Lxiv. the Penetration of Electrolytes into Gels. v. the Diffusion of Mixtures of Chlorides in Gels

CONSIDERABLE emphasis has been laid during recent years on the analogies between colloidal systems and lving cells in regard to their behaviour towards water and dissolved substances and it has become evident that the study of colloidal systems must throw light on the constitution and behaviour of living tissues. It is therefore of interest to enquire whether anything analogous to the phenomenon of antagonism between ions in their entrance into living tissues is exhibited in the penetration of electrolytes into gels. Among the many antagonistic actions recorded for various plant tissues, those between different chlorides were among the earliest, and are perhaps now the best, known. Thus a very definite antagonism between sodium and calcium chlorides, between potassium and calcium chlorides, and between potassium and magnesium chlorides, and even between chlorides of the univalent metals, has been recorded by different writers [see Stiles, 1923, 1]. Experiments were therefore made on the diffusion of mixtures of chlorides through gels of agar-agar and gelatin with a view to determining whether any mutual hindrance to the penetration of salts through the gel resulted from the presence of one salt along with the other, such as might be compared with the antagonistic effects observed in living systems.