528 EDMUND NEWTON HARVEY 



apparently enters into combination with the albumen. The 

 following experiment illustrates this: 



A stock solution of unknown strength in 0.1 N NaCl was made 

 from Merck's powdered egg albumen. When filtered it was 

 opalescent. 



To 5 cc. was added one drop of 0.05 per cent neutral red and 

 the solution titrated with to KOH. 0.6 cc. was added before the 

 original pink color began to turn and 0.9 cc. fb KOH before it 

 was yellow. Phenolpthalein was then added and the solution 

 found to be neutral. In all 1.6 cc. was added before the phenol- 

 pthalein began to turn pink and 2.0 cc. before it became dis- 

 tinctly pink. 



0.6 cc. TO NH4OH was also required before the neutral red 

 began to fade and 1.1 cc. before a distinct yellow appeared. The 

 solution was still neutral to phenolpthalein and 3.00 cc. were re- 

 quired before a light pink appeared. 



The effect of chloroform on the power of neutralization was 

 also determined. The solutions compared were: 



A 5 cc. albumen + 10 cc. water + 1 drop 0.1 per cent neutral red. 

 B 5 cc. albumen + 10 cc. chloroform-saturated water + 1 drop 0. 1 per cent 

 neutral red. 



Exactly the same amounts of Vir KOH and t¥ NH4OH were 

 required to induce the color change in A as in B. Chloroform has 

 no effect on the combining power. 



Yet one drop (0.05 cc.) of to KOH or NH4OH is more than 

 sufficient to render 0.1 n NaCl solution alkaline to both neutral 

 red and phenolpthalein. 



Any difference in permeability between KOH and NH4OH — 

 and there is a very great difference — cannot therefore be attrib- 

 uted to a difference in combining power of K and NH4. The 

 use of chloroform in killing cells must affect the surface layer of 

 the cell in some way, and not the combining power of the cell pro- 

 teids within. 



4. It is quite possible that the cell (especially plant cells) may 

 actively secrete an acid which neutralizes the alkali as it enters. 

 But when we consider that the mass of the material studied rel- 

 ative to that of the alkaline solution is very small and that the 



