Chapter V: The Paraffin Method 



39 



ing manner : Remove the disk from the machine and by means of 

 a heated steel spatula or copper wire flattened at one end, melt a 

 small chip of paraffin on to it. Likewise warm the end of the 

 paraffin block and quickly press it into the melted paraffin on 



FIG. 28. Minot Automatic Rotary Microtome. 



The object carrier is adjustable in three planes and is perfectly rigid. The knife carrier 

 is also adjustable and extra heavy and solid. The feed is controlled by an adjustable cam, 

 giving cuts of any number of microns in thickness from 1 to 25. By means of an automati- 

 cally closing split-nut the carriage is returned to the beginning position after the screw is 

 fed out the entire length. 



the disk. Cement it firmly in place by means of the heated wire 

 or spatula and cool in water. 



10. With a sharp scalpel trim the free end of the block so 

 that it presents a perfectly rectangular outline (however, see 

 caution c). The length should exceed the breadth by at least 

 one-fourth. 



Cautions. o) In trimming do not cut farther back than the 

 base of the object. This leaves a wide shoulder for support. 



&) Leave a margin of about 2 mm. around the object. 



