Davy, from boracic acid.
About the same time Davy showed that two pieces of ice could be melted by rubbing them together in a vacuum, although everything surrounding them was at a temperature below the freezing point.
Though we may allow that the results obtained by Rumford and Davy demonstrate satisfactorily that heat is in some way due to motion, yet they do not tell us to what particular dynamical quantity heat corresponds.
Davy on the decomposition of the solutions of salts by the voltaic current were turned to account in the water voltameter telegraph of Sdmmering and the modification of it proposed by Schweigger, and in a similar method proposed by Coxe, in which a solution of salts was substituted for water.
This was the principle of the chemical telegraph proposed by Edward Davy in 1838 and of that proposed by Bain in 1846.
Davy showed that they were oxides of various metals.
Davy, Count Rumford, all concerned themselves with thermochemical investigations of such processes.
The Board of Agriculture in 1803 had commissioned Sir Humphry Davy to deliver a course of lectures on the connexion of chemistry with vegetable physiology.
By the market house is a statue of Sir Humphry Davy, who was born here in 1778.
Rouelle, while in England Humphry Davy expounded the same idea in the experimental demonstrations which gave his lectures their brilliant charm.
Berzelius's investigation of the action of the electric current on salts clearly demonstrated the invaluable assistance that electrolysis could render to the isolator of elements; and the adoption of this method by Sir Humphry Davy for the analysis of the hydrates of the metals of the alkalis and alkaline earths, and the results which he thus achieved, established its potency.
In 1808 Davy isolated sodium and potassium; he then turned his attention to the preparation of metallic calcium, barium, strontium and magnesium.
The discovery of boron by Gay Lussac and Davy in 1809 led Berzelius to investigate silica (silex).
The chemical analogy of this substance to chlorine was quickly perceived, especially after its investigation by Davy and Gay Lussac. Cyanogen, a compound which in combination behaved very similarly to chlorine and iodine, was isolated in 1815 by Gay Lussac. This discovery of the first of the then-styled " compound radicals " exerted great influence on the prevailing views of chemical composition.
Hydrochloric acid was carefully investigated at about this time by Davy, Faraday and Gay Lussac, its composition and the elementary nature of chlorine being thereby established.
Serullas and Roscoe; Davy and Stadion investigated chlorine peroxide, formed by treating potassium chlorate with sulphuric acid.
Davy also described and partially investigated the gas, named by him " euchlorine," obtained by heating potassium chlorate with hydrochloric acid; this gas has been more recently examined by Pebal.
Both phosphoric and phosphorous acids became known, although imperfectly, towards the end of the 18th century; phosphorous acid was first obtained pure by Davy in 1812, while pure phosphorous oxide, the anhydride of phosphorous acid, remained unknown until T.
Of other phosphorus compounds we may here notice Gengembre's discovery of phosphuretted hydrogen (phosphine) in 1783, the analogy of which to ammonia was first pointed out by Davy and supported at a later date by H.
In 1800, and Rumford himself selected Sir Humphry Davy as scientific lecturer there.
Jacques Davy Duperron >>
In 1806 Sir Humphry Davy proved that the formation of acid and alkali when water was electrolysed was due to saline impurities in the water.
He was knighted in 1897, and received the Royal (1875), Davy (1888), and Copley (1904) medals of the Royal Society, besides filling the offices of president of the Chemical Society and of the Institution of Electrical Engineers.
He was elected interim president in June 1820, on the death of Sir Joseph Banks; but he did not care to enter into competition with Sir Humphry Davy, and the latter was elected president at the anniversary meeting in November 1820.
C. Oersted (1777-1851) had shown that a magnetic needle is deflected by an electric current, he attempted, in the laboratory of the Royal Institution in the presence of Humphry Davy, to convert that deflection into a continuous rotation, and also to obtain the reciprocal effect of a current rotating round a magnet.
He failed in both respects, and when Michael Faraday, who overheard a portion of his conversation with Davy on the subject, was subsequently more successful, he was inclined to assert the merit of priority, to which Faraday did not admit his claim.
JACQUES DAVY DUPERRON (1556-1618), French cardinal, was born at St L6, in Normandy, on the 15th of November 1556.
Here Jacques Davy received his education, being taught Latin and mathematics by his father, and learning Greek and Hebrew and the philosophy then in vogue.
Davy, who in 1807 (Phil.
In common with Gay Lussac and Davy, he held subterraneous thermic disturbances to be probably due to the contact of water with metals of the alkalis and alkaline earths.
His experiments with Sir Humphrey Davy in endeavouring to fix the images of natural objects as seen in the camera were published in 1802 (Journ.
Davy by electrolysing the moist hydroxide or chloride, and has been obtained by A.
