Apothecaries' system

Apothecaries' System

The Apothecaries' system is a historical system of mass and volume units that were used by physicians and apothecaries for medical prescriptions and also sometimes by scientists. The system is derived from the older pharmacy practices of the Middle Ages, with its roots deeply set in the ancient systems of the Greeks and Romans. It was widely used in England, Scotland, and the United States until the 20th century, when it was largely supplanted by the metric system.

History

The Apothecaries' system originated in the 13th century in the Medieval European context. It was a time when the need for a standardized system of measurement became apparent for the preparation of medicines. The system was officially adopted in England by the Worshipful Society of Apothecaries in London in 1617. It provided a unified method of measuring liquids and solids, crucial for the accurate compounding of prescriptions.

Units of Measurement

The Apothecaries' system includes several key units for both weight and volume.

Weight

• Grain (gr) - The basic unit of weight, which is equivalent to the weight of a single grain of wheat.
• Dram (dr) - Equal to 60 grains.
• Ounce (oz) - Equal to 8 drams.
• Pound (lb) - Equal to 12 ounces.

Volume

• Minim - The basic unit of volume, roughly equivalent to a single drop of water.
• Fluid dram (fl dr) - Equal to 60 minims.
• Fluid ounce (fl oz) - Equal to 8 fluid drams.
• Pint (pt) - Equal to 16 fluid ounces.
• Quart (qt) - Equal to 2 pints.
• Gallon (gal) - Equal to 4 quarts.

Usage

The Apothecaries' system was primarily used in the prescribing and dispensing of medication. It facilitated a high degree of precision in the formulation of remedies, which was essential for their effectiveness and safety. The system was taught in medical schools and used in pharmacopoeias, including the influential London Pharmacopoeia.

Decline and Legacy

The introduction of the metric system, with its simpler base-10 structure, led to the gradual decline of the Apothecaries' system from the late 19th century onwards. However, traces of the system can still be found today, particularly in the field of pharmacy where certain units, such as the grain, are still used to measure doses of medication.

See Also

• Metric system
• Pharmacy
• Worshipful Society of Apothecaries
• London Pharmacopoeia

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