from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The ratio of the mass of a solid or liquid to the mass of an equal volume of distilled water at 4°C (39°F) or of a gas to an equal volume of air or hydrogen under prescribed conditions of temperature and pressure. Also called relative density.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The ratio of the mass of a substance to that of an equal volume of water at 4°C (or to some other reference substance)
from the GNU version of the Collaborative International Dictionary of English
- n. the ratio of the weight of a body to the weight of an equal volume of some other body taken as the standard or unit. This standard is usually water for solids and liquids, and air for gases. Thus, 19, the specific gravity of gold, expresses the fact that, bulk for bulk, gold is nineteen times as heavy as water.
- adj. See under Gravity.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the density of a substance relative to the density of water
Sorry, no etymologies found.
One of the key measurements in all fermentation is the relative measurement of the initial specific gravity in relation to the final specific gravity, as measured with a hydrometer.
Water with sugar mixed in is denser than water without sugar, and the hydrometer measures the specific gravity and relates it to a potential alcohol content.
My hydrometer told me that I had specific gravity right around 1.100, which promises a potential alcohol of 13 percent in the wash.
Bacon occupies it by specific gravity or levity, not by any feat he did, or by any tutoring more or less of Newton &c., but an effect of the same cause which showed itself more pronounced afterwards in Hooke, Boyle, and Halley.
Some of what I was there to buy cleaning agents, a spigot were innocent enough, but among the goods I finally laid on his table were five more packets of champagne yeast and a proofing hydrometer, which instead of measuring the specific gravity of sugar in water, measures the density of alcohol and gives you a percentage.