+Teacher+.--What did you learn in the previous Lesson?

+Pupil+.--I learned that a spoken word is composed of certain sounds, and
that letters are signs of sounds, and that spoken and written words are the
signs of ideas.

This question should be passed from one pupil to another till all of these
answers are elicited.

All the written words in all the English books ever made, are formed of
twenty-six letters, representing about forty sounds. These letters and
these sounds make up what is called artificial language.

Of these twenty-six letters, +a, e, i, o, u+, and sometimes +w+ and +y+,
are called +vowels+, and the remainder are called +consonants+.

In order that you may understand what kind of sounds the vowels stand for,
and what kinds the consonants represent, I will tell you something about
the _human voice_.

The air breathed out from your lungs beats against two flat muscles,
stretched like strings across the top of the windpipe, and causes them to
vibrate. This vibrating makes sound. Take a thread, put one end between
your teeth, hold the other in your fingers, draw it tight and strike it,
and you will understand how voice is made.

If the voice thus produced comes out through the mouth held well open, a
class of sounds is formed which we call _vowel_ sounds.

But, if the voice is held back by your palate, tongue, teeth, or lips,