. Elementary chemical microscopy. Microscopy; Microchemistry. 162 ELEMENTARY CHEMICAL MICROSCOPY light in dark-ground illumination or with vertical illuminators, but for oblique reflected light in the study of opaque objects, the size of the lamp bulb and the position of the tungsten fila- ment renders the lamp and condensers somewhat clumsy and apt to be in the way. To avoid eye fatigue, when using one of these powerful tungsten lamps, it should be screened or treated with frosting compound and graphite or aluminum. Two or three dippings will be required to produce a coating absolutely opaque
. Elementary chemical microscopy. Microscopy; Microchemistry. 162 ELEMENTARY CHEMICAL MICROSCOPY light in dark-ground illumination or with vertical illuminators, but for oblique reflected light in the study of opaque objects, the size of the lamp bulb and the position of the tungsten fila- ment renders the lamp and condensers somewhat clumsy and apt to be in the way. To avoid eye fatigue, when using one of these powerful tungsten lamps, it should be screened or treated with frosting compound and graphite or aluminum. Two or three dippings will be required to produce a coating absolutely opaque. A window is then made by washing off a circular area with alcohol. As a general purpose lamp that shown in Fig. 95 leaves little to be desired. It consists of a concentrated filament, 6 volt,. Fig. 95. Bausch & Lomb Optical Co. Adjustable Microscope Lamp. 24 watt, tungsten lamp set in a cylindrical housing fitted with a powerful condensing lens. A small constant service step- down transformer is provided in order that it may be attached to a no volt lighting circuit. Although not quite power- ful enough for dark field illumination, fair results may never- theless be obtained; but for ordinary uses and especially for the illumination of opaque objects lying upon the stage this little lamp is the most satisfactory of those now on the American market. It is made with two types of condensing lenses — " Spherical ' and " ; The latter is much the better. As listed by the maufacturers the vertical supporting rod is only 17 cm. high. It should be not less than 30 cm. for chemical micros- copy. The purchaser should therefore specify a 30 cm. 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 Chamot, Emile Monnin, 1868-1950. New York, Wiley
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectmicroscopy, bookyear1
