illustrating it and applying it in the most diverse domains. He began,
as we have seen, with physical principles; he determined the numerical
relation between heat and work; he revealed the source of the energies
of the vegetable world, and showed the relationship of the heat of our
fires to solar heat. He followed the energies which were potential in
the vegetable, up to their local exhaustion in the animal. But in
1845 a new thought was forced upon him by his calculations. He then,
for the first time, drew attention to the astounding amount of heat
generated by gravity where the force has sufficient distance to act
through. He proved, as I have before stated, the heat of collision of
a body falling from an infinite distance to the earth, to be
sufficient to raise the temperature of a quantity of water, equal to
the falling body in weight, 17,356°C. He also found, in 1845, that
the gravitating force between the earth and sun was competent to
generate an amount of heat equal to that obtainable from the
combustion of 6,000 times the weight of the earth of solid coal. With
the quickness of genius he saw that we had here a power sufficient to
produce the enormous temperature of the sun, and also to account for
the primal molten condition of our own planet. Mayer shows the utter
inadequacy of chemical forces, as we know them, to produce or maintain
the solar temperature. He shows that were the sun a lump of coal it
would be utterly consumed in 5,000 years. He shows the difficulties
attending the assumption that the sun is a cooling body; for,
supposing it to possess even the high specific heat of water, its
temperature would fall 15,000' in 5,000 years. He finally concludes
that the light and heat of the sun are maintained by the constant
impact of meteoric matter. I never ventured an opinion as to the
truth of this theory; that is a question which may still have to be
fought out. But I refer to it as an illustration of the force of
genius with which Mayer followed the mechanical theory of heat through
all its applications. Whether the meteoric theory be a matter of fact
or not, with him abides the honour of proving to demonstration that
the light and heat of suns and stars may be originated and maintained
by the collisions of cold planetary matter.
It is the man who with the scantiest data could accomplish all this in
six short years, and in, the hours snatched from the duties of an
arduous profession, that the Royal Society, in 1871, crowned with its
highest honour.
Comparing this brief history with that of the Copley Medalist of 1870,
the differentiating influence of 'environment,' on two minds of
similar natural cast and endowment, comes out in an instructive
manner. Withdrawn from mechanical appliances, Mayer fell back upon
reflection, selecting with marvellous sagacity, from existing physical
data, the single result on which could be founded a calculation of the
mechanical equivalent of heat. In the midst of mechanical appliances,
Joule resorted to experiment, and laid the broad and firm foundation
which has secured for the mechanical theory the acceptance it now
enjoys. A great portion of Joule's time was occupied in actual
manipulation; freed from this, Mayer had time to follow the theory
into its most abstruse and impressive applications. With their places
reversed, however, Joule might have become Mayer, and Mayer might have
become Joule.
It does not lie within the scope of these brief articles to enter upon
the developments of the Dynamical Theory accomplished since Joule and
Mayer executed their memorable labours.
********************
XXI. DEATH BY LIGHTNING.
PEOPLE in general imagine, when they think at all about the matter,
that an impression upon the nerves--a blow, for example, or the prick
of a pin--is felt at the moment it is inflicted. But this is not the
case. The seat of sensation being the brain, to it the intelligence
of any impression made upon the nerves has to be transmitted before
this impression can become manifest as consciousness. The
transmission, moreover, requires time, and the consequence is, that a
wound inflicted on a portion of the body distant from the brain is
more tardily appreciated than one inflicted adjacent to the brain. By
an extremely ingenious experimental arrangement, Helmholtz has
determined the velocity of this nervous transmission, and finds it to
be about eighty feet a second, or less than one-thirteenth of the
velocity of sound in air. If therefore, a whale forty feet long were
wounded in the tail, it would not be conscious of the injury till half
a second after the wound had been inflicted. [Footnote: A most
admirable lecture on the velocity of nervous transmission has been
published by Dr. Du Bois Reymond in the 'Proceedings of the Royal
Institution' for 1866, vol. iv. p. 575.] But this is not the only
ingredient in the delay. There can scarcely be a doubt that to every
act of consciousness belongs a determinate molecular arrangement of
the brain--that every thought or feeling has its physical correlative
in that organ; and nothing can be more certain than that every
physical change, whether molecular or mechanical, requires time for
its accomplishment. So that, besides the interval of transmission, a
still further time is necessary for the brain to put itself in
order--for its molecules to take up the motions or positions necessary
to the completion of consciousness. Helmholtz considers that
one-tenth of a second is demanded for this purpose. Thus, in the case
of the whale above supposed, we have first half a second consumed in
the transmission of the intelligence through the sensor nerves to the
head, one-tenth of a second consumed by the brain in completing the
arrangements necessary to consciousness, and, if the velocity of
transmission through the motor be the same as that through the sensor
nerves, half a second in sending a command to the tail to defend
itself. Thus one second and a tenth would elapse before an impression
made upon its caudal nerves could be responded to by a whale forty
feet long.
