BACTERIOLOGY OF THE BLOOD.
Of the total number of 175 cases of lobar pneumonia in which I have made blood cultures, 145 cases were reported in another article,1 and 30 have been made since. In this series of 175 cases the pneumococcus was isolated in all but 15—that is, in over 91 per cent. Usually, only one culture (3 to 4 flasks) was required to demonstrate the presence of pneumococci in the blood, though occasionally a second culture was necessary to obtain the organism. In 11 of the 15 negative casea, only one culture was made, there being no opportunity for a subsequent examination. In the remaining 4 cases it was impossible, by repeated cultures, to demonstrate the pneumococcus in the blood. In one of these 4 a careful search in smears prepared directly from the blood showed undoubted pneumococci.The leucocytosis in these 4 cases was high, and I was inclined to believe that the negative findings were the result, possibly, of an active phagocytosis; but the fact that in other cases with equally high leucocyte counts there were positive results, made this explanation seem improbable.