ACIDITY IN DETERMINING SOUNDNESS OF CORN. 



17 



RELATION TO THE PERCENTAGE OF SOUND KERNELS. 



In Table XI the degree of acidity as found in approximately 2,400 

 samples is compared in a general way with the percentage of sound 

 kernels found in the same samples by mechanical analysis. The 

 results in section A of the table represent samples from all grades 

 of car receipts at a principal terminal market from December, 1911, to 

 November, 1912, inclusive. The samples represented in section B of 

 the table were taken at the time the cargoes were discharged at Euro- 

 pean ports from nine vessels loaded at the United States seaboard. 



Table XI. — Comparison of the degree of acidity of samples of corn which were found upon 

 mechanical analysis to contain a low percentage of sound kernels with the degree of 

 acidity of samples xchich contained higher percentages of sound kernels. 



A. — Representative of All Grades of Car Receipts at a Terminal Market. 



Basis of comparison. 



Sound kernels (per cent). 



Less 

 than 50. 



61 to 70. 



Number of samples 



Average acidity c. c. 



28 

 34.8 



13 



32.0 



26 



27.4 



91 

 25.9 



456 

 22.5 



1,467 

 18.6 



B. — Representative of Nine Cargoes Discharged at European Ports. 



Number of samples 



Average acidity c. c. 



Average germination per cent. 



58 



18 



17 



25 



91 



40.9 



31.1 



32 9 



28.8 



24 4 



5.3 



18.6 



29.8 



38.8 



41.0 



92 



21 2 

 55.9 



RELATION TO THE PERCENTAGE OF DAMAGED KERNELS. 



In figure 15 is shown the relation of the percentage of damaged 

 kernels to the degree of acidity found in samples of corn of all grades, 

 representing 2,454 cars received at a principal terminal market (C) 

 from December, 1911, to May, 1913, inclusive. These cars of corn 

 ranged from 10 to 60 c. c. in degree of acidity. The percentage of 

 cob-rotten kernels and the percentage of heat-damaged kernels, if 

 any, was determined by the mechanical analysis of a representative 

 sample from each car. 



It is the purpose of figure 15 to illustrate the general way in which 

 the acidity of corn increases with the amount of damaged kernels 

 as detected by the eye in mechanical analysis. The point at which 

 the curve intersects a perpendicular cross-section line denotes the 

 average percentage of damaged kernels found in the samples, which 

 ranged in degree of acidity as designated at the top of the perpen- 

 dicular cross-section line. The average percentage of damaged ker- 

 nels is shown at the left. The curve designated "cob rot" (solid line) 

 represents the percentage of kernels damaged by agencies other than 

 42125°— 14 3 



