TECHNIQUE. 55 



absolute alcohol, after which they are cleared in xylol 

 and mounted in xylol balsam. 



Eosin and Methylene Blue Stain. This stain 

 gives good results although it does not differentiate 

 the amoebae from the cells of the tissues. However, 

 to one accustomed to the examination of such tissues 

 there is no difficulty experienced in recognizing the 

 amoebae. If this stain is used the sections should be 

 fixed in Zenker's fluid and imbedded in paraffin. 



The method of staining is as follows: Paraffin 

 sections are stained in 10 per cent, aqueous solution 

 of eosin for from 15 to 30 minutes; washed in water 

 until the excess of eosin is removed; and stained in 

 Unna's alkaline methylene blue solution diluted 5 

 times with water, for from 10 to 15 minutes. The 

 Unna solution consists of the following: 



Methylene blue (Grubler) 1.0 gram. 



Carbonate of potass 1.0 gram. 



Distilled water 100.0 c.c. 



After remaining in this solution for the required 

 time the sections are washed in water and differen- 

 tiated and dehydrated in 95 per cent, alcohol. This 

 procedure should be controlled under the microscope 

 and should be continued until a pink color has re- 

 turned to the section and the nuclei of the cells appear 

 a deep blue; absolute alcohol is then used to com- 

 plete the dehydration, the sections are cleared in xylol, 

 and mounted in xylol balsam. Care should be taken 



