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

Capa
 

Índice

Outras edições - Ver tudo

Palavras e frases frequentes

Passagens conhecidas

Página 17 - 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...
Página xiv - 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.
Página 246 - 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...
Página 282 - ... 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.
Página xvii - No paper shall be placed in the programme, unless admitted by the Sectional Committee ; nor shall any be read, unless an abstract of it has been previously presented to the Secretary of the Section, who shall furnish to the chairman the titles of papers of which abstracts have been received. RULE 12. The author of any paper or communication shall be at liberty to retain his right of property therein, provided he declare such to be his wish before presenting it to the Association.
Página 246 - In his own words the theory is as follows : " 1. The action of solutions of bicarbonate of soda upon sea water separates, in the first place, the whole of the lime in the form of carbonate, and then gives rise to a solution of bicarbonate of magnesia, which, by evaporation, deposits hydrous magnesian carbonate. " 2. The addition of solutions of bicarbonate of lime to sulphate of soda or sulphate of magnesia gives rise to bicarbonates of these bases, together with sul33. " Origin of Gypsum Plaister...
Página 46 - 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.
Página 107 - 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...
Página 246 - 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...
Página 196 - ... with decomposition. But in this case also decomposition supplies the force by which recomposition is effected, and growth and development carried on. As this is an important point I will attempt to explain it more fully. It is well known that in the animal body there are, going on constantly, two distinct and apparently opposite processes, viz., decomposition and recomposition of the tissues ; and that the energy of the life is exactly in proportion to the rapidity of these processes.

Informação bibliográfica