Dalton's law

from The Century Dictionary.

• noun See law.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• proper noun chemistry, physics The total pressure of a mixture or gases is the sum of the partial pressures of each gas in the mixture; it is only true for ideal gases.
• proper noun chemistry When two elements can combine to form more than one compound then the amounts of one which combines with a fixed amount of the other will have a simple multiple relationship.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun (chemistry) law stating that when two elements can combine to form more than one compound the amounts of one of them that combines with a fixed amount of the other will exhibit a simple multiple relation
• noun (chemistry and physics) law stating that the pressure exerted by a mixture of gases equals the sum of the partial pressures of the gases in the mixture; the pressure of a gas in a mixture equals the pressure it would exert if it occupied the same volume alone at the same temperature