Fig. 41.—Round Cover Glass Fig. 42.—Square Cover Glass Fig. 43.—Rectangular Cover Glass
Cover glasses are circular (Fig. 41), square (Fig. 42), or rectangular (Fig. 43) pieces of transparent glass used in covering the specimens mounted on glass slides. A few years ago much difficulty was experienced in obtaining uniformly thick and transparent cover glasses, but no such difficulty is experienced to-day. The type of cover glass used depends largely upon the character of the specimen to be mounted. The square and rectangular glasses are selected when a series of specimens are to be mounted, but in mounting powdered drugs and histological specimens the round cover glasses are preferable because they are more sightly and more readily cleaned and rinsed.
GLASS SLIDES
Fig. 44.—Glass Slide
Glass slides (Fig. 44) are rectangular pieces of transparent glass used as a mounting surface for microscopic objects. The slides are usually three inches long by one inch wide, and they should be composed of white glass, and they should have ground and beveled edges. Slides should be of uniform thickness, and they should not become cloudy upon standing.
SLIDE AND COVER-GLASS FORCEPS
Slides and cover glasses should be grasped by their edges. To the beginner this is not easy. In order to facilitate holding slides and cover glasses during the mounting process, one may use a slide and a cover-glass forceps. The slide forceps consists of wire bent and twisted in such a way that it holds a slide firmly when attached to its two edges.
