KC1 
GASTRIC JUICE 
ASPERGILLUS 
LIMIT 
YEAST LIMIT 
WINES 
SILAGE 
ESCHERICHIA 
COLI LIMIT 
MILK 
NEUTRALITY 
BLOOD 
BORAX 
*NH 4 0H 
FIG. 15—D IA G R A M M A T I C 
REPRESENTATION OF THE 
pH SCALE OF TRUE ACIDITY 
The pH values, given as the log of 
-, are shown on the numbered 
horizontal lines. The acid end is at 
the top, the alkaline at the bottom. 
The diagonal line shows the pro¬ 
portion of H ions to OH ion 3 at each 
TT 
pH. Thus neutrality whe:e 577 -= 1 
H.O 
is at pH 7.0. The true acidity given 
in pH values for some familiar sub¬ 
stances is indicated The working 
range of brom-cresol purple is shown 
by the curved line. 
ALKALINE 
