132 BACTERIOLOGY FOR NURSES 



"The activity of the poison is destroyed by an 

 exposure of one and one half hours to 55° C. (131° 

 F.), of twenty minutes to 60° C. (140° F.), and of five 

 minutes to 65° C. (149° F.). 



"By drying at the temperature of the body under 

 access of air the poison is destroyed, but by drying 

 at the ordinary temperature of the room it is not 

 destroyed. 



"Diffuse dayhght diminishes the intensity of the 

 poison. Its intensity is preserved for a much longer 

 time when kept in the dark. 



"Direct sunHght robs it of its poisonous properties 

 in from fifteen to eighteen hours. 



"Its activity is not diminished by diluting a fixed 

 amount with water or nutrient bouillon. 



"Mineral acids and strong alkahes diminish its 

 intensity." 



The chemical nature of tetanus toxin is not posi- 

 tively known, but it is one of the most powerful 

 poisons known. 



Tetanus Antitoxin or Antitetanic Serum. — The 

 principles involved in the production of an antitoxin 

 in diphtheria are identical in tetanus ; in fact, it was 

 through the researches into tetanus that the prin- 

 ciples were first worked out. 



Animals are immunized from tetanus by the 



