_soon find_ the habit running into his hours
of _rest_, into which he would _calmly_ enter; dismissing the nervous
anxieties of the day, as he firmly closed his teeth and his lips, only
to be opened _after_ his eyes and his ears in the morning, the rest of
_such_ sleep would bear him daily and hourly proof of its value."

Catlin regards the habit of sleeping with the mouth open the most
pernicious of _all bad habits_. The horrors of nightmare and snoring
are, according to him, but the _least_ of its evil effects. He thinks
"for the greater portion of the thousands and tens of thousands of
persons suffering with weakness of lungs, with bronchitis, asthma,
indigestion, and other affections of the digestive and respiratory
organs," the correction of this habit is a _panacea_ for their ills!

He insists that "_mothers_ should be looked to as the first and
principal _correctors_ of this most destructive of human habits; ... and
the united and simultaneous efforts of the civilized world should be
exerted in the overthrow of a monster so destructive to the good looks
and life of man. Every physician should advise his patients, and every
boarding-school in existence and every hospital should have its surgeon
or matron, and every regiment its officer, to make their nightly and
hourly 'rounds,' to force a _stop_ to so unnatural, disgusting, and
dangerous a habit! Under the working of such a system, mothers guarding
and helping the helpless, schoolmasters their scholars, hospital
surgeons their patients, generals their soldiers, and the rest of the
world protecting themselves, a few years would show the glorious results
in the bills of mortality, and the next generation would be a
_regeneration_ of the human race."

=The Windpipe= (pl. I, W).--Having examined the bellows of our vocal
organ, we next notice the windpipe, by means of which the air is carried
into and out of the lungs. It is an elastic tube kept open by 18 or 20
rings which do not quite meet at the back. It enters the lungs by means
of two smaller tubes, which in their turn branch out very much like the
roots of a tree, until their ramifications end in the microscopic cells
of the lungs. The windpipe is capable of being slightly elongated or
shortened, and narrowed or widened, and its interior is covered with a
mucous membrane, which, as its name implies, is continually kept in a
moist state.

=The Voicebox, or Larynx= (pl. V) may be described as resembling a funn