ANTIBODY AND AGGLUTININ IN PNEUMOCOCCUS PNEUMONIA.

1. Protective substances and agglutinins were not demonstrated in the blood of patients with pneumonia untreated with serum before the fall in the temperature by crisis or lysis. 2. Protective substances and agglutinins were frequently demonstrated in serum treated patients during the course of the disease. 3. Protective substances and agglutinins were usually present at the time of the temperature fall in patients untreated with serum and persisted for days or weeks thereafter. 4. Protective substances have an important bearing on the outcome. A large proportion of those with protection recover and a large proportion without it die. 5. Agglutinin and antibody may appear simultaneously or one may precede or be present without the other. 6. Tests for agglutinin are unreliable as a control of dosage of specific serum.