428 TETANUS 



occurrence of what they call tetanus [dolorosus. This is a 

 great hypersesthesia and a paroxysmal hyperalgesia which can be 

 caused by injecting toxin into the spinal cord or into a sensory 

 root on the spinal side of the posterior root ganglion. These 

 symptoms are unaccompanied by motor spasms, but the animal 

 may die from exhaustion. The same observers have also made 

 interesting observations on the action of antitoxin. They found 

 that the injection of this substance into the course of a mixed 

 nerve could prevent toxin from passing up to the cord, but that if 

 antitoxin were injected even in great excess intravenously, and a 

 short time thereafter toxin were introduced into a nerve, the 

 death of the animal was not prevented. This they attribute 

 to the fact that antitoxin can only neutralise the toxin which 

 is still circulating in the blood. This is a very far-reaching 

 conclusion, as it throws doubt on what has been held to be a 

 possibility, namely, that toxin can be actually detached from 

 cells in which it is already anchored. But a still more 

 significant observation was made, for in one case of an animal 

 actively immunised against tetanus, and which contained in its 

 serum a considerable quantity of antitoxin, the injection of toxin 

 into the sciatic nerve was followed by tetanus. This would 

 appear to militate against Ehrlich's position that antitoxin is 

 manufactured in the cells which are sensitive to the toxin (see 

 Immunity). 



Reference may here be made to the effects of injecting tetanus 

 toxin into the brain itself, as investigated by Roux and Borrel. 

 It was found th'at the ordinary type of the disease was not 

 produced, but what these observers called "cerebral tetanus." 

 This consisted of general unrest, symptoms of a psychic character 

 (apparent hallucinations, fear, etc.), and epileptiform convul- 

 sions. Death occurred in from twelve to twenty hours without 

 any true tetanic spasms. In this manifestation of tetanus the 

 incubation period was much shorter than with subcutaneous 

 injection, and the fatal dose was one twenty-fifth of the minimal 

 subcutaneous dose. Further, the injection of antitoxin forty-eight 

 to ninety-six hours previously did not prevent an animal from 

 succumbing to the intracerebral inoculation. In the light of 

 what has been already said, these results would seem to indicate 

 a special effect of the toxin when brought into direct contact 

 with the protoplasm of the brain cells. 



We have seen that unless suitable precautions are adopted in 

 experiments with tetanus cultures in animals, death results not 

 from the multiplication of the bacilli, but from an intoxication 

 with toxin previously existent in the fluid in which the 



