362 Mr. S. B. Schryver and Miss M. Hewlett. Investigations 



activities for a longer period in a solution which contains, in addition to 

 sodium and calcium salts, also potassium and magnesium salts, and has 

 formulated the conception of " balanced " salt solutions as necessities for the 

 maintenance of the maximal activities of plants. 



The investigations on the salt actions already published have, so far, 

 revealed only the analogy between biological antagonism of calcium to certain 

 other salts, and. an antagonistic action of a similar nature on the cholate gel. 

 In view of the conception advanced by one of the authors of this paper, that 

 the protoplasm or cell-membrane contains a gel-forming substance alike in 

 many of its physical properties to cholate gels, it was of interest to determine 

 whether further analogies exist between the biological action of salts and 

 their erosive action on the cholate gel — to ascertain, for example, whether 

 mixtures other than those of calcium chloride and one of the chlorides of 

 alkali metals could form " balanced " solutions in which the gel can maintain 

 its stability. 



Now as the hypothesis has been put forward that plant and animal cells 

 contain gel-like structures, and that their normal activities are intimately 

 connected with the maintenance of a certain state of aggregation of such 

 structures, it was of importance to study the action of salts on gels which 

 might simulate as closely as possible those postulated for in the living cell. 

 These should contain, in addition to the substance to which the gel structure 

 is primarily due, certain salts and other bodies to which must be ascribed the 

 relatively high osmotic pressure of the cell. ISTow in all the experiments 

 already carried out on the erosion of the cholate gel, the material employed 

 has been relatively poor in inorganic salts ; the solution from which the gel 

 was prepared by heating contained, in fact, 2 per cent, sodium cholate (the 

 concentration of which was less than IST/20) and calcium chloride in the 

 concentration of 1ST/40 (M/80). In the present communication are contained 

 the results of a series of experiments on the action of salts on gels containing 

 larger amounts of added salts. The results indicate that gel stability in the 

 presence of salts is determined by the action of several factors. Much 

 research remains to be accomplished before the laws governing gel formation 

 and disaggregation can be elucidated and the biological actions of salts 

 explained. 



Experimental. 



The experimental method employed was the same as that described in the 

 last communication.* 



* Loc. cit., p. 176. 



