100 VACCINE AND SERUM THERAPY. 



The overproduction of these receptors occurs as a result of the 

 presence of specific toxins, found in infections with specific or- 

 ganisms, or after experimental injection of certain toxins. As is the 

 case with other anti-bodies, anti-toxins are present to some de- 

 gree in many normal individuals, thus diphtheria anti-toxin was 

 found by Bolt on to be present in the blood serum of 30 per cent 

 of the horses examined, and in 50 per cent of the children and 81 

 per cent of the adults examined by Wasserman. Various sub- 

 stances have been used to produce an increase of specific anti- 

 toxins and as a result a considerable number of anti-toxins have 

 been made. Among these may be mentioned the anti-toxins 

 which combine with the toxins of the organisms of diphtheria, 

 tetanus, pyocyaneaus, symptomatic anthrax, and botulism, with 

 snake and spider venoms, with ricin, aprin and robin, and 

 with the glucosids of toad stools and poison ivy. Of the anti- 

 toxic sera, the anti-diphtheritic and anti-tetanic have been of 

 most importance. 



In the treatment of diseases for which anti-toxic sera have 

 been made, it must always be remembered that anti-toxin neu- 

 tralizes prepared toxin and combination can take place only when 

 the receptors of the toxins and anti-toxins are free. As soon as 

 the cells and toxins have combined and the body cells have been 

 injured as a consequence, no amount of anti-toxin can protect 

 the cell from the action of the poison molecule. Anti-toxic 

 bodies can only anchor and render inert or harmless such toxins 

 as are free or have uncombined receptors. This emphasizes the 

 importance of the early administration of anti-toxic serum be- 

 cause at this time the poison molecules can be anchored by the 

 anti-toxic substances instead of combining with the cells of the 

 body. 



DIPHTHERIA ANTI-TOXIN. 



Ferran, early in 1890, and Fraenckel and Behring later in the 

 same year, published methods by which experimental animals 

 can be immunized to diphtheria. Behring and Kitashima, in 

 1891, published methods for the immunization of guinea pigs to 

 diphtheria toxin. In 1892 Behring and Wernicke emphasized 

 the presence of protective substances in serum of diphtheria-im- 

 mune animals. Serum therapy as applied to the treatment of 



