Science Lectures for the PeopleJohn Heywood, 1877 |
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absorption ancient animal beds bones bright lines bromine burning calcium call your attention carbon Carboniferous chemical constitution chemical elements chemistry chemists chlorine chromosphere colour colourless comets compounds conclusion creatures Cretaceous crust Cuttle-fishes density deposits Devonian diamond discovered earth Edition elementary bodies elements Eningen Eocene evidence evolution exactly existence experiment exterior fact falling stars fishes fossil gases geologist heat Hipparion hydrogen hypothesis incandescent inches interior planets iron known last lecture Lavoisier light limestones living LOCKYER magnesium mass matter means metal metalloids meteorites Miocene nebulæ numerous Illustrations observe Oolitic organisation oxygen Paleozoic particles peculiar period physical portions present probably Professor question remarkable represented reptiles rocks Roscoe screen shells Silurian sodium solar solid species specific gravity spectra spectroscope spectrum strata substances tail teeth telescope temperature Tertiary Triassic Trilobite true types vapour vegetable vibrations whilst
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Page 21 - A small piece of pure potash, which had been exposed for a few seconds to the atmosphere, so as to give conducting power to the surface, was placed upon an insulated disc of platina, connected with the negative side of the battery, of the power of...
Page 21 - Under these circumstances a vivid action was soon observed to take place. The potash began to fuse at both its points of electrization. There was a violent effervescence at the upper surface; at the lower, or negative surface, there was no liberation of elastic fluid; but small globules having a high metallic lustre, and being precisely similar in visible characters to quicksilver, appeared, some of which burnt with explosion and bright flame, as soon as they were formed, and others remained, and...
Page 53 - Suppose some stars have very large coronal atmospheres ; if the area of the coronal atmosphere is small compared with the area of the section of the true disk of the sun, of course we shall get an ordinary spectrum of the star ; that is to say, we shall get the indications of absorption which make us class the stars apart ; we shall get a continuous spectrum barred by dark lines. But suppose that the area of the coronal atmosphere is something very considerable indeed, let us assume that it has an...