The frequency of the pulse corre sponds, as a rule, to the intensity of the fever. Early in the disease it is full, bounding, and tense, and in frequency ranges from 100 to 120. Later, when hepatization is extensive, it becomes feeble, small, and irregular, and occasion ally becomes dicrotic. Collapse from heart-failure may occur during the later periods of the disease, when an extensive area of the lung is involved and is espe cially to be apprehended at the period of the crisis.
Leucocytosis is a marked feature of the disease, but does not invariably occur.
The leucocytcs arc increased from the earliest periods of the disease and this in crease persists during the continuance of the fever. At the time of the crisis the increase in the white cells disappears, the decrease frequently beginning a few hours before its actual occurrence. When defervescence is by lysis, the decline of leucocytosis is more gradual. The num ber of white cells may vary from the nor mal to 35,000 or more, as in the case reported by Cabot, in which the count was 94,600. The absence of leucocytosis indicates a very unfavorable prognosis in all but the mildest cases. All the instances in the Philadelphia-Hospital series in which leucocytosis did not cur terminated fatally. Its occurrence, however, is to be regarded as neither a good nor bad sign. In one instance at the Philadelphia Hospital, in which the white-cell count was 37,000, death oc curred. The red blood-cells show a slight decrease. This is pointed out by Cabot as being partly due to blood-destruction, as is evidenced by the presence of bilirubin in the urine and the not infre quent occurrence of jaundice." Letteocytosis usually occurs both in croupous and in catarrhal pneumonia, varying, however, both in degree and in duration. The leucocytosis is of the act ive polymorphous variety, the actively aniceboid corpuscles being increased in greater proportion than the other forms. The eosinophile-cells are usually greatly reduced in number. Absence of leucocy tosis is, as a rule, an unfavorable sign, and cases in which the number of white cells is normal or subnormal usually ter minate fatally. The leucocytosis of pneu monia is the result. of chemotactie in fluences, the toxic substances elaborated by the pnemnoeoccus being positively chemotactic and attracting to the circu lation the amceboid polymorphous cor puscles. In addition there is the reaction of the tissues to the irritant influence of toxic agents. When this reaction does not occur, as when the systemic condi tion is bad, then there is no leucocytosis. Alfred Stengel (Jour. Amer. Med. Assoc., Aug. 19, '99).
Study based upon 50 cases of lobar pneumonia. Early in the disease the alveoli contain many cells almost iden tical in appearance with the so-called transitional cell of the blood. They are
usually slightly larger than the polynu clear leucocyte, and contain an irregular vesicular nucleus, surrounded by a rim of protoplasm, containing either a few granules or none at all. In a case in which death occurred eleven hours after onset, there were great numbers of these cells in the exudate and no polynuclear leueocytes. Large phagocytic cells are found in all stages of the disease, but in greatest number in gray hepatization. The inclusions consist chiefly of polynu clear leucoeytes and lymphocytes, more rarely of red blood-corpuscles. These phagocytic cells probably play an impor tant part in resolution. Similar cells are found in the lymphatics, in the pleural exudate, and in the bronchial lymph nodes. The fibrin is not formed by a de generation of the alveolar epithelium, but conies exclusively from the exuded blood-plasma. The lymphatics are in volved late in the disease. There is pro liferation of the endothelium, and they become distended with cells, serum, and fibrin. Early in the disease there is no infiltration of the interstitial tissue. In patients dying during the second week there is often a great infiltration with lymphoid and plasma-cells. As a rule, the longer the duration of the disease, the greater the number of plasma-cells. J. H. Pratt (Phila. Med. Jour., June 2, 1900).
Anorexia, nausea, and vomiting are not uncommon, and jaundice is of not in frequent occurrence. This, when slight, possesses no prognostic significance, but deep jaundice occurring in the course of the disease is usually an evidence of seri ous constitutional infection, and occurs only in the severe cases. To these cases the term bilious pneumonia has been ap plied, and the jaundice is usually asso ciated with vomiting, diarrhoea, tympa nites, marked nervous symptoms, and sometimes slight hepatic enlargement. In most cases of pneumonia, as in all acute infectious diseases, the spleen is en larged. The kidneys are to some extent involved and occasionally an acute ne phritis develops. Febrile albuminuria is present in many cases, and occurred in 45 cases of the Philadelphia-Hospital series. There is marked diminution of the chlorides, which is probably due partly to the amount accumulated in the exudate and partly to the diminished in take, the result of the loss of appetite; reappearance of the chlorides takes place during the stage of resolution. Other wise the urine possesses the ordinary characteristics of febrile urine,—scanty, high colored, and acid in reaction. At the time of crisis it may be markedly in creased and shows upon standing a heavy deposit of urates. In cases attended with jaundice the urine presents the evidences of the coloring matter of the bile.