definite proportions, law of
- definite proportions, law of
-
statement that every chemical compound contains fixed and constant proportions (
by weight)
of its constituent elements.
Although many experimenters had long assumed the truth of the principle in general,
the French chemist Joseph-
Louis Proust (
Proust, Joseph-Louis)
first accumulated conclusive evidence for it in a series of researches on the composition of many substances,
especially the oxides of iron (
1797).
Another French chemist,
Claude Berthollet,
who held for indefinite proportions,
contested Proust'
s findings,
but the Scottish chemist Thomas Thomson confirmed some of them and wrote in his article “
Chemistry”
in the Supplement to the Encyclopædia Britannica (
1801)
that Proust had definitely proved “
metals are not capable of indefinite degrees of oxidation.”
The principle was then concretely formulated by the English chemist John Dalton in his chemical atomic theory (
1808).
* * *
Universalium.
2010.
Look at other dictionaries:
Law of definite proportions — Definite Def i*nite, a. [L. definitis, p. p. of definire: cf. F. d[ e]fini. See {Define}.] 1. Having certain or distinct; determinate in extent or greatness; limited; fixed; as, definite dimensions; a definite measure; a definite period or… … The Collaborative International Dictionary of English
Law of definite proportions — In chemistry, the law of definite proportions, sometimes called Proust s Law, states that a chemical compound always contains exactly the same proportion of elements by mass. An equivalent statement is the law of constant composition, which… … Wikipedia
law of definite proportions — law of def·i·nite pro·por·tions def (ə )nət prə pȯr shənz n a statement in chemistry: every definite compound always contains the same elements in the same proportions by weight * * * any compound always contains the same kind of elements in the … Medical dictionary
law of definite proportions — noun (chemistry) law stating that every pure substance always contains the same elements combined in the same proportions by weight • Syn: ↑law of constant proportion • Topics: ↑chemistry, ↑chemical science • Hypernyms: ↑law, ↑ … Useful english dictionary
law of definite proportions — Date: 1830 a statement in chemistry: every definite compound always contains the same elements in the same proportions by weight … New Collegiate Dictionary
Law of multiple proportions — In chemistry, the law of multiple proportions is one of the basic laws and a major tool of chemical measurement (stoichiometry). It states that when elements combine they do so in a ratio of small whole numbers. For example, carbon and oxygen… … Wikipedia
law of nature — noun a generalization that describes recurring facts or events in nature (Freq. 3) the laws of thermodynamics • Syn: ↑law • Hypernyms: ↑concept, ↑conception, ↑construct • … Useful english dictionary
Definite — Def i*nite, a. [L. definitis, p. p. of definire: cf. F. d[ e]fini. See {Define}.] 1. Having certain or distinct; determinate in extent or greatness; limited; fixed; as, definite dimensions; a definite measure; a definite period or interval. [1913 … The Collaborative International Dictionary of English
Definite article — Definite Def i*nite, a. [L. definitis, p. p. of definire: cf. F. d[ e]fini. See {Define}.] 1. Having certain or distinct; determinate in extent or greatness; limited; fixed; as, definite dimensions; a definite measure; a definite period or… … The Collaborative International Dictionary of English
Definite inflorescence — Definite Def i*nite, a. [L. definitis, p. p. of definire: cf. F. d[ e]fini. See {Define}.] 1. Having certain or distinct; determinate in extent or greatness; limited; fixed; as, definite dimensions; a definite measure; a definite period or… … The Collaborative International Dictionary of English
