42 ELEMENTS OF APPLIED MICROSCOPY. 
ing the glass. A narrow, even ring may thus be pro- 
duced, and, by a gradual process of upbuilding, one of 
considerable depth. If an object of greater thickness is 
to be examined, a ring of brass or hard rubber may be 
attached to the slide by a ring of cement similarly ap- 
plied. 
When the cell has become so dry that there is no dan- 
ger of the cement running, the object to be mounted may 
be placed within it or attached to the under surface of a 
Fic. 24.—TurntaBie. (After Gage.) 
cover-slip. The cover is then pressed gently down on 
the ring of cement so that contact is complete all. the 
way round, and, after placing the slide on the turntable 
once more, a fresh ring of cement is applied partly on 
the edge of the cover and partly on the slide. 
When thus prepared the dry mount is completed and 
should be labelled on the left-hand end of the slide, the 
nature of the specimen, the treatment to which it has 
been subjected, the mounting medium, and the date being 
indicated. 
5. Mounting in Glycerin Media. — Glycerin mounts, 
although not easy to make and less permanent than bal- 
