498 
JACOB HELMER. 
blocked with exudate and the vesicular murmur lost in that 
part; but it will be found increased in other parts of the 
middle third not diseased. 
We shall next consider the class of abnormal sounds known 
as rales. These are moist and dry. Moist rales are sub-divided 
with mucus, submucus and subcrepitant. Dry rales are divided 
into sonorous, crepitant and sibilant. The sonorous rales are 
heard over the large bronchial tubes in the middle and upper 
portions of the chest, in the first stage of bronchitis. The 
sibilant rale is heard in the upper and lower portions of the 
chest over the small bronchial tubes. It is a hissing sound. 
Bronchitis is a bilateral disease, hence these sounds may be 
heard over both sides of the chest, both on inspiration and 
expiration. The crepitant rale is heard in the first stage of 
pneumonia principally over the middle portion of the lung. 
It is a snapping sound and is closely imitated by stroking the 
hair of a cat in the opposite direction than it lies. We may 
not see our patients early enough to hear this rale. It is 
caused by the air rushing into the air cells and separating 
their walls which have become more or less adherent by the 
exudate. Mucus rales are a bubbling sound, heard in the up¬ 
per portion of the chest on both sides. It sounds like minute 
bubbles due to blood, pus or serum, or an admixture of them. 
They are heard both on inspiration and expiration. If heard 
on the lower portion of the chest they are called sub-mucus 
rales. These bubbling sounds change their place as the 
material moves along in the bronchial tubes. The sub-crepi¬ 
tant rale is heard in croupous pneumonia. Here we have the 
exudate in the air cells changing with liquid. The air pass¬ 
ing in and out gives rise to a minute bubbling sound. It is 
heard in the third or revolving stage of pneumonia, both on 
inspiration and expiration. 
Other Sounds .—Gurgling sounds may be heard in the 
second stage of pneumonia. It is due to the movement of 
fluid in the large tubes, and heard on inspiration and expira¬ 
tion. It is heard at the anterior part of the chest over the 
trachea and bronchi. Another sound is metallic tinkling. It 
is heard over the chest and at the nostrils, in pleurisy. It is . 
