Anthrax. 201 



H, or N. It stains readily in aniline colors, and also by Gram's 

 method. It grows freely on a variety of culture media (blood 

 serum, aqueous humor, urine, vegetable infusions, milk, meat 

 bouillon, peptonized gelatine, potatoes, etc.) at a temperature of 

 20° to 38° C. Growth ceases below 12" C, and above 45° C. 

 Growth is most active in neutral or slightly alkaline media, and 

 is arrested by that which is decidedly acid. 



Action of physical and chemical agents on the bacillus anthracis. 

 The bacilli survive a temperature of — 45° C. ( — 49° F.), but they 

 perish in 10 minutes at a temperature of 100"^ C. (212° F). A 

 temperature of 55° C. (131" F.), proves fatal if sufficiently pro- 

 longed. The spores are much more resistant. They have sur- 

 vived — 130° C.(— 202° F.)and though they may die in 10 minutes 

 in liquid media kept at 95° C. (203° F.), yet when old and dry 

 it may require several hours at 140° C. (282° F.) to sterilize 

 them. 



Even the bacilli are comparatively resistant to ordinary disin- 

 fectants, and, as spores form in the body very rapidly after death, 

 and in virulent products, it is always best to assume their pres- 

 ence. In a moist medium CI. 44.7% destroyed the .spores in 3 

 hours: HCl (i: iioo) in 2 hours: HgCl (i:ioool in a few 

 minutes: Hgl, (1:20000) in 2 hours: Malachite green (1:40,- 

 000) in 2 hours: Methyl violet (1:5000) in 2 hours: Aseptol 

 (i: 10) in ID minutes : Carbolic acid (4: 100) with HCl (2: 100) 

 in I hour. 



Action of septic ferments on the bacillus anthracis . Rapid putre- 

 faction in the anthrax carcass which has not been opened tends to 

 speedy granular degeneration and death of the bacillus anthracis, 

 so that the blood and tissues may be no longer infecting after six 

 days in summer. In such cases the irrespirable gaseous products 

 of decomposition drive out the oxygen without which the bacillus 

 cannot live. If, however, spores have already formed or if air is 

 freely admitted the infection survives in spite of decomposition. 

 The search for the bacilli may thus be fruitless as soon as decom- 

 position is well advanced and the material can only be virulent 

 through any spores that may have formed. Eventration serves 

 to retard sepsis and admit air to form spores, and salting operates 

 in a similar manner. 



The infected hides, the nasal, buccal, kidney and bowel dis- 

 charges, and spilt blood and exudates mingling freely with the 



