CfJ.X] SECTIONING 289 



A saw edge may be all right for rough cutting and for shaving 

 razors, but if one wishes to get perfect sections 2 to io/* in thick- 

 ness a saw edge will not do. In removing the nicks one should 

 of course bear on very lightly. The weight of the knife is usually 

 enough. 



In honing use both hands, draw the knife, edge foremost, along 

 the hone with a broad curved motion. In turning the knife for the 

 return stroke, turn the edge up, not down. Continue the honing 

 until the hairs on the arm, wrist or hand can be cut easily or until 

 a hair from the head can be cut within 5 mm. from the point where 

 it is held. The sharper the knife becomes the lighter must one 

 bear on. One should also use the finest stone for finishing. If one 

 bears on too hard toward the end of sharpening, the edge will be 

 filled with nicks. 



In honing and stropping large section knives, there has come 

 into use during the last few years the so called " honing backs". 

 These elevate the razor slightly so that the wedge is blunter and 

 one does not have to grind away so much steel, (Fig. 227). 



Strop. A good strop may be made from a piece of leather 

 (horse hide) about 50 cm. long and 5 to 6 cm. wide, fastened to a 

 board of about the same size. 



The strop is prepared for use by rubbing into the smooth sur- 

 face some carborundum powder, i. e. 60 minute carborundum, that 

 which is so fine that it remains in suspension in water for 60 

 minutes, or one may use diamantine or Jewelers' rouge. 



Stropping. With the back foremost draw the knife length- wise 

 of the strop with a broad sweep. For the return stroke turn the 

 edge up as in honing. Continue the stropping until a hair can be 

 cut i to 2 centimeters from where it is held. 



436. Free-Hand Sectioning. To do this one grasps the 

 section knife in the right hand and the object in the left. Let the 

 end to be cut project up between the thumb and index finger. One 

 can let the knife rest on the thumb or index finger nail and with a 

 drawing cut make the section across the end of the piece of tissue. 

 By practice one learns to make excellent sections this way. If the 

 whole section is not sufficiently thin, very often a part will be and 

 one can get the information needed. 



437. Sectioning with a Hand or Table Microtome. 



