4 QUATERCENTENARY STUDIES IN PATHOLOGY 



Active Immunity. — The methods employed in actively immunising 

 animals have been very numerous, attenuated cultures, small doses of 

 virulent cultures, filtrates of fluids containing the pneumococcus, cultures 

 killed by heat or chemicals, etc. Many investigators, disappointed with 

 the varying results obtained by these methods, endeavoured to concentrate 

 the immunising substance. Thus, the Klemperer (3) brothers produced 

 from filtered cultures a yellowish-white powder, which they regarded as 

 the specific poison of the pneumococcus — the pneumotoxin — and they 

 tried to obtain immunity by inoculating it on animals. Foa and Scabia 



(4) produced by similar means a " pneumo-protein." 



Passive Immunity. — In 1891, researches on the subject of passive 

 immunity were published almost simultaneously by Foa and Carbone, 

 Emmerich and Fawitzky, and the Klemperers. Emmerich and Fawitzky 



(5) demonstrated that by injection of the blood serum or of pieces of 

 muscles or organs of immunised rabbits, animals could be protected 

 against a dose of culture injected simultaneously or a short time before. 

 Foa and Carbone were pioneers in the therapeutic employment of serum 

 in pneumonia in man, and in the four cases treated the favourable issue 

 was hastened, the critical fall of temperature occurring in 24 to 48 hours 

 after injection. Serum from pneumonia patients, in different stages of 

 the disease, was inoculated into animals, but with no beneficial result — 

 in fact, in several cases the fatal issue seemed hastened ; if used 24 hours 

 after the infection no beneficial result was obtained in any case. 



G. and F. Klemperer used therapeutically the serum taken from 

 pneumonic patients by leeches or blisters in the treatment of artificial 

 pneumococcal infection in rabbits, and with apparently favourable results. 

 In the 12 cases treated thus, the crisis occurred immediately in 5, and 

 there was a transient fall of temperature in 7. 



Washbourn (6), however, noticed that the serum of immunised animals 

 often completely failed to protect other animals from infection, and, 

 to attain still higher degrees of immunity, injected a pony with 

 broth cultures killed by heat, then agar cultures, and subsequently living 

 and highly virulent broth cultures. Better results were obtained, the 

 serum protecting animals against infection, but, on its employment in 

 two cases in man, whether the cure obtained was due to the serum or 

 not, Washbourn was uncertain. 



The Italian investigator, Pane (7), immunised cows and donkeys. 



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