322 PROTEIN POISONS 



of several antigens are given, a multisensitization of the 

 plain muscle can be demonstrated. Desensitization of the 

 muscle to one antigen is not without effect on its sensitiveness 

 to the others. (6) The washed plain muscle from guinea-pigs 

 immunized to an antigen by a series of injections, is sensi- 

 tive to the antigen, like that from anaphylactic pigs. But 

 the sensitiveness is in this case less rigidly specific, e. g., 

 plain muscle from a guinea-pig immunized to horse serum 

 showed a subsidiary sensitiveness to sheep serum. (7) 

 The sensitiveness of the washed, plain muscle is seen in 

 passive as in active anaphylaxis, whether the serum pro- 

 ducing passive sensitization is obtained from sensitive or 

 immune guinea-pigs. (8) The actively or passively sensi- 

 tized plain muscle after being desensitized in vitro can be 

 resensitized in vitro by mere contact for some hours with a 

 not too great amount of sensitive serum. It has not been 

 found possible to sensitize normal plain muscle in exactly 

 the same way; but perfusion of a normal uterus for five 

 hours, with diluted serum from sensitive guinea-pigs, pro- 

 duced a decided passive sensitization. (9) The response 

 to the specific antigen of the bronchioles of the anaphylactic 

 guinea-pig is not impaired by excluding the abdominal 

 viscera and the brain from the circulation, and is produced 

 with apparently undiminished vigor in the isolated lungs 

 perfused with Ringer's solution." 



Dale suggests that the response of plain muscle to its 

 specific sensitizer might be used for medico-legal purposes. 

 The suspected material might be used to sensitize a guinea- 

 pig. After allowing time for full sensitization the uterus 

 could be excised and a suspended horn tested with various 

 sera until the one giving the typical response was detected. 

 With the other horn the limits of the response. might 

 be determined. A second method might be as follows: 

 "Guinea-pigs could be sensitized with a small injection of 

 known serum from the suspected species, e. g., human 

 serum. After the usual incubation period one pig would 

 be killed, the uterus excised, and the degree of sensitiveness 

 of the first horn to human serum tested. If the sensitiveness 



