. A practical treatise on the use of the microscope, including the different methods of preparing and examining animal, vegetable, and mineral structures. Microscopes; Microscopy. ACCESSORY INSTRUMENTS. 121 denser; upon this plate the tube carrying the prism is made to revolve, by turning the large circular plate at the bottom with. Fig. 66. a milled edge; this lower prism is termed the polarizer, in contradistinction to another fitted to the top of one of the eye-pieces, and termed the analyzer. An end view of one of the prisms is seen at fig. 67, and a vertical section at fig. 68. When appli
. A practical treatise on the use of the microscope, including the different methods of preparing and examining animal, vegetable, and mineral structures. Microscopes; Microscopy. ACCESSORY INSTRUMENTS. 121 denser; upon this plate the tube carrying the prism is made to revolve, by turning the large circular plate at the bottom with. Fig. 66. a milled edge; this lower prism is termed the polarizer, in contradistinction to another fitted to the top of one of the eye-pieces, and termed the analyzer. An end view of one of the prisms is seen at fig. 67, and a vertical section at fig. 68. When applied to the mi- croscope, it is necessary that the axes of both crys- tals should coincide with each other and with the optical parts of the mi- croscope, as in the case of the achromatic conden- ser; this may be known by revolving either of the prisms after the light has been sent through them by the mirror. If they are properly ad- justed, it will be found that there are two positions in which no light will pass through the prisms at aU; if this does not take place, and only part of the field of view is darkened, then, either ^by turning the arm carrying the compound body or the screw in the plate bearing the polarizer, the two can be made to obscure each other; they are then in a condition to be used. If now a crystalline plate of sulphate of lime be placed in the focus of the object-glass, it will be. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Quekett, John, 1815-1861. London, H. Bailliere; [etc. , etc. ]
Size: 2415px × 1035px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, booksubjectmicroscopes, booksubjectmicroscopy
