130 



METHODS OF MICROSCOPICAL RESEARCH. 



can be obtained of the respective thicknesses of 

 s-io, rio, rib, Ts 9 <nj, and /zjth mm., or of from about 

 3 to 20 mikrons. 



In Model II. thinner sections are obtained by 

 means of a differential gear. A second wheel is 

 used, and the various spokes, 1 to 6, give sections 

 of from 1 to 6 mikrons. 



In Model III. the fine adjustment is again modi- 

 fied by the use of two ratchets engaging in the 

 toothed wheel, one of which is a half tooth shorter 



than the other. The co-operation of this shorter 

 ratchet allows further tenuities of section of from 

 \ to 1^ mikrons. 



* The advantages and improvements secured by the 

 Minot microtome are, briefly, as follow : 



1. The practically indestructible solidity of all its 

 parts. 



