REQUIREMENTS FOR SOUNDNESS 79 



should as a rule not fall below 462 grams (46.2 kg. per hectoliter or 

 35.67 + pounds per Winchester bushel)." The weight of rye should 

 not be less than 716 grams per liter or 55,28 pounds per bushel.^^ In 

 general, the individual grain weight, or weight of a standard number of 

 grains, constitutes a better basis for the grading of grain as to quality. 

 The larger grains are heavier and relatively richer in nutrients than the 

 smaller ones which contain more crude fiber. One hundred grains of 

 rye of the best grade will weight 2.70, medium grade 2.20 to 2.70, low 

 grade 2.00 grams. One hundred grains of oats weigh 3.30, 2.85 to 3.20, 

 and 2.50 to 2.70 grams, respectively, for high, medium and low grades. 

 Moisture causes grains to swell, and increase in individual or grain 

 weight. The weight of a standard measure of grain does not, however, 



Fig. 36. Awned oats 

 (rough oats). 



Fig. 35. Germinated grains. 



increase in the same proportion from absorbed moisture, because the 

 additional moisture increases the size of the grains and reduces their 

 number per standard unit of measure. 



3. Purity. — The best grades of grain must be absolutely clean arid 

 pure. Good medium grades must not contain more than 1 per cent for- 

 eign matter, including chaff and dust. The degree of impurity is de- 

 termined by separation of the foreign matter and subsequent weighing. 



Of the foreign matter occurring in grains we distinguish : 



a. Harmless material like sand, dust, pebbles, earth, pieces of wood, 

 manure, or feces of rodents and insects; chaff; broken, undeveloped, 

 sterile, and germinated grains ; parts of weeds like calyxes, capsules, 

 hulls, seeds, etc. ; vetch seed, peas, rape seed, plantain, etc. 



b. Harmful or noxious substances like ergot, rust and smut fungi, 

 molds, cockle seed (black or brown, roundish or reniform, 2.5 to 3 mm. 



iiUnited States Standard, determined by State law. 



