to rhythm a great æsthetical power,
considering it the sublimest part of music.

When the Egyptians wanted to transport one
of their gigantic obelisks, placing it on a number
of wheeled carriages, they harnessed men
to them, not by hundreds but by thousands;
and, as represented on ancient bas-reliefs, in
order to animate this multitude by the same
impulsion, a man, mounted on the monolith,
sang a song, beating the measure with his hands.
On board ship, the heaviest anchors are heaved
by sailors stepping to a rhythmical chant.
Horses feel the effects of rhythm. Not to
mention the obedience of cavalry to the trumpet,
note how the steeds in a circus alter their pace
at a change in the music.

A troop of dancers amused a small Spanish
town with their cachuchas. The monks of the
Inquisition charged them with impiety. Arrested
and brought before the Holy Office; after
defending themselves as well as they could, as a
last argument they begged the Tribunal to
allow them to execute the dance which, they
declared, was a very simple and innocent
performance. The more spiritedly the music played,
the more the dancers waxed in zeal. The
excitement felt by the executants soon communicated
itself to the spectators. The reverend
fathers fidgetted on their seats, swaying themselves
backwards and forwards, until, overpowered
by the electric rhythm, they joined the
culprits in their dance.

The effects of music are ascribed by M. de
Pontécoulaut to a special agent which he thinks
he has discovered—there are mare's nests in
every civilised country and which, like electricity
and caloric (in 1868!) escaping the
notice of most of our senses by its tenuity and
extreme transparence, may nevertheless possess
sufficient active power to produce the observed
physical phenomena. After long research, he
was driven to admit the existence of a particular
fluid, which may be regarded as the
sonorous or musical element. The existence of
this fluid, he urges, is admissible, "for it
contradicts no mathematical truth and changes
nothing in the existing laws of acoustics." The
sonorous fluid, he explains, belongs to the same
family as the electric fluid, the luminous fluid,
and the caloric fluid.

The sonorous fluid, or musical magnetism, is
made to account for the circumstance that, by
lying flat on the ground, you may hear cannon
fired more than sixty miles off. It also
explains the quivering of peas placed on a drumhead,
at a short distance from a field of battle,
every time a shot is fired. At Laon, the Waterloo
cannon were heard by applying the ear close
to the ground, although they were inaudible to
persons standing upright. The same agent
renders audible at one end of a long beam, the
taps of a pin's head at the other, although they
are imperceptible through air at the distance of
a yard.

By maintaining that vibrations in the air are
the productive cause of sound, you may
certainly explain some acoustic problems; but you
can account for no important fact relating to
the influence of sound on the human organisation.
Whereas, by admitting the existence of
the sonorous fluid, you can understand and
easily explain all those phenomena, however
astonishing—those, for instance, of sympathy.

Music being the art of combining sounds
agreeably, sound is the raw material of music.
No sound, no music. But, if you please, what
is sound? We all thought we knew what it
was long ago

Sound, according to M. de Pontécoulant, is
due to a series of vibrations in elastic bodies,
or in parts of those bodies, which communicate,
not to the air, but to the invisible sonorous
fluid, a series of like vibrations. The ear is not
the only organ able to perceive sonorous vibrations.
They are perceptible by other organs
not in contact with the air, and must therefore
be communicated by the invisible sonorous
fluid. The old experiment of the soundless
bell under the exhausted receiver of an air-
pump, will be urged as an objection. But to
make the experiment successful, there must be
no solid communication between the bell and
the table on which the air-pump stands. Otherwise,
the sonorous fluid will escape outside,
exactly as the electric fluid escapes by means
of a conductor.

Sound is weakened or stifled in a vacuum,
not because the sonorous fluid therein has
become too rarified, but because the fluid finds
there no medium whereby to propagate its
repercussions. Aërial waves may accompany
sound, but they are themselves set in motion
by the sonorous fluid. In short, the science of
acoustics may remain as it stands, even if we
accept M, de Pontécoulant's sonorous fluid
into the bargain. It is like the well-washed
pebble in the soldier's flint soup an additional
ingredient, which, if it does no good, certainly
does no harm; the speculations of Chladni,
Helmholtz, and Tyndall, are certainly not in
any way upset by it.

   THE NEW SERIAL TALE, HESTER'S HISTORY,
commenced in Number 488, will be continued
from week to week until completed in the present
volume.

            FAREWELL SERIES OF READINGS.
                                   BY
                    MR. CHARLES DICKENS.

   MESSRS. CHAPPELL AND Co. have the honour
to announce that MR. DICKENS'S FINAL SERIES
OF READINGS, comprehending some of the chief
towns in England, Ireland, and Scotland, will
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October 6.

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