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actinium action apparatus appears atmosphere atomic weight Becquerel bodies cathode rays cent charge chemical chemistry coil cold compressed condensation containing cooled corpuscles Crookes tube Curie deflected density dissociation drop earth effect electric electric charge electrified electrolytic electrons electroscope elements emanation emission emitted energy ether existence expansion experiments fact field force gaseous gases glass gram heat helium hypothesis increase investigation ionization ions J. J. Thomson light liquefaction liquefier liquid air liquid hydrogen luminous magnetic mass material matter means measured metal method molecular molecules N rays nature negative nitrogen nuclei observed obtained ordinary oxygen particles pass penetrating phenomena phosphorescent physicists plate polonium pressure produced properties quantity radiations radio-active radiograph radium refrigerating rocks Rontgen Rontgen rays salts shown solid solution spectrum substances surface theory thickness thorium tion uranium vacuum vapor velocity vessel volume wire X rays zero
الصفحة 215 - On partially liquefying carbonic acid by pressure alone, and gradually raising at the same time the temperature to 88° Fahr., the surface of demarcation between the liquid and gas became fainter, lost its curvature, and at last disappeared. The space was then occupied by a homogeneous fluid, which exhibited, when the pressure was suddenly diminished or the temperature slightly lowered, a peculiar appearance of moving or flickering striae throughout its entire mass.
الصفحة 238 - ... that the smallest particles of matter may cohere by the strongest attractions, and compose bigger particles of weaker virtue ; and many of these may cohere and compose bigger particles whose virtue is still weaker ; and so on for divers successions, until the progression end in the biggest particles, on which the operations in chemistry, and the colours of natural bodies, depend, and which, by adhering, compose bodies of a sensible magnitude.
الصفحة 208 - New experiments and observations touching cold, or, An experimental history of cold, begun.
الصفحة 278 - Accurate and minute measurement seems to the non-scientific imagination a less lofty and dignified work than looking for something new. But nearly all the grandest discoveries of science have been but the rewards of accurate measurement and patient long-continued labour in the minute sifting of numerical results.
الصفحة 215 - Andrews called the critical temperature. He showed that this temperature is constant, and differs with each substance, and that it is always associated with a definite pressure peculiar to each body. Thus the two constants, critical temperature and pressure, which have been of the greatest importance in subsequent investigations, came to be defined, and a complete experimental proof was given that ' the gaseous and liquid states are only distinct stages of the same condition of matter and are capable...
الصفحة 235 - ... interplanetary space, becoming, as Wilson has shown, nuclei of aggregation of condensable vapours and cosmic dust. The liquid and solid particles thus formed will be of various sizes ; the larger will gravitate back to the sun, while those with diameters less than one and a half thousandths of a millimetre, but nevertheless greater than a wavelength of light, will, in accordance with Clerk-Maxwell's electromagnetic theory, be driven away from the sun by the incidence of the solar rays upon them,...
الصفحة 279 - Every substance must be assumed to be impure, every reaction must be assumed to be incomplete, every measurement must be assumed to contain error, until proof to the contrary can be obtained. Only by means of the utmost care, applied with ever-watchful judgment, may the unexpected snares which always lurk in complicated processes be detected and rendered powerless for evil.
الصفحة 244 - This disclosure was made in a letter to Sir Joseph Banks, president of the Royal Society of London, dated March 20, 1800. Before this letter was published in the Philosophical Transactions its contents had become known to London physicists, and Nicholson and Carlisle had decomposed water by means of Volta "s pile.
الصفحة 232 - ... way in which we stimulate them appear to be equally brilliant, and for the absence, with one doubtful exception, of all the rays of nitrogen. If we cannot give the reason of this, it is because we do not know the mechanism of luminescence — nor even whether the particles which carry the electricity are themselves luminous, or whether they only produce stresses causing other particles which encounter them to vibrate — yet we are certain that an electric discharge in a highly rarefied mixture...