1825. ] 
nistering, “constantancously, or alter- 
nately, both to the modification of the 
tones, and the enunciation of the ele- 
ments; but this is a difficulty which 
belongs to them in common with all 
the discriminative classifications. of the 
scientific nomenclature. 
‘1. Tur Vocat Oreans consist of 
those portions of the organic system em- 
ployed by the human or other animal in 
the production and variation of voluntary 
and tunable sounds. 
2. Tur Envunciative Orcans (which 
in the perfection and complication of 
their structure are peculiar to man) 
include those portions and members of the 
mouth, 5c., by means of which we super- 
add to the tunable impulses of voice, the 
specific phenomena of literal and verbal 
utterance. 
Turory or Sounps.—To treat of 
the subject, in the most natural and 
intelligible order, it is necessary to 
commence with the organs of voice; 
and that the action and offices of these 
may be more fully comprehended, it is 
equally necessary to premise a few 
words on the Theory of Sounds ina 
general, and of Vocal Sounds in_par- 
ticular. I state it, therefore, as an ad- 
mitted axiom among  philosophers— 
that sounds exist not in the bodies 
usually deemed sonorous, or in the seve- 
ral apparatus of nature or of art, from 
which they appear to originate. That 
they are, in fact, only perceptions of 
the sentient mind,* originating in im- 
pressions on the tympanum of the ear ;+ 
* Perceptions of the Mind.—Sounds in 
reality are not things existing, or without 
us ; but sensations originating in the audi- 
tory nerves. Their predisposing cause is 
the state of the tympanum itself. If all 
organized beings were deaf, there would be 
no sound in the universe. “ Sound,”’ says 
Mr. Gough, “ is a sensation excited in the 
ear by a quick succession of aerial pulses, 
corresponding to the vibrations of an elastic 
substance.” —Gough on Variety of Voices— 
Manchester Memoirs. 
+ The Tympanum of the Ear.—As it is 
not my intention to enter into all the mi- 
_nutiz of every philosophical theory con- 
nected with my science, I confine myself, 
in this statement, to.the popular creed of 
the day, as I shall.do in all collateral 
points, where such creed (howeyer imper- 
fect) is not inconsistent (so far as it goes) 
with essential truth and demonstrabie 
theory. It is an act of justice, however, 
to the indefatigable researches of the acute 
and accurate Mr. John Gough (of Middle- 
shaw) to acknowledge the validity of those 
experiments, by which he has proved, that 
it is not, exclusively, to the tympanum of 
Montuty Mas. No. 407. 
The Anatomy of Speech. 
121 
and which impressions are communi- 
cated to that organ, by certain pulses 
of the atmospheric air, thrown into 
agitation by the percussions or vibra- 
tions of some impelling implement, 
which may be regarded as the remote 
cause of such impression.* 
To speak less abstractedly, all sounds 
(from the hollow whisperings of the wind, 
or the crash of one heavy body falling 
wpon another, to the exquisite trillings of 
the nightingale, or the varied modulations 
of the human voice) are immediately pro- 
duced by percussions and vibrations of 
the air striking upon the auditory organs. 
The validity of this theory has been 
sufficiently demonstrated by the simple 
experiment of the bell in vacuo. 
if a bell, accompanied with proper 
apparatus, be placed under the receiver 
of an air pump, and the air, from such 
receiver, be efiectually exhausted, -so 
that the communication between the 
beil and the external atmosphere be 
sufficiently cut off by the intervening 
vacuum,—although the bell should be 
put into the strongest agitation, so that 
the clapper may be seen, through the 
glass receiver, striking with great ‘force 
against the cup, no sound whatever 
will be produced ;+ but if the air be 
gradually 
the ear, that those pulses are communi- 
cated, which are the causes of our sensa- 
tions of sound. 
*. Dr. Smith, in his Harmonics, sec.. Ist, 
gives the following definition upon this 
subject: ‘‘ Sound is caused by the vibra- 
tions of elastic bodies, which communicate 
the like vibration to the ear, and these the 
like again to our organs of hearing. Phi- 
losophers are agreed in this, because sound- 
ing bodies communicate tremours to dis- 
tant “bodies: For instance, the vibrating 
motion of a musical string puts others in 
motion, whose tension and quantity of 
matter dispose their vibrations to keep 
time with the pulses of air, propagated from 
the string that was struck.” 
Mr. Gough, with his usual perspicuity, 
still further explains this process. ‘ An 
elastic body,” says he, “ upon receiving a 
tremulous motion, immediately communi- 
cates it to the portion of air in contact with 
itself; and it is, in like manner, succes- 
sively propagated through the whole of the 
air, extending from the vibrating surface 
to the auditory organs, by which means 
men acquire a notion of sound, together 
with the whole class of ideas depending 
on the sense of hearing.”’—On Variety of 
Voices.—Manch. Mem. 
No sound whatever will be produced. 
The impracticability of producing an abso- 
Jute vacuum, by the usual means, will al- 
R ways 
