PHYSICAL DIAGNOSIS. 
497 
the former, an instrument, the stethoscope, is placed between 
the ear and the part to be examined. Immediate auscultation 
is when the ear is laid directly against the part. The veter¬ 
inary practitioner should depend upon the ear only. An ex¬ 
cuse for the use of a stethoscope is afforded when parts have 
been blistered, but a handkerchief may be laid between the 
ear and the part. To use the stethoscope successfully, it is 
necessaiy to press the chest-piece quite hard against the parts, 
an action which the animal resists. Applied to the chest, the 
object of auscultation is to discover sounds, normal or abnor¬ 
mal, in connection with the lung substance, pleura or bron¬ 
chi. It also notes absence ol sound and sounds conducted 
from other parts. 
The class of normal sounds heard over the lungs are bron¬ 
chial breathing and the vesicular murmur. Bronchial breath¬ 
ing is normal when heard in the middle and upper third of 
the chest. The respiratory murmur is normal when heard 
over the middle portion and less distinctly over the superior 
and inferior thirds. Bronchial breathing sounds like a mod¬ 
erate current of air passing steadily through a tube or out of 
the nozzle of a bellows. It is closely imitated by making the 
sound of the letter K in the roof of the mouth. It is best 
heard over the anterior part of the chest at the bifurcation 
of the trachea. In health, at the sides of the chest it is apt to 
be lost in the vesicular murmur. The vesicular murmur is 
a sighing sound. It may be plainly heard over the chest of 
bovine, or over the human chest. It is likened to the sound 
produced by the wind blowing steadily through green leaves. 
Bronchial breathing and the vesicular murmur are abnormal 
when heard in places other than in health. In pneumonia 
the vesicular murmur may be lost in the middle third and 
heard more plainly in the superior and inferior thirds of the 
chest. It then becomes an abnormal sound. Bronchial 
breathing is also an abnormal sound when it is heard plainly 
in the upper and lower third, and lost in the middle third due 
to blocking of that part of the lung with exudate. These two 
sounds may be increased or diminished in their normal situa¬ 
tion. In pneumonia, one part of the middle third may be 
