74 



Modern Microscopy. 



Now put the cylinder of carrot and specimen into the well 

 of the microtome and commence cutting the sections. A 

 good razor will do, but it is better to use the knife which 

 Messrs. Watson supply with the microtome. While cutting, 

 keep the knife and plate of the microtome well wetted with 

 dilute methylated spirit, and as the sections are cut place 

 them in a saucer of dilute spirit. A number of sections 



FIG. 29. Cathcart Microtome. 



may be cut and preserved in methylated spirit until 

 required. 



When a specimen has a very irregular outline, it cannot 

 be successfully embedded in carrot. Paraffin should then 

 be used. Place the tissue in the well of the microtome in 

 the desired position, pour in enough melted paraffin to 

 cover it, and when cold cut the sections. 



Freezing Microtome. Cathcart's is the most simple 



