338 Veterinary Medicine. 



the disease among those living or working about stables, gar- 

 deners, agricultural laborers, soldiers on campaign, and children 

 and others walking with bare feet. The contact with rich 

 infected soil greatly favors inoculation in any accidental wound. 



An important feature in the pathology of tetanus is that the 

 bacillus is confined to the seat of the inoculation wound. The 

 many attempts to transmit the infection by blood, nervous matter, 

 and by one or other of the tissues have uniformly failed, though 

 the pus of the infected wound has proved virulent. Similarly, 

 the attempts of Kitasato and others to obtain cultures from the 

 animal liquids or tissues apart from the wound have been futile. 



By inoculating the toxins remaining in the pus of the infection 

 wound, however, or in virulent cultures from which the bacilli 

 have been removed by filtration or in which they have been de- 

 stroyed by heat, all the symptoms of tetanus can be produced 

 (Kitasato, Kund Faber, etc.) In such cases too, the symptoms 

 appear at once, as soon as the toxin is absorbed, and not after a 

 definite period of incubation as in inoculation of the unaltered 

 virus. Kitasato, Vaillard and Vincent reached this conclusion 

 by another channel. They inoculated mice at the root of the tail 

 with virulent tetanus cultures, and at definite intervals after, 

 namely, half an hour, one hour, and one and a half hour, they 

 made a circular incision round the wound and thoroughly cauter- 

 ized the whole, thus destroying all the inoculated bacilli. They 

 found that tetanus was prevented in those animals only which 

 were operated on in the first half hour. Again, Kitasato injected 

 mice with 0.2 to 0.3 cc of the blood from the heart of a fresh 

 tetanus cadaver, and thereby produced typical tetanic symptoms 

 and death in i to 3 days. 



Various poisons have been separated from cultures of bacillus 

 tetani. Brieger isolated three substances — tetanin, tetano-toxin 

 and spasmo- toxin — which in large doses caused tetanic symptoms 

 and even death. Brieger and Frankel later isolated a toxalbumen 

 which proved of incomparably greater potency. Again, Brieger, 

 Kitasato and Wehl separated what appeared to be an enzyme or 

 diastase which proved 500 times more potent than atropia. This 

 was in form of yellow, transparent flakes, soluble in water, 

 but which was not destroyed by drying, nor in the dry state by ab- 

 solute alcohol, chloroform nor anhydrous ether, but which, like 



