Protective vaccinations 495 



horse-dung or other matters which may contain the spores of tetanus. 

 In these cases, as in many other forms of injury, vaccination with 

 antitetanus serum is indicated. Thus it happens from time to time 

 at the Pasteur Institute that injured persons come and ask for a [518] 

 protective injection of serum. Several medical men and surgeons are 

 now accustomed to vaccinate such of their patients as have had their 

 wounds contaminated by earth or dung. All the cases of this treat- 

 ment which have come to our knowledge have been followed by very 

 good results. 



XII. Vaccinations against diphtheria. Antidiphtheria vaccinations 

 have been the subject of much discussion since the discovery of the 

 antidiphtheria serum and its introduction into routine practice. A 

 large number of works were published for and against the application 

 of serum in protective treatment against diphtheria, especially in the 

 early years of its use. Later the controversy has subsided somewhat, 

 and at present very few writers are found who continue to decry 

 antidiphtheria vaccinations. 



The antidiphtheria serum was discovered in 1890 by von Behring 

 working in collaboration with Kitasato ; these observers demonstrated 

 in laboratory animals its neutralising action upon the diphtheria toxin. 

 A little later von Behring began to apply it in the treatment of 

 diphtheria, but the early results were far from satisfactory, and 

 von Behring soon recognised that it was necessary to obtain much 

 more active serum. Along with Ehrlich of the Institute for Infective 

 Diseases at Berlin he set to work to study this problem. In colla- 

 boration with several investigators, among whom I may cite Wernicke, 

 Wassermann, and Kossel, he succeeded in obtaining very encouraging 

 results as regards the antitoxic strength of the serums and their 

 therapeutic action on children attacked by diphtheria. 



At this time, also, Roux in Paris began, assisted by Martin and 

 Chaillou, to study the same question. These observers prepared 

 serums which for that period were very active and made a very 

 effective application of them upon more than 300 diphtheria patients. 



From the year 1894 the use of serum began to spread in all 

 countries, and it was then that an attempt was made to apply it to 

 the protection of children in good health, but who had been specially 

 exposed to contagion. 



It was necessary to have at command large supplies of anti- 

 diphtheria serum; this was prepared by injecting into horses 



