82 TOXIN AND ANTITOXIN 



control animal in thirty to forty hours) and six hours afterward the serum is injected. 

 The animals remaining alive on the sixth day are considered as cured. 



The French method of standardization is built upon the belief of Roux 

 that no parallelism necessarily exists between the protective and curative 

 values of a serum. Kraus and Schwarz have recently published accounts 

 of experiments which corroborate Roux's views. They claim that a very 

 highly valent diphtheria serum has a lower curative value than one less so; 

 that the curative power of a serum does not depend upon the increase or 

 decrease of the antitoxin content during the immunization of an animal, 

 and that Ehrlich's process of standardization, taking into consideration 

 only the protective power, requires additional modification. Berghaus 

 working in Ehrlich's Institute answered the above exceptions in so satis- 

 factory a manner that up to the present day Ehrlich's views are still 

 upheld by the majority of workers in this field. 



On the basis of former experiments by Ehrlich and Marx, Roemer has 

 recently suggested the intracutaneous method for estimating diphtheria 

 antitoxin. Its principle depends upon the finding that with intracutaneous 

 injection of mixtures of toxin and antitoxin, even the smallest amount of 

 toxin if not fully neutralized will produce edema. 



While in some countries the government institutes have complete control over the 

 production of diphtheria serum, in Germany it is manufactured by private concerns, 

 but under government supervision. 



The serum must be absolutely clear, free of bacteria and toxins, especially tetanus 

 toxin, and must not contain more than 1/2 per cent, of phenol. It should contain at 

 least the number of antitoxin units designated by the factory.. 



In the United States the standard antitoxin is distributed by the Public Health and 

 Marine Hospital Service Laboratories. Since 1902 the production and sale of diph- 

 theria antitoxin has been regulated by law. 



At frequent intervals, antitoxin is bought in the open market and examined at the 

 hygienic laboratories of the United States Public Health and Marine Hospital Service. 

 Antitoxic serum containing less than a hundred units to each cubic centimeter is pre- 

 cluded from sale. 



The Serum Therapy of Diphtheria. 



In man the antitoxic diphtheria serum is used with success for both 

 curative and prophylactic purposes. 



For therapeutic application it is of the greatest importance to employ 

 the serum in sufficient quantities and as soon as possible. The value of 

 early intervention can be seen from the following chart of Kossel: 



Large doses of antitoxin should be administered right from the start. The 

 old practice, still employed by few, of using small doses is to be condemned, 

 for the aim in the treatment is to neutralize as soon as possible all the free 

 and partly bound toxin. 



