288 PROTECTIVE INOCULATIONS. 



"This question of quantity was manifest in our experiments. Not only 

 did it vary in different species, the rabbit and the dog, for example, but it 

 may vary in the same species/' 



The identity of " Davaine's septicaemia " with Pasteur's cholera des 

 ponies is made still more probable by the experimental evidence 

 offered by Toussaint in a communication to the French Academy of 

 Sciences, made by M. Bouley at the seance of July 25th, 1881. In 

 this communication Toussaint says : 



"Three years ago, July 8th, 1878, I had the honor to present to the 

 Academy an account of a malady due to microbes, which I identified with 

 that studied by Davaine in 1864 and 1865, and which he differentiated from 

 anthrax, for which it had been mistaken by Leplat and Jaillard. 



"In the month of December, 1878, I made acquaintance with fowl 

 cholera, and already, in my thoughts, I identified this disease with that 

 which I had observed in my experiments made early in the year. The mi- 

 crobes of the two diseases resembled each other perfectly and behaved the 

 same when inoculated in rabbits. I had, even in 1879, sent to M. Bouley 

 two notes, in which I called attention to the analogies which exist between 

 the parasites of the two diseases and the lesions which they determine, not 

 only in the rabbit but also in pigeons and fowls. 



"The experiments of the same kind made at the end of 1879 and in 1880 

 caused me to insert the note published on page 301, vol. xci., of the Comptes- 

 rendus, under the title of ' Identity of Acute Experimental Septicaemia 

 and Fowl Cholera.' I gave a resume in this note of five series of experi- 

 ments which had demonstrated to me that inoculations of the microbe of sep- 

 ticaemia give rise to the manifestations of fowl cholera. These results have 

 recently been confirmed by additional facts." 



Toussaint closes his paper by some remarks upon the origin of 

 epidemics of fowl cholera, which we quote because we believe that the 

 additions made to our knowledge of the microbe which causes this 

 disease give support to the views advanced by him in 1881 : 



" The causes which determine epidemics of fowl cholera are yet unknown. 

 It has been supposed that putrefactive substances may give rise to them, and 

 this has led to the recommendation of cleanliness and disinfection for their 

 prevention. The microbe which kills the first fowl in an epidemic certainly 

 came from some anterior generation which had killed others. But how was 

 it perpetuated ? Do not the facts which demonstrate the development of sep- 

 ticaemia from material undergoing putrefaction throw some light on the ques- 

 tion of etiology ? Is it not probable that the fowls find the conditions of 

 infection with cholera in the presence of organic matter undergoing putrefac- 

 tion, which may serve as a culture medium for the germs of septicaemia 

 which are in suspension in the air together with the ordinary germs of putre- 

 faction?" 



Pasteur's first communication relating to the etiology of fowl 

 cholera was made to the French Academy at the seance of February 

 9th, 1880. In this communication he calls attention to the fact that 

 when fowls are fed with bread or meat soiled with a small quantity 

 of a culture of the microbe of fowl cholera they become infected and 

 their discharges contain the bacillus in large numbers, a fact which 