Now, it is quite conceivable that an injury might be inflicted so
rapidly that within the time required by the brain to complete the
arrangements necessary to consciousness, its power of arrangement
might be destroyed. In such a case, though the injury might be of a
nature to cause death, this would occur without pain, Death in this
case would be simply the sudden negation of life, without any
intervention of consciousness whatever.
The time required for a rifle-bullet to pass clean through a man's
head may be roughly estimated at a thousandth of a second. Here,
therefore, we should have no room for sensation, and death would be
painless. But there are other actions which far transcend in rapidity
that of the rifle-bullet. A flash of lightning cleaves a cloud,
appearing and disappearing in less than a hundred-thousandth of a
second, and the velocity of electricity is such as would carry it in a
single second over a distance almost equal to that which separates the
earth and moon. It is well known that a luminous impression once made
upon the retina endures for about one-sixth of a second, and that this
is the reason why we see a continuous band of light when a glowing
coal is caused to pass rapidly through the air. A body illuminated by
an instantaneous flash continues to be seen for the sixth of a second
after the flash has become extinct; and if the body thus illuminated
be in motion, it appears at rest at the place where the flash falls
upon it. When a colour-top with differently-coloured sectors is
caused to spin rapidly the colours blend together. Such a top,
rotating in a dark room and illuminated by an electric spark, appears
motionless, each distinct colour being clearly seen. Professor Dove
has found that a flash of lightning produces the same effect. During
a thunderstorm he put a colour-top in exceedingly rapid motion, and
found that every flash revealed the top as a motionless object with
its colours distinct. If illuminated solely by a flash of lightning,
the motion of all bodies on the earth's surface would, as Dove has
remarked, appear suspended. A cannon-ball, for example, would have
its flight apparently arrested, and would seem to hang motionless in
space as long as the luminous impression which revealed the ball
remained upon the eye.
If, then, a rifle-bullet move with sufficient rapidity to destroy life
without the interposition of sensation, much more is a flash of
lightning competent to produce this effect. Accordingly, we have
well-authenticated cases of people being struck senseless by lightning
who, on recovery, had no memory of pain. The following circumstantial
case is described by Hemmer:
On June 30, 1788, a soldier in the neighbourhood of Mannheim, being
overtaken by rain, placed himself under a tree, beneath which a woman
had previously taken shelter. He looked upwards to see whether the
branches were thick enough to afford the required protection, and, in
doing so, was struck by lightning, and fell senseless to the earth.
The woman at his side experienced the shock in her foot, but was not
struck down. Some hours afterwards the man revived, but remembered
nothing about what had occurred, save the fact of his looking up at
the branches. This was his last act of consciousness, and he passed
from the conscious to the unconscious condition without pain. The
visible marks of a lightning stroke are usually insignificant: the
hair is sometimes burnt; slight wounds are observed; while, in some
instances, a red streak marks the track of the discharge over the
skin.
Under ordinary circumstances, the discharge from a small Leyden jar is
exceedingly unpleasant to me. Some time ago I happened to stand in
the presence of a numerous audience, with a battery of fifteen large
Leyden jars charged beside me. Through some awkwardness on my part, I
touched a wire leading from the battery, and the discharge went
through my body. Life was absolutely blotted out for a very sensible
interval, without a trace of pain. In a second or so consciousness
returned; I vaguely discerned the audience and apparatus, and, by the
help of these external appearances, immediately concluded that I had
received the battery discharge. The intellectual consciousness of my
position was restored with exceeding rapidity, but not so the optical
consciousness. To prevent the audience from being alarmed, I observed
that it had often been my desire to receive accidentally such a shock,
and that my wish had at length been fulfilled. But, while making this
remark, the appearance which my body presented to my eyes was that of
a number of separate pieces. The arms, for example, were detached
from the trunk, and seemed suspended in the air. In fact, memory and
the power of reasoning appeared to be complete long before the optic
nerve was restored to healthy action. But what I wish chiefly to
dwell upon here is, the absolute painlessness of the shock; and there
cannot, I think, be a doubt that, to a person struck dead by
lightning, the passage from life to death occurs without consciousness
being in the least degree implicated. It is an abrupt stoppage of
sensation, unaccompanied by a pang.
