316 STUDIES IN IMMUNITY. 



If colloids are flocculated about corpuscles before agglutinating 

 them, as Mme. Girard-Mangin and V. Henri think, such a concen- 

 tration depends on the difference of saline concentration between 

 the rich pericorpuscular zone and the relatively weak fluid between 

 the corpuscles. If this difference in concentration were eliminated, 

 there would be no reason for the colloids to flocculate about the 

 corpuscles, and consequently the agglutination of the latter by the 

 colloids would be nil or, at least, very much diminished. We have en- 

 deavored to determine whether such a result may be verified experi- 

 mentally. We introduce in a large volume of normal saline a certain 

 amount of well-washed red blood corpuscles and allow the mixture 

 to stand for 3 or 4 hours, taking care to shake it from time to 

 time. It is evident that the longer a diffusion of intracorpuscular 

 salts goes on the more will the fluid between the corpuscles in- 

 crease in tonicity and the more perfect will the equilibrium between 

 this fluid and the pericorpuscular zone become. And, what is 

 more, in proportion as the corpuscles lose their electrolytes, the 

 concentration of the fluid surrounding them becomes more nearly 

 equal to their tonicity. Consequently, after a certain period there 

 will be an equilibrium between the corpuscles and the surrounding 

 fluid. If we ccntrifugalize at this point and decant the supernatant 

 fluid, we shall have a fluid A (salt solution plus diffused salts from 

 the corpuscles) and the red blood cells D, which have lost their 

 salts. 



Let us place in tube 1 a given amount of fluid A and in tube 2 

 an equal amount of salt solution; we then add to both the same 

 amount of CaFl 2 and allow the mixtures to stand for a half hour 

 in order to allow the intracorpuscular salts in fluid A to act upon 

 the suspension. We then add to each tube the same amount of 

 corpuscles D. Agglutination of the corpuscles immediately takes 

 place and there is no difference in its intensity in the two tubes, 

 although the experimental conditions differ. It is indeed to be 



nate corpuscles. Landsteiner and Jagic, however, find that the previous floccu- 

 lation of colloids does not diminish their agglutinating property for corpuscles. 

 It is possible that both experimenters are correct, and that one may flock out 

 colloids at various stages and so obtain colloids that are either agglutinating or 

 not so, in accordance with whether the electrolytes have formed loose or dense 

 clumps, that is to say, depending on whether a mixture of the colloids with the 

 corpuscles is or is not possible. 



