The Microscope and Its Revelations, Volumes 1-2 |
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Common terms and phrases
achromatic acid adjustment angle angular aperture animal animalcules aperture apochromatic appearance arrangement attached axis balsam body calcareous Canada balsam canal cavity cells centre chambers cilia colour condenser cone conjugation consists cover cover-glass diameter diaphragm diatoms diffraction disc edge elongated employed endochrome extremely eye-piece filaments flagella flagellum fluid focal focus Foraminifera frustules glass glycerin illumination imbedded inch Infusoria instrument Journ larvæ layer lens lenses light magnifying power membrane micro microscope microscopist microtome milled head minute mounted movement nucleus numerical aperture object object-glass oblique observed obtained optical ordinary organs particles pencil plane plants plate portion present prism Professor protoplasm pseudopodia rays refractive index resembling screw seen segments shell shown in fig side slide sometimes species specimens spherical spherical aberration spores stage stem structure sub-stage substance surface thickness thin tion tissue tube valves whilst zoospores zygospore
Popular passages
Page 741 - Suppose a human mason to be put down by the side of a pile of stones of various shapes and sizes, and to be told to build a dome of these, smooth on both surfaces, without using more than the least possible quantity of a very tenacious, but very costly, cement, in holding the stones together. If he accomplished this 42 well, he would receive credit for great intelligence and skill. Yet this is exactly what these little 'jelly specks...
Page 530 - ... preserved by Saxo. But to the origin of the rest the genealogies give us no clue. If they were all of royal origin — and apparently they did claim divine descent — the Angli must have possessed a numerous royal class ; and we are scarcely justified in denying that this may have been the case1. On the other hand it is by no means impossible that some of them were sprung from foreign peoples, such as the Danes, Swedes or Warni. But what we may regard as practically certain is that the individual...
Page 2 - It may also be defined as the sine of the angle of incidence divided by the sine of the angle of refraction, as light passes from air into the substance.
Page 374 - Carpenter attributes these movements to heat ; he says, " the movement is not due (as some have imagined) to evaporation of the liquid, for it continues without the least abatement of energy in a drop of aqueous fluid that is completely surrounded .by oil, and is, therefore, cut off from all possibility of evaporation ; and it has been known to continue for many years in a small quantity of fluid enclosed between two glasses in an air-tight case. It is, however, greatly accelerated and rendered more...
Page 531 - are literally covered in the first warm days of spring with a ferruginous-coloured mucous matter, about a quarter of an inch thick, which, on examination by the microscope, proves to be filled with millions and millions of these exquisitely beautiful siliceous bodies. Every submerged stone, twig, and spear of grass is enveloped by them, and the waving plume-like appearance of a filamentous body covered in this way is often very elegant.
Page 572 - Fungus spreads by the extension of its own minute stems and branches ; and also by the production of minute germs, which are taken up by the circulating blood, and carried to distant parts of the body. The disease invariably occasions the death of the Silk-worm ; but it seldom shows itself externally until afterwards, when it rapidly shoots forth from beneath the skin.
Page 671 - Supposing it to rest upon its convex surface, it consists of a lower plate, shaped like a deep saucer or watch-glass; of an upper plate, which is sometimes flat, sometimes more or less watch-glass-shaped; of the oval, thick-walled, flattened corpuscle, which connects the centres of these two plates ; and of an intermediate substance, which is closely connected with the under surface of the upper plate, or more or less...
Page 529 - is not avoided but pushed aside ; or, if it be sufficient to avert the onward course of the frustule, the latter is detained for a time equal to that which it would have occupied in its forward projection, and then retires from the impediment as if it had accomplished its full course.
Page 305 - If the radiant is now made to approach the glass, so that the course of the ray, fde g, shall be more divergent from the axis, as the angles of incidence and emergence become more nearly equal to each other, the spherical aberration produced by the two will be found to bear a less proportion to the opposing error of the .single correcting curve acb ; for such a focus, therefore, the rays will be over-corrected.
Page 742 - ... having a short neck and a single large orifice. Another picks up the finest grains and puts them together with the same cement into perfectly spherical ' tests ' of the most extraordinary finish, perforated with numerous small pores, disposed at pretty regular intervals.