1825. ] 
In conjunction with these should be 
mentioned 
Tur Diapuracm, which is connected 
with the arch of the lower ribs from 
the breast to the spine, separating the 
chest from the lower cavity of the 
body ;* and 
Tue InvercostaL Musctes, which, 
by their office of raising the ribs, alter- 
nately enlarge and contract the cavity 
of the chest, and thereby admit and 
re-expel the air from the cells of the 
lungs. 
Without the instrumentality of these, 
the lungs (which in themselves are 
merely passive) would be totally impo- 
tent and inapplicable to their important 
functions. So that when the action of 
the lungs is spoken of, it is, in truth, 
the action of these muscles that is refer- 
red to, and the consequent elevation 
and depression of the diaphragm, by 
which the lungs are alternately ex- 
panded and compressed. 
They are, however, altogether, to be 
regarded rather as remote than as im- 
mediate organs of voice, especially as 
in the act of declamation, no greater 
labour or effort should be imposed 
upon them, than that which they are 
regularly performing for the purposes 
of life. An axiom this which, however 
contradictory to generally received no- 
tions, and to the actual practice of 
pipe). Hence a variety of sounds are pro- 
duced by various collision, so far as respects 
the intonations rather than the articulation. 
But the diversity is not produced by the 
lungs themselves, but by other organs, as 
shall be shewn hereafter: for no other va- 
riation of sound depends upon the lungs 
than what arises from the greater or less 
force with which the breath is exploded ; 
fromm whence (other circumstances being 
equal) the yoice becomes more or less 
strong and sonorous. For the lungs give 
the first impulse to speech, as the bellows 
to a church organ.”—Expulmone per As- 
peram Arteriam, &c., Sect. Ist. General 
utility being the object of these disquisi- 
tions, I have preferred giving an English 
translation at once, instead of quoting the 
original Latin in which Dr. Wallis’s 
grammar is written. 
* It it described by anatomists—“ A 
large, robust, musculous membrane, or 
skin, placed transversely in the trunk, and 
dividing the thorax from the abdomen.”— 
Greg. Encyc. 
“* The muscle which separates the two 
cavities of the abdomen and thorax, and is 
the chief agent in inspiration. It is also 
known among anatomists by the name of 
septum transversum, and septum musculare.; 
and, in common language, by that of the 
midriff.” —Rees’s New Cyclop. 
The Anatomy of Speech. 
197 
many injudicious speakers, cannot be 
too strongly insisted upon or im- 
pressed. 
In something like the same point. of 
view must also be regarded 
Tuer Guiortis, or Winp-ripr, which 
is principally to be considered: as a 
channel or medium for the inhalation and 
exhalation of the air, and its consequent 
communication from the lungs to the 
organs of vocal impulse. 
It is called by anatomists Tracuea, 
or Aspera ARTERIA; and is thus de- 
fined and described: “ The ¢artilagi- 
nous and membranous canal, through 
which the air passes into the lungs. 
It is formed of cartilages separated from 
each other by an intervening membra- 
nous and ligamentary substance. It is 
furnished with fleshy and muscular 
fibres ; some of which pass through its 
whole extent, longitudinally, while the 
others are carried round it, in a circu- 
lar direction ; so that, by the contrac- 
tion and relaxation of these fibres, it is 
enabled to shorten or lengthen itself, 
and likewise to dilate or contract the 
diameter of its passage.” — Encyc. 
Brit. 
Differences of structure in this organ, 
as far as relatesto the length and dia- 
meter of the tube, do indeed affect, in 
some degree, the pitch of the voice, as 
the length and diameter of a flute, or 
any other canular instrument, affects 
the character of its tone, as to tenor, 
bass, or treble, and the like. And as 
this organ is furnished with voluntary 
muscles, its elongations, dilations and 
constrictions, by increasing or dimi- 
nishing the force and volume of the air 
expelled, assist, to a certain degree, the 
modifications cf tune, both in Speech 
and in Song.* 
PRIMARY 
e 
The variety of tones, with respect 
to gravity or sharpness, have their rise, 
partly, from the trachea, or aspera arteria ; 
for asa tube, when it is made long and 
narrower, makes a more acute sound; and 
when shorter and more dilated, a graver ; 
so with the trachea; whence, at least in 
part, a variety of tones is constituted in the 
voices of different men; and, indeed, in 
the same man at different ages. But. the 
difference principally arises from the larynx 
or knot of the throat. For as the opening 
of the larynx is expanded, more or less, so 
the tone of the voice is more or less grave. 
This is the seat of musical modulation. 
From the same source, a reason may be 
sought for the difference between close 
whispering and open speech: for as the 
trembling concussion of the larynx and 
trachea, in open speech, is produced by the 
tension 
