TETANUS TOXINE. Ill 



It has been established by numerous experiments that a rat into 

 whose tail the toxine has been injected can no longer be saved 

 by amputation of the tail even after two to three hours. 



At the same time tetanus poison shows an unmistakable 

 period of incubation. COURMONT and DoYON 1 state that, in the 

 case of guinea-pigs, the symptoms appear at the earliest after 

 twelve hours, and in mice after six to eight hours. With 

 medium doses the latent period for mice is two to three days ; 

 for guinea-pigs, two days ; rabbits, two to four days ; the ass, 

 four days ; and for the horse five days. In the case of man it 

 fluctuates between one day and sixty days. The action is much 

 more rapid after subdural injection (BLUMENTHAL and JACOB 2 ), 

 or intercerebral poisoning (Roux and BORREL 3 ), as well as after 

 direct injection into the spinal cord (MEYER and RANSOM 4 ). 



According to a table given by MEYER and RANSOM the periods 

 of incubation after subcutaneous injection are as follows : 



Mouse, . . . . . . 8 to 12 hours. 



Guinea-pig, 13 ,, 18 ,, 



Rabbit 18 36 



Cat, 28 70 



Dog, 36 48 



Man, ...... 4 days. 



Ass, 4 ,, 



Horse, 5 ,, 



Hence it increases with the size of the body, and thus stands 

 in relationship to the slowness with which the poison is diffused 

 (vide infra). 



The incubation period becomes smaller with the increase of 

 the dose, but not proportionally so, and still occurs even after 

 the largest doses. In the case of mice it never falls below eight 

 hours. Thus, in one series of experiments, the incubation 

 periods for mice were as follows : 



1 Courmont and Doyon, vide supra. 



2 Blumenthal and Jacob, "Zur Serumtherapie des Tetanus," Berl. klin. 

 Woch., 1898, 1079. 



3 Roux and Borrel, "Tetanos cerebral," Ann. Past., xii., 1898. 



4 Meyer and Ransom, " Unters. lib. d. Tetanus," Arch. exp. Path., 

 xlvi., 369, 1903. 



