Weights -

Approximate.

Exact.

1 milligram, 0.001 (mg.).

1/60 or 1/65 grain

0.0154 grain.

1 centigram, 0.01 (eg.).

1/6or10/65 grain.

0.1543 grain.

1 decigram, 0.l (dg.).

1 1/2 grains.

1.5432 grains.

1 gram, 1.0 (Gm.).

15 grains.

15.4324 grains.

30 grams, 30.0 (Gm.).

1 ounce.

462.9 grains.

31 grams. I ounce Troy or 480 grains.

478.4 grains.

1 grain (gr. j).

0.065 or 0.06 Gm.

0.065 Gm.

10 grains (gr. x).

0.65 or 0.7 Gm.

0.648 Gm.

15 grains (gr. xv).

1.0 Gm.

0.972 Gm.

1 scruple (j).

1.3 Gm.

1.296 Gm.

1 dram (3j).

4 Gm.

3.89 Gm.

1 ounce, troy (3j).

30 or 31 Gm.

31.1 Gm.

1 ounce, avoirdupois (oz.).

28 Gm.

28.35 Gm.

Measures -

1 cubic centimeter (c.c).

15 minims.

16.23 minims.

1 liter (1000 c.c).

34 ounces.

33.8 Cc.

1 minim (m).

0.06 Cc.

0.061 Cc.

1 fluidram (f 3j).

4 Cc.

3.696 Cc.

1 fluidounce (f 3j).

30 Cc.

29.57 Cc.

1 pint (Oj).

480 Cc.

473.18 Cc.

Lengths -

1 meter (m.).

40 inches.

39.37 inches.

1 decimeter (dm.).

4 inches.

3.937 inches.

1 centimeter (cm.).

0.4 or 2/3 inch.

0.3937 inch.

1 inch.

2.5 cm.

2.54 centimeters.

As these equivalents are only approximate, it is well to learn the foregoing "Table of Equivalents" and to avoid multiplying the equivalent of any term by too large a factor, for this likewise multiplies the error. For example: 6 centigrams are approximately 1 grain, but 60 grains are not 36o centigrams, the error for the equivalent of 1 grain being multiplied sixty times; 60 grains are 1 dram, and the approximate equivalent of 1 dram is 4 grams or 4.00 centigrams, a much larger figure.

N. B. - It is perfectly legitimate for a physician to use approximate equivalents, for in using equivalents he is merely translating, for his own understanding, prescriptions which have been already written. A pharmacist should not need to translate at all, because he should have at hand both the metric and apothecaries' weights and measures, and use whichever the prescription calls for.