52 



MOUNTING. 



147. Whether stained or unstained, prepared for micro- 

 scopical examination by isolation or sectioning, and especially if it 

 is desired to keep the preparation, it is necessary to mount it in 

 some way, i. e., so arrange it upon some suitable support (glass 

 slide) and in some suitable mounting medium that it may be satis- 

 factorily studied with the microscope. 

 Mounting may be 



I. Temporary, or 

 II. Permanent, as 



A. Dry 7 , or in air, 



B. In a medium miscible with water, or 



C. In a resinous medium, in which case it is necessary 

 first to remove all water by either (a) drying Desiccation, or (6) 

 a series of displacements, i. e., I. Removing the water with strong 

 alcohol Dehydration; %. Removing the alcohol with clearer 

 Clearing:, 3. Replacing the clearer with balsam or other resinous 

 mounting medium. 



148. Temporary mounting. Illustrations may be found in 

 the examination of blood corpuscles and living ciliated cells ( 35). 

 Temporary examination of tissues is quite simple, though important, 

 and for this it is only necessary to place the teased tissue or section 

 on the slide in a drop of the fluid in which it is at the time, normal 

 salt solution, dissociator, or alcohol, and cover. The examination of 

 preparations intended for permanent mounts during the staining 

 or before mounting will often serve to detect faulty treatment at a 

 time when it may be remedied without great expenditure of time, or 

 to discard the specimen as worthless. 



149. Permanent mounting. These usually include (a) mount- 

 ing dry on a ring or in a cell, (6) in glycerin or glycerin jelly, media 

 miscible with water, and (c) in Canada balsam or damar, resinous 

 media. 



150. Mounting dry. The preparation, may be either upon 

 the under side of the cover-glass (best if possible) or rest upon the 

 bottom of the cell. 



In the first case a shallow cell made by a shellac ring will be 

 sufficient; in the second, a shellac ring may not give a deep enough 

 > cell and a paper, hard rubber, or metal ring may be cemented to the 

 slide. 



