X PREFACE 



antibody. The sensitisation of the animal is due to 

 the presence of the latter. Indeed, it is sufficient to 

 introduce a little blood from a rabbit sensitised to 

 horse serum subcutaneously into another guinea-pig 

 to witness the latter becoming sensitive in its turn 

 in the space of a few hours. The foreign blood intro- 

 duced into the animal as a fully prepared antibody 

 confers upon it a state of passive anaphylaxis. The 

 sudden symptoms which follow the exciting injec- 

 tion are caused by the affinity of the antigen for the 

 antibody. 



So far there is entire agreement between scientists,, 

 but divergences begin to manifest themselves when 

 one is called upon to explain how the reaction of the 

 antigen and the antibody set up the anaphylactic 

 shock. In the opinion of one school the product of 

 this reaction is a very potent poison and the anaphy- 

 lactic symptoms depend upon an intoxication. This 

 is the opinion of Charles Richet, and it is shared by 

 the majority of authors. 



Dr. Besredka maintains that there is no anaphy- 

 lactic poison. A harmless complex results from the 

 union of antigen with antibody. The antibody be- 

 comes attached to certain nerve-cells, and the antigen 

 combines with it and suddenly penetrates the nerve-^ 

 cells. This produces the disturbance which finds its 

 expression in the anaphylactic shock. If the cells are 

 rendered anaesthetic they do not react, and this ex- 

 plains the harmlessness of the second injection in the 

 sensitised guinea-pig when it is anaesthetised with 

 ether. In the same way there will be no anaphy- 

 lactic shock if the introduction of the antigen be 

 graduated so that the combination with antibody is 

 brought about slowly and not hurriedly. 



This conception of anaphylaxis is a simple one; 

 it takes account of known facts, and it has led Dr. 

 Besredka to carry out the practice of graduated injec- 



