386 TETANUS. 



The other bodies were those soluble in alcohol and also in ether. 

 They were non-proteid, and to them he attributed the excitation 

 of the muscular spasms in tetanus. Uschinsky, moreover, has 

 found that the 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 it no doubt has a 

 digestive action on these. Brieger also now apparently thinks 

 that the toxicity of the toxalbumins originally described by him 

 is due to the presence of a non-proteid body. 



It is thought by some that a diastase is concerned in the toxic 

 action of the tetanus bacillus. Like a ferment, the toxin is de- 

 stroyed, as we have seen, by comparatively low temperatures, 

 but, as has already been pointed out (Chap. VI.), it may simply 

 be an unstable chemical compound, for albuminous bodies not 

 diastatic in nature may be changed at similar temperatures. 

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

 advances pan passu with the development of toxins, and filtered 

 bacterium-free cultures will still liquefy gelatin. It is probable, 

 however, that there is developed, in addition, a peptic ferment 

 which will, of course, also pass through the filter. For if equal 

 portions of the filtered culture be left in contact with equal por- 

 tions of gelatin for various lengths of time, there is no increase 

 of toxicity in those kept longest. There is thus no fresh devel- 

 opment of toxin during the advancing liquefaction of the gelatin. 

 Thus peptic digestion and toxic formation are apparently due to 

 different vital processes on the part of the tetanus bacillus. 



An argument in favour of a ferment being concerned in the 

 toxin production is derived from the occurrence of a definite 

 incubation period between the introduction of the toxin into an 

 animal's body and the appearance of symptoms. The incubation 

 period varies according to the species of animal employed, and 

 the path of infection. In the guinea-pig it is from thirteen to 

 eighteen hours, in the horse five days, and the incubation is 

 shorter when the poison is introduced into a vein than when 

 injected subcutaneously. The interpretation put on the occur- 

 rence of this period of incubation by the upholders of the fer- 

 ment theory has been that a time is required for the supposed 

 diastase to elaborate from the tissues albumoses, which are the 

 immediately toxic agents. 



