THE STORY OF NINETEENTH-CENTURY SCIENCE 



the world made investigations along the line of this al- 

 luring possibility, the leaders perhaps being Drs. Behring 

 and Kitasato, closely followed by Dr. Roux and his as- 

 sociates of the Pasteur Institute of Paris. Definite re- 

 sults were announced by Behring in 1892 regarding two 

 important diseases tetanus and diphtheria but the 

 method did not come into general notice until 1894, 

 when Dr. Roux read an epoch-marking paper on the sub- 

 ject at the Congress of Hygiene at Buda-Pesth. 



In this paper, Dr. Roux, after adverting to the labors 

 of Behring, Ehrlich, Boer, Kossel, and Wasserman, de- 

 scribed in detail the methods that had been developed 

 at the Pasteur Institute for the development of the cura- 

 tive serum, to which Behring had given the since familiar 

 name antitoxine. The method consists, first, of the cul- 

 tivation, for some months, of the diphtheria bacillus 

 (called the Klebs-Loeffler bacillus, in honor of its dis- 

 coverers) in an artificial bouillon, for the development 

 of a powerful toxine capable of giving the disease in a 

 virulent form. 



This toxine, after certain details of mechanical treat- 

 ment, is injected in small but increasing doses into the 

 system of an animal, care being taken to graduate the 

 amount so that the animal does not succumb to the 

 disease. After a certain course of this treatment it is 

 found that a portion of blood serum of the animal so 

 treated will act in a curative way if injected into the 

 blood of another animal, or a human patient, suffering 

 with diphtheria. In other words, according to theory, 

 an antitoxine has been developed in the system of 

 the animal subjected to the progressive inoculations 

 of the diphtheria toxine. In Dr. Roux's experience 

 the animal best suited for the purpose is the horse, 



