152 ANTHRAX AND ANTHRACOID DISEASES. 



appear in liquids in the presence of carbonic acid, and the blood 

 soon loses its specific property. 



This proves that, to live and grow, the bacilli require to 

 absorb oxygen and give out carbonic acid : hence they are what 

 M. Pasteur terms " aerobic." If the fluid which contains them 

 begins to putrefy they are destroyed, not only by being deprived 

 of oxygen, but by being brought into contact with other 

 organisms, such as the vibrios of putrefaction, in the presence of 

 which, and of all other low forms of organisms, they either do 

 not develop at all, or develop with great difficulty. The vibrios 

 of putrefaction are not aerobic, and cease to move when brought 

 in contact with oxygen; disappear, being transformed into refract- 

 ing corpuscles, which in a suitable soil reproduce motile vibrios 

 and multiply with extreme rapidity in a putrefying fluid. If an 

 animal be inoculated with it when in this condition, it does not 

 die of anthrax, but of septicaemia, the symptoms of which, when 

 produced in guinea-pigs with the blood of a horse which had 

 been dead of charbon twenty-four hours, and which contained 

 vibrios of putrefaction as well as some bacilli, and with the blood 

 of a cow which had been dead forty-eight hours, and which con- 

 tained a preponderating quantity of vibrios, were violent inflam- 

 mation of all the muscles of the abdomen and limbs, and here 

 and there, especially on the ears, bullae formed containing gas. 

 The blood was diffluent, and on examining these animals imme- 

 diately after death, M. Pasteur found that the muscles were 

 filled with active vibrios of putrefaction, and in the peritoneal 

 cavity they had undergone extraordinary development ; one drop 

 of this serosity taken from an animal still living, affected another 

 animal profoundly, while a drop of blood from the heart had no 

 effect. 



Again, dilution of the fluid containing the bacilli with a 

 moderate amount of water has no eff"ect on its virulence, but a 

 large quantity destroys it, and traces of carbolic acid prevent the 

 development of the bacilli. 



It has been stated that the bacilli destroy life — (1) by acting 

 as asphyxiants, depriving the blood of its oxygen ; and (2) by 

 mechanically obstructing the blood-vessels. Against both these 

 theories must be placed the fact that they are very few in 

 number, indeed often absent altogether in the blood during 

 life. 



Anthrax is not transmitted by infection from one animal to 

 another, for animals kept in the closest proximity to diseased 

 ones, and placed under the most favourable conditions for 

 infection through the air, do not become diseased. 



Mice and rabbits seem capable of eating food containing 

 bacilli with impunity, and flies can gorge themselves with the 

 infected blood and suffer no harm ; but horses, cattle, pigs, dogs, 