********************
XXII. SCIENCE AND THE 'SPIRITS.'
THEIR refusal to investigate 'spiritual phenomena' is often urged as a
reproach against scientific men. I here propose to give a sketch of
an attempt to apply to the 'phenomena' those methods of enquiry which
are found available in dealing with natural truth.
Some years ago, when the spirits were particularly active in this
country, Faraday was invited, or rather entreated, by one of his
friends to meet and question them. He had, however, already made
their acquaintance, and did not wish to renew it. I had not been so
privileged, and he therefore kindly arranged a transfer of the
invitation to me. The spirits themselves named the time of meeting,
and I was conducted to the place at the day and hour appointed.
Absolute unbelief in the facts was by no means my condition of mind.
On the contrary, I thought it probable that some physical principle,
not evident to the spiritualists themselves, might underlie their
manifestations. Extraordinary effects are produced by the
accumulation of small impulses. Galileo set a heavy pendulum in
motion by the well-timed puffs of his breath. Ellicot set one clock
going by the ticks of another, even when the two clocks were separated
by a wall. Preconceived notions, can, moreover, vitiate, to an
extraordinary degree, the testimony of even veracious persons. Hence
my desire to witness those extraordinary phenomena, the existence of
which seemed placed beyond a doubt by the known veracity of those who
had witnessed and described them. The meeting took place at a private
residence in the neighbourhood of London. My host, his intelligent
wife, and a gentleman who may be called X, were in the house when I
arrived. I was informed that the 'medium' had not yet made her
appearance; that she was sensitive, and might resent suspicion. It
was therefore requested that the tables and chairs should be examined
before her arrival, in order to be assured that there was no trickery
in the furniture. This was done; and I then first learned that my
hospitable host had arranged that the séance should be a dinner-party.
This was to me an unusual form of investigation; but I accepted it, as
one of the accidents of the occasion.
The 'medium' arrived--a delicate-looking young lady, who appeared to
have suffered much from ill health. I took her to dinner and sat
close beside her. Facts were absent for a considerable time, a series
of very wonderful narratives supplying their place. The duty of
belief on the testimony of witnesses was frequently insisted on. X.
appeared to be a chosen spiritual agent, and told us many surprising
things. He affirmed that, when he took a pen in his hand, an
influence ran from his shoulder downwards, and impelled him to write
oracular sentences. I listened for a time, offering no observation.
'And now,' continued X, 'this power has so risen as to reveal to me
the thoughts of others. Only this morning I told a friend what he was
thinking of, and what he intended to do during the day.' Here, I
thought, is something that can be at once tested. I said immediately
to X: 'If you wish to win to your cause an apostle, who will proclaim
your principles to the world from the housetop, tell me what I am now
thinking of.' X. reddened, and did not tell me my thought.
Some time previously I had visited Baron Reichenbach, in Vienna, and I
now asked the young lady who sat beside me, whether she could see any
of the curious things which he describes--the light emitted by
crystals, for example? Here is the conversation which followed, as
extracted from my notes, written on the day following the séance.
Medium.--'Oh, yes; but I see light around all bodies.'
I--'Even in perfect darkness?'
Medium.--'Yes; I see luminous atmospheres round all people. The
atmosphere which surrounds Mr. R. C. would fill this room with
light.'
I.--'You are aware of the effects ascribed by Baron Reichenbach to
magnets?'
Medium.--'Yes; but a magnet makes me terribly ill.'
I.--'Am I to understand that, if this room were perfectly dark, you
could tell whether it contained a magnet, without being informed of
the fact?'
Medium.--'I should know of its presence on entering the room.'
I.--'How?'
Medium.--'I should be rendered instantly ill.'
