The progress of tubercular consumption has been divided by pathologists
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
already deposited in the lungs in sufficient quantity to give rise to
the physical signs by which their presence is proved, this carefully
compiled table shows that the diminution of the vital capacity already
amounts to one-third of that considered by Dr. Hutchinson to be
necessary to the maintenance of health.
During the pre-tubercular stage the breathing capacity rarely falls so
much as 33 per cent. below the healthy standard, but it is never up to
the normal vital volume. This fact is most significant, especially
when it occurs in an individual whose relatives have succumbed to this
disease; but it rarely attracts sufficient attention from such persons
as to induce them to have their breathing capacity measured, much less
to take effective measures to bring and keep it up to the healthy
standard. So long as there are, to them, no tangible symptoms of
approaching mischief, and they feel fairly well, they act as if they
thought "that all men were mortal but themselves." Yet it is from
among persons who have an inherited but latent tendency to tubercular
disease, and whose lung power is below par, that the great army of
consumptives who die every year is recruited. It is very difficult to
induce persons who ought to be interested in this matter to take
effective measures for their future safety when the terrible symptoms
accompanying the last stages of the disease often fail to shake the
sufferer's confident expectation of recovery; and we sometimes see
them engaged in laying plans for the future when death is imminent. I
regret deeply to be obliged to make these statements, because I am
convinced that if the suggestions laid down in this work were
generally reduced to practice by those who have reason to dread the
development of tubercular disease, many valuable lives would be saved.