Protective vaccinations 493 



^P constitutes, however, a very formidable disease against which all 

 therapeutic methods have only a very limited effect. This is a further 

 reason for drawing the whole attention of medical and veterinary 

 men to the prevention of tetanus by vaccinal injections. Tetanus is 

 a disease in which the intoxication plays an altogether dominant part 

 The tetanus bacilli do not develop, at the point where they are 

 introduced into the body, unless favoured by auxiliary conditions, [516] 

 such as the multiplication of other micro-organisms. Even then the 

 organism of tetanus reproduces itself with difficulty, and without 

 becoming generalised throughout the body. The poison which it 

 secretes is however sufficient to produce a very grave intoxication, 

 ending most frequently in death. In certain countries tetanus, as 

 a sequel to various wounds, is very frequently met with in man and 

 in certain domestic animals, such as the horse, donkey, pig, etc. 



It is only since the discovery by von Behring and Kitasato of an 

 effective method of immunisation against tetanus that it has been 

 possible to consider the practical application of antitetanus vacci- 

 nations. These observers demonstrated that the tetanus poison, 

 when treated with trichloride of iodine, had its toxic action weakened 

 and was transformed into an effective vaccine. Roux and Vaillard 

 found that the addition of LugoFs iodo-iodurated solution to the 

 tetanus poison renders It capable of vaccinating all kinds of suscep- 

 tible animals. It was shown later, that even with modified active 

 tetanus toxin, we can still obtain good results when care is taken 

 to inject the poison with great circumspection. 



But it is not these vaccines obtained from tetanus cultures that 

 have come to be used in practice. The best results are obtained by 

 the use of antitetanus serums. After von Behring and Kitasato's 

 discovery of the power of the serum of animals immunised against 

 tetanus to neutralise the action of the tetanus poison, very numerous 

 experiments were made on the same subject. It has now become 

 possible by treating horses with large quantities of tetanus toxin to 

 obtain specific serums of extraordinary activity Thus several serums 

 are capable of preserving mice against a lethal dose of tetanus poison 

 if we inject into them a quantity of serum equal to the one-thousand- 

 millionth of their weight. 



Serums of this strength protect domestic animals against tetanus. 

 We know that many operations on horses, sheep, goats, pigs, and 

 other mammals are very often followed by a tetanus which is usually 

 fatal. Castration, amputation of the tail, the ablation of proud flesh 



