212 METHODS OF SERO-DIAGNOSIS. 



Oher workers, such as Arthus, made similar observations 

 as to the increased sensibility shown to horse serum by rabbl ts> 

 and the " Theobald Smith phenomenon," which is manifested by 

 an increased sensibility of guinea-pigs to secondary injections of 

 mixtures of diphtheria toxin plus antitoxin, was shown by Rose- 

 nau and Anderson to be dependent on the presence of the horse 

 serum containing the antitoxin, and not on the toxic nature of 

 the mixture, since the horse serum alone was capable of producing 

 the same symptoms as those produced by the toxin-antitoxin 

 mixtures. . 



Since then it has been shown that the anphylactic condition 

 can be produced in the presence of most of the members of that 

 class of organic substance which we have termed antigens. 



If we illustrate these remarks by an example, for instance, 

 the injection of a guinea-pig, with a foreign proteid such as horse 

 serum, we find that on injecting this material on the first occasion 

 it has no appreciable effect. When, however, a certain time, 

 roughly, about 7 to 14 or 21 days, is allowed to elapse, and then 

 a second injection of the same material is made, it is capable of 

 producing marked characteristic symptoms and death of the 

 animal either immediately after or almost immediately after this 

 injection, depending on the route by which the material is 

 injected. 



It was further shown that not alone could an active anaphy- 

 laxis be thus produced, but that also a passive anaphylaxis could 

 be conferred on another animal by injecting it with the serum 

 of an animal in a condition of active anaphylaxis, this second 

 animal reacting to the introduction of the material against which 

 the anaphylactic condition was produced in the first animal, after 

 an interval of about 24 hours, and in a similar fashion to the 

 actively anaphylactic animal. 



Generally speaking, the anaphylactic reaction is specific, 

 though not absolutely so, since it occurs in the presence of pro- 

 teids of closely-allied natures. 



If we wish to utilise the anaphylactic reaction' for diagnostic 

 purposes, we can attempt to use it in two different ways, either 

 by a direct method, where we inject into the subject to be 

 examined a small quantity of antigen similar to that we suspect 

 to be present in the subject's body, and noting whether the subject 

 shows an anaphylactic reaction or not to the introduction of this 

 antigen ; or, on the other hand, we may take some of the subject's 

 serum, inject it into another animal and then by injecting this 

 animal with the suspected antigen, find whether or not we have 

 been able to confer on this animal a passive anaphylaxis. 



As before-mentioned, however, these methods have not been 

 tried to a sufficient extent to allow us to judge their real value. 

 Lately. Miessner has applied the last-mentioned method to the 

 diagnosis of glanders, but the results were negative in this case. 



We can, unfortunately, not enter into any further details 

 concerning anaphylaxis, but it may be noted here that Von 

 Pirquet and Schick explain the symptoms of the " serum disease " 

 of man as being manifestations of anaphylaxis to the serum, and 



