Proceedings of the American Association for the Advancement of Science, Band 13

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Seite 18 - What a boundless field of observation, inquiry, and conjecture, does this subject open before us! — a field scarcely yet entered upon, but one which is, no doubt, destined to yield the richest harvest to the labors of future astronomers. What are the physical- conditions which determine Algol, in the short space of three and a half hours, to change from a star of the second, to one of the fourth, magnitude, remain at its minimum brightness fifteen minutes, and then in three and a half hours more...
Seite xv - Association are, by periodical and migratory meetings, to promote intercourse between those who are cultivating science In different parts of America, to give a stronger and more general impulse and more systematic direction to scientific research, and to procure for the labors of scientific men increased facilities and a wider usefulness.
Seite 247 - Dolomites, magnesites, and magnesian marls have had their origin in sediments of magnesian carbonate formed by the evaporation of solutions of bicarbonate of magnesia. These solutions have been produced either by the action of bicarbonate of lime upon solutions of sulphate of magnesia, in which case gypsum is a subsidiary product, or by...
Seite 283 - ... in a direction contrary to the motion of the hands of a watch, with — and be this particularly noted — a constant tendency to turn inwards towards the centre of lowest barometer.
Seite 241 - But while some of these saline lakes may be supposed to be basins of sea-water, modified by evaporation either alone or conjoined with the influx of foreign saline matters, others were evidently once freshwater lakes in which, the loss of water being equal to the supply, have gradually accumulated the soluble salts of all the rivers and springs flowing into the lake. We may arrive at some notion of the diverse natures of the different saline lakes which would be formed in this way if we suppose the...
Seite 47 - It is believed that the honor of first suggesting a geodetic survey of the American coast, is due to the elder Professor Patterson, of Philadelphia ; * who, as early as the year 1806, availed himself of his intimacy with the President, Mr. Jefferson, and the gentlemen who formed his cabinet, to impress them with the feasibility and policy of the measure.
Seite 108 - Board composed of officers of elevated rank in the army and navy, with two civilians selected for their high scientific attainments, the examination of suitable sites for these structures was assigned to the superintendent of the Coast Survey. In the six years that have since elapsed, preliminary surveys or examinations have been made in more than one hundred localities on the Atlantic, Gulf and Pacific coasts of the United States, and at least half of the cases reported are based upon recommendations...
Seite 247 - Quar. Jour. Geol. Soc., vol. 5, p. :«9, 1W9. 36. Quar. Jour. Geol. Soc., vol. 16, p. 154, 1859; Chem. and Geol. Essays, pp. 80-92, 1878. phate of lime, which latter may be thrown down by alcohol. By the evaporation of a solution containing bicarbonate of magnesia and sulphate of lime, either with or without sea salt, gypsum and hydrous carbonate of magnesia are successively deposited. "3. When the hydrous carbonate of magnesia is heated alone, under pressure, it is converted into magnesite: but...
Seite 198 - ... decomposition and recomposition of the tissues; and that the energy of the life is exactly in proportion to the rapidity of these processes. Now according to the ordinary view, the animal body must be looked upon as the scene of continual strife between antagonistic forces chemical and vital ; the former constantly tearing down and destroying, the latter as constantly building up and repairing the breach. In this unnatural warfare the chemical forces are constantly victorious, so that the vital...
Seite 247 - Dolomites, magnesites, and magnesian marls, have had their origin in sediments of magnesian carbonate formed by the evaporation of solutions of bicarbonate of magnesia. These solutions have been produced by the action of bicarbonate of lime upon solutions of sulphate of magnesia, in which case gypsum is a subsidiary product ; or by the decomposition of solutions of sulphate or chlorid of magnesium by the waters of rivers or springs containing bicarbonate of soda. The subsequent action of heat upon...

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