PATHOGENIC BACTERIA 109 



general pyemia; there is severe edema of the tissues in and 

 about the wound, and a pulmonary edema likewise 'occurs. 

 Wounds about the face and neck are more fatal. 



Pneumonia by inhalation and intestinal infection also occurs 

 in man. 



Susceptibility of Animals, Dogs, birds, and cold-blooded 

 animals affected the least; while mice, sheep, and guinea-pigs 

 quickly and surely. 



Products of Anthrax Bacilli. A basic ptomain has not been 

 found, but a toxalbumin or proteid, called anthraxin, has been 

 obtained. A certain amount of acid is produced by the virulent 

 form, alkali by the weak. 



Attenuation and Immunity. Cultures left several days at a 

 temperature between 40 and 42 C. soon become innocuous, 

 and when injected into animals protect them against the viru- 

 lent form. 



The lymph obtained from lymph-sac of a frog destroys the 

 virulence of anthrax bacilli and spores temporarily. 



Hankin obtained an alexin from the blood and spleen of rats, 

 they being naturally immune. It destroyed the anthrax bacilli 

 in vitro, and used by injection in susceptible animals, made 

 them immune. It is insoluble in alcohol or water. 



Protective Vaccination. Animals have been rendered immune 

 by various ways by inoculation of successive attenuated cul- 

 tures; also with sterilized cultures that is, cultures containing 

 no bacilli, and with cultures of other bacteria. 



Habitat. In the serum about the wound and in the blood 

 anthrax bacilli are readily found. Tannery employes are 

 frequent sufferers. 



The bacillus has never been found free in nature. 



Bacillus Tuberculosis (Koch). This very important 

 bacillus was first described, demonstrated, and cultivated by 

 Koch, who made his investigations public on the 24th of March, 

 before the Physiological Society of Berlin, in the year 1882. 



Origin. In various tuberculous products of man and other 

 animals. 



Form. Very slender rods, nearly straight, about one-quarter 



