March 21, 1913] 



SCIENCE 



437 



that the normal gastrocnemius of a frog 

 contains little or no NaCl, but compara- 

 tively much KCl, while in the blood the 

 reverse is the case. From this it has been 

 plausibly argued that the NaCI of the 

 blood can no more enter the muscle than 

 can CaCL. One fails, however, to see how 

 on this assumption the fact can be ex- 

 plained that in a pure NaCl or LiCl solu- 

 tion the muscle keeps its weight or gains 

 slightly, while in CaCla it loses consider- 

 ably in weight, since in a pure NaCl solu- 

 tion the K-salts should leave the muscle as 

 well as in a CaClj solution. 



In all hypertonic solutions the muscle 

 loses water and the higher the concentra- 

 tion of the solution is the more water it 

 loses. This is what should be expected 

 according to Avogadro's law. But the 

 writer noticed that if the muscles remain 

 in the hypertonic solution they begin after 

 a certain time to absorb water and the 

 higher the concentration the sooner, so that 

 finally the muscle begins to swell even in a 

 grammolecular solution of NaCl! 



This paradoxical behavior finds its ex- 

 planation in the writer's observations on 

 Fundulus eggs, which show that the im- 

 permeability of the membrane for salts and 

 sugars is destroyed the more rapidly the 

 higher the concentration of a solution. As 

 soon as this impermeability is destroyed 

 the cells no longer follow Avogadro's law, 

 but show a behavior which is comparable 

 to that of a piece of solid gelatine, i. e., 

 water is absorbed not by osmotic forces but 

 by "imbibition." The degree of imbibi- 

 tion varies with the nature of the sur- 

 rounding salt and on this assumption the 

 writer explained the differences of be- 

 havior of dead muscle in KCl and CaCla 

 solutions.^" 



~ Loeb, I. 0. 



Vm. THE ANTAGONISM BETWEEN ACIDS 

 AND SALTS 



The influence of the chemical character 

 of the surrounding solutions upon imbi- 

 bition in the dead muscle is well illustrated 

 by the following observations: 



The writer showed sixteen years ago that 

 the muscle absorbs water from an m/8 

 solution of NaCl if HCl (or any other 

 acid) is added.-^ In this case the law of 

 Avogadro-van't Hoff is apparently vio- 

 lated. It was pointed out by Overton that 

 in this case the acid destroys the semi- 

 permeability of the muscle and that the 

 subsequent absorption of water was a mere 

 phenomenon of imbibition. It had been 

 shown previously that the swelling of a 

 solid plate of gelatine in water is increased 

 if acid is added. 



In a subsequent paper it was shown by 

 the writer that there exists a curious an- 

 tagonism between salts and acids. "While 

 a muscle swells in an m/8 NaCl solution if 

 the latter is rendered acid, it does not 

 swell, or it may be even dehydrated in an 

 acid solution when the concentration of the 

 NaCl in the solution is sufiiciently raised; 

 notwithstanding the fact that in the highly 

 concentrated neutral NaCl solution the 

 muscle will finally absorb water. 



The following table illustrates this: 



"While the muscle gains in weight in 

 eighteen hours in a neutral 4.9 per cent. 



'^'Loeb, Pfliiger's Arehiv, Vol. 69, p. 1, 1897; 

 Vol. 71, p. 457, 1898. "Studies in General Phy- 

 siology," Vol. II., pp. 450 and 501, Chicago, 1906. 



