Proceedings of the American Academy of Arts and Sciences, Volumen20

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Vol. 12 (from May 1876 to May 1877) includes: Researches in telephony / by A. Graham Bell.

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Página 189 - On the Primordial Fauna and the Taconic System, by Joachim Barrande. With Additional Notes by Jules Marcou.
Página 497 - A surface of platinum of standard dimensions, raised to a standard temperature by a voltaic current, will always emit a constant light. A strip of that metal, one inch long and...
Página 423 - Experiment has shown that the surface energy between two media is a function not only of the temperature, but also of the difference of electrical potential across the surface.
Página 254 - as characterizing the ' Lower Silurian ' division, and which I have named Second fauna. It is then just to recognize this priority, and I think it all the more fitting to state it at this time, that it has not been claimed to this day.
Página 534 - with the great discovery of the quantification of the predicate," adds : — " I must continue to hold that the principle of quantification is explicitly stated by Mr. Bentham ; and it must be regarded as a remarkable fact in the history of logic, that Hamilton, while vindicating in 1847 his own claims to originality and priority as against the scheme of De Morgan, should have overlooked the much earlier and more closely related discoveries of Bentham.
Página 183 - In addition to the evidence heretofore possessed regarding the position of the shales containing the trilobites, I have the testimony of Sir WE Logan, that the shales of this locality are in the upper part of the Hudson River group, or forming a part of a series of strata which he is inclined to rank as a distinct group, above the Hudson River proper. It would be quite superfluous for me to add one word in support of the opinion of the most able stratigraphical geologist of the American continent.
Página 346 - Stems often tall (6 or 8 feet high, or less), with mostly rather slender straight or recurved spines, often scattered, or wanting : stipules and rhachis as in the last ; leaflets 5 or 7 (very rarely 9), oblong to oblong-obovate, more or less cuneate at base and often petiolulate, usually glaucous, very finely pubescent beneath or glabrous or somewhat resinous, the teeth usually simple : flowers small, often solitary, the short pedicels, receptacles, and sepals glabrous, or the last subpubescent :...
Página 446 - This mode of treatment appears to remove the last traces of alumina, and yields a reasonably good separation. It appears, therefore, to recapitulate, that for the separation of titanium and aluminum either of the processes set forth in the preceding work may serve. The first, however, which is, in brief, the treatment of the solution containing salts of the elements in question with a mixture of microcosmic salt and formic acid, in the proportion of two to three by weight, together with enough ammonic...
Página 501 - One observer tested the light photometrically, whilst another observed the galvanometer, with the result that with similar photometric observations the thermopile indicated a large change in the amount of heat received. In conclusion the Author thinks it possible to assume as a practical standard, a carbon loop in an exhausted vessel raised to such a point of incandescence that it will radiate a definite amount of energy, this energy being measured by a bolometer strip or the thermopile at a definite...
Página 447 - ... filtrates, — always undesirable, — and that process which involves the precipitation of iron by ammonic sulphide in presence of ammonic tartrate to hold up the hydrates which would be precipitated in its absence. This latter method has been regarded as an undesirable one chiefly on account...

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