ANAEROBIC BACTERIA 183 



Tetanolysin. The blood and the urine contain the toxin 

 and are fatal to animals. 



The virus enters the circulation, but does not remain in the 

 tissues. The toxin is most virulent. It acts on the end- 

 plates of the muscles, and then on the motor nerve-cells. 

 The incubation period is from two to fourteen days after 

 receipt of injury. The spores are very resistant to heat, 

 drying, and chemicals. 



Burns and injuries from firearms, cartridges, powder, and 

 fireworks, a common cause of tetanus. 



Immunity. Kitasato, by inoculation of sterilized cultures, 

 has caused immunity to the effects of virulent bacilli. 



An antitoxin obtained by Tizzoni and Cattani from the 

 serum of animals made immune by sterilized cultures is used 

 with curative effects in cases of tetanus in man. It is a 

 globulin, but differs from the diphtheria antitoxin. By pre- 

 cipitation with alcohol and drying in vacuo the antitoxin is 

 obtained in a solid state. The aqueous solution is used for 

 injection subcutaneously or subdurally through a trephine 

 opening. Its injection into the spinal canal by lumbar punc- 

 ture has also been recommended. Antitoxin is more beneficial 

 in chronic cases than in acute. 



The dried antitoxin has been spread on the wound with 

 some curative action. 



The antitetanic serum, to be effective, must be given very 

 early and in large doses. Its greatest use is in preventing 

 tetanus in wounds liable to be infected. From 50 c.c. to 100 

 c.c. of a billion-unit serum should be given in divided doses; 

 only sera with very high protective powers should be used. 



United States Government Unit for Tetanus Antitoxin. 

 "The immunity unit is ten times the least quantity of anti- 

 tetanic serum necessary to save the life of a 350-gram guinea- 

 pig for ninety-six hours against the official test dose of a 

 standard toxin furnished by the Hygienic Laboratory at 

 Washington." 



Habitat. The bacillus is present in garden-earth, in man- 

 ure, and it has been isolated even from mortar. 



