TACHYPHYLAXIS OR SKEPTOPHYLAXIS 151 



found that peptone protects animals against fatal injections 

 of colon bacilli and streptococci, in short that certain antigens 

 protect the animal against the pathogenic action of other 

 antigens (living bacilli or toxic extracts), and therefore that 

 these reactions are not exclusively specific. Gley and Le Bas 

 (1897) showed at the same time that a non-pathogenic dose 

 of peptone, insufficient to prevent the coagulation of the 

 injected animal's blood, protects this animal against an 

 ordinarily fatal dose, and that this immunity is very rapidly 

 acquired in a few minutes. Hence the name of tachyphylaxis 

 given to this phenomenon. 



Schenk (1889) made the same observation for placental 

 extract, and Lambert, Ancel and Bouin later (1910) showed 

 that a first injection of a non-pathogenic dose of a large 

 number of extracts: testicle, thyroid, liver, brain, muscle, 

 kidney, etc., immunized in a few minutes (skeptophylaxis) 

 against the injection of a fatal dose. In this case the immun- 

 ity was not an exclusively specific one : the first injection of 

 the extract from one organ not only protected against a fatal 

 injection of the same extract, but also against the extract 

 from any other organ. 



This category of phenomena should also include passive 

 anaphylaxis, first studied by M. Nicolle, Charles Richet 

 (1906-1907), and more recently (1910) by Novy and his 

 collaborators. This research showed that by injecting into a 

 normal animal first a small amount of serum from an anaphy- 

 lactized animal, and then, shortly afterward, some of the 

 original antigen, there resulted an anaphylactic crisis exactly 

 as with a prepared animal; and that it was possible to prevent 

 this crisis by a small injection of the same antigen. 



An anaphylactic crisis is also caused by injecting into a 

 normal animal a mixture made in vitro of serum from an 

 anaphylactized animal with the antigen. 



In this last case, the mixture therefore of serum with 

 antigen acts in exactly the same way as an organ extract, a 

 peptone, or as other directly toxic albuminoid products, so 

 that all these products can be grouped under the common 

 name of anaphylatoxins. 



