. A text-book of bacteriology, including the etiology and prevention of infective diseases and a short account of yeasts, and moulds, haematazoa, and psorosperms. Bacteriology. THE BACTERIOLOGICAL MICROSCOPE. 81 on a piece of paper, and a drawing made, and the object to be measured can then be projected on the paper and compared with the scale. In the Eamsden micrometer eye-piece (Fig. 24) two fine wires are stretched across the field of an eye-piece, one of which can be moved by a micrometer screw. In the field there is also a scale with teeth, and the interval between them corresponds to tha
. A text-book of bacteriology, including the etiology and prevention of infective diseases and a short account of yeasts, and moulds, haematazoa, and psorosperms. Bacteriology. THE BACTERIOLOGICAL MICROSCOPE. 81 on a piece of paper, and a drawing made, and the object to be measured can then be projected on the paper and compared with the scale. In the Eamsden micrometer eye-piece (Fig. 24) two fine wires are stretched across the field of an eye-piece, one of which can be moved by a micrometer screw. In the field there is also a scale with teeth, and the interval between them corresponds to that of the threads of the screw. The circumference of the brass head is usually chvided into one hundred parts, and a screw with one hundred threads to the inch is used. The bacterium to be measured is brought into a. Fig. 25.—Micrometeh Eye-piece by Zeis position in which one edge appears to be iu contact with the fixed wire, and the micrometer screw is turned until the travelling wire appears to be in contact with tlie other edge. The scale in the field and the scale on the milled head together give the number of complete turns of the screw and the value of a fraction of a turn in separating the wires. In the micrometer eye-piece constructed by Zeiss, the eye-piece with a glass plate with crossed Hues is carried across the field by means of a mici'ometer screw (Fig. 25). Each on the edge of the drum corresponds to '01 mm. Complete I'evolutions of the drum are counted by means of a figured scale in the visual field. Another method of measuring bacteria will be referred to in the C. 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 Crookshank, Edgar M. (Edgar March), 1858-1928. Philadelphia, W. B. Saunders
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Keywords: ., bookcentury1800, bookdecade1890, bookpublisherphila, bookyear1897
