THE PERMEABILITY OF CELLS 551 



control, C, were uncytolyzed in one hour and about one-half of 

 them cytolyzed in the course of two hours. Eggs of the ether 

 control, E, were unaffected in 30 minutes and one-half of them 

 cytolyzed in 45 minutes. 



DISCUSSION 



In an extensive paper, Barratt ('04) has studied the action of 

 both acids and alkalies on Paramoecium; my results on alkalies 

 are in fair quantitative agreement with his. Barratt came to 

 the conclusion that neither the alkali nor acids produced their 

 effect by a catalytic splitting of any substances in the organism 

 but by a combination of the acid and alkali with the protoplasm. 

 It was proved that the concentration of acids and alkali decreases 

 in solutions in which a large number of Paramoecia had been 

 placed. Three methods of determining this were used, viz.: (1) 

 the use of an indicator, (2) measuring the electrical conductivity, 

 (3) ('05) determining the E. M. F. by means of hydrogen elec- 

 trodes. Only a relatively small amount of acid and alkah com- 

 bines. One hundred parts of living Paramoecium take up 0.25 

 parts of HCL and 1.5 parts of NaOH. 



I fully agree with Barratt that the toxicity of the alkalies bears 

 no relation to the OH ion concentration. The order of toxicity 

 for Paramoecium is N(CoH5)40H (?) <Na or K or Ca <Sr or 

 Ba <NH4 < amines. The degree of dissociation is NH4 <N 

 (CH3)3H < primary and secondary amines <N(C..H5)4 <Ba, Sr, 

 Ca, K, Na. 



Comparison of all the alkalies above mentioned in regard to 

 toxicity is hardly legitimate since che two distinct classes, the 

 strong and the weak, differ so in their power of penetrating the 

 cell. It is to the rapid entrance of the weak alkahes, that their 

 greater toxicity and general difference in physiological action is 

 to be referred. 12 But even among the strong alkahes, equally 



12 Mathews (American Journal of Physiology, vol. 18, p. 58, 1907) states that 

 the nucleolus of Asterias eggs immediately disappears from view in NH4OH and 

 (NH4)2C03 but not in NaOH or Na2C03. This is possibly due to solution in the 

 entering NH4OH. The NaOH cannot enter and no solution takes place. The 

 carbonates are hydrolytically dissociated into NH4OH and NaOH respectively. 