The existence of acids not containing oxygen was, in itself, sufficient to overthrow this idea, but, although Berthollet had shown, in 1789, that sulphuretted hydrogen (or hydrosulphuric acid) contained no oxygen, Lavoisier's theory held its own until the researches of Davy, Gay-Lussac and Thenard on hydrochloric acid and chlorine, and of Gay-Lussac on hydrocyanic acid, established beyond all cavil that oxygen was not essential to acidic properties.
In later years Berzelius renounced the " oxygen acid " theory, but not before Davy, and, almost simultaneously, Dulong, had submitted that hydrogen and not oxygen was the acidifying principle.
Opposition to the " hydrogen-acid " theory centred mainly about the hypothetical radicals which it postulated; moreover, the electrochemical theory of Berzelius exerted a stultifying influence on the correct views of Davy and Dulong.
Borch, Oliver Drapper, John Davy, G.
Davy in 1810.
Edmund Davy first made acetylene in 1836 from a compound produced during the manufacture of potassium from potassium tartrate and charcoal, which under certain conditions yielded a black compound decomposed by water with considerable violence and the evolution of acetylene.
This kept him absent from home for many years, during which letters were written to him by " little Davy," acquainting him with the doings at Lichfield.
He was awarded the Longstaff medal of the Chemical Society in 1900, and the Davy medal of the Royal Society in 1904.
CALCIUM [[[symbol]] Ca, atomic weight 40.0 (0= 16)], a metallic chemical element, so named by Sir Humphry Davy from its occurrence in chalk (Latin calx).
This view was questioned in the 18th century, and in 1808 Sir Humphry Davy (Phil.
Davy, inspired by his successful isolation of the metals sodium and potassium by the electrolysis of their hydrates, attempted to decompose a mixture of lime and mercuric oxide by the electric current; an amalgam of calcium was obtained, but the separation of the mercury was so difficult that even Davy himself was not sure as to whether he had obtained pure metallic calcium.
Davy; but in the teeth of this statement we have Mayer's own words, "We might much rather assume the contrary - that in order to become heat motion must cease to be motion."
For this work he was in 1889 awarded a Davy medal by the Royal Society, which ten years previously had bestowed upon him a Royal medal in recognition of his investigations in the coal-tar colours.
He received the Davy medal from the Royal Society in 1904.
Davy obtained it by electrolysing caustic soda.
A broadside entitled Davy Dycars Dreame, a short and seemingly alliterative poem in the manner of Piers Plowman, brought him into trouble with the privy council, but he was dismissed with a reprimand.
Carbonyl chloride (phosgene), COC1 2, was first obtained by John Davy (Phil.
To Sir Humphry Davy belongs the merit of isolating this element from potash, which itself had previously been considered an element.
Meyer, the Davy medal of the Royal Society, and in 1905 he received its Copley medal.
Its recapture by Santa Anna, February-March 1836, was distinguished by the heroic defence of the mission (particularly the chapel of the Alamo) by Colonels William Barrett Travis, James Bowie and Davy Crockett, and 178 others against the attack of about 4000 Mexicans.
In 1903 they were awarded the Davy medal of the Royal Society in recognition of this work, and in the same year the Nobel prize for physics was divided between them and Henri Becquerel.
Black showed that the two substances were entirely different; and in 1808 Davy pointed out that it was the oxide of a metal, which, however, he was not able to isolate.
Davy, enclosing these notes.
He continued to work as a journeyman bookbinder till the 1st of March 1813, when he was appointed assistant in the laboratory of the Royal Institution of Great Britain on the recommendation of Davy, whom he accompanied on a tour through France, Italy and Switzerland from October 1813 to April 1815.
Faraday's earliest chemical work was in the paths opened by Davy, to whom he acted as assistant.
Davy to the laboratory of the Royal Institution to make an experiment.
Sir Humphry Davy described him as a "very coarse experimenter," who "almost always found the results he required, trusting to his head rather than his hands."
Thus he distrusted, and probably never fully accepted, Gay-Lussac's conclusions as to the combining volumes of gases; he held peculiar and quite unfounded views about chlorine, even after its elementary character had been settled by Davy; he persisted in using the atomic weights he himself had adopted, even when they had been superseded by the more accurate determinations of other chemists; and he always objected to the chemical notation devised by J.
In 1810 he was asked by Davy to offer himself as a candidate for the fellowship of the Royal Society, but declined, possibly for pecuniary reasons; but in 1822 he was proposed without his knowledge, and on election paid the usual fee.
In a speech to the House of Representatives at this same time, Congressman Davy Crockett told the story of getting chewed out by a constituent for voting for a $20,000 emergency relief bill for the homeless in a city just wiped out by a fire.