62 



Scientific Proceedings (51). 



Inasmuch as animals can not be killed by the pure toxin, it is 

 impossible to demonstrate antitoxic effect in the serum of animals 

 that have received repeated doses of the toxin. The Bordet- 

 Gengou fixation reaction failed to demonstrate the presence of 

 antibodies in the sera of animals so treated. 



The simplest prophylactic measure against Rhus poisoning is 

 to wash well with soap and hot water as soon after exposure as 

 possible. The protection of the skin by anointing with cotton- 

 seed oil before exposure and washing this off within a few hours 

 with soap and water, renders prophylaxis fairly certain. The 

 following remedies have therapeutic value: hot water, ichthyol 

 collodion, permanganate of potassium, magnesium sulfate, and 

 tincture of iodine. 



45 (74i) 



The failure of union between antigen and precipitin 

 when present in the same serum. 

 By Hans Zinsser and Stewart Young. 



[Stanford University.] 



It has been frequently observed that the serum of rabbits, 

 immunized with foreign protein, may, at certain times, contain not 

 only precipitin, but also unaltered antigen remnants. Such sera 

 not only precipitate the antigen, but also give precipitates when 

 mixed with other antisera prepared with the same antigen (Linosier 

 et Lemoine, Eisenberg, Michaelis, and Fleischmann, Ascoli, Von 

 Dungern). They have been recently studied by Gay and Rusk. 

 It has been difficult to explain why such sera do not spontaneously 

 precipitate since both reacting factors are present. 



In the cases of two sera recently studied by us the phenomena 

 observed were as follows: Sera "3" and "4," obtained by injecting 

 two rabbits with horse serum on three successive days and bleeding 

 eight days after the last injection, were perfectly clear and showed 

 no spontaneous precipitation on standing several days. Serum 

 "3" precipitated horse serum in dilutions of 1 to 1,000, and serum 

 " 4 " in dilutions of I to 500. When mixed with equal quantities of 

 an antihorse serum precipitin, which contained no antigen, both 

 sera were precipitated, "3" more strongly than " 4." Neither of 



