TOXINS OF THE TETANUS BACILLUS. 385 



gallol and also by sunlight. Behring has more recently pointed 

 out that after the filtration of cultures containing toxin, the lat- 

 ter may very rapidly lose its power, and in a few days may only 

 possess -j^th of its original toxicity. This he attributes to such 

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

 oxygen. The effect of these agents on the crude toxin is un- 

 doubtedly to cause a degeneration of the true toxin into a series 

 of 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 contains toxic 

 substances of probably quite a different nature. Ehrlich has 

 shown that besides the predominant spasm-producing toxin 

 (called by him tetanospasmin), there exists in crude toxin a 

 poison capable of producing the solution of certain red blood 

 corpuscles. This hsemolytic agent he calls 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. i ']6'). This substance also has the power 

 of originating an antitoxin so that certain antitetanic sera can 

 protect red blood corpuscles against its action. Madsen, study- 

 ing the interactions of this antitetanolysin with the tetanolysin, 

 has shown that the latter may appear in the form of an active 

 poison, and of bodies corresponding to toxoids, and he has con- 

 firmed Ehrlich's views on the possession by true toxins of 

 haptophorous and toxophorous groups. That there are close 

 resemblances in nature between the tetanus and diphtheria tox- 

 ins is further shown by the fact that the action of an acid on 

 tetanus toxin is to cause an apparent disappearance of toxicity, 

 but if before a certain time has elapsed the acid be neutralised 

 by alkali, then a degree of the toxicity returns. 



Various attempts have been made to find out the nature of 

 the tetanus poisons. Sidney Martin derived from the organs of 

 persons dead of tetanus two classes of bodies. One of these 

 consisted of a purified alcoholic precipitate (formed chiefly of 

 albumoses). To these he attributes a fever-producing action. 



