A grain is a unit of mass equal to 0.06479891 gram, in the avoirdupois, Apothecaries' and troy weight systems. An avoirdupois pound is 7000 grains, whereas a troy pound is 5760 grains. In physics and metrology, units are standards for measurement of physical quantities that need clear definitions to be useful. ... Mass is a property of physical objects that, roughly speaking, measures the amount of matter they contain. ... The gram or gramme, symbol g, is a unit of mass, and is defined in the SI system of units as one one-thousandth of a kilogram (i. ... The avoirdupois system is a system of weights defining terms such as pound and ounce. ... The apothecaries system of mass is an obsolete system formerly used by apothecaries (now called pharmacists or chemists) in English-speaking countries. ... Troy weight is a system of units of mass customarily used for precious metals and gemstones. ... Officially the pound is the name for at least three different units of mass: The pound (avoirdupois). ...

Grains are currently used to measure the mass of bullets and gunpowder, and for older drugs such as aspirin. 0. ... Gunpowder is a substance which burns very rapidly and is used as a propellant in firearms. ... A drug is any substance that can be used to modify a chemical process or processes in the body, for example to treat an illness, relieve a symptom, enhance a performance or ability, or to alter states of mind. ... A very old bottle of Aspirin Aspirin or acetylsalicylic acid is a drug in the family of salicylates, often used as an analgesic (against minor pains and aches), antipyretic (against fever), and anti-inflammatory. ...

A metric or pearl grain is equal to 50 milligrams or 1/4 of a carat as used in pearl and diamond nomenclature. The milligram (symbol mg) is an SI unit of mass. ... ... For other things called pearl, see pearl (disambiguation). ... A scattering of round-brilliant cut diamonds shows off the many reflecting facets. ...

Originally, a grain was the weight of a grain seed from the middle of an ear of barley. Binomial name Hordeum vulgare L. Barley (Hordeum vulgare) is a major food and animal feed crop, a member of the grass family Poaceae. ...