SYMPTOMATOLOGY.--The most common form of acute bronchitis, by many writers styled catarrhal bronchitis, acute bronchial catarrh, etc., presents considerable variety of symptoms, according to the extent of the membrane involved and the intensity of the inflammatory process. As a general rule, the disease commences with slight chilliness or unusual sensitiveness to slight changes of temperature, accompanied by a sense of soreness and oppression behind the sternum and sometimes across the whole chest, with a frequent and rather dry, harsh cough. In many cases there is during the first day or two coincident congestion of the membrane lining the nostrils, fauces, and larynx, causing sneezing, with some feeling of soreness in the throat and hoarseness, also a heavy dull pain in the head, much increased by coughing. By the second day a moderate general fever has supervened, characterized by dryness and moderate heat of the skin, flushed face, slight increased frequency and fulness of the pulse, more sense of oppression and soreness in the chest, with a continuance of harsh, dry cough, which often causes soreness in the epigastrium, radiating laterally in the direction of the attachments of the diaphragm to the inner surface of the ribs. On the second or third day the inflamed membrane begins to be less dry and the paroxysms of coughing bring up a scanty expectoration of a tenacious, somewhat frothy mucus, which gradually increases until about the fourth or fifth day, when it becomes more opaque, sometimes yellowish, and much more easily expectorated. At the same time that the expectoration changes to a more opaque condition, the general febrile symptoms begin gradually to abate, and the cough is accompanied by less sore pain both in the chest and head. In the milder class of cases, the decline in all the general symptoms is so rapid that by the seventh or ninth day, convalescence is established. But in the more severe cases the more important symptoms may continue through {170} two weeks, and convalescence not be complete until the end of the third week. And in some of the cases the inflammation does not disappear on the subsidence of the febrile symptoms, but degenerates into a chronic form, causing a continuance of cough, with some muco-purulent expectoration and slight soreness in the chest, through an indefinite period of time. The disease is most likely to take this course when it occurs in young persons having a scrofulous diathesis, or in connection with eruptive fevers or pertussis, or in the aged afflicted with rheumatism. During the active stage of ordinary cases of bronchitis the urinary secretion is diminished in quantity, redder than natural, and deficient in chloride of sodium, and the bowels are inactive. But after the crisis of the disease is passed, as indicated by the character of the expectoration, the renal and intestinal discharges soon return to their normal condition.