STUDIES ON THE PNEUMOCOCCUS : III. DISSOLUTION OF PNEUMOCOCCI IN PNEUMONIC CELLULAR MATERIAL AT VARYING HYDROGEN ION CONCENTRATIONS. RESISTANCE OF CERTAIN OTHER ORGANISMS TO DISSOLUTION.

Pneumococci of Types I, II, and III undergo dissolution when mixed with cellular material from the pneumonic lung at a pH of 6.95 and 5.5, but not at a pH of 4.5. An enzyme derived from the bacteria themselves or from the cellular material may be the cause of the dissolution. Streptococcus hœmolyticus and Streptococcus viridans do not undergo dissolution under similar experimental conditions.