Cutting 



NITROCELLULOSE SECTIONS 



147 



Fig. 83. Cutting celloidin sections. 



and each section is received (Fig. 83) on a 

 brush saturated with oiL From time to 

 time the blade of the knife should be 

 moistened with more cedar oil, and the 

 sections as they come onto the knife may 

 be left to accumulate — they will be held 

 to the blade by the cedarwood — until a 

 considerable area of the blade is covered. 

 These sections may then be picked up 

 with a brush moistened with oil of cedar 

 and transferred to a container of the same 

 fluid; or, if there are enough of them, they 

 may merely be washed off the knife, which 

 has been removed, and placed in the 

 beaker or watch glass. 



Both the methods just described i:)re- 

 suppose that the object has been stained, 

 as should usually be the case, before em- 



bedding, and that the sections will require 

 no further manipulation beyond flattening 

 and mounting. When the sections are be- 

 ing cut with a view to staining them subse- 

 quently, the method of cutting a block 

 moistened with 70% alcohol is to be pre- 

 ferred. By this method the block, which 

 must have been hardened in chloroform, 

 is placed directly in a considerable volume 

 of 70% alcohol. Stronger alcohol should 

 not be employed because it will tend to 

 soften the block. After a day or tw'o in 

 70% alcohol, most of the chloroform will 

 have been removed, the block is then 

 mounted in the usual manner, and sections 

 are cut from it with a knife which is 

 moistened with 70% alcohol. The blade 

 must be moistened with a brush dipped in 



