Liver. 85 



1. The Chromic Acid method. The liver must be per- 

 fectly fresh and cut into small pieces about half an inch 

 square, these should be placed at once in the fluid 

 without washing. A large quantity of blood will exude 

 from them after being in the hardening fluid a short 

 time, and it will be necessary to change it in many cases 

 at the end of 12 hours. It is a good plan to shake the 

 bottle containing the specimen in process of hardening 

 occasionally, this must be done gently, so as to just alter 

 their position, and when there is a quantity of sediment 

 at the bottom of the bottle, and the fluid has lost its 

 yellow color and begins to look muddy, it is time to 

 change it. Portions of liver require changing a little 

 oftener at first than other normal structures. 



2. The spirit method is used in the ordinary manner 

 for liver, but the dilute spirit will generally require 

 changing once before using the pure methylated spirit. 



3. Midler's Fluid. This may be used when large 

 portions of the organ are to be hardened and when 

 time is no object. 



When the material is well hardened by either of these 

 processes, beautiful sections may be cut with the freez- 

 ing microtome, and they show best when stained with 

 logwood. 



The intra-cellular and intra-nuclear network is seen 

 very well in the cells of the liver, and makes an in- 

 teresting object for a moderately high power. The 

 specimens should be searched for bile ducts cut trans- 

 versely, looking like minute triangular openings between 

 the cells. 



