Page 29 - My FlipBook

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WEIGHTS AND MEASURES. 5

SCALE OF COMPARISON,
T. cwt. qr. lb. oz. dr.
= ^ 2000 = 32000 =
1 20 So 512000
= = 4000 =
I 4 lOO 25600
= = 400 =
I 25 6400
I =^ 16 = 256
I 16
THE METRIC OR FRENCH DECIMAL SYSTEM OF WEIGHTS AND
MEASURES.
The metric system is based upon the meter, which is the
standard unit of lefigth of that system, and equal to 39^370,432
inches, or about 10 per cent, longer than the yard.
The metric unit o^ fiu'id ?ueasure is the liter—the cube of
^Q meter, or 1000 cubic centimeters—equal to about 34 fluid
ounces.
The metric unit of weight is the Gram, which represents the
weight of one cubic-centimeter of water as its maximum
density. It is equal to 15 (43,234,874) troy grains.
One cubic-centimeter is equal to 16,231 minims.
In writing prescriptions it is sufficiently accurate
and safe to consider i gram as exactly equal to 1
troy grains, and to consider i cubic centimeter as equal
to 15 minims.
We accordingly have
I gram equal to y troy grains.
I troy grain equal to yV gram.
I cubic centimeter equal to \ fluidrachm.
I fluidrachm equal to f cubic centimeter.
Hence
1. To CONVERT TROY GRAINS INTO GRAMS, OR MINIMS INTO
CUBIC CENTIMETERS
a. Divide by 10^ and from the quotient subtract one-third; or., b.
Divide by 75 ; and
2. To CONVERT apothecaries' DRACHMS INTO GRAMS, OR
FLUIDRACHMS INTO CUBIC CENTIMETERS, multiply by ^.
In writing prescriptions, the "gram" (abbreviated " Gm.")
and "cubic centimeter" (abbreviated "C.C.," which may be
called " fluigram," and written " fGm ") only should be used.