Induced cell-reproduction and . Fig. 4.—The photomicrographicwater-cooling tank and Nernst burner,for direct observation. apparatus. Showing positions ofThe microscope mirror is in position SPECIAL PHOTOMICROGRAPHY 31. Fig. o.—The photomicrographic apparatus. The microscope mirror isswung aside for photography. SPECIAL PHOTOMICROGRAPHY 33 If preferred, focusing may be done with a lens;but in the case of a specimen of blood, the edges ofthe red cells afford a good indication of its accuracy, forthey seem just to disappear when the accurate focusis obtained. When they are out of focus t
Induced cell-reproduction and . Fig. 4.—The photomicrographicwater-cooling tank and Nernst burner,for direct observation. apparatus. Showing positions ofThe microscope mirror is in position SPECIAL PHOTOMICROGRAPHY 31. Fig. o.—The photomicrographic apparatus. The microscope mirror isswung aside for photography. SPECIAL PHOTOMICROGRAPHY 33 If preferred, focusing may be done with a lens;but in the case of a specimen of blood, the edges ofthe red cells afford a good indication of its accuracy, forthey seem just to disappear when the accurate focusis obtained. When they are out of focus the edges ofthe cells stand out in high relief. Having obtained thefocus—and stress must be laid on this point—the cellor other object is deliberately thrown out of focus to theextent of about 6+0th of a millimetre1 by screwing downthe fine adjustment so as to bring the objective nearerthe object. The reason for this is that the cells areresting on a jelly under a cover-glass which is all thetime slowly sinking into the jelly, and, of course,carrying the cells with it. The latter, therefore, aresinking out of focus all the time. By deliberatelyover-focusing, when the exposure is actually madethe focus will become a
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Keywords: ., bookcentury1900, bookdecade1910, bookidinducedce, bookpublishernp
