into three stages. The first stage being that in which a deposit of
tubercular matter occurs in the lung tissue, the second is entered on
when the tubercles soften, and the third when they have melted down,
been expectorated, and cavities have formed. But the real beginning of
this most insidious and justly dreaded disease not infrequently
antedates for a long time, often for several years, the deposit of any
tubercular matter. During all this time an expert examiner can detect
the slight but very significant changes already taking place in the
pulmonary organs. Physicians determine the condition of the lungs
chiefly through the sounds elicited by percussion of the chest walls
by the end of the middle finger, or a small rubber hammer adapted to
the purpose, and by those produced by the respired air rushing in to
and out of the bronchial tubes and air vesicles. The percussion sounds
yielded by the chest during what has been aptly called the
pre-tubercular stage do not differ from those elicited in health,
because it is only when some morbid matter exists in the lungs that
the percussion note is altered, therefore negative results only are
obtained in the real first stage by this mode of examination. But
important information can be obtained by interrogating the sounds due
to the inspired air rushing into and distending the air vesicles. When
the lungs are perfectly healthy, these are breezy and almost musical.
During the pre-tubercular stage they become drier and harsher;
qualities of evil omen that continue to increase as time passes, if
properly directed means be not adopted to correct the evil; but so far
none of the symptoms that indicate the slightest deposit of tubercle
can be detected, but the breathing capacity of such persons is never
up to the full requirements of the system. The reader is referred to
the table already given, which exhibits the decline of the breathing
capacity of persons suffering from consumption in its several stages.
When the disease has made such decided progress that tubercles are