PARIS Academy of Sciences, September 5.—M. Wurtz in the chair;—The following papers were read:—The direct-vision spectroscope applied to physical astronomy, by M. Zenger. One may (as before shown) compound refringent media whore index for the red ray A is less than that of crown glass or quartz, while the index for the violet ray H is much greater. The spectrum so produced is fan-shaped, and, with a single dispersion parallelepiped (two similar prisms with their refringent angles opposite), may be made of considerable length (250 and more). With one arrangement all the rays, except blue or red, may be eliminated, and the sum, e.g., viewed in monochromatic light. M. Zenger specifies various combinations of quartz or crown glass with anethol, benzene, alcohol, &c. He obtains effects equal to those of the most powerful spectroscopes hitherto made.—Influence of nutrition on poisoning with strychnine, by M. Delaunay. Strychnine affects more quickly and intensely strong frogs than weak ones; frog; well fed than those which have been fasting; frogs that have been in vigorous exercise than those at rest; frogs that are exercised immediately after injection than those which are not; a frog hung by the leg than one hung by the head; an intact frog than one which has been bled; the right side of frogs than the left, &c. Observations of Cruls' comet (b 1881) at Marseilles Observatory, with an equatorial of 0·26n. aperture, by MM. Borelly and Coggia.—Observations of Schäberle's comet (c 1881) in the same way and place, by M. Coggia. —Observations of Encke's comet, by M. Tempel. He observed it on the 21st ult. A letter from M. Loewy stated that M. Struve found it on the 24th (MM. Winnecke and Hartwig at Strasburg about the same time). The comet (according to M. Tempel) was large, but very diffuse, without nucleus or condensation towards the centre, and so, very difficult to observe.—On the light of comets, by M. Respighi. He considers we are not yet in a position to say that comets have a light of their own, due to incandescence of cometary matter. The discontinuity of the spectrum, and the bright lines and bands, may arise from reflected light as affected in traversing the gases and vapours of the comet; the same cause as affects the spectrum of the sun when near the horizon. Only the phenomenon is exaggerated in comets by reason of the enormous thickness of the absorbent layers, their richness of chemical composition, and the weakness of the light they reflect to us.—On observations of meteors from July 25 to 30, 1881, by M. Cruls (Rio). More than 90 per cent, of the meteors seemed to radiate from near Fomalhaut. The horary average increased rapidly between the evening and morning hours, and there was a remarkable recrudescence shortly before sunrise. It would thus seem that the stream of meteors moves in opposite direction to the earth. This is corroborated by the fact that the morning meteors, especially after 5 a.m., all moved with great velocity, and were very brilliant. They were all sensibly displaced in the plane of the ecliptic; their direction is probably very little inclined to this plane.—On ferruginous carbonated waters, by M. Ville. Neutral alkaline carbonates precipitate such water immediately; neutral alkaline earthy carbonates also have this effect, but more slowly. Alkaline and alkaline-earthy bicarbonates do not alter ferruginous water. Chlorides and sulphates sensibly retard the decomposition of ferruginous water in air. The disturbing influence of neutral alkaline carbonates may explain the relation between the richness of ferruginous carbonated waters and the presence of these saline compounds. The action of neutral carbonate of calcium explains the existence of considerable beds of limonie in calcareous strata.—On absorption by the vesical mucus, by MM. Cazeneuve and Lépane. The sound bladder absorbs the normal elements of urine. Certain toxical or medicamentary substances (e.g., sulphate of strychnine) are not absorbed.—On experimental tuberculosis, by M. Brunet.