OF VITAL PHENOMENA 117 



might account for the bioelectric phenomena. Prof. A. F. 

 Kovarik kindly took the readings with an improved Dolezalek's 

 electrometer. Benzol was used as a membrane. Its conductivity 

 is so low that the concentration cell had to be enclosed in a metal 

 cage before constant results were obtained. The H ion solutions 

 were PH = 6 and 7 made with the aid of Sorensen's phosphate 

 mixtures and tested with the hydrogen electrode. The emf was 

 31 mv, whereas the theoretical is 59 mv. This is not, however, 

 a greater discrepancy than in some of Haber and Klemensiewicz's 

 experiments with benzol, the potential difference between n/10 

 and n/100 HC1 being only 18 mv. The emf of living muscle 

 as measured, is not usually greater than 31 mv, and since the 

 PH of the blood is about 7.5 the reaction of the muscle contents 

 need only be PH = 6.5. 



Whereas, in the above membranes, their chemical nature 

 seemed unimportant, ice, glass and carbocyclic compounds be- 

 having in the same manner, the permeability of certain other 

 membranes depends, according to Beutner (1913 d), on a chem- 

 ical reaction. Beutner used one series of membranes permeable 

 only to cations and another only to anions. An example of the 

 first class is salicylic aldehyde, that on oxidation formed traces 

 of salicylic acid. If such a membrane separates solutions of the 

 same salt of different concentrations, the dilute side becomes 

 negative. If both solutions are very dilute, Nernst's formula 

 may be used to calculate the emf approximately. According to 

 Beutner the cations pass through the membrane by being trans- 

 formed into salicylates, which are soluble in salicylic aldehyde. 

 Beutner's experiments were repeated with n/100 and n/1000 

 KC1 on the two sides' of the membrane, and an emf = 36 mv 

 obtained on Prof. Kovarik's electrometer. 



The conductivity of the salicylic membrane is too low to use 

 the potentiometer if the ordinary U-tube is used in making the 

 concentration cell, but at least qualitative results were obtained 

 in the following manner : A solution of CaCl 2 of greater specific 

 gravity than the aldehyde was placed in the bottom of a beaker 

 and a glass tube introduced into it. A layer of salicylic aldehyde 

 (to which some salicylic acid had been added to increase its 

 conductivity) was floated on top of the CaCl 2 solution, and a 

 dilute solution of CaCl 2 added as a third story. In this way 



