THEORIES RELATING TO ANAPHYLAXIS 107 



Further, Friedberger's theory as it was first 

 enunciated — that is to say, founded on the reaction 

 of precipitin as its starting-point — is faulty at its 

 base. 



Kraus has observed that the parallehsm noted 

 between the power of precipitation and of sensitisation 

 often fails, contrary to what is maintained by Fried- 

 berger, Doerr, and Russ, and the others of their school. 

 Thus the guinea-pig, which is easily sensitised, is a 

 mediocre producer of precipitin ; the rabbit, which con- 

 tains, after suitable preparation, a powerful anaphy- 

 lactic antibody, does not necessarily possess precipitin ; 

 finally, the goat, which readily produces precipitins, 

 has a serum which completely lacks the power of 

 conferring passive anaphylaxis. 



We may add that Doerr, who was at first an ardent 

 believer in the theory of anaphylotoxins, was after- 

 wards constrained to abandon it in favour of the 

 physical theory which we shall put forth later. 



Kraus and Biedl,^ when studying anaphylaxis in 

 the dog, were especially impressed with the fact that 

 the second injection of serum, or the trial injection, 

 is always followed by a lowering of arterial pressure. 



According to immunologists, this arterial depres- 

 sion is the keystone to anaphylaxis, and explains 

 by itself all the symptoms: excitement followed by 

 depression, vomiting, defsecation, anuria, etc. 



Another fact which has struck the Vienna workers 

 with regard to the anaphylactic dog is the diminution 

 in coagulability of the blood almost to the point of 

 non-coagulability . 



Now, when peptone is injected into the veins of 

 a dog, a lowering of arterial pressure and non-coagu- 

 lability of blood are both observed. From thence, 

 CO establish a connexion between the two phenomena 

 was a temptation that Kraus and Biedl could not 

 1 Zeitschr. f. Immunitdtsf., I. Orig., vii., p. 408, 1910. 



