⁂ The standard of the above measure is 1 cubic inch of distilled water, which, at 62° Fahr. and 30 inches of the barometer, weighs 252·458 troy grains.
The carat used in weighing diamonds is 31⁄6 grains (nearly). Troy weight is employed in weighing gold, jewelry, &c., and, under a somewhat modified form, in prescribing and dispensing medicines. (See below.)
2. Apothecaries’ Weight.
(Modified Troy Weight.)
| Grains (Troy). ℈ gr. | Scruples. [scruples] | Drachms. ʒ | Ounces. ℥ | Pounds. ℔ |
| 1· | ·05 | ·01666 | ·002083 | ·0001736 |
| 20· | 1· | ·3333 | ·0416 | ·003472 |
| 60· | 3· | 1· | ·1250 | ·0104166 |
| 480· | 24· | 8· | 1· | ·0833333 |
| 5760· | 288· | 96· | 12· | 1· |
| Grains (Troy). gr. | Eqiv. in French grammes. | Equiv. in Minims or measured drops. | Equiv. in cubic inches. | Equiv. in Avoirdupois. weight. | |
| 1· | ·06475 | 1·09 | ·003961055 | 1· gr. | |
| 20· | 1·295 | 21·94 | ·07922109 | 20· gr. | |
| 60· | 3·885 | 65·82 | ·23766329 | 60· gr. | |
| 480· | 31·08 | 526·62 | 1·90130635 | 1 oz 42·5 gr. | |
| 5760· | 372·96 | 6319·54 | 22·81567609 | 13 oz 72·5 gr. |
⁂ Apothecaries’ weight is employed in prescribing and dispensing medicines according to the Ph. L., E., and U. S. But in the last Ph. D. and the new Brit. Ph. it has been superseded by avoirdupois weight.
| Troy | Avoirdupois. | |
| 1 ℔ | is equivalent to | 0·822857 lb. |
| 1 oz. | ” | 1·097143 oz. |
WEIGHTS, FOREIGN.
Binary Weights. (Système usuel.) French.