MANUAL OF NATURE STUDY. 
75 
3. Care of the throat . Show that the apparatus 
for the voice is in the throat. 
Illustrate by chalk box or other device with fine 
strings stretched and fastened across the top. Pick 
the strings between the fingers as you would a banjo. 
Notice the change in sound when the strings are 
tightened or loosened. A violin, banjo or guitar will 
be a still better illustration. In either case the 
makingof a new sound requires change of fingering, 
tightening or loosening of the string. 
What produces the change of sound in our 
voices ? While singing the musical scale let the 
children place their hands upon their own throats 
and observe the muscular changes that take place. 
With a severe cold could these muscular changes 
be made as easily ? If the strings of a violin were 
covered with a sticky substance would they give us 
as clear a sound? When the vocal cords are 
covered with phlegm, as they must be during a 
severe cold, can you speak as clearly ? What tubes 
belong in the region of the throat? (The tube 
which leads to the lungs and the one to the stomach, 
—two very important ones). If the trachea be in¬ 
flamed, what effect npon our breathing? It pro¬ 
duces a cough which only adds to the inflammation, 
and is otherwise very disagreeable, not only to our¬ 
selves but to others. A heavy cold will often cause 
