4 Scientific Proceedings (55). 



2 (819) 



On analogous effects exerted by antagonistic calcium and citrate 

 ions in physical and biological systems. 



By G. H. A. Clowes. 



[From the Biological Chemical Department of the State Institute for 

 the Study of Malignant Diseases, Buffalo, N. Y.\ 



From the preceding paper it appears that antagonistic ka- 

 tions and anions exert their effect upon the equilibrium of aque- 

 ous oil systems by causing variations in the relative solubility of 

 a concentration film of fatty acid salts in oil and water. The 

 resemblance between the effects observed in purely physical sys- 

 tems of this type and in biological systems suggests the possibility 

 that protoplasm may consist essentially of an aqueous lipoid sys- 

 tem in which a film of lipoid material functions as the continuous 

 phase. If this is the case, an excess of either positive or nega- 

 tive ions should exert a disturbing effect upon the physical equi- 

 librium of the protoplasm corresponding with that observed above, 

 and a critical point at which kations and anions exactly counter- 

 balance one another should be found in biological systems corre- 

 sponding with that observed in purely physical systems, the pre- 

 cipitation of lipoids and fatty acid salts, for example. 



To test this question calcium was selected as a suitable kation, 

 and citrate as a suitable anion on account of the facility with 

 which the proportions in which they counterbalance one another 

 in the process of blood coagulation may be estimated (see subse- 

 quent communication). A ra/5 CaC^ and a chemically equivalent 

 solution of sodium citrate were prepared and admixed in varying 

 proportions ranging from o per cent, of Ca and 100 per cent, of 

 citrate to 100 per cent, of Ca and o per cent, of citrate. On 

 mixing these solutions with aqueous sodium oleate suspension, 

 the following results were obtained. 



Precipitation was complete from 100 per cent, to 40 per cent, 

 of calcium, gradually diminishing from this point until virtually 

 no precipitation was visible between 35 per cent, and 30 per cent, 

 of calcium, once more rising to an almost complete precipitation 

 between 25 per cent, and 5 per cent, and subsequently diminishing 



