OF VITAL PHENOMENA 135 



Fundulus eggs may be increased by certain solutions of salts, 

 alkaloids or other substances in concentrations that do not kill 

 them (McClendon, 1912 a, e, 1913 a). The eggs of the pike 

 behave similarly. These eggs are impermeable to water or to 

 salts, but when placed in 0.1 mol NaN0 3 they lose chlorides, 

 which pass out into the nitrate solution and may be accurately 

 estimated with Richards's nephelometer. Three per cent ethyl 

 alcohol causes retardation in the development of these eggs and 

 is therefore considered an anesthetic. If the eggs are placed 

 in 0.1 mol NaN0 3 containing 3 per cent alcohol only half as much 

 chlorides diffuse out of them as when placed in 0.1 mol pure 

 NaN0 3 . The anesthetic inhibits the permeability increasing ac- 

 tion of the pure salt solution (McClendon, 1914 b, 1915 b). 



The skin current of the frog disappears when the skin is an- 

 esthetized, indicating that the hypothetical increase in permeabil- 

 ity of the outer surfaces of the gland cells during secretion may 

 be inhibited by anesthetics. In this case we do not know whether 

 nervous stimulants are exclusively the cause of the increase in 

 permeability. 



It seems clear, therefore, that anesthetics inhibit the increase 

 in permeability of the plasma membranes of the irritable ele- 

 ments. In order for them to do this it is necessary for them 

 to penetrate only the surface film of the cell. But anesthetics 

 belong to the group of substances which penetrate cells easily, 

 and the question arises as to their effect on the interior. Some 

 experiments on catalysis are suggestive. If blood charcoal is 

 mixed with a solution of oxalic acid containing atmospheric 

 oxygen the acid is burned to C0 2 and H 2 0. Blood charcoal con- 

 tains mineral matter, including iron, which is not entirely re- 

 moved by extraction with HC1 and we cannot say that it is the 

 carbon that acts as the catalyzer. Warburg found that the cata- 

 lyzing power of charcoal varies with its power of adsorbing 

 oxalic acid, hence the combustion must take place near the sur- 

 face of the charcoal. He observed further that anesthetics (of 

 the urethane series) inhibit the oxidation, and explained this as 

 due to the displacement of the oxalic acid from the surface of 

 the charcoal by the anesthetic (which is adsorbed to a greater 

 extent than the acid) . The author confirmed these results, using 

 charcoal extracted with concentrated HC1 followed by H 2 for 



