Mounting

(mown' '-ting). In microscopy, the arrangement of a microscopic object upon some suitable support (slide) and in some suitable medium. M.-cell, in microscopy, a ring of card-board, metal, or rubber, for the support of the cover-gla , or to prevent the mounting-medium from spreading when the object is thick. M. -media, various fluids, or resins in the fluid state, afterward becoming solid, that are employed in the examination and temporary or permanent preservation of microscopic objects. See also Stains, Table of. The most important are as follows: Acetate of Copper, for preserving and mounting green algae. Acetate of copper I grm, glacial acetic acid 1 c.c, camphor water 250 c.c, glycerin 250 c.c, corrosive sublimate 4 The glycerin is sometimes omitted with advantage, as in the case of volvox. Acetati: OP Pota ium, used in a strongly concentrated solution; it behaves much as glycerin, but does not dry at the edges and is le refractive. Benzol, employed as a solvent for Canada balsam and in preparing objects for balsam-mounts, but unfit for use as a medium for preliminary examination, on account of its great volatility. Bergamot, Oil of. Schiefferdecker first recommended this oil as a clearing-agent and mounting-medium; it clears 95 per cent, alcohol, preparations and celloidin preparations, and dor attack anilin colors. Canada Balsam. This should be deprived of certain volatile products before using. Solutions free from chloroform are to be preferred, es pecially for bacteria. Baumgarten recommends equal parts of Canada balsam and oil of cloves. Pure xylo answers equally well. Owing to the high refractive index of Canada balsam, bacteria are poorh de fined in it. Carbolic Acid. One of the best 1 for clearing and temporary examination of ti u is best used in concentrated solution in alcohol, whei it clears instantaneously even very watery pi tions. For clearing sections imbedded in celloidin. us a mixture of xylol and carbolic acid in equal parts Caustic Potash. A very useful clearing-agent in mod erately strong solutions, for the exatnim tion of plant-sections. If sections are to be perman mounted, they should be washed in water, pa through dilute alcohol, and mounted in glycerin DAR-OIL. On account of its refractive index. resembles that of crown-gla ; this is the widely-used fluid for homogeneous immersion ol jectives. It is miscible with chloroform-bals an with castor oil.