Grain (unit)

Image:148 grain 38 special.jpg ({{convert|0.357|in|mm|disp=out}}) cartridges that have {{convert|148|gr|g|adj=on}} bullets]]

Grains are commonly used to measure the mass of bullets and propellants.{{cite web |ref= {{sfnref|IPSC Rules|2019}} |url= http://www.ipsc.org/pdf/RulesHandgun.pdf |title= Handgun Competition Rules |edition= January 2019 |author= International Practical Shooting Confederation |date= 2019 |publisher= International Practical Shooting Confederation |location= Mallorca, Spain |page= 40 |access-date= 2024-10-13}}{{cite book |last1= Meyer |first1= Rudolf |last2= Köhler |first2= Josef |last3= Homburg |first3= Axel |date= 2007 |title= Explosives |url= https://books.google.com/books?id=ATiYCfo1VcEC |access-date= 4 July 2012 |edition= Sixth, completely revised |publisher= Wiley-VCH |location= Weinheim, Germany |isbn= 978-3-527-31656-4 |oclc= 255797039 |page= 152 |chapter= Grain |chapter-url= https://books.google.com/books?id=ATiYCfo1VcEC&pg=PA152}} In archery, the grain is the standard unit used to weigh arrows.{{cite book |last= Sorrells |first= Brian J. |title= Beginner's Guide to Traditional Archery |url= https://books.google.com/books?id=P5miJc4EbYwC |access-date= 4 July 2012 |edition= 1st |date= 2004 |publisher= Stackpole Books |location= Mechanicsburg, Pennsylvania |isbn= 978-0-8117-3133-1 |oclc= 474105699 |page= 23 |chapter= The Right Equipment |chapter-url= https://books.google.com/books?id=P5miJc4EbYwC&pg=PA23 |quote= Arrow weight is measured in grains}}

In North America, the hardness of water is often measured in grains per U.S. gallon ({{abbr|gpg}}) of calcium carbonate equivalents.{{cite book |last1= Wist |first1= William |last2= McEachern |first2= Rod |last3= Lehr |first3= Jay H. |date= 2009 |title= Water Softening with Potassium Chloride: Process, Health, and Environmental Benefits |url= https://books.google.com/books?id=GJbdjEvQd1kC |access-date= 4 July 2012 |publisher= John Wiley & Sons |location= Hoboken, New Jersey |isbn= 978-0-470-08713-8 |oclc= 496960317 |page= 116 |chapter= Chapter 8: Comparison of KCl and NaCl as Regenerant |chapter-url= https://books.google.com/books?id=GJbdjEvQd1kC&pg=PA116}}{{cite book |last1= Vaclavik |first1= Vickie A. |last2= Christian |first2= Elizabeth W. |date= 2008 |chapter-url= https://books.google.com/books?id=iCCsvwZrguUC&pg=PA29 |chapter= Chapter 2: Water — Water Hardness and Treatments |title= Essentials of Food Science |edition= 3rd |editor-last= Heldman |editor-first= Dennis R. |editor-link= Dennis R. Heldman |series= Food Science Text Series |location= New York; London |publisher= Springer |page= 29 |isbn= 978-0-387-69939-4 |oclc= 230744052}} Otherwise, water hardness is measured in the dimensionless unit of parts per million ({{abbr|ppm}}), numerically equivalent to concentration measured in milligrams per litre. One grain per U.S. gallon is approximately {{val|17.1|u=ppm}}.{{NoteTag|The exact value of one grain per U.S. gallon is {{sfrac|{{val|64.79891}}|{{val|3.785411784}}}} mg/L (ppm).{{rp|C-12, C-14}} }} Soft water contains {{val|1|–|4|u=gpg}} of calcium carbonate equivalents, while hard water contains {{val|11|–|20|u=gpg}}.

