ANTI-ANAPHYLAXIS OF ANIMALS 147 



of " serum disease" in children to be fought or avoided. This 

 was a complication which, although rare and often very mild, 

 was nevertheless very troublesome in cases where the illness 

 required prolonged treatment; in relapses, or also when it 

 was necessary to apply serotherapy to the same patient, 

 successively in different diseases. 



In this research, as in many other cases where the logical 

 deductions from a general and well established law offers no 

 guide, chance once more proved itself more ingenious than 

 the experimenters. Considering that the serum which causes 

 an anaphylactic crisis must contain a poison, Rosenau and 

 Anderson in America and Otto in Germany, had simul- 

 taneously the same idea of endeavoring to immunize guinea- 

 pigs against this poison by intraperitoneal injections of large 

 doses (5.0 c.c.) of horse serum, at regular intervals of from 

 five to six days. In this way they hoped to obtain a specific 

 antidote similar to antitoxin. 



It will be conceded that this idea was rather peculiar: 

 they were trying to obtain an anti-anaphylactic product by a 

 process which, as was already well known, should lead 

 straight to anaphylaxis, which should cause a poison, not a 

 counter-poison to appear; and they did not obtain what they 

 were seeking. 



But a well performed experiment is never completely 

 wasted. Rosenau and Anderson found that when injections 

 were made every twelve days, there were often anaphylactic 

 accidents at the time of the second injection, whereas when 

 the injections were made every five days, no apparent acci- 

 dent occurred at the third injection, that is twelve days 

 after the first one; that, therefore, the intermediary dose 

 protected the animal against the following injection. Soon 

 after this, Besredka and Steinhardt, who at first followed 

 the errors of their predecessors, finally discovered that, in 

 order to avoid an anaphylactic crisis in a duly anaphylactized 

 animal, it was sufficient to inject a very small dose of the 

 product a few minutes before the shocking dose. 



The explanation of these phenomena is very simple. It 

 logically follows the results of the series of experiments 

 quoted above, beginning with those of Hayem. 



