DIPHTHERIA BACILLUS. 



367 



the same antitoxic serum, but with different diphtheria 

 toxins, proved this opinion to be incorrect. Ehrlich 1 

 deserves the credit for first clearly perceiving and 

 publishing this. He obtained from various sources 

 twelve toxins and compared their neutralizing value 

 upon antitoxin ; these tests gave most interesting and 

 important information. The results in six toxins, 

 which are representative of the twelve, are as shown 

 in the following table : 



From the facts set forth in the tables, Ehrlich has 

 derived interesting theories, which, if true, would add 

 greatly to our knowledge of toxins, and would also have 

 a very direct influence upon the present methods of 

 standardizing antitoxin. He believes that the diphtheria 

 bacilli in their growth produce a toxin which, so long as 



1 " Die Wertbemessung des Diphtherieheilserums und deren theoretische 

 Grundlagen," Klinisches Jahrbuch, 1897. 



