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acetic acetic acid aether alcohol alkaline ammonia analysis apparatus appears ascertain Astronomer Astronomer Royal atmosphere barometer barytes binocular centre bodies calm calm calm carbonic acid cent chemical action chloride Cloudy coil colour columbite comet containing copper crystals decomposed diameter diluted dissolved distance Ditto effect electricity employed equation evaporated examined experiments fluid frost fungiform papilla galvanometer Geysir glass gun-cotton heat hydrochloric acid hydrogen inch iron light lime liquid Magnetic intensity means mercury metal nearly needle nerves nitrate nitric acid observations obtained oxide oxygen paper papilla particles passed phosphate phosphoric acid planet plate platinum polarity portion potash precipitate prism produced quantity rain rays remarkable Royal salt Silurian silver snow soda soluble solution spectrum steam substance sulphate sulphuric acid surface Tangent of deflection temperature thialdine tion tube Uranus vapour vessel voltaic wave wire zinc
Página 98 - I believe, towards the close of the last century, and the beginning of the present, sent out more living writers, in its proportion, than any other school.
Página 194 - It must be recollected that the inductive influence takes place at a distance through all bodies, conductors and nonconductors; and hence no coating that can be put upon the wire will prevent the formation of induced currents. I think it not improbable, since the earth has been made to act the part of the return conductor, that some means will be discovered for insulating the single wire beneath the surface of the earth; the difficulty in effecting this is by no means as great as that of insulating...
Página 128 - ... washed with the usual solution, excepting those small portions upon which dark images of the lower parts of the pendulums of the electrometer are projected through the slit. These small portions of course retain the light...
Página 352 - The introduction of this constant depends on the operation of the theory of exchanges of heat ; for a body, when cooling under the circumstances here given, is simultaneously receiving back a constant amount of heat from the medium of constant temperature. Whilst Newton's law represents the rate of cooling of bodies, and therefore the quantities of heat they emit, when the range of temperature is limited, and the law of Dulong and Petit holds to a wider extent, there are in our inquiry certain circumstances...
Página 351 - I conclude that as the temperature of an incandescent body rises, it emits rays of light of an increasing refrangibility, and that the apparent departure from this law, discovered by an accurate prismatic analysis, is due to the special action of the eye in performing the function of vision.
Página 186 - ... on the 19th of June, when I was so fortunate as to be present in the office of the telegraph in Philadelphia, while a series of very interesting electrical phenomena was exhibited. In connexion with the facts derived from these sources, I must ask the indulgence of the society in frequently referring, in the course of this communication, to the results of my previous investigations in dynamic electricity, accounts of which are to be found in the Proceedings and Transactions of this Institution....
Página 346 - I had remained there a sufficient length of time to enable my eyes to become sensible to feeble impressions of light, I caused the current to pass, gradually increasing its force, until the platinum was visible. In several repetitions of this experiment it was uniformly found that the index to which the platinum was attached, stood at the eighth division when this took place. The metal had therefore dilated...
Página 351 - ... but in the analysis of the spectrum made by Sir D. Brewster by the aid of absorptive media, this principle is indirectly controverted; that eminent philosopher showing that red, yellow, blue, and consequently white light, exist in every part of the spectrum. This must necessarily take place when a prism which has a refracting face of considerable magnitude is used ; for it is obvious that a ray falling near the edge, and one falling near the back, after dispersion, will paint...
Página 359 - When the platinum is thin, so as to be quite flexible at the point b, where it is fastened to the index, the movements take place with such promptitude and precision as to leave nothing to be desired. When the heat has been very high and long continued, the limit of elasticity of the platinum is somewhat overpassed, and it suffers a slight permanent extension. But as the ivory scale pp can slide up and down a little, the index is readily re-adjusted to the zero point. The temperature of the platinum...