microscope (mi'kro-skop)

An optical apparatus by which one may obtain a clear image of a minute, near object, the image being always larger than the object. achromatic m. A m. in which the chromatic aberration is corrected so1 that the image is not bordered by colored fringes, but appears, except in size, practically as if seen with the unaided eye. binocular m. A m. in which the rays are divided, after traversing the objective, and part of them pa through a properly arranged ocular to the right and a part to the left eye, so that in using it one looks with both eyes, compound m. A m. consisting of two e ential optical parts: ( i ) a converging lens or lens system, called an objective, to give an enlarged, inverted real image of an object; and (2) an ocular acting like a simple m. to give an enlarged virtual image of the real image. Unle an erecting prism is used, the image seen in a compound m. is therefore always inverted, demonstration m. A simple or compound m. which may be held in the hand and pa ed around in a cla to show some microscopic object. The object is fixed and properly focused, then the m. is held toward the window or other source of light, di ecting m. A m. for use in di ecting minute objects or for making very delicate di ections of parts of large objects. It may be simple, compound, uni ocular, binocular, or erecting. erecting m. A m. in which a prism is placed somewhere above the objective to cro the rays and thus render the image erect as with the simple m.; used mostly with di ecting m's. hand m. A m. for folding in the hand for purposes of dem- 534 on strati on. See demonstration m. monocular m. See uni ocular m. perspective m. Of Burch, a form of m. giving constant magnification along the optic axis, so that objects are shown by its microscopic perspective, petrographic m., petrographical m., petrologic m. A m. especially designed for the study of the structure of rocks. It has a revolving stage graduated in degrees, a polariscope, etc. polarizing m. Am. with a polariscopic attachment, the polarizer being placed somewhere below the object and the analyzer somewhere above the objective, frequently just above the objective or the eye lens of the ocular. simple m. A converging lens or lens system enabling the eye to obtain an enlarged erect image of an object. The object is always placed somewhere within the principal focus of the magnifier, thus giving a virtual image, solar m. A m. illuminated with sunlight. Sometimes the direct rays of the sun are used for the purposes of projection, stereoscopic m. A binocular m. giving a stereoscopic image comparable to the image seen in a stereoscope, traveling m. A compound m. which may be folded up and packed in a small space for special convenience in traveling, uni ocular m. A m. in which one looks with one eye, instead of with both eyes, as with a binocular m. [Lat., microscopium, from Gr., mikros, small, + skopein, to examine.] microscopic, microscopical (mi-kroskop'ik, mi-kro-skop'ik-al). 1. Pertaining to or observed with the microscope. 2. Of such minute size as to be visible only through the microscope. Most writers use the two words indifferently; some use microscopic in the second sense, and microscopical in the first sense, m. examination of cerebrospinal fluid, see in appendix, page 909. m. examination of sputum, see in appendix, page m. examination of stomach contents, see in appendix, page 904. m. examination of stool, see in appendix, page 906. microscopist (mi-kros'ko-pist). One who croscopy. uses the microscope or is versed in mimicroscopy (mi-kros'ko-pe). The art of using the microscope. microsomes (mi'kro-soms). 1. The very minute, highly refringent granules imbedded in protoplasm, especially in the inner achromatic portions. 2. The granules of chromatin which, together with a homogeneous ground substance, form the nuclear fibrils of a resting nucleus. [Lat., microsomal, from Gr., mikros, small, + soma, the body.]