Microtomes: their Choice and Use 229 



and with a slight, even pressure draw it back foremost, 

 and from heel to point, from left to right, upon the strop ; 

 turn the razor with its back upon the strop, and pass it 

 from right to left. Maintain the process as in honing, but 

 with the back of the razor forwards. After several dozen 

 strokes upon the paste side, repeat the work upon the 

 finishing side. Draw the edge of the razor between the 

 finger and thumb or through a piece of elder-pith. If 

 the sharpening has been accomplished successfully, a micro- 

 scope having a magnification of 80 diameters will show the 

 edge as a straight unbroken line. This microscopic ex- 

 amination is best made by laying the razor upon a sheet 

 of glass. By allowing the handle to form an angle of 45 

 with the blade the edge will be preserved from injury. 

 Another test is to take a hair from the head, and if the 

 razor will cut it at half an inch from the fingers that hold 

 it the edge is good. 



Microtomes. 



It is not the object of these pages to discuss every 

 microtome which invention and ingenuity have placed 

 within the reach of workers, neither is it any part of 

 our intention to give the history and evolution of the 

 beautiful instruments now obtainable. We will rather 

 introduce the reader to a selection of well-tried instruments 

 of variable pretensions to perfection, in order that he may 

 be placed in a position of being able to choose from the 

 labyrinth that or those most suited to his intended work. 



Various simple forms of microtomes, such as the Cole's 

 pattern, the Cathcart (originally made by Mr. Fraser of 

 Edinburgh), and many others, some of which have already 

 been referred to in previous pages of this book, appeal to 

 workers as of practical value, according to the class of work 

 they may undertake. But viewed from the standpoint of 

 serious laboratory research, in which the production of the 

 best possible results in the various departments of micro- 



