Apothecaries' system

German postage stamp from 1991, commemorating 750 years of the apothecary profession

The apothecaries' system, or apothecaries' weights and measures, is a historical system of mass and volume units that were used by physicians and apothecaries for medical prescriptions and also sometimes by scientists.[1][2][3] The English version of the system is closely related to the English troy system of weights, the pound and grain being exactly the same in both.[4] It divides a pound into 12 ounces, an ounce into 8 drachms, and a drachm into 3 scruples of 20 grains each. This exact form of the system was used in the United Kingdom; in some of its former colonies, it survived well into the 20th century.[5][6] The apothecaries' system of measures is a similar system of volume units based on the fluid ounce. For a long time, medical recipes were written in Latin, often using special symbols to denote weights and measures.

The use of different measure and weight systems depending on the purpose was an almost universal phenomenon in Europe between the decline of the Roman Empire and metrication.[7] This was connected with international commerce, especially with the need to use the standards of the target market and to compensate for a common weighing practice that caused a difference between actual and nominal weight.[8][9] In the 19th century, most European countries or cities still had at least a "commercial" or "civil" system (such as the English avoirdupois system) for general trading, and a second system (such as the troy system) for precious metals such as gold and silver.[10] The system for precious metals was usually divided in a different way from the commercial system, often using special units such as the carat. More significantly, it was often based on different weight standards.

The apothecaries' system often used the same ounces as the precious metals system, although even then the number of ounces in a pound could be different. The apothecaries' pound was divided into its own special units, which were inherited (via influential treatises of Greek physicians such as Dioscorides and Galen, 1st and 2nd century) from the general-purpose weight system of the Romans. Where the apothecaries' weights and the normal commercial weights were different, it was not always clear which of the two systems was used in trade between merchants and apothecaries, or by which system apothecaries weighed medicine when they actually sold it.[11][12] In old merchants' handbooks, the former system is sometimes referred to as the pharmaceutical system and distinguished from the apothecaries' system.[1][13][14]

