200 SCIENCE PROGRESS. 



months, and this condition tends to disappear, but so long 

 as immunity exists, the blood, milk and muscles of the 

 animal yield antitoxins, which may be separated and dis- 

 solved in eight to ten times the weight of water. Beyond 

 doubt the most valuable remedy is serum preserved in 

 sterilised flasks. A piece of camphor should be added, and 

 the fluid protected from light. 



Human beings suffering from diphtheria may be con- 

 sidered to recover from the disease since the toxin of the 

 bacillus encounters antitoxins that either pre-exist or are 

 developed in the body as the results of the struggle of the 

 cells of the organism against the deadly action of the 

 diphtheria poison. Consequently, in patients who are 

 convalescent, antitoxins should, if this view is correct, 

 be present in the organism. In the case of typhoid fever 

 this question has been admirably worked out by Stern (26) ; 

 the serum of patients dead or convalescent from this disease 

 possesses a destructive power upon the Bacillus typhosus and 

 its products. The serum of persons convalescent from 

 diphtheria is found also to be antitoxic. The experiments 

 of Escherich and Klemensiewicz proved that such serum 

 has a marked protective power, and more recently Rudolf 

 Abel found five out of six convalescent patients yielded 

 antitoxic serum (27). The efficacy of this was tested upon 

 guinea pigs by introduction of serum subcutaneously, or 

 into the peritoneum, and then twenty-four to forty-eight 

 hours later a lethal dose of diphtheria toxin was adminis- 

 tered. The antitoxic value of the serum is at a maximum 

 about the tenth day after the membrane in the throat has 

 disappeared. A fact, however, must be noticed which 

 conforms with the experiments made by Stern on typhoid 

 fever, that apparently healthy persons yield antitoxic serum, 

 indeed five out of six who were examined. Possibly in 

 this discovery of protective bodies in the naturally immune 

 organism may lie a partial solution of the mystery of immunity. 



The chemical and physical properties of the bodies 

 which give to serum an antitoxic power are almost un- 

 known. Like the toxin of the bacillus these are destroyed 

 by heat, coagulated by alcohol, and tend to adhere to bulky 



