There are three forms of pneumonia, croupous, catarrhal, and chronic. We will first call attention to

Croupous Pneumonia

The Symptoms of Croupous Pneumonia

Marked chill, followed by fever which rises often very high, even on first day; headache; shortness of breath, patient breathing thirty to fifty times a minute instead of sixteen to twenty times; pain in chest, at the seat of the disease, of a piercing or stabbing character; short, ringing cough; expectoration of rust-colored mucus, which is very tough and tenacious; careful examination of sputa shows casts of small tubes; pulse rapid, ninety to one hundred and fifty; sometimes jaundice; redness of cheek upon the affected side; eruption upon the lips; crackling sound heard upon placing ear to affected side.

The above-named symptoms generally follow one another in succession, with exception of the high pulse, which is present all through the disease. They are sometimes separated into three groups, known as the three stages of the disease. 1. Engorgement. In this stage the affected part of the lung is intensely congested with blood, and the air-passages contain a viscid mucus which glues together the walls of the small bronchial tubes, producing a crackling sound when the patient takes a deep breath, which can be easily heard by listening at the point of pain. The latter symptom is always present in this stage, except in very old persons, in whom it is sometimes absent. It is similar to the pain of pleurisy, which is also present at this stage, the covering of the affected portion of the lung participating in the inflammation. 2. Hepatization. In this stage the air-cells are filled with a tenacious exudation, which causes the chest to lose its natural resonance. When percussed, the sound obtained is flat or dull. 3. Resolution or purulent infiltration. At this stage, the matter in the air-cells is usually liquefied and absorbed-not expectorated as many suppose. In case absorption does not occur, suppuration sometimes takes place, often extending to the lung, even forming cavities of greater or lesser size. In other cases, the lung remains solidified, and the patient suffers with chronic pneumonia, or consumption.

Pneumonia sometimes occurs as a complication of typhoid fever and other acute diseases. It is also sometimes attended by acute catarrh of the stomach and bowels. It is not a very fatal disease in young and healthy subjects, but in weak children, in old persons, and in habitual drinkers, it is a very fatal malady.

The Causes of Croupous Pneumonia

The exciting causes of the disease are not well understood. It is generally attributed to "taking cold;" but there is some doubt whether this is an important cause of the disease. From an extended study of the subject, Dr. H. B. Baker, Secretary of the State Board of Health of Michigan, has ascertained that pneumonia is most frequent when the temperature and amount of moisture in the air is low, and the amount and force of wind and the proportion of ozone is high. This conclusion he has reached by a comparison of the weekly reports of diseases made to the Board of Health, by its numerous correspondents, with the daily records of the various meteorological observers in various parts of the State. While this kind of investigation is still in its infancy, the results which have already been obtained are exceedingly interesting, and may probably be considered as reliable. Pneumonia occurs at all periods of life, but is most frequent in males and in aged and feeble persons.