fluidram

1 a British imperial capacity measure (liquid or dry) equal to 60 minims or 3.5516 cubic centimeters [syn: fluid dram, fluid drachm, drachm]

2 a unit of capacity or volume in the apothecary system equal to one eighth of a fluid ounce [syn: fluid dram, fluid drachm, drachm]

The dram (archaic spelling drachm) was historically both a coin and a weight. Currently it is both a small mass in the Apothecaries' system of weights and a small unit of volume. This unit is called more correctly fluid dram or in contraction also fluidram.

Ancient unit of mass

• The Greek drachm was a weight of Greek mine, which is about 4.37 grams.
• The Roman drachm was a weight of Roman pounds, which is about 3.41 grams.

Greek and Roman drachm were related by the approximate ratio 25 : 32.

The Ottoman dirhem is based on the Sassanian drachm which was itself based on the Roman dram/drachm. Modern Armenian drams, the currency of the Republic of Armenia, share this origin.

Modern unit of mass

The dram is the mass of pound avoirdupois or ounce. So the dram weighs grains or about 1.771845 grams.

The dram (symbol: ʒ) was also the mass of pound (℔) or ounce (℥) in the apothecaries' system that survived until the middle of the 20th century in English-speaking countries. It was equal to 3 scruples (℈) or 60 grains (G). Thus, it was equal to 3.888 grams (in the SI).

Unit of volume

The fluid dram is defined as of a fluid ounce, which means it is exactly equal to

• 3.696 691 195 312 5 mL in the United States and
• 3.551 632 812 500 0 mL in the Commonwealth and Ireland.

In the United Kingdom, a teaspoon was formerly defined as 1 fluid dram.

Dram is also used informally to mean a small amount of liquid, especially Scotch whisky.

See also

• Avoirdupois
• Imperial unit
• U.S. customary units