The American Journal of Science, Volumes 159-160

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J.D. & E.S. Dana, 1900 - Science

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Page 61 - Of late, petrographers have begun to demand, with considerable reason, an arrangement "which shall bring the essential chemical features — both the percentage figures and the molecular ratios — prominently and compactly before the eye, so that the general chemical character and the relations of the various constituents may be seen at a glance.
Page 144 - The body called carnotite is probably a mixture of minerals of which analysis fails to reveal the exact nature. Instead of being the pure uranyl-potassium vanadate, it is to a large extent made up of calcium and barium compounds. Intimately mixed with and entirely obscured by it is an amorphous substance — a silicate or mixture of silicates — containing vanadium in the trivalent state, probably replacing aluminum.
Page 68 - Report on the geology of the area covered by the Seine River and Lake Shebandowan map sheets, comprising portions of Rainy River and Thunder Bay districts, Ontario.
Page 221 - THE KINETIC THEORY OF GASES. Elementary Treatise, with Mathematical Appendices. By Dr. OSKAR EMIL MEYER, Professor of Physics at the University of Breslau. Second Revised Edition. Translated by ROBERT E. BAYNES, MA, Student of Christ Church, Oxford, and Dr. Lee's Reader in Physics.
Page 77 - Plants,' p. 283. of heat observed by Pictet appearing to be due, not so much to the materials themselves, as to the air contained in their interstices. Good exhaustion in the ordinary vacuum vessels used in low temperature work, reduces the influx of heat to one-fifth of what is conveyed when the annular space of such double-walled vessels is filled with air."* It is to be noticed that in Professor Dewar's first experiment, the seeds were practically in a vacuum. It is obvious from what has been...
Page 34 - Marquesas rises from a plateau having a depth of 2000 fathoms, and about 50 miles in width, as at station No. 29 we obtained 1932 fathoms. The deep basin developed by our soundings between lat. 24 30
Page 130 - ... and the deposits described may simply represent a concentration of this material under certain favorable conditions of solution and redeposition. In the absence of exploitation it is manifestly impossible to predict the probable shape and size of ore bodies formed in this manner. The roscoelite seen near Placerville appears, however, to be much more persistent than the carnotite. There is no apparent reason why a mass of sandstone, impregnated with roscoelite, which is continuously exposed for...
Page 295 - ... .and that even when the most favourable conditions are selected, and the intensity of current and the length of the arc are maintained constant, it is difficult to obtain consistent results, variations of over 5 per cent, being by no means unfrequent. The crater of the arc does not, therefore, possess the qualities required of a standard. Incidentally the experiments made confirm the theory that the crater of the arc is at the temperature of volatilization of carbon.
Page 84 - William was a Presbyterian of the old school and strongly opposed to all theories of the evolution of man from brute ancestors, nor would he allow anything more than a very moderate antiquity for the species. The study of geology, too, he would have emancipated from " that materialistic infidelity which by robbing nature of the spiritual element and of its presiding divinity makes science dry, barren, and repulsive and diminishes its educational value.
Page 443 - Effect. As foreseen by the theory, the rate of effusion of argon, when compared with that of oxygen, is very considerably greater than the value as calculated by the law of the inverse square root of the density. The foregoing experiments agree uniformly in showing that the deviation amounts to 3J per cent. On the other hand, the results obtained with helium, although not very uniform, show pretty conclusively that its behaviour is unlike that of argon. According to the theory, however, it should...

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