THE RELATION OF THE PNEUMOCOCCUS TO THE PRODUCTION OF ACID IN FLUID CULTURE MEDIUMS AND THE REACTION OF THE PNEUMONIC LUNG

The pneumococcus may continue to live in plain bouillon and in calcium carbonate-glucose bouillon for a period of from three to six months. Its viability in glucose bouillon without calcium carbonate is only a few days. The acidity of a 1 per cent. glucose bouillon culture, for example, rises rapidly, as indicated by titration from an initial reading of 0.3 c.c. twentieth-normal sodium hydroxid to 3 c.c. twentieth-normal sodium hydroxid and by colorimeteric determination of the H-ion concentration from an initial reading of from 7.3 to 5.5 with death of the organisms. That an increase in the acidity is to be regarded as an important factor in the death of the organisms is suggested by the fact that the addition of calcium carbonate to the glucose bouillon before implantation of the pneumococcus maintains the life of the culture for a long period, and that after reimplantation of a real-kalinized glucose