United States Congressional Serial Set

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U.S. Government Printing Office, 1908
Reports, Documents, and Journals of the U.S. Senate and House of Representatives.

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Sayfa 8 - All tests shall be made in accordance with the methods proposed by the Committee on Uniform Tests of Cement...
Sayfa 17 - A third pat is exposed in any convenient way in an atmosphere of steam, above boiling water, in a loosely closed vessel for five hours.
Sayfa 279 - Levy' repeatedly obtained hematite from artificial magmas, and similar observations have been made by others. In ordinary furnace slags, however, according to JHL Vogt, » hematite rarely if ever occurs. Ferric oxide can crystallize out as hematite only when ferrous compounds are either absent or present in quite subordinate amounts, for ferrous oxide unites with it to form magnetite.
Sayfa 391 - PROXIMATE CALCULATIONS. It is clear, from what has been already said, that it is rarely possible to predict, with anything like quantitative accuracy, what minerals will form when a magma of given composition solidifies. Partial and semiquantitative forecasts are practicable; we can say, for instance, that the proportion of orthoclase will lie between assignable limits; and if the analysis shows a ratio of silicon to oxygen lower than Si3O8, or 1 : 2.667, we may be reasonably sure that a calculable...
Sayfa 587 - Bismuth ores, wolfram, and arsenopyrite are common associates of the tinstone. These mineralogical data, the usual presence in stanniferous veins of species containing fluorine and boron, and also the alteration of the granite walls, have led to the very general belief that tin deposits of the ordinary type have been formed by the injection of vapors carrying the two elements above named and also the tin. This belief is strengthened by the various syntheses of cassiterite, in which boric oxide and...
Sayfa 51 - The procedure may not be rigorously exact, but the error in it is usually very small. If we consider an analysis as representing the composition of the anhydrous inorganic matter which is left when a water has been evaporated to dryness, the difficulty as regards iron disappears, for ferrous carbonate is then decomposed and ferric oxide remains. A similar difficulty in respect to the presence of bicarbonates also vanishes at the same time, for the bicarbonates of calcium and magnesium can only exist...
Sayfa 68 - In short, where the rainfall is abundant and the soil is naturally fertile, carbonate waters are the rule; in arid regions sulphates and chlorides prevail. This statement applies to the evidence now in hand, and must not be construed too sweepingly. We are dealing, not with invariable laws, but with tendencies. The condition thus indicated is probably the outcome of various causes, but one of the latter is easily found. In a fertile region organic matter is abundant and great quantities of carbonic...
Sayfa 439 - ' gives the mineral a very different composition. In the same memoir Carnot described a substance similar to minervite, from a cave near Oran, in Algeria. In this case the phosphatic deposits seem to have been formed by infiltrations from without the cavern, and the same is true of a white, pulverulent substance described by JC II.
Sayfa 518 - Loss on ignition. METAMORPHOSED SHALES. Shales, slates, phyllites, and mica schists form a continuous series of rocks which can be derived from clay, mud, or silt by progressive dehydration and crystallization. Some mica schists, of course, are traceable back to igneous rocks, but they fall outside of the present category. In order to study the development of schists from shales or clays, we must consider what compounds the latter contain capable of dehydration and what arc produced in this class...
Sayfa 604 - Bell." had a similar origin. The quartz veins, however, were near altered magnesian eruptives, in which no platinum was found. The occasional presence of platinum in sulphide ores has long been known, although it has attracted serious attention only within recent years. E.

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