244 Modern Microscopy 



long enough to allow of the use of the knife-holder illus- 

 trated in Fig. 66, as this form of knife (Jung's pattern) 

 cannot be fixed to the block without the holder. A knife- 

 holder is also supplied, which allows the knife-edge to be 

 tilted at any usable angle. The beginner, however, should 

 avoid this piece of apparatus.* From the under side of the 

 knife-block an arm is extended below the tramway (not 

 seen in the illustration), and by means of a milled-head 

 screw the knife-block may be fixed at any portion of its 



FIG. 66. MODEL ' C ' MICROTOME BY SCHANZE. 



travel. The same screw, when properly adjusted, prevents 

 the block from being pushed accidentally off the end of the 

 tramway. The object-holder is exceedingly strong, com- 



* By this advice we would not be understood to write derogatorily 

 of this valuable addition to the microtome. A beginner should master 

 the initial stages of microtomy before attempting to use the knife at 

 various inclinations to the horizontal. It is useful to give the knife a 

 little inclination when cutting thinner than usual, or when working 

 hard material. Useful inclination may be given by placing a half- 

 penny under the tang of the ' Henking ' knife, behind the fixing screw, 

 and another above the knife in front of the screw. 



