HISTORY OF PNEUMOCOCCUS: 1890-1900 21 



The decade of the eighties saw the first important chapter in the 

 history of Pneumococcus written, edited, and given to the medical 

 world. Its causative association with pneumonia, meningitis, and 

 certain localized infections was accepted as established despite 

 some confusion concerning its various identities. Fraenkel, and not 

 Friedlander, was now looked upon as its true sponsor. The early 

 and necessarily crude and incomplete immunization experiments 

 were to encourage a closer study of this phase of the activity of 

 Pneumococcus. The next ten years were to be less fruitful, but here 

 and there facts were disclosed which, with a better understanding, 

 were to take on a new significance. 



1890-1900 



In the second decade, Foa and Carbone 463 used soluble products 

 of Pneumococcus to stimulate the immune response in rabbits, and 

 sought by chemical means to refine and concentrate the antigenic 

 principle — believed to be a poison or toxin — elaborated during 

 pneumococcal growth. The authors went no further than to say 

 that while the refined substance, which had been precipitated by 

 ammonium sulfate and refined by dialysis, failed to kill the animal, 

 it produced marked physiological changes — a statement which is 

 scarcely descriptive of any specific action. 



The Klemperers (1891) 723 " 6 might justly be looked upon as the 

 forefathers of antipneumococcic serum therapy. They immunized 

 rabbits with sputum obtained from pneumonia patients after re- 

 covery, with purulent, but bacteria-free, pleural exudate, with 

 heated glycerol extracts of pneumococci, and with heated whole 

 and filtered broth cultures. They introduced the intravenous route 

 of injection, finding that the immunity to subsequent infection ap- 

 peared far more rapidly than after subcutaneous injection — in 

 two to three days against fourteen days. They found that duration 

 of immunity varied from twenty-one days to more than six months. 

 Their greater contribution was the observation that the young of 

 immunized mother rabbits were usually passively protected, and 



