36 
cated by the acidity test, and the results of this investigation suggest 
the acidity test as a method to be used in determining accurately the 
soundness and quality of corn. 
Let us consider, for example, that a sample of seed corn showed 
upon test a degree of acidity of 15 c. c. This represents approxi- 
mately the acidity of 
range in percentage of damaged tr£M£Ls ^he average corn se- 
lected for seed. Now, 
let us consider that a 
sample of corn con- 
sisting entirely of cob- 
rotten or otherwise 
damaged kernels 
showed upon test a 
degree of acidity of 
45 c. c. This repre- 
sents the degree of 
acidity of corn selected 
by the Office of Gram 
Standardization as be- 
ing most typical of 
damaged kernels 
found in commercial 
corn arriving at termi- 
nal markets through- 
out the country. Sup- 
pose the two samples 
be mixed in the pro- 
portion of 90 per cent 
seed corn and 10 per 
cent damaged corn. 
The degree of acidity 
of this sample would 
be theoretically 90 per 
cent of 15 c. c. plus 
10 per cent of 45 c. c, 
or 1 8 c . c . This would 
stamp the sample as 
being commercially 
sound corn. 
Let us consider fur- 
ther a sample of average sound corn as determined by mechanical 
separations of samples from several thousand cars of corn arriving 
at terminal markets. The acidity of such corn is shown by this 
investigation to be approximately 19.5 c. c. If a sample be 
LE 55 THAN 
60 
V 
\ 
\ 
\ 
\ 
\o 
«*r 
^h 
*<?>. 
N Co 
\f- 
\ 
\ 
\ 
\ 
\ 
\ 
\ 
\ 
\ 
\ 
\ 
^ \ 
^ \ 
c initO^ 
J^> — 
i- ^-— -" 
~"---^_ 
^--~. 
—ZLQJSTURE 
Fig. 2 
Curves showing the relation of the degree of acidity 
and the percentages of germination and moisture to the range 
in percentage of damaged kernels as found in samples of corn 
(average of all grades) arriving at a principal terminal market 
(C) from December, 1911, to November, 1912, inclusive. 
