1 ounce, avoirdupois,

= 437.5 grains.

1 ounce, troy or apothecaries',

= 480 grains.

1 fluidounce of water (the standard of volume)

= 455.7 grains.

1 pound, avoirdupois,

= 7000 grains.

1 pound, troy or apothecaries',

= 5760 grains.

1 minim of water weighing 455.7/480

= 0.95 grains.

15 grains of water

= 16 minims.

(In the metric system, as seen below, there is but one group of weights, and these bear a definite relation to volume; for one cubic centimeter of water, the standard of volume, weighs exactly one gram.)