Image:5 grain aspirin.jpg

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.{{cite book |last= Zentz |first= Lorraine C. |date= 2010 |title= Math for Pharmacy Technicians |url= https://books.google.com/books?id=PvriGp6ZEhMC |access-date= 5 July 2012 |publisher= Jones & Bartlett Learning |location= Sudbury, Massachusetts |isbn= 978-0-7637-5961-2 |oclc= 421360709 |pages= 7–8 |chapter= Chapter 1: Fundamentals of Math — Apothecary System |chapter-url= https://books.google.com/books?id=PvriGp6ZEhMC&pg=PA7}}{{cite book |last= Boyer |first= Mary Jo |date= 2009 |title= Math for Nurses: A Pocket Guide to Dosage Calculation and Drug Preparation |url= https://books.google.com/books?id=FCfCGwqNt4QC |access-date= 2 July 2012 |edition= 7th |publisher= Wolters Kluwer Health / Lippincott Williams & Wilkins |location= Philadelphia |isbn= 978-0-7817-6335-6 |oclc= 181600928 |pages= 108–109 |chapter= Unit 2 Measurement Systems: The Apothecary System |chapter-url= https://books.google.com/books?id=FCfCGwqNt4QC&pg=PA108}} For example, the dosage of a standard {{val|325|u=mg}} tablet of aspirin is sometimes given as {{val|5|u=grains}}.{{cite book |last= Howell |first= David C. |date= 2010 |title= Statistical Methods for Psychology |url= https://books.google.com/books?id=5WFohzuwzP0C |access-date= 5 July 2012 |edition= 7th |publisher= Wadsworth, Cengage Learning |location= Belmont, California |isbn= 978-0-495-59784-1 |oclc= 689547756 |page= 402 |chapter= Chapter 12: Multiple Comparisons Among Treatment Means — 12.10 Trend Analysis |chapter-url= https://books.google.com/books?id=5WFohzuwzP0C&pg=PA402}} In that example the grain is approximated to {{val|65|u=mg}}, though the grain can also be approximated to {{val|60|u=mg}}, depending on the medication and manufacturer. The apothecaries' system has its own system of notation, in which the units symbol or abbreviation is followed by the quantity in lower case Roman numerals.{{cite book |last1= Buchholz |first1= Susan |last2= Henke |first2= Grace |date= 2009 |title= Henke's Med-Math: Dosage Calculation, Preparation and Administration |url= https://books.google.com/books?id=ZlKqGHGNrtIC |access-date= 5 July 2012 |edition= 6th |publisher= Wolters Kluwer Health / Lippincott Williams & Wilkins |location= Philadelphia |isbn= 978-0-7817-7628-8 |oclc= 181600929 |pages= 55–6 |chapter= Chapter 3: Metric, Apothecary, and Household Systems of Measurement — Apothecary System |chapter-url= https://books.google.com/books?id=ZlKqGHGNrtIC&pg=PA55}}{{cite book |last1= Pickar |first1= Gloria D. |last2= Swart |first2= Beth |last3= Graham |first3= Hope |last4= Swedish |first4= Margaret |date= 2012 |title= Dosage Calculations |url= https://books.google.com/books?id=wFEsup6KhuQC |access-date= 5 July 2012 |edition= 2nd Canadian |publisher= Nelson Education |location= Toronto |isbn= 978-0-17-650259-1 |oclc= 693657704 |pages= 527–528 |chapter= Appendix B: Apothecary System of Measurement |chapter-url= https://books.google.com/books?id=wFEsup6KhuQC&pg=PA527}} 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).{{cite book |editor-last= Biblis |editor-first= Margaret M. |date= 1992 |title= Dorland's Medical Abbreviations |url= https://books.google.com/books?id=iFZqAAAAMAAJ |access-date= 5 July 2012 |publisher= Saunders |location= Philadelphia |isbn= 978-0-7216-3751-8 |oclc= 246565261}}{{rp|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],{{rp|34}}{{cite book |last= Steen |first= Edwin Benzel |date= 1971 |title= Medical Abbreviations |url= https://books.google.com/books?id=LWvKBnlAY_4C |access-date= 5 July 2012 |edition= 3rd |publisher= F.A. Davis |location= Philadelphia |isbn= 978-0-7020-0360-8 |oclc= 165344}}{{rp|8}} c̄ for "with",{{rp|56}}{{rp|14}} and cod. for codeine).{{rp|70}}{{rp|19}} The apothecaries' system has gradually been replaced by the metric system, and the use of the grain in prescriptions is now rare.

In the U.S., particulate emission levels, used to monitor and regulate pollution, are sometimes measured in grains per cubic foot instead of the more usual {{abbr|ppm|parts per million}} by volume.{{cite book |last= Averdieck |first= William J. |editor1-first= Randy D. |editor1-last= Down |editor2-first= Jay H. |editor2-last= Lehr |date= 2005 |title= Environmental Instrumentation and Analysis Handbook |url= https://books.google.com/books?id=6jhELyGJOm0C |access-date= 5 July 2012 |publisher= Wiley-Interscience |location= Hoboken, New Jersey |isbn= 978-0-471-46354-2 |oclc= 469979932 |page= 330 |chapter= 15: Continuous Particulate Monitoring |chapter-url= https://books.google.com/books?id=6jhELyGJOm0C&pg=PA330}}{{cite encyclopedia |editor-first= Craig L. |editor-last= Chase |date= 1998 |title= Particulate Emissions |encyclopedia= Biomass Energy: A Glossary of Terms |url= https://books.google.com/books?id=NT3JvB4JWYUC |access-date=5 July 2012 |series= Western Regional Biomass Energy Program |publisher= DIANE Publishing |isbn= 978-0-7881-7256-4 |oclc= 256903828 |page= 40 |entry-url= https://books.google.com/books?id=NT3JvB4JWYUC&pg=PA40 }} This is the same unit commonly used to measure the amount of moisture in the air, also known as the absolute humidity.{{cite web |url= http://www.boemre.gov/glossary/aa-ab.htm |title= Glossary: AA–AB |access-date= 5 July 2012 |date= 17 September 2010 |work= Offshore Energy and Minerals Management |publisher= Bureau of Ocean Energy Management, Regulation and Enforcement, United States Department of the Interior |location= Washington, D.C. |url-status= dead |archive-url= https://web.archive.org/web/20120729121218/http://www.boemre.gov/glossary/aa-ab.htm |archive-date= 29 July 2012 }} The SI unit used to measure particulate emissions and absolute humidity is mg/Cubic metre. One grain per cubic foot is approximately {{val|2288|u=mg/m{{sup|3}}}}.{{NoteTag|The exact value of one grain per cubic foot is {{sfrac|{{val|64.79891}}| {{val|0.028316846592}}}} mg/m³.{{rp|C-10, C-14}} }}

