372 MICROSCOPY. 
revolve a turntable represented by Fig. 80. A is the plate, B the 
turntable, the use of which in locating the object is apparent, C 
Fig. 79. 
an aperture about } inch in diameter for the transmission of light 
to the cover on which the arrangement is being made. 
The cover should be coated by a very thin film of the purest 
gelatine dissolved in distilled water. 
he process is now easily consummated. The cleaned diatoms 
Fig. 80. 
being evenly spread upon a glass slip and the slip placed po 
stage, select the specimen desired, let the sliding shaft 0 
