ts, and marine at that, and can live only saturated with, and bathed
in, warm saline solution. Dry them, or even half-dry them, and they die.
Even the pavement-cells coating our skin surfaces are practically dead
before they reach the air, and are shed off daily in showers.

We speak of ourselves as "land animals," but it is only our lungs that
are really so. All the rest of the body is still made up of sea
creatures. It is little wonder that our lungs should pay the heaviest
penalty of our change from the warm and equable sea water to the gusty
and changeable air.

Even if we have set down the lung as a point of the least resistance in
the body, we have by no means thereby explained its diseases. Our point
of view has distinctly shifted in this respect within recent years.
Twenty years ago pathologists were practically content with tracing a
case of illness or death to an inflammation or disease of some
particular organ, like the heart, the kidney, the lung, or the stomach.
Now, however, we are coming to see that not only may the causation of
this heart disease, kidney disease, lung disease, have lain somewhere
entirely outside of the heart, kidney, or lung, but that, as a rule, the
entire body is affected by the disease, which simply expresses itself
more violently, focuses, as it were, in this particular organ. In other
words, diseases of definite organs are most commonly the local
expressions of general diseases or infections; and this local
aggravation of the disease would never have occurred if the general
resisting power and vigor of the entire body had not been depressed
below par. So that even in guarding against or curing a disease of a
particular organ it is necessary to consider and to treat the whole
body.

Nowhere is this new attitude better illustrated than in pneumonia. Frank
and unquestioned infection as it is, wreaking two-thirds of its visible
damage in the lung itself, the liability to its occurrence and the
outlook for its cure depend almost wholly upon the general vigor and
rallying power of the entire body. It is perfectly idle to endeavor to
avoid it by measures directed toward the protection of the lung or of
the air-passages, and equally futile to attempt to arrest its course by
treatment directed to the lung, or even the chest. The best place to
wear a chest-protector is on the soles of the feet, and poulticing the
chest for pneumonia is about as effective as shampooing the scalp for
brain-