Hittorf examined the phenomena exhibited in so-called high vacua, that is, in exceedingly rarefied gases.
This phenomenon is connected with the fact that incandescent bodies, especially in rarefied gases, throw off or emit electrons or gaseous negative ions.
There he continued his researches on the discharge of electricity in rarefied gases, only just missing the discovery of the X-rays described by W.
Earlier still the sun must have reached to where Neptune now revolves on the confines of our system, but the mass of the sun could not undergo an expansion so prodigious without being made vastly more rarefied than at present, and hence we are led by this mode of reasoning to the conception of the primaeval nebula from which our system has originated.
Such a reduction of temperature is brought about along the greater part of the coasts of India and of the BurmoSiamese peninsula by the interruption of the wind current by continuous ranges of mountains, which force the mass of air to rise over them, whereby the air being rarefied, its specific capacity for heat is increased and its temperature falls, with a corresponding condensation of the vapour originally held in suspension.
The problem of the stresses in rarefied gaseous media arising from inequalities of temperature, which is thereby opened out, involves some of the most delicate considerations in molecular physics.
He lays stress on the dimensional relations of the problem, pointing out that the phenomena which occur with large vanes in highly rarefied gas could also occur with proportionally smaller vanes in gas at higher pressure.
In 1871 he began to turn his attention to experimental physics, his earlier researches bearing upon the polarization of light and his later work upon the electrical discharge in rarefied gases.
If the sodium is only gently heated, so as to produce a comparatively rarefied vapour, and a grating spectroscope employed, the spectrum obtained is like that shown in fig.
The most peculiar feature about the chiru is, however, its swollen, puffy nose, which is probably connected with breathing a highly rarefied atmosphere.
The exalted atmosphere of the great man's ideas was too rarefied for the child's intellectual health, and a brain well fitted to do excellent work in the world was ruined by the effort to live up to an impossible ideal.
Yet even he did not conceive this Reason as incorporeal; it was in reality only the most highly rarefied form of matter in existence.
It has long been known that air and other gases at the pressure of the atmosphere were very perfect insulators, but that when they were rarefied and contained in glass tubes with platinum electrodes sealed through the glass, electricity could be passed through them under sufficient electromotive force and produced a luminous appearance known as the electric glow discharge.
The particular details of the phenomena observed will be found described in the article Electric conduction (§ The main fact discovered by researches of Plucker, Hittorf and Crookes was that in a vacuum tube containing extremely rarefied air or other gas, a luminous discharge takes place from the negative electrode which proceeds in lines normal to the surface of the negative electrode and renders phosphorescent both the glass envelope and other objects placed in the vacuum tube when it falls upon them.
In addition the purer and rarefied air of the Swiss mountains seems to produce a sense of exhilaration which is not felt nearer the sea-level.
In some persons rarefied air is too stimulating, so that they find difficulty in sleeping, and for those who suffer from insomnia a warm moist air nearer the sea-level is preferable.
The heights of peaks determined by exact processes of trigonometrical observation are bound to be more or less in error for three reasons: (1) the extraordinary geoidal deformation of the level surface at the observing stations in submontane regions; (2) ignorance of the laws of refraction when rays traverse rarefied air in snow-covered regions; (3) ignorance of the variations in the actual height of peaks due to the increase, or decrease, of snow.
Ciii.) he published the first of his classical researches on the action of the magnet on the electric discharge in rarefied gases.
Electrical studies, however, engaged most of his attention, especially in connexion with the theory of the voltaic cell and the electric discharge in rarefied gases.
Frederick Slare noticed that the luminosity increased when the air was rarefied, an observation confirmed by Hawksbee and Homberg, and which was possibly the basis of Berzelius's theory that the luminosity depended on the volatility of the element and not on the presence of oxygen.
The sun shone somewhat to the left and behind him and brightly lit up the enormous panorama which, rising like an amphitheater, extended before him in the clear rarefied atmosphere.
Fleming discovered that if the filament is made incandescent by the current from an insulated battery there is a unilateral conductivity of the rarefied gas between the hot filament and the metal plate, such that if the negative terminal of the filament is connected outside the lamp through a coil in which electric oscillations are created with the platinum plate, only one half of the oscillations are permitted to pass, viz., those which carry negative electricity from the hot filament to the cooled plate through the vacuous space.
Minnesota has the characteristic climate of the North Central group of states, with a low mean annual temperature, a notably rarefied atmosphere that results in an almost complete absence of damp foggy weather, and an unusual dryness which during the rather long winters considerably neutralizes the excessive cold.
On lowering the piston its valve opens and air passes in from the vessel to be exhausted; this is further rarefied on the next stroke and so on.
But to the man of ordinary understanding, unused to the rarefied atmosphere of abstract thought, this conception of a transcendental, impersonal Spirit and the unreality of the phenomenal world can have no meaning: what he requires is a deity that stands in intimate relation to things material and to all that affects man's life.
Varley discovered the interesting fact that no current could be sent through the rarefied gas unless a certain minimum potential difference of the electrodes was excited.
In contrast with these, it is considered one of the glories of the Olympian mythology of Greece that it believed in happy manlike beings (though exempt from death, and using special rarefied foods, &c.), and celebrated them in statues of the most exquisite art.