Making Sections 167 



Zimmerman's Lacquer: 



Absolute alcohol 50 ml 



Anhydrous ether 50 ml 

 Pyroxylin U.S.P. 



or Parlodion 0.5 g 



Gum mastic 0.1 g 



The first solution is used exactly as water is used to flatten a paraffin 

 section. The amount of warming necessary depends on the degree of 

 wrinkling of the section but is usually less than for paraffin ribbons. As 

 soon as the slide has been drained, absolute alcohol is dropped gently on 

 the section from a pipette, left for a few moments, and then drained off. 

 A few moments now suffice to dry the sections, which become opaque. 

 A piece of lens paper is then laid over the slide, and each section is pressed 

 firmly with the finger. The slide is now quickly dipped in absolute alcohol, 

 drained, and dipped in Zimmerman's solution. This last is allowed to 

 evaporate from the surface, leaving behind a coat that will hold the sec- 

 tion in place through subsequent staining techniques. Any of the stains 

 discussed in Chapter 7 may be used save those involving differentiation 

 in absolute alcohol, which would dissolve the lacquer. The slides are 

 treated exactly as though they carried paraffin sections except that the 

 final transfer should be from 95 per cent alcohol to terpineol to xylene. 

 Even terpineol has a slight solvent action on the slide, which should re- 

 main in it, therefore, only long enough to remove the alcohol. 



