While it is advisable, in any scientific study, to form the habit of thinking in dexcimal units, the following table of approximate relations is given to allow those unfamiliar with the metric system to form a definite conception of the magnitudes expressed in grams, cubic centimeters, etc. It should be understood that the equations are merely approximate and cannot be used for the accurate translation of values.

Metric Weight Equivalents

1 milligram = 1/1000 of a gram = 1/64 of a grain. 1 centigram = 1/100 of a gram = 1/6 of a grain (or minim) - J of a drop of water.

1 decigram = 1/10 of a gram = 1 1/2 grains (or minims.)

[The dekagram and hektogram units, like the eagle in our currency, are not in common use; quantities up to a kilogram are read in grams.]

1 kilogram (commonly abbreviated and pronounced kilo) = 1000 grams = 2.2 pounds.

1 tonneau or metric ton =1,000,000 grams = intermediate between short and long English Ton.

The gram is defined as the weight of a cubic centimeter of pure water at its point of greatest density, in vacuo. For practical purposes, temperature and atmospheric pressure may be disregarded and the gram and the cubic centimeter may be considered identical for all liquids of about the same density as water.

The same correspondence exists for the milligram and cubic millimeter.

1 grain = 6 1/2 centigrams.

1 drachm = 3.9 grams.

1 ounce (Troy or Apothecary's) =31.1 grams.

1 ounce Avoirdupois = 28.35 grams.

1 pound (Troy or Apothecary's) = 373.23 grams.

1 pound Avoirdupois = 453.6 grams.

Metric Linear Equivalents

For practical, scientific purposes, only five linear metric units are in use:

1 micron or micro-millimeter = 1/1000 of a millimeter =1/25,000 of an inch.

This unit is used in measuring microscopic objects and is about 1-7 of the diameter of an average human red blood corpuscle.

1 millimeter = 1/1000 of a meter = 1/25 of an inch.

1 centimeter =1/100 of a meter = 2/5 of an inch.

1 inch = 2.54 centimeters.

1 foot = 30.48 centimeters.

1 meter = about 40 inches.

1 kilometer =1000 meters = 5/8 of a mile.

Metric Surface Equivalents

While a table of units of surface exists in theory, for practical scientific purposes, areas are expressed in squares of the various linear units.

Metric Volume Equivalents

The unit of volume is the Liter, or cubic decimeter, equivalent to 1000 cubic centimeters.

The Kiloliter, or liquid ton, is a cubic meter; a Kiloliter of pure water at its greatest density, in vacuo, weighs 1 metric ton or 1000 kilograms.

For practical scientific purposes, the theoretic fractional and multiple units indicated by the prefixes mili-, centi-, deci-, deka-, hecto-, kilo-, are not employed but volume is expressed in cubic millimeters, centimeters, and meters. Even the term Liter is not always used but is expressed in cubic centimeters, commonly abbreviated and pronounced c.c. As a matter of convenience, the equations between English and metric units of volume, are given in reverse order to those of weight.

1 drop = 0.03 of a c.c. 1 minim = 0.06 of a c.c. 1 fluid drachm = 3.75 c.c.

(An old teaspoon contains about 4 c.c, a new one about 5 c.c, a coffee-spoon about 1 c.c, a dessert spoon about 10 c.c a tablespoon about 15 c.c.)

1 fluid ounce (apothecary's) = 30 c.c.

(While the correspondence between metric measures of volume and weight, expressed in terms of water, is mathematically exact, a similar correspondence between the various English measures is only approximate. For example, the apothecary's fluid ounce equals 29.57 c.c, while the same ounce by weight equals 31.10 grams. The ounce avoirdupois equals only 2S.35 grams.)

1 pint = 475 c.c (more exactly 473.11 c.c)

(A pound, apothecary's measure, equals 373.23 grams. 16 ounces, apothecary's measure, equal 497.60 grams; a pound avoirdupois equals 453.60 grams.)

1 quart = 946 c.c. - considerably less than a liter. 1 gallon = 3785 c.c