Abstract
PARIS. Academy of Sciences, January 2.—M. Janssen, President, in the chair.—On an objection made to the employment of electro-magnetic regulators in a system of synchronous timepieces, by M. A. Cornu, This is a reply to M. Wolf's recent communication, in which several objections were urged against the apparatus in question. It is shown (1) that such a regulator does not necessarily tend to stop the system to which it is applied; (2) that in any case the stoppage may be prevented without complication or expense; and (3) that in a public time-distributing service the stoppage should not only not be prevented, but efforts should be made to bring it about whenever the synchronizing system gets out of order. The paper was followed by some further remarks on the part of M. Wolf, who reiterated his objections, and trea ed M. Cornu's third point as somewhat paradoxical.—Remarks on Père Dechrevens's letter regarding the artificial reproduction of whirlwinds, by M. H. Faye. The author complains that, like other partisans of the prevailing ideas on the subject of tornadoes, typhoons, and cyclones, M. Dechevrens endeavours to suit the facts to the exploded theory of an ascending motion in the artificial reproduction of these aërial phenomena.—On the meteorite which fell at Phû-Long, Cochin China, on September 22, 1887, by M. Daubree. In supplement to M. Delauney's communication of December 19, the author adds that this meteorite was an oligo-siderite of somewhat ordinary type, closely resembling those of Tabor (Bohemia), July 3, 1753; Weston (Connecticut), December 14, 1807; Limerick, September 10, 1813; and Ohaba (Transylvania), October 10, 1817.—Remarks in connection with the presentation of the “Annuaire du Bureau des Longitudes” for 1888, the “Connaissance des Temps” and the “Extrait de la Connaissance des Temps” for 1889, by M. Faye. Amongst the fresh matter added to the “Annuaire” this year are papers by M. Janssen on the age of the stars, by Admiral Mouchez on the pi ogress of stellar photography, and by M. d'Abbadie on his recent expedition to the East in order to determine the elements of terrestrial magnetism in Egypt, Palestine, and Syria.—Observations of Olbers' comet made at the Observatory of Nice (Gautier's 0.38 m. equatorial), by M. Charlois. These observations are for December 25, 26, and 27, after the comet was discovered on December 23, when the nucleus was of the tenth magnitude, surrounded by a bright nebulosity, and with tail from 20′ to 25′ in length.—On the total eclipse of the sun observed on August 19, 1887, at Petrovsk, Government of Jaroslav, by M. G. M. Stanoiewitch. Owing to the extremely unfavourable atmospheric conditions the observer was unable to carry out any important part of his programme. A chief result of his observations was the conclusion that the gloom prevailing during eclipses is all the deeper the less clouded is the sky and the flatter the ground, especially on the horizon. The sky being on this occasion almost completely overcast, he was able to read the title of a pamphlet printed on a red cover at a distance of 2 metres.—On the variations of temperature of gases and vapours which preserve the same quantity of heat under different tensions, by M. Ch. Antoine. A simple means is proposed for avoiding the laborious calculations required to determine the values? and?1 in the formula y = 25?? -?1 deduced from V. Regnault's experiments on atmospheric air.—On the energy needed to create a magnetic field and to magnetize iron, by M. Aimé Witz. The researches here described serve to verify Lament's statement that the effect produced by a magnetic field on a magnet is greater when the force acts to diminish than it is when the force acts to increase the magnetizing power.—On the rapidity of transformation of metaphosphoric acid, by M. Paul Sabatier. Solutions of metaphos phoric acid are transformed spontaneously with greater or less rapidity. Berzelius and Thomsen suppose that there is at first production of pyrophosphoric acid, which is afterwards changed to orthophosphoric acid. Others, with Graham, think that there is immediate formation of tribasic orthophosphoric acid, and the author's researches tend to show that this is normally the case. It is also established that the rapidity of transformation is at each instant proportional to the mass of transformable substance present in the system.—On an alloy of titanium, silicium, and aluminium, by M. Lucien Lévy. Wöhler indicated two alloys of these metals without giving their composition. The author here determines a similar alloy differing in some of its properties from those of Wöhler. He has also determined its composition, as apparently a mixture of two isomorphous bodies crystallized together with formula TiAl4 and SiAl4. The same preparation with zinc or magnesium substituted for aluminium yielded no results.—On some derivatives of cinchonine, by MM. E. Jungfleisch and E. Leger. The authors were able some time ago to announce that the sulphate of cinchonine being heated to 120° C. for forty-eight hours with a mixture in equal parts of sulphuric acid and water, the alkaloid changes to diverse bases, of which they have isolated the six most abundant. Here they explain the process by which they have succeeded in separating the alkalies. —On the presence of diaphragms in the aeriferous ducts of roots, by M. C. Sauvageau. The transverse diaphragms intersecting the aëriferous ducts of vascular plants have hitherto been supposed to be confined to the middle region of the bark of their various members. But the author has now determined their presence also in the root of at least one such aquatic plant, the Hydrocharis morsus-ranæ.
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Societies and Academies . Nature 37, 263–264 (1888). https://doi.org/10.1038/037263a0
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DOI: https://doi.org/10.1038/037263a0