380 TETANUS 



sunlight. Behring has more recently pointed out that after the 

 nitration of cultures containing toxin, (the latter may very rapidly 

 lose its power, and in a few days may only possess y^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 undoubtedly 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. (jEhrlich has shown that besides the pre- 

 dominant 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 haemolytic 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. 167). This 

 substance 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 the phenomena 

 can be demonstrated similar to those noted by Ehrlich as 

 occurring with diphtheria toxin, and which he interpreted as 

 indicating the presence .of degenerated toxins (toxoids) in the 

 crude poison. With tetanus as with diphtheria toxin the action 

 of an acid 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. 



As with other members of the group, nothing is known of the 

 nature of tetanus toxin. Uschinsky has found that the tetanus 

 bacillus can produce its toxin when growing in a fluid containing 

 no proteid matter. The toxin may thus be formed independently 

 of the breaking up of the proteids on which the bacillus may be 

 living, though the latter no doubt has a digestive action on 

 these. The liquefaction (i.e. probable peptonisation) of gelatin 

 cultures advances pari passu with the development of toxins, 

 and filtered bacterium-free cultures will still liquefy gelatin. /It 

 is probable that there is an independent peptic ferment which 

 will, of course, also pass through a filter^ For if equal portions 



if 



