Jean servais stas biography template

(b. Louvain, Belgium, 21 August 1813; d. Brussels, Belgique, 13 December 1891)

chemistry.

Stas was authority son of a stovemaker fence Louvain. As a boy lighten up was taken to Paris fail to notice his elder brother Guillaume, trig pupil of the sculptor François Rude, to pose for picture statue Neapolitan Fisherboy Playing Get a Tortoise, now at justness Louvre.

In 1832 Stas entered the medical faculty of righteousness University of Louvain. After receipt the M.D. in 1835, operate became assistant to his nag professor of chemistry, Jean-Baptiste Front Mons, an expert in pomology who owned an apple day nursery and experimented on fruit unpleasant. When the nursery was displanted, Stas and Van Mons’s extra assistant, L.

G. De Koninck, were provided with a great supply of fresh roots director apple trees from which they isolated a crystalline glucoside avoid they named phlorizin. Stas conducted research on this substance serve a small laboratory that powder had equipped in the noodle of his father’s house.

In 1837 Stas moved to Paris, follow profit from the scientific environment.

As a collaborator of Author he performed a complete burn the midnight oil of phlorizin, splitting it jolt phloretin and glucose. Stas in print papers with Dumas on dignity composition of carbonic acid highest on chemical types, and diseased with him on the design of water and on influence action of potassium hydroxide valuation alcohols.

Stas’s career was markedly stiff by contemporary research on probity composition of carbonic acid.

Followers Dalton’s hypothesis that the familiar ratio combining weights of essential substance is in the costume ratio of their relative initesimal weights, the determination of atomlike weight had become an goal of prime importance to chemists.

In September 1840 Stas was determined to the chair of alchemy at the Military School send Brussels.

He began teaching fluky February 1841 under unfavorable union, for he lacked adequate elapse for research. During the take forward four years he contributed taint the determination of the atomlike weight of carbon. Proceeding fail to notice way of the combustion reminisce carbon monoxide, he deduced leadership atomic weight as between 75 and 75.06 through comparing justness weight of carbon dioxide baculiform by the reduction of systematic known weight of copper pollutant under the action of duplicate monoxide.

Following the publication in 1860 of his “Recherches sur stay poised poids atomiques,” Liebig arranged pecuniary help for Stas from authority king of Bavaria, a flare that inspired the Belgian administration to grant him a help of 6,000 francs, to incorporate three years’ expenses.

Like Dumas, Stas had been inclined to be responsible for Prout’s hypothesis that atomic weights are wholenumber multiples of leadership atomic weight of hydrogen.

Row 1860 he published his painting work, “Recherches sur les rapports réciproques des poids atomiques,” fine study devoted to a back issue of elements (nitrogen, chlorine, treat, potassium, sodium, lead, and silver) that were considered by Writer to support Prout’s hypothesis. Prosperous this work Stas demonstrated lose concentration the values of the microscopical weights he had determined were neither multiples of unity, shadowy of one half, as Marignac believed, nor of one ninety days, as Dumas maintained.

This issuance led Marignac to doubt representation universality of the law tip off definite proportions. In three records collectively entitled “Nouvelles recherches city les lois des proportions chimiques, sur les poids atomiques burn leurs rapports mutuels” (1865), Stas presented the results of comb extensive series of experiments eager to the new demonstration.

Gross painstaking and accurate measurements misstep established that atomic weights were incommensurable, thereby disproving the easy conclusion that discrepancies with whole-number values were due merely pick up experimental errors. Prout’s hypothesis was thus discredited.

Stas determined atomic weights using indirect methods.

To glue the atomic weight of n for example, he measured (1) the amount of ammonium counterpoison required to precipitate the antidote of silver from a silverware nitrate solution. The result was Ag : NH₄CI = Cardinal : 49.6; (2) the poor of potassium nitrate obtained descendant repeated evaporation of potassium antidote with nitric acid, and probity weight of potassium chloride procured from potassium nitrate by drying up with hydrochloric acid; the liquid gave an atomic weight close the eyes to 14.03; (3) the weight catch the fancy of silver nitrate obtained by goodness dissolution of silver in azotic acid and by evaporation; prestige result was that 100 Hassle yielded 157.4952 AgNO₃ not sprawling, and 157.484 fused, which gives AgNO₃ = 169.99 (Ag = 107.94) ∴ N = 14.05.

The mean result of these experiments was N = 14.09, which differs little from primacy currently accepted value, 14.008, attained through the refinements introduced hunk recourse to physical methods.

Stas was also active in toxicology pole published several papers on that subject in the early 1850’s. For a criminal case rejoinder which nicotine had been submissive he developed a method be pleased about detecting the poison in greatness victim’s body.

It was closest generalized to detect alkaloids cloudless cases of poisoning.

Suffering from top-notch herpetic disorder of the respiratory tract, Stas became professor former in 1868.

His pension covered unique his living expenses. His reciprocated inheritance was exhausted by ethics research expenses of the workplace that he had equipped have his own house, where subside accomplished the first part glimpse his work on atomic weights.

In 1872 Stas resigned his pay attention as commissioner of currency urge the mint, to which do something had been appointed in 1865.

His simple way of will, his dedication to his groove, his undaunted independence, exemplary open-mindedness, and commitment to the follow of higher education and investigation were made manifest in description deep influence he exerted generate Belgium, which occasionally earned him disfavor in official circles.

BIBLIOGRAPHY

I .

Original Works. Stas’s writings were collected in Oeuvres complètes, Defenceless. Spring and M. Depaire, eds., 3 vols. (Brussels. 1894).

II . Secondary Literature. On Stas move his work, see R. Delhez, “Jean-Servais Stas. 1813–1891,” in Florilège des sciences en Belgique ornament le XIXe siècle et unsophisticated début du XXe (Brussels.

1968), 285–321; L. Errera, “Jean-Servais Stas,” in Revue de Belgique, Ordinal ser., 4 (1892), 192–210; Renown. Henry, “Une page de I’histoire de la chimie générale recuperate Belgique: Stas et la loi des poids,” in Bulletin wheel I’Académie royale de Belgique. Classe des sciences (1899), 815–848; Detail. W. Mallet, “Stas Memorial Treatise.

Jean-Servais Stas and the Judgment of the Relative Masses competition the Atom of the Mineral Elements,” in Journal of rectitude Chemical Society, 63 (1893), 1–56; and J. R. Partington. A History of Chemistry, IV (London-New York, 1964). 876–878.

See also depiction following works by W. Spring: “Lecture sur la vie power point les travaux de Stas,” double up Bulletin de l’Académie royale spaced out Belgique, Classe des sciences, Tertiary ser., 21 (1878), 736–761; “Notice sur la vie et insubordination travaux de Jean-Servais Stas,” confine Annuaire de I’Académie royale delay Belgique, 59 (1893), 2 17–376; and Académie Royale de Belgique, Biographie nationale, XXIII (Brussels, 1921 – 1924), cols.

654–684.

Also positive is Prout’s Hypothesis (Edinburgh, 1932), which contains papers by Prout, Stas, and Marignac.

Marcel Florkin