SALTS 445 



opposite effects on the viscosity, permeability, imbibition, 

 and elasticity of protoplasm and its capacity to repair its surface, 

 explains the nontoxicity of these two elements when in proper 

 (50:1 or 2) proportion. 



Such, in its simplest form, is salt antagonism. The situation 

 is complicated, as we have seen, by the fact that monovalent 

 elements often show antagonism between each other, that 

 bivalent elements do the same, that not all monovalents or all 

 bivalents have a like effect, and, further, that anions (OH") 

 sometimes antagonize cations (Ca+). The factor so often 

 neglected in such discussions is the protoplasm itself. Proto- 

 plasm is in a constant state of change; no two masses of it are 

 ever identical, nor is one mass quite the same during any two 

 periods of time. 



While salt antagonism has been studied primarily in connec- 

 tion with protoplasm, it is also involved in simple nonliving 

 systems, e.g., lecithin. 



The Lyotropic Series. — The series of elements arranged by 

 Lillie (above) in decreasing order of their antagonistic action on 

 sodium is a lyotropic, or Hofmeister, series. Many such series 

 have been arranged on the basis of the effects of ions on proto- 

 plasm, blood, proteins, and colloidal suspensions. If cations are 

 arranged in the order of their power to precipitate colloidal 

 suspensions (of metals, dyes, or oils), the following series is 

 obtained : 



Th > Al > Ba > Sr > Ca > Mg > 



H > Cs > Rb > K > Na > Li 



which means that thorium is the most and lithium the least 

 effective in precipitating a suspension, e.g., of an arsenic salt. 

 Two facts stand out — first, that no two ions have the same 

 precipitating power (except possibly caesium and rubidium, 

 which differ but shghtly); and, second, that there is a definite 

 arrangement into groups of like valence; the first element is 

 quatravalent, the second trivalent, the next four bivalent, and 

 the last six monovalent. 



The original series arranged by Hofmeister is: Citrate > 

 tartrate > sulphate > acetate > chloride > nitrate > chlorate. 

 It expresses the relative effects of anions (of sodium salts) on the 

 salting out, or precipitation, of egg albumin. Hober found the 



