1893.] MICRO'SCOPICAL JOURNAL. 317 



METHODS. 



1. Cut a si de 3 in. x 1 in. Irom the paste board. 



2. Apply lightly to each side o it a piece of adhesive plaster 

 3 in. long. 



3. Center the slide by drawing diagonal 1 nes from ihe up- 

 j)cr to the lower corners. 



4. Place the slide upt)n a blork of hard wood and cut a disc 

 from its e.xact center l)y ine.ma of the p uudi or tlie cork borer. 



5. Coat the margins of the opening vvith B.m is vi ik bl ick. 



6. Strip the plaster t'roin one surt ice of t'le slide s > i-; to 

 fully uncover the opening. 



7. Apply marine glue to the m ir in of a cover-iil is3 pi ice 

 it over the opening on the uncovered surlace of t'le s'i le and re- 

 place the plaster with tirm press ire. 



8 Place the object in the cell. 



9. Instil the preservative or other medium. 



10. Strip the other surface of the slide, apfdy the second cover- 

 glass after tiie manner of the first and replace the plaster with 

 care. 



11. Apply ornamental back and front to si de, if desired. 



12. J>abei." 



If the object to be mounted is an opaque one, apply but one 

 strip of the plaster before the opening is made in tlie slide. 



Then put the other strip in place so as to form a bottom to 

 the cell, which, together with the sides, is to be covered with 

 the Brunswick black. To finish, repeat the detail^ given above 



If the object is so minute as not to require a cell, place it be- 

 tween two cover glasses with a proper amount of Canada bal- 

 sam, clip and harden, mount in slides of thin paste board or of 

 metal having a central opening just large enough to receive the 

 covers and retain them with stripsof the plaster having an open- 

 ing i inch less than that of the slide. The metal slides of tin or 

 sheet iron .should be ordered in quantity, ready for use, from a 

 dealer in hardware. If preferred, rings of the plaster, cut by 

 means of circular label punches, may be used instead of strips 

 of the material. Court plaster has been recommended as a 

 mounting me lium, but the rubber plaster is superior to it for 

 the reason that it is used dry, that it is impervious to moisture, 

 that it adheres more firmly and does not crack. 



The rubber plaster may also be used upon glass slides. Cut 



