HOST RESPONSE TO ANTIGENIC ACTION 467 



of non-sensitive children no reaction took place, whereas the serum 

 of sensitive children failed to neutralize or inhibit the action of the 

 antigen. Gutfeld and Nassau assumed that individuals failing to 

 react to the intradermal test possessed in the skin or in the serum 

 a specific antibody similar to antitoxin, inherited in the case of 

 young nurslings or developed during an attack of bronchopneu- 

 monia and then later lost. 



Jamieson and Powell (1931) 676 believed that pneumococci pro- 

 duce toxic substances not unlike those obtained from various 

 streptococci. The substances could be detected and measured by 

 skin tests on human subjects and by similar tests performed on 

 rabbits of a suitable breed. Serum yielded by horses that had been 

 treated by subcutaneous injections of the toxic substance pos- 

 sessed the ability to neutralize the skin-reactive property of the 

 toxic antigen. In a second paper, Jamieson and Powell reported 

 the development of positive reactions when filtrates of pneumo- 

 cocci of Types I, II, III, and IV were injected intradermally into 

 large rabbits. Similar reactions to filtrates of all four pneumo- 

 coccal types were also observed in the case of twelve normal hu- 

 man subjects, who exhibited a degree of sensitivity approximately 

 one hundred times that shown by rabbits. The toxic filtrates could 

 be neutralized by the special immune serum developed in horses by 

 the injection of the same antigen. 



The work of Coca 245 bears certain resemblances to that of 

 Jamieson and Powell. 676 Filtrates of pneumococci exhibiting toxic 

 action for young children when injected subcutaneously also in- 

 duced local inflammatory reactions in the skin at the site of punc- 

 ture. In Coca's first experiments the filtrate was introduced into 

 the child's skin and at the same time a considerably larger dose of 

 the filtrate was injected subcutaneously. Subsequent skin tests per- 

 formed with the filtrate on the children so treated were attended 

 by a diminished reaction. Treatment of the subjects with a toxoid 

 prepared by heating the filtrates with formalin tended to reduce 

 the number of positive reactions. When applied to adults giving no 



