The 'dram' (archaic spelling 'drachm') was historically both a
coin and a
weight. Currently it is both a small
mass in the
avoirdupois system of
weights and a small
unit of
volume. This unit is called more correctly ''fluid dram'' or in contraction also ''fluidram''.
Drachm (ancient mass)
★ The
Greek drachm was a weight of {{#if:|100
+â„| Greek
mine, which is about 4.37 grams.
★ The
Roman drachm was a weight of {{#if:|96
+â„| 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 Roman dram/drachm.
Dram (mass)
The dram is the mass of {{#if:|256
+â„|
pound avoirdupois or {{#if:|16
+â„|
ounce. So the dram weighs {{#if:|875
+32â„|
grains or about 1.771845
grams.
The dram (symbol:
Ê’) was also the mass of {{#if:|96
+â„|
pound (â„”) or {{#if:|8
+â„|
ounce (â„¥) 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).
Dram (volume)
The ''fluid dram'' is defined as {{#if:|8
+â„| 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
★
Apothecaries' system