TOXINS OF THE TETANUS BACILLUS 429 



originally have been either neutral or slightly alkaline. Kitasato 

 further found that the toxin was easily injured by heat. Exposure 

 for a few minutes at 65° C. destroyed it. It was also destroyed 

 by twenty minutes' exposure at 60° O, and by one and a half 

 hours' at 55° C. Drying had no effect. It was, however, 

 destroyed by various chemicals such as pyrogallol, and also by 

 sunlight. 



To prepare the toxin, freshly made veal bouillon not too long 

 autoclaved should be used and a massive inoculation, preferably 

 from a fluid culture, practised. Individual strains of the bacillus 

 differ in their capacity for producing toxin. The culture must 

 be incubated under anaerobic conditions and the maximum 

 toxicity is developed in from ten to fifteen days. Behring 

 pointed out that after the filtration of cultures containing toxin, 

 the latter may very rapidly lose its power, and in a few days may 

 only possess xj^th of its original toxicity. This is due to such 

 factors as temperature and light, and especially to the action of 

 oxygen. Toxins should thus have a layer of toluol floated on the 

 surface and be kept in a cool, dark place. The effect of harm- 

 ful agents on the crude toxin is apparently to cause a degenera- ■ 

 tion of the true toxin so as to form what it is convenient at 

 present to call toxoids, similar to those produced in the case of 

 diphtheria toxin, and it is also true here that the toxoids while 

 losing their toxicity may still retain their power of producing 

 immunity against the potent toxin. Further, altogether apart 

 from the occurrence side by side in the crude toxin of strong and 

 weak poisons, it has been shown that such crude toxin may 

 contain different varieties of toxic substances. Ehrlich showed 

 that besides the predominant spasm-producing toxin (called 

 by him tetanospasmin), there often exists in crude toxin a 

 poison capable of producing the solution of certain red blood 

 corpuscles. This hemolytic agent he called tetanolysin. It does 

 not occur in all samples of crude tetanus toxin, nor is it found 

 when a bouillon culture of the bacillus is filtered through 

 porcelain. To obtain it, the fresh culture must be treated by 

 ammonium sulphate, as described in the method of obtaining 

 concentrated toxins (p. 190). Tetanolysin also has the power 

 of originating an antitoxin, so that certain antitetanic sera 

 can protect red blood corpuscles against its action. Madsen, 

 studying the interactions of this anti- tetanolysin with the 

 tetanolysin, has shown that phenomena can be demonstrated 

 similar to those noted by Ehrlich as occurring with diphtheria 

 toxin, and which the latter interpreted as indicating the presence 

 of degenerated toxins (toxoids) in the crude poison. With 



