886 



SCIENCE 



[N. S. Vol. XXXIV. No. 88« 



tion of the kation remains the same the 

 E.M.F. remains unaltered. The E.M.F., if 

 liquid a is m/1,000 NaCl, is .139 volt, and if it 

 is m/2,000 ]Si"a,SO, is .141 volt; practically 

 identical values. If the liquid a is m/100 

 NaCl it is .090 volt, if it is m/200 Na.SO, it 

 is .092 volt; again practically identical values. 



4. It was necessary to convince ourselves 

 that v?e were not dealing with purely osmotic 

 effects (and possibly diaphi-agm currents). In 

 one experiment the external liquid a was 

 m/100 NaCl, the liquid b on the injured side 

 of the a^iple was m/10 KCl. The E.M.F. was 

 + .092 volt. Then enough cane sugar in 

 crystals was added to the liquid a to make its 

 total concentration about m/2. After the 

 sugar was dissolved the E.M.F. was .093 and 

 remained so. Changes in concentration by a 

 non-electrolyte like cane sugar, therefore, do 

 not alter the E.M.F. 



5. Continuing an investigation by Haber 

 and Beutner on " Phasengrenzkrafte," Haber 

 and Klemensiewicz described a concentration 

 cell for H-ions of the type, acid; glass; alkali, 

 the acid representing the solution with a high, 

 the alkali with a low concentration of H-ions. 

 Haber pointed out that this type of concen- 

 tration element might correspond to the type 

 represented by muscle, the muscle fibrils corre- 

 sponding to the glass in the acid alkali ele- 

 ment. Since the liquids in the cells are prac- 

 tically neutral a slight production of acid in 

 the fibril (or the injured spot) would give rise 

 to a considerable E.M.F. We fully expected 

 at the beginning of these experiments to find 

 that the E.M.F. of living organs was of the 

 tjrpe of that found by Haber. We found, how- 

 ever, that for the apple this is not the case, as 

 the following experiment shows. The internal 

 liquid 6 was throughout the whole experiment 

 m/10 KCl (neutral). The external liquid a 

 was in succession m/20 NaCl, neutral, alka- 

 line, acid and alkali again. It was rendered 

 acid through addition of enough HCl to 

 render the m/20 NaCl solution m/1,000 acid, 

 and it was rendered alkaline through the ad- 

 dition of enough NaHO to render the m/20 

 NaCl solution m/1,000 alkaline. 



TABLE in 

 Liquid a. E.M F. 



m/20 NaCl, neutral -j- .051 volt 



m/20 NaCI, m/1,000 alkaline -1- .052 volt 

 m/20 NaCl, m/1,000 acid . . -f .048 volt 

 m/20 NaCl, m/1,000 alkaline + .052 volt 



The differences found between neutral, acid 

 and alkaline m/20 NaCl are slight and within 

 the limits of purely accidental variations. If 

 we were dealing with a reversible cell in 

 regard to H-ions we should expect a difference 

 of almost .5 volt between m/1,000 acid and 

 m/1,000 alkali. 



6. It may be of interest to mention also 

 that acids and alkalis behave in regard to the 

 E.M.F. to which they give rise like the salts. 

 The experiments we made in this respect show 

 also that if the concentrations of these sub- 

 stances are a little too high the regularity of 

 the results suffers, and the irregularities are 

 always of such a nature as should be expected 

 if the injury or the etching effect of acids and 

 alkalis increased the anion permeability of the 

 skin of the apple. Liquid h in the apple was 

 m/10 NaCl throughout the experiment. 



TABLE rv 

 Liquid a. E.M F. 



m/10 NaCl -f .003 volt 



m/10 NaHO + .009 volt 



OT/100 NaHO -(- .041 volt 



m/1,000 NaHO + .085 volt 



m/10,000 NaHO -\- .125 volt 



m/100 NaHO + .042 volt 



m/1,000 NaHO -f .085 volt 



m/100 NaHO + .044 volt 



m/10,000 HCl -f- .126 volt 



m/1,000 HCl -f- .064 volt 



m/100 HCl -t- .021 volt 



The m/10 NaHO and the m/100 HCl act as 

 if they had a slight etching effect on the skin, 

 otherwise we notice the same influence of di- 

 lution as in the case of salts. 



7. We believe that these and other experi- 

 ments, which will be published in the full 

 report, show that the influence of the concen- 

 tration of electrolytes on the E.M.F. of living- 

 organs agrees quantitatively with the values 

 to be expected if the skin is permeable for 



