THE RELATION BETWEEN THE RATE OF PENETRATION OF MARINE 



TISSUES BY ALKALI AND THE CHANGE IN FUNCTIONAL 



ACTIVITY INDUCED BY THE ALKALI. 



By E. Newton Harvey. 



OBJECT AND METHOD. 



The present study, made at Tortugas in the summer of 191 1, is a con- 

 tinuation of permeability investigations undertaken at Columbia Univer- 

 sity in 1910 to 1911.1 My aim has been twofold. First, to compare the 

 permeability of the cells and tissues of salt-water organisms with those of 

 fresh-water forms. Second, to determine the relation between the rate of 

 penetration of the alkali and the appearance of structural or functional 

 changes in the cell. Rate of penetration of the alkali may be best deter- 

 mined by the color change of some indicator within the cell. As in previous 

 work, neutral red was used for the purpose. It is non-toxic, readily staining 

 the living cell, and the color change (of red in acid or neutral to yellow in 

 alkaline solution) is sharp and well marked. 



Neutral red was first made use of as an indicator in studying perme- 

 ability by Bethe.2 Medusae stained in the dye become a deep orange-red, 

 which changes to bright red in HCl and to yellow in NaOH. 



Warburg^ found that sea-urchin eggs stained in neutral red were entered 

 readily by NH4OH but not by NaOH. My own experiments* gave similar 

 results for another species of sea-urchin {Toxopneiistes variegatus) and for 

 Paramcecium, Elodea, and Spirogyra cells. 



The penetration of the following alkalies was studied : 



I. Weakly Dissociated: 2. Strongly Dissociated: 



Ammonia NH4OH Tetraethylammonium hydroxide 



Methylamine NH3CH3OH N(C2H6)40H 



Dimethylamine NH2(CH3)20H Sodium hydroxide NaOH 



Trimethylamine NHCCHsjsOH Potassium hydroxide KOH 



Ethylamine NH3C2H6OH Strontium hydroxide Sr(0H)2 

 Normal propylamine NH3C2H5CH2OH 

 Isopropylamine NH3(CH3)2CHOH 



The addition of the stronger alkalies to sea-water precipitates the Mg 

 so that a Mg-free sea-water containing 0.625 m. (100 NaCl + 2.2 KCl -\- 

 2.5 CaCl2) was used to dissolve the alkali. Such a solution is a fairly well- 

 balanced medium for marine tissues, being only slightly inferior to van't 

 Hoff's solution. The salt present in solution with the alkali affects also 

 the rate of entrance of the latter, so that it is important to use always the 



* Harvey, E. N. Jour. Exp. Zool., vol. lO, p. 507. 1911. 



* Bethe. Pfluger's Archiv, vol. 127, p. 219. 1909. 

 'Warburg, O. Zeit. f. Physiol. Chem., vol. 66, p. 305. 1910. 



* Harvey, E. N. Loc. cit. 



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