The scruple (℈) is a small unit in the apothecaries' system,1 derived from the old Roman scrupulum (lit. 'small pebble') unit2 (scrupulus/scrupulum).
Mass unit
The scruple is 8⁄175 of an ounce (or 1⁄24 of a troy ounce), 1⁄3 dram, or 20 grains:1 it is therefore exactly 1.2959782 grams.
The Roman scruple was 11.875% smaller, therefore being exactly 1.14208078875 grams.
Volume unit
The fluid scruple is 1⁄24 fluid ounce, 1⁄3 fluid dram, 20 minims, 1⁄4 teaspoon, or 1 saltspoon.
It is therefore equal to 1.2322304 milliliters in the US customary system, or 1.1838776 milliliters in the imperial customary system (to eight significant figures).
References
References
- Cardarelli, François (2003). Encyclopaedia of Scientific Units, Weights and Measures. London: Springer. pp. 38, 45. ISBN 978-1-4471-1122-1.
- "scruple, n.1", Oxford English Dictionary, 1st ed., Oxford: Oxford University Press, 1911