272 MANUAL OF BACTERIOLOGY. 



believes that it may occur in vaccine virus when that is care- 

 lessly prepared, which would explain the rare occurrence of 

 tetanus after vaccination. 1 Tetanus bacilli have been found 

 in gelatin, and it is stated that the tetanus has followed the 

 injection of gelatin as a hemostatic. The infection appears 

 almost always, if not always, to be introduced through 

 some wound. 2 Clinically, persons having the disease suffer 

 from spasms of the muscles about the neck and the lower 

 jaw (lock jaw). The spasms finally become general. 



Inoculation with a pure culture produces tetanus in mice ; 

 also in rats, guinea-pigs and rabbits. The tetanic spasms 

 begin in the vicinity of the point of inoculation and after- 

 ward become general. The bacilli are not widely scattered 

 through the body ; they occur only in the immediate vicinity 

 of the original lesion, and there are no important macro- 

 scopic alterations in the internal viscera. 



Tetanus is the type of the purely toxic disease. Its 

 symptoms may be produced in animals by the injection of 

 liquid cultures which have been deprived of their bacteria 

 by filtration. The toxic substance appears not to be a pto- 

 maine, as was at first supposed, and its exact nature is not 

 determined. 



The poison is tremendously powerful (see page 174). It 

 acts as an excitant to the motor cells of the central nervous 

 system, especially the spinal cord. Bolton and Fisch have 

 pointed out the possibility that horses used for the prepara- 

 tion of diphtheria antitoxin may be infected with tetanus, 

 and have tetanus toxin in the blood. :: 



The activity of the poison is destroyed by heat, and by 

 direct sunlight ; various chemicals diminish its intensity. 



Antitoxins for tetanus have been prepared according to 

 the principles employed for antitoxins in general. They 



1 Journal Medical Research, Vol. VII., 1902. 



2 Wells, "Fourth of July Tetanus,'' American Medicine, June 13, 1903. 



3 Trans. Association A^ncrican Physicians, 1902. 



