COLLOIDS 97 



strated. They found that "the rapid diminution of antigen 

 follows the rapid rise of precipitin and is coincident with 

 recovery from serum disease"; so that although the two 

 reagents can coexist, they cannot both be "in excess." 



Under what conditions then is an organism sensitive to 

 anaphylaxis? There will be a surcharge of antibodies. 

 That is, all the cells which possess a special affinity for the 

 injected antigen will have multiplied a substance which 

 fixes the antigen, holding a certain quantity en surcharge 

 and allowing the remainder to pass into the blood. There 

 will thus be an excess of antibody in the cells and in the 

 blood. If at this time we inject a sufficient quantity of the 

 same antigen there will be produced a reaction of the same 

 nature as the first time but the effects of this reaction on 

 the organism will be different, because the quantities and 

 the proportions of the two products will be no longer the 

 same and because the reaction will take place not only in 

 the cells but also in the blood. 



We have seen above that the compounds of the antigen 

 with their antibodies may be soluble and under these condi- 

 tions they are neutral for the organism (diphtheria, tetanus) 

 or else they form coagula or precipitates, and are pathogenic. 

 Whenever there are antibodies in excess both in the blood 

 and in the cells, there will be pathogenic reactions intra- 

 vascular and intracellular. 



The reactions will be pathogenic not because there is 

 formed on the second injection a toxic body different from 

 that which is formed at the first injection, but only because 

 this new body will form much more rapidly and in much 

 larger quantities than the first time. Precipitates formed 

 in the blood will result in emboli, infarcts, etc., from which 

 apoplectic attacks, syncope, abdominal congestion, pulmon- 

 ary and cutaneous edema accompanied by fall of tempera- 

 ture and intracellular lesions will be expressed by a variety 

 of symptoms, all the more severe as the cells in question play 

 a more important role in the general economy. These last 

 reactions, especially when they concern the nervous cells 

 to a greater or less degree, are accompanied by fever. Let 

 us note in passing that intravascular reactions when they 

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