The therapeutic measures used in the treatment of infections may be divided into two general classes : first, those specific substances which are supposed to destroy the infecting organism or neutralize its toxins, and second, those which aim to strengthen the natural processes that normally bring about recovery.
Of the specific substances which either destroy the infecting organism or render toxic products innocuous, we have specific antiserums and certain chemotherapeutic substances. Among the most effective antiserums may be mentioned diphtheria antitoxin, tetanus antitoxin, antimeningitis serum, and a serum for the treatment of one form of pneumonia. Many others have been prepared, but there is still some doubt as to their real value as therapeutic agents. Of the chemical substances which have a direct destructive action on the infecting organisms, quinin, salvarsan and emetin are probably the most important. Bacterial vaccines, autogenous and stock, have been extensively used in the treatment