CHAPTEE III. 



PRODUCTION OF SECTIONS, 



Sections may be eut from many substances having a firm 

 consistency simply by clamping them in the jaws of the 

 microtome. Where material does not naturally possess 

 such firm consistency as to enable it to be held in the jaws 

 of the microtome without its being damaged, the necessary 

 firmness may possibly be imparted to it by artificial harden- 

 ing processes — such, for example, as immersion in strong 

 alcohol for a few days. Other material from which sections 

 are wanted may be too flabby even after hardening, or too 

 small to be held in the jaws directly ; such may be sup- 

 ported in elder-pith in the same manner as for hand- 

 cutting. The elder-pith, being itself too delicate to be 

 placed directly in the jaws, may be held between corks. 

 For this purpose, inch cubes of the best cork may be 

 procured from the chemical dealer. Through the centre 

 a hole is cut with a cork-borer, subsequently the cork 

 is halved with a keen knife, cutting longitudinally the 

 cylinder made by the cork-borer. Each half of the cork 

 will then have a half-cylinder upon one side; between these 

 half-cylinders the elder-pith may be placed, and the whole 

 fixed in the jaws of the microtome without hurt. 



In cutting sections after this manner, the knife must be 

 fixed to the carrier so as to cut obliquely to the direction of 

 the tramway — i.e., the knife must make a long slicing cut, 

 not a square chop. The greater the obliquity of the knife 

 the better. It will be noticed that the short Henking 



