360 Tetanus 



the development of the bacilH, because of the loosely combined 

 oxygen contained in the blood, and they grow with great slowness, 

 remaining localized at the seat of inoculation, and never entering the 

 blood. Doubtless most cases of tetanus are mixed infections in 

 which the baciUus enters with aerobic bacteria, that aid its growth 

 by absorbing the oxygen in the neighborhood. The amount of 

 poison produced must be exceedingly small and its power tremen- 

 dous, else so few baciUi growing under adverse conditions could not 

 produce fatal toxemia. The toxin is produced rapidly, for Kitasato 

 found that if mice were inoculated at the root of the tail, and the skin 

 and the subcutaneous tissues around the inoculation afterward either 

 excised or burned out, the treatment would not save the animal un- 

 less the operation were performed within an hour after the inoculation. 



Some incline to the view that the toxin is a ferment, and the 

 experiments of Nocard* might be adduced in support of the theory. 

 He says: "Take three sheep with normal tails, and insert under the 

 skin at the end of each tail a splinter of wood covered with the dried 

 spores of the tetanus baciUus; watch these animals carefully for the 

 first symptoms of tetanus, then amputate the taUs of two of them 20 

 cm. above the point of inoculation, .... the three animals suc- 

 cumb to the disease without showing any sensible difiEerence." 



The circulating blood of diseased animals is fatal when injected 

 into susceptible animals because of the toxin it contains; and the 

 fact that the urine is also toxic to mice proves that the toxin is ex- 

 creted by the kidneys. 



Two classes of infected wounds are particularly apt to be followed 

 by tetanus — namely, those into which soil has been carried by the 

 injuring implement and those of considerable depth. The infecting 

 organism reaches the first class in large numbers, but finds itself 

 under aerobic and other inappropriate conditions of growth. It ■ 

 reaches the second class in smaller numbers, but finds the conditions 

 of growth better because of the depth of the wound. 



The severity of the wound has nothing whatever to do with the 

 occurrence of tetanus, pin-pricks, nail punctures, insect stings, 

 vaccination, and a variety of other mild injuries sometimes being 

 followed by it. 



An interesting fact has been presented by Vaillard and Rouget, f 

 who found that if the tetanus spores were introduced into the body 

 freed from their poison, they were unable to produce the disease 

 because of the promptness with which the phagocytes took them up. 

 If, however, the toxin was not removed, or if the body-.ceUs were 

 injured by the simultaneous introduction of lactic acid or other 

 chemic agent, the spores would immediately develop into bacilli, 

 begin to manufacture toxin, and produce the disease. This suggests 

 that many wounds may be infected by the tetanus baciUus though 



* Quoted before the Acad^mie de Medicine, Oct. 22, 1895. 



t See "Centralbl. f. Bakt. Infekt., u. Parasitenk.," vol. xvi, p. 208. 



