80 ANTHRAX 



presence of the bacilli in the blood of sick animals before death. It is 

 interesting to note that he fell into an error concerning the motility of 

 the bacilli. He states that when seen in fresh blood they are non- 

 motile, but later they become highly motile. This was, of course, due 

 to contamination. It should be noted that Brauel also made examina- 

 tion of the blood of various domestic animals suffering from other 

 diseases, and demonstrated the absence of the bacillus in these. 



In 1863 Davaine published three valuable papers on anthrax. In 

 the first he states that in 1850 Rayer inoculated sheep with the blood 

 of others dead from anthrax, and in this way transmitted the disease. 

 It appears that Rayer published a short note of this work in the 

 Bulletin de la Societe de Biologic in 1850, but I have not had access 

 to this publication. Davaine's own work was of the greatest value 

 and shows great skill for that time. Probably the most important 

 experiments that he made were those in which he demonstrated that 

 the blood of an animal sick with anthrax is not capable of transmitting 

 the disease to others unless it contains the bacillus. It may be of 

 interest to describe briefly the experiments which led to the establish- 

 ment of this fact. Rabbit A was inoculated with anthrax blood. 

 Forty-six hours later, examination showed no bacilli in the blood of 

 Rabbit A. At that time twelve or fifteen drops of blood were taken 

 from the ear of this animal and injected into Rabbit B. Nine hours 

 later the blood of Rabbit A was reexamined and found to contain a 

 large number of bacilli. This blood was injected subcutaneously into 

 Rabbit C. One hour later Rabbit A died, and twenty hours later 

 Rabbit C died, while Rabbit B remained free from infection. Space 

 will not permit us to follow the literature of anthrax further. Pasteur, 

 DeBarry, Koch and others studied the morphology, life history, and 

 cultural characteristics of the bacillus, and in this way founded the 

 science of bacteriology. 



The Bacillus. This is a long (4-10 microns), slender (1-1.3 

 microns) rod with rounded ends. A drop of blood from the spleen of 

 an animal dead of this disease discloses, even without stain, great 

 numbers of these bacteria. They are non-motile and take the basic 

 aniline dyes easily. Often many bacilli are attached end to end, form- 

 ing what is known as bamboo rods. These are quite characteristic but 