At least since antiquity, grains of wheat or barley were used by Mediterranean traders to define units of mass; along with other seeds, especially those of the carob tree. According to a longstanding tradition, one carat (the mass of a carob seed) was equivalent to the weight of four wheat grains or three barleycorns.{{cite journal |last= Ridgeway |first= William |author-link= William Ridgeway |date= 1889 |title= Metrological Notes: III.- Had the People of Pre-historic Mycenae a Weight Standard? |journal= The Journal of Hellenic Studies |volume= 10 |pages= 90–97 |publisher= The Council for the Society for the Promotion of Hellenic Studies |location= London |issn= 0075-4269 |oclc= 51205085 |doi= 10.2307/623588 |jstor= 623588 |s2cid= 164030519 |url= https://zenodo.org/record/1449896 }}{{rp|95}} Since the weights of these seeds are highly variable, especially that of the cereals as a function of moisture, this is a convention more than an absolute law.{{cite book |last1= Connor |first1= R. D. |last2= Simpson |first2= A. D. C. |date= 2004 |title= Weights and Measures in Scotland: A European Perspective |editor-last= Morrison-Low |editor-first= A. D. |location= East Linton}}{{rp|120–1}}

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 King Offa (eighth century).{{cite book |last= Zupko |first= Ronald Edward |date= 1977 |title= British Weights and Measures |publisher= University of Wisconsin |location= Madison, Wisconsin |isbn= 0-299-07340-8 |pages= 11}} The Tower pound was one of many monetary pounds of 240 silver pennies.{{Citation needed|date=January 2021}}

{{Blockquote|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.|Tractatus de Ponderibus et Mensuris{{rp|119}}}}

The pound in question is the Tower pound. The Tower pound, abolished in 1527, consisted of 12 ounces like the troy pound, but was {{frac|16}} (≈6%) lighter. The weight of the original sterling pennies was 22½ troy grains, or 32 "Tower grains".{{rp|116}}

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.{{cite web |title= The Grains of History |url= http://www.apothecariesweights.com/articles/the-grains-of-history/ |access-date= 2016-09-21}}

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 currency reform, and was in full use in 1284 (Assize of Weights and Measures, King Edward I), but was restricted to currency (the pound of pennies) until it was abolished in 1527. This pound was progressively replaced by a new pound, based on the weight of 120 silver dirhems of 48 grains. The new pound used a barley-corn grain, rather than a wheat grain.{{cite book |last= Watson |first= C. M. |year= 1910 |author-link= Charles Moore Watson |title= British Weights and Measures as described in the laws of England from Anglo-Saxon times |publisher= John Murray |location= London |pages= 32–34 |url= https://archive.org/details/britishweightsme00watsuoft}}

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 {{val|7680|fmt=commas}} grains was inadvertently created as 16 troy ounces, referring to the new troy rather than the old troy. Eventually, the wool pound won out.

The avoirdupois pound was defined in prototype, rated as {{val|6992|fmt=commas}} to {{val|7004|fmt=commas}} grains. In the Imperial Weights and Measures Act 1824 (5 Geo. 4. c. 74), the avoirdupois pound was defined as {{val|7000|fmt=commas}} grains exactly. The Weights and Measures Act 1855 authorised Miller's new standards to replace those lost in the fire that destroyed the Houses of Parliament. The standard was an avoirdupois pound, the grain being defined as {{sfrac|{{val|7000}}}} of it.{{Cite web |url= http://www.global-converter.com/unit-to-unit/pound-avoirdupois-pound-mass-to-grain-avoirdupois-mass-converter/ |title= Pound (Avoirdupois, pound-mass) to grain (Avoirdupois) conversion | Units of Mass}}

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.{{cite book |last= Woolhouse |first= W. S. B. |date= 1890 |title= Measures, Weights and Measures of all Nations |publisher= Crosby Lockwood and Son |location= London |page= 33 |url= https://archive.org/details/measuresweights00woolgoog/page/n6/mode/2up |author-link= Wesley S. B. Woolhouse}}

• English unit

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Category:Units of mass

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