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UNITED STATES DEPARTMENT OF AGRICULTURE 
§, BULLETIN No. 516 4g 
f° Joint Contribution from the Bureau of Piant Industry aN a | 
WM. A. TAYLOR, Chief, and the Office of Markets and 
Rural Organization, CHARLES J. BRAND, Chief 
Washington, D.C. Vv December 28, 1916 
TABLE FOR CONVERTING WEIGHTS OF MECHAN- 
ICAL SEPARATIONS INTO PERCENTAGES OF THE 
SAMPLE ANALYZED.’ 
By E. G. Boerner, Assistant in Grain Standardization. 
INTRODUCTION. 
The rules and regulations for the enforcement of the United States 
Grain Standards Act prescribe a definite procedure for securing a 
representative sample upon which the grade of any particular lot or 
parcel of shelled corn is to be based. 
The rules provide that the original sample must be not less than 
2 quarts in quantity, of which approximately 1% pints must be placed 
in an air-tight container and the remainder inclosed in a cloth sack. 
The portion in the container is intended for the determination of the 
percentage of moisture, and this portion should be used for that test 
only. The remainder of the sample, contained in a cloth bag, will 
approximate 24 pints, and this portion is to be used for the remain- 
ing determinations, including color, damaged corn (not including 
heat damage), heat-damaged corn, and foreign material and cracked 
corn. The grades specify the maximum and minimum percentages 
permitted for the factors mentioned, and these percentages are to be 
determined by weight. 
Because of the time involved, it is impracticable to make the 
mechanical separations for color, damage, and foreign material and 
cracked corn on the entire 24 or more pints, and it therefore becomes 
necessary, in most cases at least, to divide the sample in order to 
obtain a smaller representative portion for the determination of the 
factors mentioned. 
Experiments have shown that the sample upon which the deter- 
minations for color, damage, foreign material, etc., are based should 
1 The work covered by this bulletin was done under the direction of Dr. J. W. T. Duvel, in charge of 
the Office of Grain Standardization of the Bureau of Plant Industry. Since August 18, 1916, the grain- 
standardization work of the Department of Agriculture has been administered jointly by the Office of 
Markets and Rural Organization and the Bureau of Plant Industry in connection with the administration 
of the United States Grain Standards Act. 
71842°—Bull. 516—16——1 
