Decouverte

232 résultats

Trier parPrix croissant

Pertinence Auteur A - Z Auteur Z - A Titre A - Z Titre Z - A Prix croissant Prix décroissant Libraire A - Z Libraire Z - A

Par page25

25 50 100

Filtres

WOLLASTON, WILLIAM HYDE - THE DISCOVERY OF THE ELEMENT RHODIUMBiblio.com

DAVY, HUMPHRY - THE DISCOVERY OF HYDROGEN TELLURIDE - THE RIVALRY WITH GAY-LUSSAC & THENARDBiblio.com

Nouvelles Recherches électro-chimiques principalement relatives aux substances métalliques tirées des alcalis et de terres et à quelques combinations de l'Hydrogène. Suite des Recherches. Sur les Observations sur les Recherches faites p.

181046377Paris J. Klostermann 1810. Contemp. hcalf. Spine gilt. Slightly rubbed. A few scratches to binding. Small stamps on verso of titlepage.In: "Annales de Chimie ou Recueil de Mémoires concernant la Chemie" Tome 75. 336 pp. a. 2 folded engraved plates. Some scattered brownspots. The papers: pp. 27-77 129-175 256-263 264-273 274-289 a. 290-316. First French version of Davy's "The Bakerian Lecture for 1809. On some new Electrochemical Researches on various Objects particularly the metallic Bodies from the Alkalies and Earth and on some Combinations of Hydrogene. Read November 16 1809." together with the controversy papers by Davy and Gay-Lussac & Thenard."Mr. Davy having from the commencement of his electro-chemical researches communicated the several steps of his progress to the Society The Royal Society takes the present opportunity of reporting the results of his further inquiries under four principal heads. First on the nature of the metals of the fixed alkalis. Second on the nature of Hydrogen and composition of ammonia. Thirdly on the metals of the earth; and Fourthly he makes a comparison between the antiphlogistic doctrine and a modified phlogistic hypothesis."Abstract. He further gives arguments for considering potassium and sodium which he discovered in 1808 as a element.""Gay-Lussac had a slight rivalry between himself and the creation scientist Sir Humphry Davy. Davy was chemically preparing Potassium and Sodium through an electrical current and this made Gay-Lussac and Thénard envious of his success. They too decided to perform the same task but they had no battery at their disposal as Davy had so they had to form another way to chemically prepare the two elements. In 1808 they used a red-hot iron fused to potash the water-soluble form of a manufactured salt containing potassium to perform this task a method that Davy admitted had its advantageous qualities. Gay-Lussac and Thénard were successful in preparing Potassium and continued to make a full analysis of its chemical properties and began to use it for their own experiments. In 1809 Davy performed the same task using it to reduce Boron in Boracic acid." unknown

Herman H. J. Lynge & Søn A/S · Danemark2 500,00 DKK≈ 335,75 €

RITTER, (JOHANN W). - THE DISCOVERY OF ULTRAVIOLET LIGHTBiblio.com

Versuche über das Sonnenlicht.

180343638Halle Rengerschen Buchhandlung 1803. Without wrappers as extracted from "Annalen der Physik. Herausgegeben von Ludwig Wilhelm Gilbert" Jahrgang 1802 Bd. 12 Zwölftes Stück. Pp. 409-416. Titlepage to vol. 12. This is Ritter's first expositon of his discovery of ultraviolet light. It was announced the year before in a halfpage letter addressed to Gilbert's Annalen and printed in the Annalen. With that discovery it became clear that visible light represents no more than a fraction of a continous spectrum.A year earlier in 1800 William Herschel discovered infrared light. This was the first time that a form of light beyond visible light had been detected. After hearing about Herschel's discovery of an invisible form of light beyond the red portion of the spectrum Ritter decided to conduct experiments to determine if invisible light existed beyond the violet end of the spectrum as well. He had heard that blue light caused a greater reaction in silver chloride than red light did. Ritter decided to measure the rate at which silver chloride reacted to the different colors of light. He directed sunlight through a glass prism to create a spectrum. He then placed silver chloride in each color of the spectrum and found that it showed little change in the red part of the spectrum but darkened toward the violet end of the spectrum. Johann Ritter then decided to place silver chloride in the area just beyond the violet end of the spectrum in a region where no sunlight was visible. To his amazement this region showed the most intense reaction of all. This showed for the first time that an invisible form of light existed beyond the violet end of the visible spectrum. This new type of light which Ritter called Chemical Rays later became known as ultraviolet light or ultraviolet radiation the word ultra means beyond. unknown

Herman H. J. Lynge & Søn A/S · Danemark2 500,00 DKK≈ 335,75 €