Potential differences between organic liquids and aqueous solutions

A typical case, one of the earliest investigated, is that of salicylic aldehyde saturated with salicylic acid for the organic substance. If X aq., the variable aqueous solution, is potassium chloride, the e.m.f. changes from + 137 mv. to —32 mv. as the salt concentration is increased from N/6,250 to 2-5 N, the e.m.f. s being established at once and remaining practically constant up to at least two hours. As the concentration of the salt increases, the organic phase, which is acid in reaction, becomes less positive to the water. 

With the basic organic phase, e.g. o-toluidine, the sign of the change of potential was opposite to the above, the organic phase becoming more positive to the water with increasing concentration of salt. If the salt was 

1 The principal papers, of which the earlier are usually more interesting, are given below. Those marked P are little more than polemics. 

Entstehung dektrischer Strdme in lebenden Oeweben (Stuttgart, 1913) Physical Chemistry of Living Tissues, etc. (1933), pp. 189 ff. 

Cells similarly constructed, but with different salts at the same concentration1 on either side of the organic phase, sometimes gave quite large potentials, e.g. 

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