318 THE AMERICAN MONTHLY [Nov., 



it into rings of proper size by the use of punches, or perforate a 

 strip of it and apply so as to seal the cover and form a front to 

 the slide. Cells can be built of it upon glass by pasting ring 

 upon ring and coating the inner suiface with Brunswick black. 

 When finished, attach the cover by means of cement. Objects 

 mounted between cover glasses in brass, tin or rubber cells may 

 be neatly set in paste board slides of corresponding thickness. 

 Punch an opening in the paper just large enough to receive 

 them and secure with a ring or a strip of the rubber plaster. 



Perforate the paste board slide and the rubber adhesive plaster 

 separately, upon the smooth end of a hard-wood block, with a 

 sharp stefel punch. Save the paper button. Let the scrips of 

 plaster be at least 4i in. long, and make the opening 2 in. from 

 one end of it. Apply the cover-glass over the opening in the 

 plaster upon the sticky side of it. Apply the plaster to the 

 paste board slide so that the cover-glass fits over the opening ac- 

 curately. Insert the slide, place a suitable amount of balsam 

 in the cell, submerge the object in it with the side to be ex- 

 amined next the cover-glass, and arrange in position with need- 

 les. If the object is very thin fit the button cut from the slide 

 with the opening and press into place, wiping away the balsam 

 as it exudes. If the object to be mounted is not thin, split the 

 button so as to obtain a layer of suitable thickness. Apply as- 

 phalt or Brunswick black to the edge of the cell and to the side 

 of the button, next the object, if a black finish is desired. Carry 

 the plaster around the end of the slide, paste over the back, trim 

 the ends and finish neatly. Place under pressure until the bal- 

 sam is hard. 



Opaque objects may be neatly mounted in Pierce's cells by 

 using tin or paste board slides without openings, connection be- 

 ing made with plaster, and the surfaces finished with paper 

 fronts and backs. Mention of Pierce's cell brings to mind the 

 fact that an excellent embedding cell for a small Army Medical 

 Museum Microtome may be made by fixing the cap of the cell 

 with marine glue, filing the rim to fit the well of the microto- 

 me and dropping it into place in an inverted position. The em- 

 bedding cell may be deepened by partly unscrewing the plate 

 of the microtome, the groove that is formed thereby serving to 

 hold the embedding material in place. 



