ELECTROLYTIC SOLUTIONS 33 



The question has an intimate bearing on practical pharma- 

 cology. When we prescribe a caeodylate or an amylarsinate, 

 we are not prescribing an arsenical treatment whose effects 

 can be compared with those of an arsenide, an arsenite, or 

 an arsenate. This fact is sufficiently indicated by the difference 

 in the toxic doses of the different salts. Each variety of 

 arsenical ion has its own special physiological and therapeutic 

 properties. We do not expect to obtain the results of a 

 ferruginous treatment from the administration of a ferrocyanide 



or a ferricyanide. Both contain iron, it is true, but neither 



+++ 

 possess the properties of the cation Ee, but rather those of the 



complex anion of which they form a part. 



We have already said that most of the therapeutic, toxic, 

 and caustic actions of an electrolyte are due to ionic action, 

 and the substances can therefore have 110 toxic action unless 

 they are dissociated. Many of the solvents employed in 

 medicine, such as alcohol, glycerine, vaseline, and chloroform 

 dissolve the electrolytes but do not dissociate them into ions, 

 and these solutions therefore do not conduct electricity. Such 

 solutions have no therapeutic action. With the absence of 

 dissociation all the ionic toxic and caustic effects also disappear 

 entirely, and only re-appear as the water of the tissue is able 

 slowly to effect the necessary dissociation. 



Carbolic acid dissolved in glycerine is hardly caustic and 

 but very slightly toxic. We have met with several instances 

 in which a tablespoonful of carbolized glycerine, in equal parts, 

 has been swallowed without any ill effect, either caustic or 

 toxic, whereas the same dose dissolved in water would have 

 been fatal. This absence of dissociation has enabled the 

 surgeon Menciere to inject carbolic and glycerine in equal 

 proportions into the larger joints, the part being subsequently 

 washed out with pure alcohol. Thus by employing vaseline, 

 oil, or glycerine as a solvent, and avoiding the access of water, 

 we are able to use electrolytic antiseptics in very concen- 

 trated form. Their action is brought out very slowly, as the 

 water of the organism effects the necessary dissociation of the 

 electrolyte. 

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