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 genus glass 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 zoophytes zoospores zygospore
Popular passages
Page 744 - ... 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.
Page 743 - 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 331 - ... of the field and the variation produced by using alternately central and very oblique illumination. When the objective is perfectly corrected for spherical aberration for the particular thickness of cover-glass under examination, the...
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 532 - ... 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 605 - The definitions are lucid and concise and are framed in the terms supplied by the latest authoritative literature, rather than by purely philological method. Obsolete words are omitted, and this has made the dimensions of the book convenient and compact. In making a dictionary, the author confesses that he has found out the labor consists in eliminating the useless, rather than adding the superfluous. The value of the work before us is increased by the large number of useful reference tables in anatomy,...
Page 305 - FDI, being probably nearly three times as great. If the radiant is now made to approach the glass, so that the course of the ray FDEG 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. ' But if F still approaches the glass, the...
Page 846 - The greater the dip of these laminse, the closer will their edges be ; whilst the less the angle which they make with the surface, the wider will be the interval between the lines. When the section passes for any distance in the plane of a lamina, no lines will present themselves on that space. And thus the appearance of a section of nacre is such as to have been aptly compared by Sir J. Herschel to the surface of a smoothed deal board, in which the woody layers are cut perpendicularly to their surface...
Page 605 - The Student's Medical Dictionary. INCLUDING ALL THE WORDS AND PHRASES GENERALLY USED IN MEDICINE, WITH THEIR PROPER PRONUNCIATION AND DEFINITIONS, BASED ON RECENT MEDICAL LITERATURE. With...
Page 916 - The manner," observes Mr. Newport, " in which the honey is obtained, when the organ is plunged into it at the bottom of a flower, is by lapping...