ANTAGONISM 167 



significant fact that we are able to extend this conception 

 to organic compounds and to show that non-electrolytes 

 which decrease permeability can also antagonize such 

 substances as NaCl. These facts indicate that the hypoth- 

 esis may perhaps be applied in a general manner so as 

 to include both electrolytes and non-electrolytes. 



As an example of antagonism between salts and 

 organic substances we may cite some experiments with 

 bile salts. The writer found, very early in the course of 

 his experiments, that Na-taurocholate increases the elec- 

 trical resistance of Laminaria. This was somewhat 

 striking in view of the fact that agents which increase 

 permeability have long been known, but the discovery of 

 substances which have the opposite effect, is compara- 

 tively recent. The number of such substances known at 

 present (especially organic substances) is very small and 

 it is therefore of interest to find that bile salts possess 

 this property. 



The experiments were made by determining the elec- 

 trical conductivity of Laminaria in solutions to which 

 Na-taurocholate was added.^® 



In the first experiments the bile salt was dissolved in 

 sea water. The amounts added to 1,000 cc. of sea water va- 

 ried from 0.8 to 1.5 gm. If the Na-taurocholate were pure, 

 1 gm. in 1,000 cc, would make the concentration about 

 0.002 M, but as its purity is doubtful the concentration can- 

 not be accurately determined. 



After dissolving the Na-taurocholate the sea water 

 was restored to the normal conductivity and made 

 approximately neutral to litmus. 



At all the concentrations employed there was an 

 immediate increase in resistance'^ followed by a fall. 



=°(7/. Osterhout (1919, B, C). 

 " See page 55. 



