PHYSICO-CHEMICAL PROPERTIES. 97 



The number of these illustrations might easily be 

 multiplied. In passing I only wish to point out that the 

 activity of the metallic ions can be increased through 

 combination with an alcohol radicle in the same way as 

 the activity of the acid ions. It is possible in this way 

 to bring about in animals most acute metallic intoxica- 

 tions with the ethylic compounds of zinc, mercury, and 

 lead. 



Besides this influence upon the effects of ions, brought 

 about through combination with alcoholic radicles, de- 

 pendent upon the fact that protoplasm is made up of 

 lipoidal and proteoidal material, there still exists another 

 way in which the specific effects of many ions can be 

 increased or decreased, namely, through combination 

 with other ions. As an example of this we may take 

 the behavior of the alkaline earths toward protein in the 

 presence of neutral salts of the alkali metals. As a glance 

 at the lists of ions given above shows, "the protein precipi- 

 tations brought about through the alkaline earths can 

 be inhibited through the addition of ions of the alkali 

 metals, or hastened through the addition of anions, most 

 powerful of which is the sulphocyanate anion. It seemed 

 possible, therefore, that through proper experiments a 

 physiological antagonism could be discovered to exist 

 between monovalent cations and the alkaline earths, as 

 well as a synergistic increase in the effect of anions 

 through the cations calcium, strontium, and barium. 

 This suspicion, prompted by analogies existing between 

 experiments carried on in vitro and certain phenomena 

 observed in vivo, could be shown to be correct by animal 

 experiments. 



If animals are kept in a half -intoxicated state with 



