638  Onthe Method of judging by the Ear 
The head isa sensitive solid, and it perceives the 
impulses made on it by sounds much more exqui« 
sitely than men generally imagine. This sensibili- 
ty is strongest in the auditory passages, and next to 
them in theparts immediately adjacent to the ears 5 
nevertheless it diffuses itself more or less perfectly 
over the face, forehead, and temples, as well as 
all the external teguments of the skull. The 
sensation in question being of but little use in- 
dependent of its connection with hearing, we 
for the most part mistake its true situation, and 
refer it to the organs of this sense, unless some 
circumstance, resembling the succeeding ex- 
periment, should happen to discover the nature 
of it to us. If any one will take the pains to 
close the orifices of his ears with wet paper, 
and will hold two slender rods of wood to his 
forehead or to one of his temples, taking care to 
keep the ends which are in contract with the skin 
separated by a small interval:and let another person 
at the same time touch the opposite ends of the rods 
with two watehes, one of which does not move: the 
beats of the active watch will immediately pass 
along the stick, and make a sensible impression 
on the spot where its other extremity rests; 
which proves, that the bones of the head do not 
simply conduct sounds to the auditory nerves, 
but that the external tegaments of this ‘member 
also assist in discovering the directions of sounds 
