HYDROGEN ION CONCENTRATION AND PROTEOLYSIS. 163 



Table IV. — Preparation of Different Ph= {2, 4, 8 and 10). 



Table IV. indicates that 3.4 cubic centimeters of n/5 HCl per 10 cubic 

 centimeters of the medium is necessary to secure Ph = 2 approximately; 

 0.75 cubic centimeters of n/5 HCl for Ph = 4:; 0.28 cubic centimeters of 

 n/5 NaOH for Ph = 8; and 0.6 cubic centimeters n/5 NaOH for Ph=10. 



The media, which have been prepared, differ in their total volume; con- 

 sequently, the concentration of the media differ from each other. Again, 

 the author observed that after subjecting these media to sterilization, on 

 the addition of the required amount of acid and alkali, both Ph and the 

 amount of formol titrating nitrogen in the media varied widely, as indi- 

 cated in Table V : — 



