12 IMMUNE SERA 



fact that we appreciate symptoms from only one 

 organ is, obviously, no proof that other tissues 

 have been unaffected. 



It may be well here to call attention to another 

 rather common misconception regarding the pro- 

 duction . of antitoxin, namely that the body cells 

 have to become educated, so to speak, to produce 

 the antitoxin. This, it is believed, is effected by 

 giving gradually increasing doses of toxin. As a 

 matter of fact the reason for this gradual increase 

 in the dose injected is quite different. The object 

 in view is the administration of an enormously 

 large dose of toxin, one that will engage the recep- 

 tors of many cells. The previous injections have 

 brought about some production of antitoxin and 

 this partially neurtalizes some of the toxin in- 

 jected, making it possible to give a larger dose than 

 before. If one gives at the outset a large amount of 

 toxin, partially neutralized by antitoxin, one will 

 produce an amount of antitoxin equal to that 

 ordinarily obtained in response to the same quan- 

 tity of unaltered toxin given as the tenth or 

 twentieth injection of a series. Park and Atkinson 

 for example, injected a fresh horse with one litre 

 of a toxin neutralized ij times for guinea pigs. 

 At the end of a week the horse had produced a serum 

 containing 60 units per cc. When the toxin was 

 neutralized 6 fold no antitoxin whatever was pro- 

 duced. 



