Grain (unit)
Grain | |
---|---|
apothecaries' weight | |
Unit of | Mass |
Symbol | gr |
Conversions | |
1 gr in ... | ... is equal to ... |
Troy | 1⁄5760 troy pound |
Avoirdupois | 1⁄7000 pound |
Apothecaries' | 1⁄5760 apothecaries' pound |
SI units | 64.79891 mg |
A grain is a
The grain was the legal foundation of
Since the implementation of the
In both
Current usage
Grains are commonly used to measure the mass of bullets and propellants.[11][12] In archery, the grain is the standard unit used to weigh arrows.[13]
In North America, the
Though no longer recommended, in the U.S., grains are still used occasionally in medicine as part of the apothecaries' system, especially in prescriptions for older medicines such as aspirin or phenobarbital.[16][17] For example, the dosage of a standard 325 mg tablet of aspirin is sometimes given as 5 grains.[16][18] In that example the grain is approximated to 65 mg, though the grain can also be approximated to 60 mg, depending on the medication and manufacturer.[16][19] The apothecaries' system has its own system of notation, in which the unit's symbol or abbreviation is followed by the quantity in lower case Roman numerals.[17][19][20] For amounts less than one, the quantity is written as a fraction, or for one half, ss (or variations such as ss., ṡṡ, or s̅s̅).[17][19][20][21]: 263 Therefore, a prescription for tablets containing 325 mg of aspirin and 30 mg of codeine can be written "ASA gr. v c̄ cod. gr. ss tablets" (using the medical abbreviations ASA for acetylsalicylic acid [aspirin],[21]: 34 [22]: 8 c̄ for "with",[21]: 56 [22]: 14 and cod. for codeine).[21]: 70 [22]: 19 The apothecaries' system has gradually been replaced by the metric system, and the use of the grain in prescriptions is now rare.[19]
In the U.S.,
History
carob seed | ≈200 mg |
barley grain | ≈65 mg |
wheat grain | ≈50 mg |
At least since
The history of the modern British grain can be traced back to a royal decree in thirteenth century England, re-iterating decrees that go back as far as
By consent of the whole Realm the King's Measure was made, so that an
English Penny, which is called the Sterling, round without clipping, shall weigh Thirty-two Grains of Wheat dry in the midst of the Ear; Twenty pennies make an Ounce; and Twelve Ounces make a Pound.: 119
The pound in question is the
Physical grain weights were made and sold commercially at least as late as the early 1900s, and took various forms, from squares of sheet metal to manufactured wire shapes and coin-like weights.[28]
The troy pound was only "the pound of Pence, Spices, Confections, as of Electuaries", as such goods might be measured by a troi or small balance. The old troy standard was set by King Offa's
Avoirdupois (goods of weight) refers to those things measured by the lesser but quicker balances: the bismar or auncel, the Roman balance, and the steelyard. The original mercantile pound of 25 shillings or 15 (Tower) ounces was displaced by, variously, the pound of the Hanseatic League (16 tower ounces) and by the pound of the then-important wool trade (16 ounces of 437 grains). A new pound of 7680 grains was inadvertently created as 16 troy ounces, referring to the new troy rather than the old troy. Eventually, the wool pound won out.[29]
The
The division of the carat into four grains survives in both senses well into the early twentieth century. For pearls and diamonds, weight is quoted in carats, divided into four grains. The carat was eventually set to 205 milligrams (1877), and later 200 milligrams. For touch or fineness of gold, the fraction of gold was given as a weight, the total being a solidus of 24 carats or 96 grains.[31]
See also
- English unit
Notes
- 1.^ The exact value of one grain per US gallon is 64.79891/3.785411784 mg/L (ppm).[6]: C-12, C-14
- 2.^ The exact value of one grain per cubic foot is 64.79891/0.028316846592 mg/m3.[6]: C-10, C-14
References
- ^ ISBN 9780951942000. Retrieved 15 September 2012.
- ISBN 978-0-11-290435-9. Retrieved 2 February 2012.
- ^ Universal Dictionary of Weights and Measures. Baltimore. 1850. Retrieved 2016-09-23.
{{cite book}}
: CS1 maint: location missing publisher (link) - ^ Oldberg, Oscar (1885). A Manual of Weights, Measures, and Specific Gravity. Chicago: author [C. J. Johnson, printer]. p. 87. Retrieved 2016-09-24.
- ^ a b c d Rowlett, Russ (13 September 2001). "G". How Many? A Dictionary of Units of Measurement. Chapel Hill, North Carolina: University of North Carolina at Chapel Hill. grain (gr) [1–3]. Retrieved 4 July 2012.
- ^ OCLC 58927093. Retrieved 30 June 2012.
- ^ S2CID 164030519.
- ISBN 9780299073404. Retrieved 18 December 2011.
- OCLC 610190761. Archived from the original(PDF) on 3 June 2011. Retrieved 30 June 2012.
- ^ "Weights and measures: the law". UK Government. Retrieved 2021-11-11.
- ^ International Practical Shooting Confederation (2011). "Handgun Competition Rules (January 2012 ed.)" (PDF). Ontario, Canada: International Practical Shooting Confederation. p. 40. Retrieved 4 July 2012.
- OCLC 255797039. Retrieved 4 July 2012.
- OCLC 474105699. Retrieved 4 July 2012.
Arrow weight is measured in grains
- ^ OCLC 496960317. Retrieved 4 July 2012.
- ^ OCLC 230744052.
- ^ OCLC 421360709. Retrieved 5 July 2012.
- ^ OCLC 181600928. Retrieved 2 July 2012.
- OCLC 689547756. Retrieved 5 July 2012.
- ^ OCLC 181600929. Retrieved 5 July 2012.
- ^ OCLC 693657704. Retrieved 5 July 2012.
- ^ OCLC 246565261. Retrieved 5 July 2012.
- ^ OCLC 165344. Retrieved 5 July 2012.
- ^ OCLC 469979932. Retrieved 5 July 2012.
- OCLC 256903828. Retrieved 5 July 2012.
- ^ Bureau of Ocean Energy Management, Regulation and Enforcement, United States Department of the Interior. 17 September 2010. Archived from the originalon 29 July 2012. Retrieved 5 July 2012.
- ^ a b c Connor, R.D.; Simpson, A.D.C. (c. 2004). Weights and Measures in Scotland. East Linton.
- ISBN 0-299-07340-8.
- ^ "The Grains of History". Retrieved 2016-09-21.
- ^ a b Watson, C. M. (1910). British Weights and Measures as described in the laws of England from Anglo-Saxon times. London: John Murray. pp. 32–34.
- ^ "Pound (Avoirdupois, pound-mass) to grain (Avoirdupois) conversion | Units of Mass".
- ^ Woolhouse, W. S. B. (1890). Measures, Weights and Measures of all Nations. London: Crosby Lockwood and Son. p. 33.