Table 1 (continued) 



Fig. 46. Sections alternately thick 

 and thin, usually with compression 

 of thin sections. 



Fig. 47. Sections bulge in middle. 



Possible Causes 



1. Block or wax holding block to holder 

 still warm from mounting 



2. Block or wax holding block to holder 

 cracked or loose 



3. Knife loose 



4. Knife cracked 



5. Microtome faulty 



Possible Causes 



1. Wax cool in center, warm on outside 



2. Only sharp portion of knife is that which 

 cuts center of block 



3. Object impregnated with hard wax and 

 embedded in soft, or some clearing agent 

 remains in object 



Remedies 



1. Cool block and holder to room 

 temperature 



2. Check all holding screws. Remove block 

 from holder and holder from microtome. 

 Melt wax off holder and make sure holder 

 is dry. Recoat holder and remount block. 

 Cool to room temperature 



3. Release all holding screws and check for 

 dirt, grit, or soft wax. Check knife car- 

 riage for wax chips on bearing 



4. Throw knife away 



5. Return microtome to maker for 

 overhauling 



Remedies 



1. Allow block to adjust to room temper- 

 ature. This is the frequent result of cool- 

 ing blocks in ice water 



2. Try another portion of knife-edge or re- 

 sharpen knife 



3. Re'^mbed object 