  1. ^ a b "Medicinal-Gewicht, Apotheker-Gewicht ist dasjenige Gewicht, nach welchem Aerzte und Apotheker die Quantitäten der Arzneimittel bestimmen. Nur an wenigen Orten werden beide Arten der Gewichte unterschieden und Medicinalgewicht bei dem Einkauf der Arzneiwaaren im Großen von dem Apothekergewicht bei der Anfertigung und dem Einzel-Verkauf in den Apotheken getrennt. In diesem Fall ist das Medicinalgewicht dem gewöhnlichen Landesgewicht beinahe oder völlig gleich und das Pfund wird dann in 16 Unzen getheilt. Bei dem eigentlichen Apothekergewicht aber nimmt man nur einen Theil des Landesgewichts und theilt dieses Pfund in 12 Unzen oder 96 Drachmen oder 288 Scrupel oder 5760 Gran oder 7452 Aß." Krüger, J.F. (1830). Vollständiges Handbuch der Münzen, Maße und Gewichte aller Länder der Erde. Quedlinburg und Leipzig. p. 186.
  2. ^ Henry, William (1831). The elements of experimental chemistry. Vol. II (11th ed.). Philadelphia. p. 493.
  3. ^ "Die deutschen Schriftsteller bedienen sich bei dem Mangel allgemeiner deutscher Maße meistens der Altfranzösischen, des Apothekergewichts, der metrischen Maße und Gewichte, die preußischen am allgemeinsten, die Baiern nicht selten der in ihren Staaten eingeführten." Gehler, J.S.T.; et al. (1836). Physikalisches Wörterbuch. Vol. VI, Part 2. Leipzig. p. 1359.
  4. ^ The avoirdupois pound, on the other hand, is defined as 7000 grains. It is subdivided into 16 (avoirdupois) ounces, or 256 (avoirdupois) drachms. These ounces and drachms are not integer multiples of a grain.
  5. ^ "Apothecaries Weights were the weights which Pharmaceutical Chemists (or Pharmacists) [in Australia] used exclusively until the late 1960s." "Apothecaries Weights". Archived from the original on 2017-09-08. Retrieved 2008-04-17. "To those Pharmacists who were in practice before the 1960s, Apothecaries Weights were old friends." Coates, David (July 1998). "The Scruples of a Chemist". Pharmacy History Australia (5): 10–1. PMID 11620282.
  6. ^ "Although fast becoming obsolete, the apothecary system for weighing and calculating pharmaceutical preparations is still used and must be taken into consideration." US Navy (2000). Hospital corpsman – Nonresident training course. DIANE Publishing. pp. 6–10–6–16. ISBN 1-4289-2660-7.
  7. ^ "An acre is not an acre, nor a bushel a bushel, if you travel but ten miles. A pound is not a pound, if you go from a goldsmith to a grocer; nor a gallon a gallon, if you go from the alehouse to the tavern. What purpose does this variety serve, or what necessity is there, which the difference of price would not better answer and supply?" Fleetwood, William (1854). The Works. Vol. III. Oxford. p. 61.{{cite book}}: CS1 maint: location missing publisher (link)
  8. ^ Connor, R.D. (1995). "The evolution of weighing". Canadian Chemical News.
  9. ^ Connor, R.D.; Simpson, A.D.C. (2004). Weights and Measures in Scotland. East Linton: NMSE. ISBN 978-1-901663-88-4.
  10. ^ "In most countries there are two kinds of Weights, one for the precious Metals, and the other for Merchandize, as the Troy and Avoirdupois Weights in England. Kelly, Patrick (1811). The universal cambist, and commercial instructor. Vol. I. London. p. xi.
  11. ^ Hasegawa, G.R. (2006). "Preparing and dispensing descriptions during the Civil War Era" (PDF). Apothecary's Cabinet. American Institute of the History of Pharmacy. Archived from the original (PDF) on August 9, 2007.
  12. ^ In 1850, an attempt was made in Ireland to solve this problem: "In relation to the weights and measures, a great innovation has been made, which, however, the College feels confident will receive the sanction of the public and the profession. [...] In the formularies, however, [of the Edinburgh Pharmacopœia], the Troy pound, with its well-known submultiples, has been retained, whereas it is now rejected by the Irish College, and its place supplied by the avoirdupois pound, the avoirdupois ounce being, like the Troy ounce, subdivided into eight drachms, and each of these, like the Troy drachm, into three scruples. [...] At present the two systems are in use with the apothecary, for his purchases are made in avoirdupois, and his sales generally, though not always, in Troy weight." Royal College of Physicians in Ireland (1850). The Pharmacopœia of the King and Queen's College of Physicians in Ireland. Dublin: Hodges and Smith. p. xxii. See also p. xlvi, and a review of the work.
  13. ^ "Im Königreich der Niederlande ist das Medicinal-Gewicht im Großen und das eigentliche Apotheker-Gewicht verschieden. Bei dem erstern gehören 8 Drachmen zu einer Once (Unze) und 128 zu einem Medicinal-Pond; die Drachme wird wie in Deutschland in 3 Scrupel oder 60 Grän getheilt. In dem eigentlichen Apotheker-Gewicht gehören auch 8 Drachemn zu einer Unze, aber nur 96 Drachmen zu einem Pond. Die Drachme selbst ist in beiden Gewichtsarten gleich [...]." Krüger, J.F. (1830). Vollständiges Handbuch der Münzen, Maße und Gewichte aller Länder der Erde. Quedlinburg und Leipzig. p. 65.
  14. ^ E.g. in Copenhagen at some time the apothecaries' system was the Prussian one, while the pharmaceutical system was the Danish commercial system. "Das Apothekergewicht ist dem unter Berlin bemerkten gleich; im Großen aber werden Medicinalartikel nach Dän. Handelsgewicht verkauft." Bock, J.H.D.; Crüger, Carl (1828). Nelkenbrecher's allgemeines Taschenbuch der Münz-, Maß- und Gewichtskunde für Banquiers und Kaufleute (14th ed.). Berlin. p. 188.