23 



Table of the Natural Cases of the Disease. 



EXPEKIMENT.S ON INFECTING CHICKENS AND PiGEONS. 



Fowl Diphtheria or Roup, prevalent in America, appears and passes for an 

 infectious disease, because we find that from twenty to ninety per cent, of all 

 chickens in a flock may become diseased. It is, therefore, of great importance 

 to know how infection takes place, and how the disease is transferred from bird 

 to bird. In order to orient our observations with what has already been noted 

 by others, it will be necessary to briefly summarize a portion of the literature 

 which ihas appeared. 



