TOOLS AND METHODS OF WORK 19 



knife may not be impeded by having to pass through it (Fig. 11). 

 Very small objects that require some support to keep them in position 

 during the time the paraffin is setting may be arranged on a piece of 

 cork (which has been previously boiled in paraffin to expel the air) with 

 a series of pins, these are withdrawn after the paraffin is set hard. 



Fig. 1 1 . — Well of Microtome, showing specimen embedded and paraffin removed 



frojn the cutting surface. 



When there are a number of specimens to be sectionised, imbedding 

 tubes, or moulds, Figs. 1 2 B may be employed ; these should be about 

 three-quarters of an inch high and of the same diameter as the well of 

 the microtome, their inner surface must be smeared with glycerine to 

 facilitate the removal of the blocks when the imbedding is complete, — 

 these can be pushed out of the tubes and placed in the well of the 

 microtome as required, a narrow groove must be cut longitudinally 

 along the surface of each block to allow the air to escape from the well 

 of the microtome, as it is being pushed in. A large series of imbeddings 



