real condition. The structures surrounding the
air cells are inflamed and from the inflamed tissues a secretion exudate
is poured out into the cells. This is expectorated, thrown out, by
coughing; but it is poured out into the cells faster than it can be spit
up and consequently it remains in some of the cells and fills them up.

The air does not get into such cells and they fill, with many others, and
make that section solid. When the patient is improving he keeps on
spitting this up, until all is out and the air cells resume their normal
work. Sometimes they remain so and we have chronic pneumonia.

Causes of Pneumonia.--Pneumonia occurs frequently as a complication of
other diseases, such as typhoid fever and measles. Yet the majority of
cases occur spontaneously. Many times the disease seems to be induced by
exposure to the cold, and there can be no doubt that such exposure does at
least promote the development of this affection. It seems, however,
probable that there is some special cause behind it without which the
exposure to cold is not sufficient to induce this disease. Pneumonia may
occur at any period of life, and is more common among males than females.
It occurs over the entire United States, oftener in the southern and
middle, than in the Northern States; it is more frequently met with during
the winter and spring months than at other times in the year.

Symptoms.--The onset is usually abrupt with a severe chill and chills
lasting from fifteen minutes to an hour, with the temperature suddenly
rising and an active fever. There is usually intense pain in a few hours,
generally in the lower part of the front of the chest, made worse by
breathing and coughing. The patient lies on the affected side so as to
give all chance for the other lung to work, cheeks are flushed, with
anxious expression; the wings of the nostrils move in and out with each
breath. The cough is short, dry and painful. Rapid, shallow, jerky
breathing, increasing to difficult breathing. On the first day the
characteristic expectoration mixed with blood appears (called rusty).
Pulse runs from 100 to 116, full bounding, but may be feeble and small in
serious cases. After three or four days the pain disappears, the
temperature keeps to 104 or 105, but falls quickly the seventh, fifth,
eighth, sixth and ninth day in this order of frequency. In a few hours,
usually twelve, the temperature falls to normal or below, usually with
profuse sweating a