PARIS Academy of Sciences, September 15.—M. Daubree in the chair.—The following papers were read:—On linen cloths dyed bluish black, with the intention of replacing the indigo blue cloths employed in the uniforms of the French army, by M. Chevreul. The blue matter in certain military cloths examined, he is able to say is neither indigotine, nor Prussian blue, nor ultramarine; it may be from aniline, and he is inquiring into this.—Experiments tending to demonstrate the compound nature of phosphorus, by Mr. J. N. Lockyer. Phosphorus heated in a tube with copper gives a gas which shows the spectrum of hydrogen very bright. Phosphorus alone, heated in a Sprengel vacuum tube, gives nothing. Fixed at the negative pole in a similar tube it gives very abundantly a gas which shows the spectrum of hydrogen, but which is not PhH3. The author also describes experiments with sodium, magnesium, lithium, &c.—Researches on erbine, by M. Lecoqde Boisbaudran. The lines of M. Cleve's holmium are precisely those indicated by M. Soret as characteristic of his earth X, and the two substances are evidently identical.—The Minister of Agriculture and Commerce called attention in a letter to the common adulteration of olive oil with oils of different sources, and desired the Academy to indicate a practical means of detecting such fraud, which is very prejudicial to cultivation of the olive.—Observations of Hartwig's comet and Palisa's comet, at the Paris Observatory, by MM. Henry.—Observations of the sun during the second quarter of 1879, by Signor Tacchini. A certain increase in the energy of solar phenomena is perceptible. The hydrogenic protuberances were about equally distributed to the north and to the south (instead of nearly all in the boreal hemisphere, as in the previous quarter). The maximum of frequency is between parallels 30° and 60° in both hemispheres. The preponderance of protuberances in the northern hemisphere seems characteristic of the minimum of solar activity. The maximum of frequency of faculee is found between parallels 10° and 30° in each hemisphere. The author considers we passed the minimum of solar activity in the beginning of this year. A metallic eruption was observed on June 19.—On the spectra of earths forming part of the group of yttria. A claim of priority with regard to what M. Cleve observed.—Determination of organic nitrogen in natural waters, by M. Pellet. He describes a method which is simpler than that given by M. Lechartier recently.—On the oxidising action of cupric oxide, transformation of acetic acid into glycolic acid, by M. Cazeneuve.—New experiments on the mode of action of chloral regarded as an anaesthetic, by M. Arloing. He concludes that chloral is decomposed into chloroform and alkaline formiates in the blood of animals; that the anaesthetic effects are due to chloroform; and that the alkaline formiates mechanically favour their production by increasing the velocity of the circulation, and thus facilitating the impregnation of the nervous elements by the anaesthetic agent.—M. Wolf's “History of Swiss Geodesy” was presented.