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Historical system of mass and volume units used by pharmacists

The apothecaries' system is a historical system of mass and volume units that was used by pharmacists and physicians for the preparation and dispensing of medicines. This system has largely been replaced by the metric system and other modern systems of measurement, but it remains of historical interest and is still used in some contexts.

Units of Measurement

The apothecaries' system includes units for both mass and volume. The primary units of mass are the grain, scruple, dram, ounce, and pound. The units of volume include the minim, fluid dram, fluid ounce, pint, and gallon.

Mass

• Grain: The smallest unit of mass in the apothecaries' system, equivalent to approximately 64.8 milligrams.
• Scruple: Equal to 20 grains.
• Dram: Equal to 3 scruples or 60 grains.
• Ounce: Equal to 8 drams or 480 grains.
• Pound: Equal to 12 ounces or 5760 grains.

Volume

• Minim: The smallest unit of volume, equivalent to approximately 0.0616 milliliters.
• Fluid dram: Equal to 60 minims.
• Fluid ounce: Equal to 8 fluid drams or 480 minims.
• Pint: Equal to 16 fluid ounces.
• Gallon: Equal to 8 pints.

Historical Context

The apothecaries' system originated in medieval Europe and was used extensively in the preparation of medicinal compounds. It was based on the troy weight system, which was used for precious metals and jewelry. The system was standardized in the 19th century, but variations existed in different countries and regions.

Usage in Medicine

In the practice of pharmacy, the apothecaries' system was used to ensure precise measurements of ingredients in prescriptions. Pharmacists and physicians were trained to convert between the apothecaries' system and other systems of measurement, such as the avoirdupois system, which was used for general commerce.

Transition to the Metric System

The apothecaries' system was gradually replaced by the metric system, which offered a more standardized and universally accepted method of measurement. The metric system's simplicity and ease of conversion between units made it more suitable for scientific and medical applications.

Related pages

• Pharmacy
• Metric system
• Troy weight
• Avoirdupois system

Gallery

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  A depiction of apothecaries' weights and measures.
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  An example of a prescription using the apothecaries' system.
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  Historical apothecaries' weights from the 1800s.