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An Elementary Text-Book of the Microscope: Including a Description of the ...
John William Griffith
No preview available - 2015
aberration Algae angle animal antennae antheridia appear archegonia arising asci balsam become body branched called capsule cell-wall cells cellular centre ceramidia Chickweed cilia coloured rays colourless common composed concave concave lens consists containing convex lens cotyledons covered curved dots easily endochrome epidermis examination exhibit fibres filaments flowers focus frond fructification fruit-stalks frustules Funaria hygrometrica Fungi Fungus furnished glass granules green hairs head Infusoria insects jointed labium larva layer leaf leaves lenses Lichens light longitudinal margins mass microscope minute mosses naked eye object-glass oblique oblong opake objects operculum organs oval paraphyses peristome piece plants plate polarized Polytrichum piliferum portion radicle refracted resembling rings rounded rows scales seed separate shell side skin slender slide species spherical spherical aberration spiral spores spores fig stalk stems structure substance surface teeth thallus thin tissue transparent objects transverse tube turpentine usually valves vegetable
Page 181 - ... and if the crystal be still further turned, the images begin to come together again until, when it has turned through another right angle, they coincide. This process of separation, or doubling the rays, is called double refraction. And the following experiment will show that one set of rays follows the ordinary law of refraction, while the other follows a different law. The image produced by the first set of rays is, in consequence, called the ordinary, and that produced by the second the extraordinary...
Page 171 - ... meniscus, in which one surface is convex and the other concave. The curved surfaces of lenses are usually portions of spheres.
Page 145 - ... has narrow linear leaves, with a blade or expanded surface, which are either scattered over the branches, as in the fir, or come out in fasciculi or bundles, as in the larch and cedar; the cypress form has the needle leaves reduced to the condition of scales, which are closely imbricated or lie on each other like the tiles on the roof of a house. The needle-leaved forest is generally found on mountains where high winds prevail, as this form of foliage presents a less amount of resisting surface...