n8 A. P. MATHEWS 



closely calculated from the available potential energy of the salt, 

 if certain constants are known. 



7. A method was found for computing the ionic potential of 

 various ions from the solution tensions. 



8. In the case of Fundulus eggs, which were particularly inves- 

 tigated from this point of view, the order is also consonant with 

 the theory, but the quantitative relationships, while fairly good, 

 are not so uniform as in the case of diastase. 



The character of the action of any given salt solution on proto- 

 plasm must of necessity depend upon the character of the ions, metal 

 and metalloid, already in combination with the protoplasm. This 

 results as a necessary consequence of the theory, and it explains 

 the fact that toward different cells, and toward the same cell after 

 exposure to different salt S9lutions, the same salt solution may exert 

 a different action, being at times stimulating, at other times 

 depressing. 



It has been shown that the physiological action of any salt solu- 

 tion is a function of the available potential energy of its ions. The 

 action of the organic drugs will, I think, also be found to depend, 

 in part at least, on the available potential energy of the dissociated 

 particles of the drug. 



