16 in The Times, and brought an action
against the medium for obtaining money under false pretenses.
Over this exposure a fierce controversy ensued. Besides
Lankester the skeptics were represented by Henry Sidgwick,
R. H. Hatton, Edmund Gurney, and W. B. Carpenter. According
. . . the Spiritualists were perhaps justified in not accepting
the incident as conclusive. Slade defended himself by asserting
that, immediately before the slate was snatched from his hand,
he heard the spirit writing, and had said so, but that his words
were lost in the confusion which followed. If we grant that
Slades testimony was as good as Prof. Lankesters or Dr.
Donkins it was difficult summarily to dismiss this plea.
The case came up for trial at the Bow Street Police Court,
London, on October 1, 1876. Evidence in favor of the genuineness
of Slades mediumship was given by Wallace, Cox, and
George Wyld. Only four witnesses were allowed. The magistrate
overruled their evidence, saying that he must base his decision
on inferences to be drawn from the known course of nature,
and, on the ground of the deposition of Lankester and
Donkin, he sentenced Slade, under the Vagrancy Act, to three
months imprisonment with hard labor.
In the course of the appeal, the conviction was nullified on
technical grounds and Slade quickly left for the Continent before
Lankester could obtain a fresh summons. However, Slade
wrote from Prague, Czechoslovakia, offering exhaustive private
tests to Lankester if he would let him come. To this he received
no answer, nor did Slade come to London again until 1878,
and later in 1887 under the assumed name of Dr. Wilson.
Armed with many testimonies of Spiritualists and other people
of distinction against the blot of the conviction, Slade spent
interesting months on the Continent in the Hague, in Berlin,
and in Denmark. In Berlin, Bellachini, the famous conjurer,
testified on oath to his powers.
In St. Petersburg the séances were satisfactory, but owing to
the disturbed state of Russia the investigation did not assume
the character originally intended. A successful sitting was given
to the Grand Duke Constantine in the presence of Alexander
Aksakof and one Professor Boutlerof. According to an account
there had been accidentally two bits of pencil on the slate.
When he held it under the table the writing of two pencils was
heard at the same time and when he drew out the slate it was
found that one pencil had written from left to right, the other
from right to left.
In December 1877, the experiments of Johann Zöllner,
well-known in psychical literature, commenced in Leipzig. Zöllner
hoped to establish his theory of four-dimensional space.
Professors Fechner, Scheibner, and Weber participated in the
investigation. Writing on sealed slates was produced under the
strictest test conditions, knots were tied on an endless string,
there were remarkable displays of force, and the apparent penetration
of matter through matter was several times demonstrated.
After this brilliant success, Slade went to Paris and placed
himself at the disposal of Camille Flammarion, but I obtained
nothing certain, stated Flammarion. He added
In the cases that did succeed, there was possible substitution
of slates. Tired of so much loss of time, I agreed with Admiral
Mouchez, director of the observatory of Paris, to confide to
Slade a double slate prepared by ourselves, with the precautions
which were necessary in order that we should not be entrapped.
The two slates were sealed in such a way with paper
of the observatory that if he took them apart he could not conceal
the fraud. He accepted the conditions of the experiment.
I carried the slates to his apartment. They remained under the
influence of the medium, in this apartment, not a quarter of an
hour, not a half hour or an hour, but ten consecutive days, and
when he sent them back to us there was not the least trace of
Charles Richet writes of the same period
I saw Slade once with Gibier. Slade handed me a slate and
put a small fragment of a slate-pencil on it. I held one end and
Slade the other, and we put the slate under the table. In a few
moments we heard a noise as of writing. There was some writing
and the bit of slate-pencil was worn. But I give this experiEncyclopedia
of Occultism & Parapsychology 5th Ed. Slade, Henry
ment (my only one of the kind) under all reserves (1) It was
long ago; (2) I cannot find the notes I took; (3) Slades honesty
is open to question; and (4) Experiments with slates lend themselves
The next stage of Slades career was his visit to Australia. His
activities there were recorded in a book by James Curtis titled
Rustlings in the Golden City (1894).
In 1885, he appeared before the Seybert Commission in
Philadelphia. He was caught in glaring fraud. On one occasion,
the sitters distinctly saw that his foot, before he had time to get
it back into its slipper, was the instrument of claimed telekinetic
phenomena. Once a slate, resting against the leg of the table,
was upset by a sitter. It was seen that it had a message on it prepared
The writing obtained was generally of two kinds. The general
messages were very legible and clearly punctuated, but when
the communication came in answer to questions it was clumsy,
scarcely legible, abrupt and vague. It bore traces of hasty work
under difficult conditions, as these impromptu messages could
not be prepared in advance.
According to the Seybert Committees report, Slade declared
that Zöllner watched him closely only during the first
three or four sittings, but afterward let him do as he pleased.
This was the starting point of Fullertons trip to Germany to interview
Zöllners surviving colleagues in an attempt to discredit
his favorable findings.
The exposure by the Seybert Commission was preceded by
J. W. Truesdells revelations. In Bottom Facts of Spiritualism
(1883), he claimed to have caught Slade in cheating and narrates
an amusing incident. He had discovered a slate with a
prepared message in the séance room. He stealthily added another
message of his own Henry, look out for this fellow; he
is up to snuffAlcinda. He says that he enjoyed Slades discomfiture
when, at the appropriate moment, the unrehearsed
message came to light.
Another highly damaging incident was recorded on February
2, 1886, in the Boston Herald, namely an account of the denunciation
of Slade as an impostor in Weston, West Virginia.
Both Slade and his business manager were arrested but they
were afterward released without prosecution.
During the last years of his life Slade fell victim to alcohol
addiction; his moral standing was far from high, and he sank
lower and lower. He died penniless and in mental decrepitude
in a Michigan sanatorium in 1905.
Curtis, James. Rustlings in the Golden City. Ballard, 1894.
Podmore, Frank. Modern Spiritualism. London Methuen,
1902. Reprinted as Mediums of the Nineteenth Century. New Hyde
Park, N.Y. University Books, 1963.
Truesdell, J. W. Bottom Facts of Spiritualism. New York, 1883.
Slade, Henry (d. 1905)