Abstract

The facts relating to the discovery of fowl cholera vaccine did not develop along the lines described by a long tradition of scientific commentators. This results very clearly from a close analysis of Pasteur's unpublished handwritten notes. The aim of the present paper is to show that: 1) the role of chance in this discovery has no importance whatsoever; 2) in the fall of 1879 Pasteur made no crucial experiment; 3) the function of "genius" in Pasteur's discovery is to be considered less important than one might think, as appears on reading the 'Cahier de laboratoire'; 4) Emile Roux played a major role in this discovery; 5) in the summer of 1880 Pasteur had no clear idea about the vaccine or about the virus attenuation method of fowl cholera