54 
BACTERIOLOGY. 
Active 
immunity 
The men¬ 
ingo¬ 
coccus 
The serum is given intravenously. The first dose 
recommended is ioo cubic centimeters diluted to 250 
cubic centimeters with salt solution. This may be 
repeated every twelve hours for 3 or 5 doses. 
The results of serum treatment in Type I infec¬ 
tions at the Hospital of the Rockefeller Institute have 
been favorable. In 107 cases treated with the serum 
8 died or 7.5 per cent. The mortality in untreated 
cases is 24 to 30 per cent. Similar results have been 
obtained by others. 
Efforts have been made in the army to immunize 
troops to pneumococcus infection by the use of vaccines 
containing many different strains of pneumococci. 
Favorable results have been reported but the time 
elapsed is too short to make any very definite state¬ 
ment as to its efficacy. 
Cerebrospinal meningitis is an infectious disease 
in which the agent of infection produces an inflamma¬ 
tion of the covering of the brain and spinal cord. The 
infection may be caused by any one of a number of 
micro-organisms—-the pneumococcus, the typhoid bacil¬ 
lus, the influenza bacillus, the tubercle bacillus, the 
Streptococcus or Staphylococcus pyogenes. When the 
meningitis results from infection with these organisms 
it is generally secondary to an infection elsewhere in 
the body, as, for example, during pneumonia, typhoid 
fever, pulmonary tuberculosis, or septicemia. 
The primary form of meningitis, the form that 
frequently occurs in epidemics and is more commonly 
called spotted fever, is due to infection with the 
