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PARIS Academy of Sciences, September 22.—M. Rolland, President, in the chair.—On algebraic equations: part third, on irrational equations, by M. de Jonquières. The author arrives at the somewhat unexpected conclusion that all algebraic equations, whether rational or not, which belong to the same “species,” possess the same maximum number of real roots, whatever be their respective degrees.—Observations on the corona now visible round the sun; variations in its form and colour; a method of increasing its luminosity; polariscopic observations; polarimetric and photometric observations, by M. A. Cornu. The author is still dispgsed to connect this phenomenon with the Krakatoa eruption. The facts adduced are regarded as numerous enough to support the natural hypothesis of a cloud of particles with a nearly constant mean diameter, projected by the volcano and held in suspension in the higher regions of the atmospheré.—On the general evolution of the vegetable functions in annual plants: the Amaranthacea;, by MM. Berthelot and Andre.—On the movement of Hyperion, by Prof. S. Newcomb. The author concludes that all the conjunctions of Hyperion with Titan take place near the aposaturn of the latter satellite. The point of conjunction oscillates about 180° on either side of the aposaturn during the period of revolution of the perisaturn of Hyperion in relation to that of Titan.—On the completion of the new method for resolving the most general linear equation into quaternions, by Prof. Sylvester. —Remarks on the third instalment of the new topographical map of Algeria presented to the Academy by Col. Perrier. This section consists of six sheets, comprising Miliana (province of Algiers), Saint Denis-du-Sig (province of Oran), Herbillon, Cap-de-Fer, Cap-de-Garde, Bugeaud (province of Constantine). The surveys are executed on a scale of 1: 40,000, and the map, eiigraved on zinc, is issued at the scale of 1: 50,000. Each sheet comprises seven plates, the relief being figured geometrically by equidistant curves of 10 m. in 10 m. and the plastic disposition of the surface being obtained by means of a dubbed drawing with lithographic crayon, based on the zenithal light and heightend by a slight touch of oblique light. The map marks a great improvement in the cartographic art.—On a development in a continuous fraction, by M. Stieltjes.—Note on the antiseptic properties of the sulphuret of carbon, by M. Ckiandi-Bey. From numerous experiments carried on for several years, the author finds that this sulphuret, which is soluble in water, arrests all fermentation, kills all microbes, is a most powerful antiseptic, and is, moreover, endowed with considerable penetrative power. Hence he strongly recommends it as a most efficacious remedy for cholera, typhus, diptheria, phthisis, and all diseases traceable to living germs.—Contributions to the study of the Cretaceous flora of the west of France, by M. L. Crie.—The Perpetual Secretary announced to the Academy thai the International Committee of Weights and Measures representing the high contracting parties to the Convention for the Metre signed at Paris on May 20, 1875, has received the adhesion of England, which had hitherto taken no part in the Convention. With the further accession of Roumania and Servia the Committee now represents an aggregate population of 421,440,396, distributed over Germany, England, Austria, Hungary, Belgium, the Argentine Republic, Denmark, Spain, the United States, France, Italy, Peru, Portugal, Roumania, Russia, Servia, Sweden, Norway, Switzerland, Turkey, and Venezuela.—The photolithographic facsimile of a letter addressed by Gauss to Olbers on September 5, 1805, was presented to the Academy by Prince Boncompagni.
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SOCIETIES AND ACADEMIES . Nature 30, 556 (1884). https://doi.org/10.1038/030556a0
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DOI: https://doi.org/10.1038/030556a0