STUDY OF MOLECULAR ADHESION. 433 



It should be noted, however, that the agglutination of corpuscles 

 with insoluble bodies like barium sulphate by means of salts in a 

 citrated medium is never so intense as when there is no citrate 

 present. We think this is owing to the fact that the salts do not 

 break up the complex of barium sulphate and thereby restore the 

 suspension to its original condition, but endow the very particles 

 of this complex with a certain amount of adhesive property. We 

 have already seen that flocculation of the complex, barium sul- 

 phate plus citrate, by a salt is reversible, that is to say, that the com- 

 plex recovers its normal appearance when the flocculating salt is 

 removed. The salt, then, endows the particles of the complex 

 with a mutual adhesive affinity (flocculation of the complex), or 

 else with an adhesive affinity for other suspended substances 

 (corpuscles). And, consequently, the agglutination of corpuscles 

 with an insoluble substance in a citrated medium when a salt is 

 present would naturally not be as great as the one produced by the 

 same amount of salt when citrate is absent; this, indeed, is what 

 we find to be true. The contrary would occur if the activating 

 salt broke up the complex and restored the suspension to its normal 

 condition. 



The action of citrate on calcium fluoride, mastic and the like, as 

 we have noted in Section II, is not immediately perceptible, as is the 

 dissemination of barium sulphate. Citrate does, however, affect 

 these various substances in a similar manner and prevents their ad- 

 hesion to other substances, such as red blood cells, as we have 

 already indicated. Calcium fluoride, an inorganic substance, is in- 

 termediary between barium sulphate, an inorganic substance 

 that is disseminated by a citrate, and mastic, which is an organic 

 substance that shows no immediate effects with citrate. From a con- 

 sideration of mastic we may go on to the study of other organic 

 bodies which in turn would seem to show no reaction to the citrate, 

 but which are, however, influenced by it in a similar manner to 

 calcium fluoride and mastic. 



* 

 * * 



We find that we can continue our comparison of the adsorption 

 phenomena that we have studied with similar phenomena in hemoly- 

 sis produced by biological agents. We find that citrate of sodium 

 inhibits hemolysis by eel serum, venom, lecithid and alexin in the 



