The Probert Encyclopaedia of General Information

GRAIN

The grain is a unit of measurement of the avoirdupois scale equivalent to 0. 0648 grams. It was invented by Henry III who ordered that a grain of wheat gathered from the middle of the ear to be the standard of weight. 12 grains to be a pennyweight, 12 pennyweights to be an ounce and 12 ounces to be a pound Troy.
Research Grain