ELECTRO-CHEMICAL PHENOMENA 357 



negative variation during action. This was long ago 

 studied in the sensitive plant. Bose has shown that 

 electric currents are present in all plant activities. He 

 has plotted curves of electric variation corresponding 

 to periods of activity and of rest, and has shown 

 that life and electric phenomena end simultaneously. 

 Osterhaut has shown that the normal electric phenom- 

 ena in kelp are changed by anesthetics, by iodin, by 

 acidity and by varying the concentration of sodium, 

 potassium and magnesium salts in the solution in 

 which the kelp is immersed. He showed that the 

 permeability of the plant cells varies with the activity 

 of the plant, and that at death this electric phenomenon 

 disappears. He also showed that the amount of energy 

 in plants corresponds with the degree of permeability 

 to electric currents at the surfaces of plant cells. R. S. 

 Lillie established similar facts regarding the perme- 

 ability of the larvae of the marine worm, Arenicola. 

 Lillie and Osterhaut believe that the electric phenomena 

 of life in animals and plants are dependent upon changes 

 in the permeability of the semi-permeable membranes 

 which surround vegetable and animal cells. 



Lillie applied Nernst's laws to the life phenomena of 

 the Arenicola. He produced strong evidence that these 

 are electric phenomena and are dependent, primarily, 

 upon the permeability of the cells. The work of Lillie 

 strongly suggests that the essential phenomena of life 

 are identical with the phenomena of electricity, that 

 is, with variations in ionic concentration and changes 

 in permeability of the semi-permeable membranes in 

 short, with the reactions of an electro-chemical mecha- 

 nism. Robertson showed, moreover, that by using oils, 



