. Pathogenic micro-organisms. A text-book of microbiology for physicians and students of medicine. (Based upon Williams' Bacteriology). Bacteriology; Pathogenic bacteria. i6 BACTERIOLOGY made in the construction of the microscope. Abbe (about 1880) introduced his substage condenser which made possible the intense illumination of the microscopic field. In collaboration with Zeiss, Abbe (1886) devised an objective lens system with more perfect chromatic correction than had been previously attained. These -objectives are constructed of several different kinds of glass and have in addition one len
. Pathogenic micro-organisms. A text-book of microbiology for physicians and students of medicine. (Based upon Williams' Bacteriology). Bacteriology; Pathogenic bacteria. i6 BACTERIOLOGY made in the construction of the microscope. Abbe (about 1880) introduced his substage condenser which made possible the intense illumination of the microscopic field. In collaboration with Zeiss, Abbe (1886) devised an objective lens system with more perfect chromatic correction than had been previously attained. These -objectives are constructed of several different kinds of glass and have in addition one lens composed of fluorite. They are called apochromatic objectives. Siedentopf and Zsigmondi (1903) devised a method of illuminating the microscopic prepa- ration by horizontal beams and so brought to view exceedingly minute refractive particles as luminous points on a dark field. The various dark-field condensers introduced in recent years â ^â *^ J *». Fig. I.âThe^formation of a leans of a simple pin-point aperture. (After A. E. Wright.) (1906) Utilize similar principles, the object being illuminated by oblique light. Recently, Gordon has devised the tandem micro- scope, an instrument which has demonstrated the possibility of achieving greater microscopic resolution than has previously been attained and even suggests that there is no necessarily final limit to the degree of magnification at which satisfactory definition and resolution may be achieved. Principle of the Microscope.âThe formation of an image by means of a simple pin-point aperture is illustrated in Fig. i. It will be noted that the magnification achieved is the quotient of aperture-image distance divided by object-aperture distance;. 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 MacNeal, Ward J. , 1881-1946; Williams, Herbert Upham, 186
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbacteri, bookyear1920