I.--'How do you feel to-day?'
Medium.--'Particularly well; I have not been so well for months.'
I.--'Then, may I ask you whether there is, at the present moment, a
magnet in my possession?'
The young lady looked at me, blushed, and stammered, 'No; I am not en
rapport with you.'
I sat at her right hand, and a left-hand pocket, within six inches of
her person, contained a magnet.
Our host here deprecated discussion, as it 'exhausted the medium.' The
wonderful narratives were resumed; but I had narratives of my own
quite as wonderful. These spirits, indeed, seemed clumsy creations,
compared with those with which my own work had made me familiar. I
therefore began to match the wonders related to me by other wonders. A
lady present discoursed on spiritual atmospheres, which she could see
as beautiful colours when she closed her eyes. I professed myself
able to see similar colours, and, more than that, to be able to see
the interior of my own eyes. The medium affirmed that she could see
actual waves of light coming from the sun. I retorted that men of
science could tell the exact number of waves emitted in a second, and
also their exact length. The medium spoke of the performances of the
spirits on musical instruments. I said that such performance was
gross, in comparison with a kind of music which had been discovered
some time previously by a scientific man. Standing at a distance of
twenty feet from a jet of gas, he could command the flame to emit a
melodious note; it would obey, and continue its song for hours. So
loud was the music emitted by the gas-flame, that it might be heard by
an assembly of a thousand people. These were acknowledged to be as
great marvels as any of those of spiritdom. The spirits were then
consulted, and I was pronounced to be a first-class medium.
During this conversation a low knocking was heard from time to time
under the table. These, I was told, were the spirits' knocks. I was
informed that one knock, in answer to a question, meant 'No;' that two
knocks meant 'Not yet;' and that three knocks meant 'Yes.'
In answer to a question whether I was a medium, the response was three
brisk and vigorous knocks. I noticed that the knocks issued from a
particular locality, and therefore requested the spirits to be good
enough to answer from another corner of the table. They did not
comply; but I was assured that they would do it, and much more,
by-and-by. The knocks continuing, I turned a wine-glass upside down,
and placed my ear upon it, as upon a stethoscope. The spirits seemed
disconcerted by the act; they lost their playfulness, and did not
recover it for a considerable time.
Somewhat weary of the proceedings, I once threw myself back against my
chair and gazed listlessly out of the window. While thus engaged, the
table was rudely pushed. Attention was drawn to the wine, still
oscillating in the glasses, and I was asked whether that was not
convincing. I readily granted the fact of motion, and began to feel
the delicacy of my position. There were several pairs of arms upon
the table, and several pairs of legs under it; but how was I, without
offence, to express the conviction which I really entertained? To
ward off the difficulty, I again turned a wine-glass upside down and
rested my ear upon it. The rim of the glass was not level, and my
hair, on touching it, caused it to vibrate, and produce a peculiar
buzzing sound. A perfectly candid and warm-hearted old gentleman at
the opposite side of the table, whom I may call A, drew attention to
the sound, and expressed his entire belief that it was spiritual. I,
however, informed him that it was the moving hair acting on the glass.
The explanation was not well received; and X, in a tone of severe
pleasantry, demanded whether it was the hair that had moved the table.
The promptness of my negative probably satisfied him that my notion
was a very different one.
The superhuman power of the spirits was next dwelt upon. The strength
of man, it was stated, was unavailing in opposition to theirs. No
human power could prevent the table from moving when they pulled it.
During the evening this pulling of the table occurred, or rather was
attempted, three times. Twice the table moved when my attention was
withdrawn from it; on a third occasion, I tried whether the act could
be provoked by an assumed air of inattention. Grasping the table
firmly between my knees, I threw myself back in the chair, and waited,
with eyes fixed on vacancy, for the pull. It came. For some seconds
it was pull spirit, hold muscle; the muscle, however, prevailed, and
the table remained at rest. Up to the present moment, this interesting
fact is known only to the particular spirit in question and myself.
