INTRODUCTORY 7 



defect is remedied in {b), a type of sliding microtomes in which the 

 knife is clamped at both ends and is a fixture, the object being carried 

 on a sledge and moved against it. 



Class A also includes some instruments in which the knife is carried 

 on the horizontal arm and swung against the object by a rotary move- 

 ment. 



Class B contains instrimients adapted for the production of con- 

 tinuous ribbons of sections by the paraffin method, but not so well 

 adapted for celloidin or other work in the wet way, or for soft objects. 



