Vol. LI I May, 1927 No. 5 



BIOLOGICAL BULLETIN 



THE EFFECT OF CYANIDES ON THE SWELLING 



OF PROTOPLASM. 



REUBEN BLUMENTHAL, 



DEPARTMENT OF ZOOLOGY, UNIVERSITY OF PENNSYLVANIA AND MARINE BIO- 

 LOGICAL LABORATORY, WOODS HOLE, MASS. 



Physiologists have long since attempted to formulate a theory 

 for the cause of anaesthesia, and the results thereof have been 

 many and varied. The exceptions to any one theory are too 

 numerous and too important to accept any one of them as the 

 correct theory. The final and real solution of so complex a 

 physiological process will probably be one which will take into 

 consideration portions of all theories now existing, or one which 

 will introduce an entirely new factor or factors. Accounts of the 

 various existing theories are set forth in a number of papers 

 among which are the following: Overton ('01), Meyer ('99), 

 Traube ('19), Warburg ('14), Mathews ('14), and Lillie ('18). 

 This paper will make no attempt to give any evidence in support 

 of any one of the theories, but will rather present the results ob- 

 tained in using HCN and KCN as anaesthetics. 



The work here reported deals with the effects of HCN and KCN 

 on the permeability of unfertilized Arbacia eggs to water. An 

 increase in the volume of the eggs, when placed in a solution, is 

 taken as showing an increase in the permeability of the egg. 

 Heilbrunn ('25), however, objects to calling an increase in the 

 volume of the egg an increase in permeability. He suggests that 

 this increase in size may be due to a decrease in surface tension; 

 an increase in the fluidity of the interior or an increase in the 

 extensibility of the plasma membrane. Since Arbacia eggs are 

 nearly all spherical, changes in their volume may be measured by 

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