A species of mental scene-painting, with which my own pursuits had
long rendered me familiar, was employed to figure the changes and
distribution of spiritual power. The spirits, it was alleged, were
provided with atmospheres, which combined with and interpenetrated
each other, and considerable ingenuity was shown in demonstrating the
necessity of time in effecting the adjustment of the atmospheres. A
rearrangement of our positions was proposed and carried out; and soon
afterwards my attention was drawn to a scarcely sensible vibration on
the part of the table. Several persons were leaning on the table at
the time, and I asked permission to touch the medium's hand. 'Oh! I
know I tremble,' was her reply. Throwing one leg across the other, I
accidentally nipped a muscle, and produced thereby an involuntary
vibration of the free leg. This vibration, I knew, must be
communicated to the floor, and thence to the chairs of all present. I
therefore intentionally promoted it. My attention was promptly drawn
to the motion; and a gentleman beside me, whose value as a witness I
was particularly desirous to test, expressed his belief that it was
out of the compass of human power to produce so strange a tremor. 'I
believe,' he added, earnestly, 'that it is entirely the spirits'
work.' 'So do I,' added, with heat, the candid and warmhearted old
gentleman A. 'Why, sir,' he continued, 'I feel them at this moment
shaking my chair.' I stopped the motion of the leg. 'Now, sir,' A.
exclaimed, 'they are gone.' I began again, and A. once more affirmed
their presence. I could, however, notice that there were doubters
present, who did not quite know what to think of the manifestations. I
saw their perplexity; and, as there was sufficient reason to believe
that the disclosure of the secret would simply provoke anger, I kept
it to myself.
Again a period of conversation intervened, during which the spirits
became animated. The evening was confessedly a dull one, but matters
appeared to brighten towards its close. The spirits were requested to
spell the name by which I was known in the heavenly world. Our host
commenced repeating the alphabet, and when he reached the letter 'P' a
knock was heard. He began again, and the spirits knocked at the
letter 'O.' I was puzzled, but waited for the end. The next letter
knocked down was 'E.' I laughed, and remarked that the spirits were
going to make a poet of me. Admonished for my levity, I was informed
that the frame of mind proper for the occasion ought to have been
superinduced by a perusal of the Bible immediately before the séance.
The spelling, however, went on, and sure enough I came out a poet. But
matters did not end here. Our host continued his repetition of the
alphabet, and the next letter of the name proved to be '0.' Here was
manifestly an unfinished word; and the spirits were apparently in
their most communicative mood. The knocks came from under the table,
but no person present evinced the slightest desire to look under it. I
asked whether I might go underneath; the permission was granted; so I
crept under the table. Some tittered; but the candid old A.
exclaimed, 'He has a right to look into the very dregs of it, to
convince himself.' Having pretty well assured myself that no sound
could be produced under the table without its origin being revealed, I
requested our host to continued his questions. He did so, but in
vain. He adopted a tone of tender entreaty; but the 'dear spirits'
had become dumb dogs, and refused to be entreated. I continued under
that table for at least a quarter of an hour, after which, with a
feeling of despair as regards the prospects of humanity never before
experienced, I regained my chair. Once there, the spirits resumed
their loquacity, and dubbed me 'Poet of Science.'
This, then, is the result of an attempt made by a scientific man to
look into these spiritual phenomena. It is not encouraging; and for
this reason. The present promoters of spiritual phenomena divide
themselves into two classes, one of which needs no demonstration,
while the other is beyond the reach of proof. The victims like to
believe, and they do not like to be undeceived. Science is perfectly
powerless in the presence of this frame of mind. It is, moreover, a
state perfectly compatible with extreme intellectual subtlety and a
capacity for devising hypotheses which only require the hardihood
engendered by strong conviction, or by callous mendacity, to render
them impregnable. The logical feebleness of science is not
sufficiently borne in mind. It keeps down the weed of superstition,
not by logic but by, slowly rendering the mental soil unfit for its
cultivation. When science appeals to uniform experience, the
spiritualist will retort, 'How do you know that a uniform experience
will continue uniform? You tell me that the sun has risen for six
thousand years: that is no proof that it will rise tomorrow; within
the next twelve hours it may be puffed out by the Almighty.' Taking
this ground, a man may maintain the story of 'Jack and the Beanstalk'
in the face of all the science in the world. You urge, in vain, that
science has given us all the knowledge of the universe which we now
possess, while spiritualism has added nothing to that knowledge. The
drugged soul is beyond the reach of reason. It is in vain that
impostors are exposed, and the special demon cast out. He has but
slightly to change his shape, return to his house, and find it 'empty,
swept, and garnished.'
*****