ANAPHYLAXIS 175 



unprejudiced by bacteriological, pathological or 

 biological findings. This alteration may relate to 

 the quality and quantity of the symptoms and to 

 their rate of development. Allergy seems to be 

 associated more with some infections than with 

 others. Experimentally it can best be studied by 

 observing the effect of cow-pox inoculation in 

 primary and subsequent vaccinations. The re- 

 vaccinated overcomes the whole process with a very 

 slight local reaction a few millimeters in size, while 

 the person vaccinated the first time shows extensive 

 local inflammation, fever, and other general symp- 

 toms. If the reaction is studied on the day follow- 

 ing the vaccination, we shall find that the re- 

 vaccinated is really hypersensitive, because at this 

 time the first vaccinated does not show any reaction, 

 while the revaccinated responds with a local inflam- 

 matory process. In tuberculosis, glanders, and 

 other infections the injection of extracts of the 

 infecting bacterium (tuberculin, mallein, etc.) pro- 

 duces characteristic local and general symptoms, 

 because of the specific hypersensitive condition 

 present in such infections. These reactions can 

 therefore be employed in the diagnosis of such in- 

 fections. The symptoms of hay fever, and of urti- 

 caria appear to be merely examples of proteid 

 hypersensitiveness. 



Supposed Relation to Precipitin Action. 

 Attempts have also been made to associate the 



