Apothecaries' system

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  Apothecaries' system
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  Example of a prescription
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  Apothecaries' weights from 1800

Apothecaries' System

The Apothecaries' system is a historical system of mass and volume units that was used by apothecaries and pharmacists for the preparation and dispensing of medicinal compounds. This system was widely used in Europe and the United States before the adoption of the metric system and the avoirdupois system.

Units of Measurement

The Apothecaries' system includes units for both weight and volume. The primary units of weight are the grain, scruple, dram, ounce, and pound.

Weight

• Grain: The smallest unit of weight 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

The Apothecaries' system also includes units for measuring volume, primarily used for liquid preparations. These units include the minim, fluid dram, fluid ounce, pint, and gallon.

• Minim: The smallest unit of volume, used for measuring small quantities of liquid.
• Fluid dram: Equal to 60 minims.
• Fluid ounce: Equal to 8 fluid drams.
• Pint: Equal to 16 fluid ounces.
• Gallon: Equal to 8 pints.

Historical Context

The Apothecaries' system originated in the Middle Ages and was used extensively by apothecaries, who were the predecessors of modern pharmacists. This system was particularly important for the precise formulation of medicines and tinctures.

In the United States, the Apothecaries' system was officially used until the early 20th century, when it was gradually replaced by the metric system and the avoirdupois system for most commercial and medical purposes. However, some remnants of the system are still in use today, particularly in the field of pharmacy and compounding.

Conversion to Other Systems

The Apothecaries' system can be converted to other systems of measurement, such as the metric system and the avoirdupois system. For example, one apothecaries' pound is approximately equal to 373.24 grams in the metric system.

Related Pages

• Pharmacy
• Metric system
• Avoirdupois system
• History of pharmacy

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