In the metric system the liter is a unit of capacity equivalent to the volume occupied by the mass of 1 kilogram of pure water at its maximum density. It is equivalent in volume to 1.000027 cubic decimeter. Under this definition a milliliter (0.001 of a liter) is different from a cubic centimeter by a very minute fraction. However, as cubic centimeter is the term used throughout medical literature we shall use it in this book, though both the U. S. and British Pharmacopoeias have adopted the term milliliter (mil) in its place.

A. Metric

 Weight Written Approximate Equivalent 1 milligram (mg.)........................... 0.001 1/65 grain 10 milligrams = 1 centigram (cg.)............... 0.01 1/6 grain 10 centigrams = 1 centigram (cg) ........................................ 0.1 1 1/2 grains 10 decigrams = 1 gram (gm.)................... 1.0 15 grains 1000 grams = 1 kilogram (kilo.).................. 1000.0 2 1/5 pounds

Volume

 1 milliliter (mil.) .................................................................. 1 15 minims 1 cubic centimeter (c.c.) ......................................................(1 c.c. of water weighs 1 gm.) 1 15 minims 1000 cubic centimeters = 1 liter (L.)............... 1000 34 fluidounces

Length

 1 millimeter (mm.) ................................................................................ 1/25 inch 10 millimeters = 1 centimeter (cm.)........................ 2/5 inch 10 centimeters = 1 decimeter (dm.) ............................................................ 4 inches 10 decimeters = 1 meter (M.)........................... 40 inches

B. Apothecaries

 Weight {Troy Weight) Approximate Equivalent 1 grain (gr.).......................................... 0.065 gm. 10 grains .................................................................................................. 0.7 gm. 20 grains = 1 scruple (Э) ........................................................................ 1.3 gm. 3 scruples = 1 dram (3) ...................................................................... 4.0 gm. 8 drams = 1 ounce .................................... 30.0 gm. 12 ounces = 1 pound (fb)..................................................................... 372.O gm.

Volume

 1 minim ........................................................................... 0.06 c.c. 60 minims = 1 dram (3)............................... 4.0 c.c. 8 drams = 1 ounce ............................... 30.0 c.c 16 ounces = 1 pint (O) .......................................................................... 475.0 c.c. 2 pints = 1 quart (Oij) .......................................................................... 950.0 c.c. 8 pints = 1 gallon (Cong.). (1 gill = 4 fluidounces.)

Length 1 inch (in.).......................................... 2.5 cm.

Noteworthy Terms

 1 ounce avoirdupois ............................................................................. 437.5 grains 1 ounce troy .......................................................................................... 480 grains 1 fluidounce of water (the standard of volume) .................................. 455.7 grains 1 pound avoirdupois is ...................................................................... 7000 grains 1 pound troy is .................................................................................. 5760 grains

1 minim of water weighs 455.5/480 grains = 0.95 grain = 61.61 mg.

15 grains of water =16 minims; one grain of water measures

1.05 minims = 0.0648 c.c. An imperial pint is 20 ounces; a United States pint is 16 ounces.

## Exact Equivalents Of Metric And Apothecaries' Weights And Measures According To The U. S. Pharmacopoeia

Volume

 1 c.c ..................................................................................................... 16.23 minims 1 liter (1000 c.c.) .................................................................................. 33.8 oz. 1 minim ....................................................................... 0.061 c.c. 1 fluidram (3) ........................................................................................ 3.696 c.c. 1 fluidounce ..................................... 29.57 c.c. 1 pint (O)........................................... 473.18 c.c.

Weight

 1 milligram, 0.001 (mg) ....................................................................... 0.0154 grain 1 centigram, 0.01 (eg.)................................. 0.1543 grain 1 decigram, 0.1 (dg.).................................. 1.543 grains 1 gram, 1.0 (gm.)..................................... 15.4324 grains 30 grams, 30.0......................................... 462.9 grains 31 grams............................................. 478.4 grains 1 grain (gr.).......................................... 0.065 gm. 10 grains ................................................................................................... 0.648 gm. 15 grams............................................. 0.972 gm. 1 scruple............................................. 1.296 gm. 1 dram (3).......................................... 3.89 gm. 1 ounce troy ..................................... 31.1 gm. 1 ounce avoirdupois................................... 28.35 gm.