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absorption acid analysis appear Appendix atmosphere bands becomes blue bodies bright lines calcium carbon caused chemical chloride coincident colour comet compared compounds contains continuous corresponding dark lines detected determined diagram direction distance distinct double drawing earth effect electric elements emitted employed examination exhibits existence experiments fact Fe Fe flame give given green heat Huggins hydrogen important intensity interesting iron Kirchhoff lecture less light lithium luminous matter means measured metals method motion nebula nitrogen notice observed obtained occur pass Phil placed PLATE portion position potassium presence prism produced quantity rays reaction reference refracting refrangible represented salt scale seen Series slit sodium solar spectrum spark spectra spectroscope stars strontium substance telescope temperature tube vapour visible wire yellow
Page 94 - The colours thus communicated by the different bases to flame afford, in many cases, a ready and neat way of detecting extremely minute Quantities of them...
Page 274 - ... something of the motions of the stars relatively to our system. If the stars were moving towards or from the earth, their motion, compounded with the earth's motion, would alter to an observer on the earth the refrangibility of the light emitted by. them, and consequently the lines of terrestrial substances would no longer coincide in position in the spectrum with the dark lines produced by the absorption of the vapours of the same substances existing in the stars.
Page 300 - F, rather greater than half the interval between b and F. The third band occurs about midway between D and E. In the two more refrangible of these bands the light was brightest at the less refrangible end, and gradually diminished towards the other limit of the bands. The least refrangible of the three bands did not exhibit a similar gradation of brightness. These...
Page 250 - ... whose mottled and curdling light evidently indicates by a sort of granular texture its consisting of stars, and when examined under the great light of Lord Rosse's...
Page 119 - For instance, the orange ray may be the effect of the strontia, since Mr. Herschel found in the flame of muriate of strontia a ray of that colour. If this opinion should be correct, and applicable to the other definite rays, a glance at the prismatic spectrum of a flame may show it to contain substances which it would otherwise require a laborious chemical analysis to detect.
Page 307 - ... the substances by which in both cases the light was emitted. The great fixity of carbon seems, indeed, to raise some difficulty in the way of accepting the apparently obvious inference from these prismatic observations. Some comets have approached sufficiently near the sun to acquire a temperature high enough to convert even carbon into vapour.
Page 248 - It may be, therefore, that the occurrence of this one line only, indicates a form of matter more elementary than nitrogen, and which our analysis has not yet enabled us to detect. " In a similar manner the faintest of the lines was found to coincide with the green line of hydrogen.
Page 179 - A, which can be removed at pleasure. Below the prism is an achromatic eye-piece, having an adjustable slit between the two lenses ; the upper lens being furnished with a screw motion to focus the slit. A side slit, capable of adjustment, admits, when required, a second beam of light from any object whose spectrum it is desired to compare with that of the object placed on the stage of the Microscope. This second beam of light strikes against a very small prism suitably placed inside the apparatus,...
Page 238 - In the first place, then, the result at which we have arrived is that the constitution of the starlight, although not identical with the light given off by the sun, is yet similar ; that is to say, the light of a fixed star gives off a continuous spectrum, interspersed by dark shadows or bands ; and hence the conclusion we come to is that the physical constitution of the fixed stars is similar to that of our sun, that their light also emanates from intensely white-hot matter, and passes through an...