AGGLUTINATION OF RED BLOOD CELLS. 321 



by studying the inhibiting effect of serum on the agglutination of 

 corpuscles by suspensions.* 



Once these colloids are removed we have a fluid (A) that allows 

 the flocculation of CaFl 2 and of ferric hydrate by the intracorpus- 

 cular salts present in this laked fluid. This flocculation, as we know, 

 takes place. This fact, however, does not prevent it from agglu- 

 tinating subsequently added corpuscles. These experiments show, 

 as we believe, that the intracorpuscular salts extracted by laking 

 do not antagonize the agglutination of fresh corpuscles by sus- 

 pensions or colloids; we have just recently seen, moreover, that 

 the stromata, deprived of intracorpuscular salts, are agglutinable 

 by colloids and suspensions as well as are corpuscles. 



As a result of this we conclude that in order to explain the agglu- 

 tinating effect of these suspensions with which we have been deal- 

 ing, on corpuscles, it is not necessary to suppose that a flocculation 

 of them by means of the intracorpuscular salts takes place. We 

 have indeed seen, first, that this agglutination is likewise possible 

 by suspensions that have previously been flocculated by electrolytes ; 

 and second, that there is no change when the excess of salts in the 

 pericorpuscular zone of the corpuscles is reduced to the minimum 

 so as to annihilate the hypothetical flocculating effect of this zone 

 on the suspension; and third, the phenomenon of the agglutination 

 of stromata is identical with that of corpuscles; fourth, the sen- 

 sitivity of these suspensions to the flocculating action of salts is 

 not a necessary preliminary to their agglutinating property toward 

 corpuscles. Inasmuch as all the phenomena of the agglutination 

 of corpuscles by a suspension take place just as well with colloids, 

 we think, whether or not these latter are flocculated by diffused 

 intracorpuscular salts, that this has no effect on their agglutinat- 

 ing property over red blood cells. We have endeavored to prove 

 this fact more directly. We have attempted to produce phenom- 

 ena of agglutination analogous to those already described by allow- 

 ing our suspensions to act upon an emulsion, the particles of which 

 contain no salts that might be diffused, in place of red blood cells. 

 For this purpose we have used emulsions of oil prepared by 



* We have already noted in our first article that although serum prevents the 

 agglutination of suspensions with corpuscles this inhibiting property may be 

 removed by treating it previously with a large dose of CaFl 2 or of barium sulphate. 



